Science.gov

Sample records for continents

  1. Our changing continent

    USGS Publications Warehouse

    ,

    1969-01-01

    Where were the land areas and oceans of the North American Continent one million years ago, compared to our present geography? Was North America always about the same size and shape as it is today? To answer these questions, we must construct maps of the lands and sea that existed during the past ages. This process of reconstructing ancient geography is called paleogeography (from the Greek word "palaios," meaning ancient).

  2. Continent vesicovaginal fistula

    PubMed Central

    de Toledo, Luís Gustavo Morato; Santos, Victor Espinheira; Maron, Paulo Eduardo Gourlat; Vedovato, Bruno César; Fucs, Moacyr; Perez, Marjo Deninson Cardenuto

    2013-01-01

    ABSTRACT Vesicovaginal fistula is an abnormal communication between the bladder and vagina and represents the most frequent type of fistula in the urinary tract. The most common cause in Brazil is iatrogenic fistula, secondary to histerectomia. Classically these women present continuous urinary leakage from the vagina and absence of micturition, with strong negative impact on their quality of life. We present a case of totally continent vesicovaginal fistula, with a follow-up of 11 years with no complications. PMID:23579756

  3. Preserving continence during robotic prostatectomy.

    PubMed

    Ahlering, Thomas E; Gordon, Adam; Morales, Blanca; Skarecky, Douglas W

    2013-02-01

    Preservation of postoperative urinary continence remains the primary concern of all men and their surgeons following robot-assisted radical prostatectomy (RARP). Without doubt, continence is the most important quality of life issue following radical prostatectomy. Identification of difficulties and lessons learned over time has helped focus efforts in order to improve urinary quality of life and continence. This review will examine definitions of continence and urinary quality of life evaluation, technical aspects and the impact of patient-related factors affecting time to and overall continence.

  4. [Continence in low resections].

    PubMed

    Rosa, G; Girardi, S; Lolli, P; Ferrara, R; Fasoli, G L

    1994-01-01

    Anorectal function is an important problem after low anterior resection procedure. This paper reports the results from 14 patients undergoing to low resection at Surgical Pathology Institute of the University of Verona. In 12 cases the restoration of the bowel continuity has been obtained by colon-anal anastomosis (Parks Operation) and in 3 cases by colo-rectal anastomosis at the anorectal ring level. The patients have been examined in the preoperative and in the postoperative period by clinical and manometric study. The results confirm that low resection does not involve faecal continence.

  5. Continence after posterior sagittal anorectoplasty.

    PubMed

    Langemeijer, R A; Molenaar, J C

    1991-05-01

    Posterior sagittal anorectoplasty (PSARP) was introduced in 1982 by Peña and De Vries as a new operation for patients with a high anorectal malformation. The degree of postoperative continence is reported to be high. During the past decade, too, new insights have been gained into the embryology of anorectal malformations. Evaluation of PSARP in relation to current understanding of the development and anatomy of the anorectum and the pelvic floor has led us to conclude that optimal continence cannot be expected. Fifty patients with a high anorectal malformation underwent PSARP between June 1983 and May 1990. Postoperative follow-up consisted of anamnesis (subjective) and electrostimulation, defecography, and anorectal manometry (objective). All patients are alive, and all but one are being evaluated regularly. Subjectively, the majority of patients were more or less incontinent, with soiling of pants at least once a day. On the basis of objective criteria, virtually all patients appeared to be incontinent, and in only one patient was the mechanism of defecation almost unimpaired after PSARP. From this study, we conclude that although PSARP provides a good aesthetic result, patients will never acquire normal continence.

  6. The mechanism of continence after posterior urethroplasty

    PubMed Central

    Bagga, Herman S.; Angermeier, Kenneth W.

    2015-01-01

    The standard of care after a pelvic fracture urethral injury is a repair via a one-stage anastomotic posterior urethroplasty using a step-wise perineal approach. The initial injury, immediate postoperative management, and surgical repair can all affect urinary continence in these patients. Proximal continence mechanisms, particularly the bladder neck, are particularly important in maintaining urinary continence in these patients. Patients with bladder neck dysfunction should be counselled about the greater risk of urinary incontinence. PMID:26019981

  7. Achieving urinary continence in children.

    PubMed

    Wu, Hsi-Yang

    2010-07-01

    Achievement of urinary continence is an important developmental step that most children attain with the assistance of their parents and caregivers. Debate continues as to the best time to toilet train; in some Asian and African cultures children are trained as infants, while training at age 2-3 years is more typical in Western cultures. Infant voiding is not merely a spinal reflex, as the sensation of bladder filling is relayed to the brain. However, the ability of the brain to inhibit bladder contractions, and to achieve coordinated bladder contraction with sphincter relaxation, matures over time. While there is a concern that later toilet training may be responsible for an increase in urinary incontinence in children, no controlled studies on early versus late toilet training exist to evaluate this hypothesis. A number of medical conditions such as spina bifida, posterior urethral valves, cerebral palsy and autism can cause incontinence and difficulties in toilet training. The decision to start toilet training a child should take into account both the parents' expectation of how independent the child will be in terms of toileting, and the child's developmental readiness, so that a realistic time course for toilet training can be implemented.

  8. Evolution of the Indiana continent urinary reservoir.

    PubMed

    Rowland, R G; Kropp, B P

    1994-12-01

    The Indiana continent urinary diversion evolved from the Gilchrist procedure. Full detubularization of the reservoir segment, tapering of the efferent limb with staples, plication of the ileocecal valve, and tunneled tenial implants have resulted in a reliable and reproducible continent cutaneous urinary reservoir. In this report the first 69 patients treated with these techniques are reviewed after a minimum 2-year followup. Overall day and night continence rates were 97% by 1 year after surgery. More than 80% of all patients are able to sleep a normal nighttime interval without catheterizing or leaking. Early plus late reoperation rates for problems related to the pouch were 17%. This rate compares favorably to other series of continent cutaneous reservoirs and even to series of ileal conduits. PMID:7966719

  9. The Kock continent ileostomy: a preliminary report.

    PubMed

    Failes, D

    1976-05-01

    A review is presented of seven patients who have undergone a continent type of ileostomy, as described by Professor Kock. There has been no mortality. Two of the early patients had considerable difficulty with the functioning of the valve and required re-operation. No patient in the series now wears an external appliance. Six of the seven are fully continent; the seventh reports occasional leakage, but is satisfied with the operation. The operation is considered to be still under trial, but is regarded as having great potential and likely to be much more widely practised in the future. PMID:1067068

  10. Understanding Barriers to Continence Care in Institutions

    ERIC Educational Resources Information Center

    Tannenbaum, Cara; Labrecque, Danielle; Lepage, Christiane

    2005-01-01

    This work seeks to identify factors that facilitate or diminish care-providers' propensity to improve continence care in long-term care (LTC) settings. We conducted a cross-sectional qualitative study using focus group methodology in four long-term care institutions in Montreal, QC. Forty-two nurses, nursing assistants, and orderlies caring for…

  11. African Universities Tackle the Continent's Agricultural Crisis

    ERIC Educational Resources Information Center

    Lindow, Megan

    2009-01-01

    Pests, population growth, and depleted soil have wreaked havoc on agriculture in Africa, so universities across the continent are rethinking how they teach the topic. Some African universities have been building their own networks and pooling their limited resources to train more agricultural scientists and improve their responsiveness to the…

  12. Spreading continents kick-started plate tectonics.

    PubMed

    Rey, Patrice F; Coltice, Nicolas; Flament, Nicolas

    2014-09-18

    Stresses acting on cold, thick and negatively buoyant oceanic lithosphere are thought to be crucial to the initiation of subduction and the operation of plate tectonics, which characterizes the present-day geodynamics of the Earth. Because the Earth's interior was hotter in the Archaean eon, the oceanic crust may have been thicker, thereby making the oceanic lithosphere more buoyant than at present, and whether subduction and plate tectonics occurred during this time is ambiguous, both in the geological record and in geodynamic models. Here we show that because the oceanic crust was thick and buoyant, early continents may have produced intra-lithospheric gravitational stresses large enough to drive their gravitational spreading, to initiate subduction at their margins and to trigger episodes of subduction. Our model predicts the co-occurrence of deep to progressively shallower mafic volcanics and arc magmatism within continents in a self-consistent geodynamic framework, explaining the enigmatic multimodal volcanism and tectonic record of Archaean cratons. Moreover, our model predicts a petrological stratification and tectonic structure of the sub-continental lithospheric mantle, two predictions that are consistent with xenolith and seismic studies, respectively, and consistent with the existence of a mid-lithospheric seismic discontinuity. The slow gravitational collapse of early continents could have kick-started transient episodes of plate tectonics until, as the Earth's interior cooled and oceanic lithosphere became heavier, plate tectonics became self-sustaining. PMID:25230662

  13. Spreading continents kick-started plate tectonics.

    PubMed

    Rey, Patrice F; Coltice, Nicolas; Flament, Nicolas

    2014-09-18

    Stresses acting on cold, thick and negatively buoyant oceanic lithosphere are thought to be crucial to the initiation of subduction and the operation of plate tectonics, which characterizes the present-day geodynamics of the Earth. Because the Earth's interior was hotter in the Archaean eon, the oceanic crust may have been thicker, thereby making the oceanic lithosphere more buoyant than at present, and whether subduction and plate tectonics occurred during this time is ambiguous, both in the geological record and in geodynamic models. Here we show that because the oceanic crust was thick and buoyant, early continents may have produced intra-lithospheric gravitational stresses large enough to drive their gravitational spreading, to initiate subduction at their margins and to trigger episodes of subduction. Our model predicts the co-occurrence of deep to progressively shallower mafic volcanics and arc magmatism within continents in a self-consistent geodynamic framework, explaining the enigmatic multimodal volcanism and tectonic record of Archaean cratons. Moreover, our model predicts a petrological stratification and tectonic structure of the sub-continental lithospheric mantle, two predictions that are consistent with xenolith and seismic studies, respectively, and consistent with the existence of a mid-lithospheric seismic discontinuity. The slow gravitational collapse of early continents could have kick-started transient episodes of plate tectonics until, as the Earth's interior cooled and oceanic lithosphere became heavier, plate tectonics became self-sustaining.

  14. 21 CFR 876.5320 - Nonimplanted electrical continence device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... vagina and used to stimulate the muscles of the pelvic floor to maintain urinary or fecal continence... nonimplanted electrical continence device and the powered vaginal muscle stimulator for therapeutic use (§...

  15. 21 CFR 876.5320 - Nonimplanted electrical continence device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... vagina and used to stimulate the muscles of the pelvic floor to maintain urinary or fecal continence... nonimplanted electrical continence device and the powered vaginal muscle stimulator for therapeutic use (§...

  16. 21 CFR 876.5320 - Nonimplanted electrical continence device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... vagina and used to stimulate the muscles of the pelvic floor to maintain urinary or fecal continence... nonimplanted electrical continence device and the powered vaginal muscle stimulator for therapeutic use (§...

  17. 21 CFR 876.5320 - Nonimplanted electrical continence device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... vagina and used to stimulate the muscles of the pelvic floor to maintain urinary or fecal continence... nonimplanted electrical continence device and the powered vaginal muscle stimulator for therapeutic use (§...

  18. 21 CFR 876.5320 - Nonimplanted electrical continence device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... vagina and used to stimulate the muscles of the pelvic floor to maintain urinary or fecal continence... nonimplanted electrical continence device and the powered vaginal muscle stimulator for therapeutic use (§...

  19. 21 CFR 876.5310 - Nonimplanted, peripheral electrical continence device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nonimplanted, peripheral electrical continence....5310 Nonimplanted, peripheral electrical continence device. (a) Identification. A nonimplanted, peripheral electrical continence device is a device that consists of an electrode that is connected by...

  20. 21 CFR 876.5030 - Continent ileostomy catheter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Continent ileostomy catheter. 876.5030 Section 876...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5030 Continent ileostomy catheter. (a) Identification. A continent ileostomy catheter is a flexible tubular device used as a...

  1. 21 CFR 876.5030 - Continent ileostomy catheter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Continent ileostomy catheter. 876.5030 Section 876...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5030 Continent ileostomy catheter. (a) Identification. A continent ileostomy catheter is a flexible tubular device used as a...

  2. 21 CFR 876.5030 - Continent ileostomy catheter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Continent ileostomy catheter. 876.5030 Section 876...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5030 Continent ileostomy catheter. (a) Identification. A continent ileostomy catheter is a flexible tubular device used as a...

  3. 21 CFR 876.5030 - Continent ileostomy catheter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Continent ileostomy catheter. 876.5030 Section 876...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5030 Continent ileostomy catheter. (a) Identification. A continent ileostomy catheter is a flexible tubular device used as a...

  4. Continence pads: have we got it right?

    PubMed

    Uchil, Dhiraj; Thakar, Ranee; Sultan, Abdul H; Seymour, Joy; Addison, Ray

    2006-05-01

    Women listed in the Croydon Community Continence database were contacted with a self-assessment questionnaire regarding continence pad usage and quality of life. Completed questionnaires were received from 763 of 1509 (51%) participants. Pads were used for bladder dysfunction (88.1%) and bowel dysfunction (44%). The majority (82.5%) had concurrent medical disorders and problems with mobility with 77.5% being on one or more types of medication. Nearly 39% of women claimed that they would be happy to continue pad use indefinitely and only 28% expressed interest in seeking further help. Compared to bowel dysfunction, bladder dysfunction appeared to have a greater impact on women's quality of life (P < 0.001). Containment products make a substantial contribution in improving the quality of lives of women with bowel and bladder dysfunction. The financial burden of containment products has a major impact on the health budget and therefore, comprehensive clinical evaluation should be mandatory before relegating women to pads as a final resort. PMID:15999216

  5. Imaging Lithospheric Structure beneath the Indian continent

    NASA Astrophysics Data System (ADS)

    Maurya, S.; Montagner, J. P.; Mangalampally, R. K.; Stutzmann, E.; Burgos, G.; Kumar, P.; Davuluri, S.

    2015-12-01

    The lithospheric structure and thickness to the LAB are the most debated issues, especially beneath continents. In this context, the structure and thickness of the Indian lithosphere has been controversial. Paleomagnetic data reveals that the Indian continent moved northwards at exceptionally high speeds (18-20 cm/year) and subsequently slowed down to 4-5 cm/year after its collision with Asia ≈40 Myr ago. This super mobility has been explained by an unusually thin Indian lithosphere (≈100 km; Kumar et al., 2007) in contradiction with the thick lithosphere that commonly underlies old cratonic nuclei. It is pertinent to note that the thermobarometric estimates on the ultramafic xenoliths from 65 Myr kimberlites of the Central India (Babu et al. 2009) suggest an approximately 175 km thick lithosphere. Also, recent results of P and S wave travel time tomography of India suggest that the lithospheric roots are not uniformly thick on a regional scale. Although high velocity roots typical of Precambrian shields are preserved beneath a few cratons of the Indian shield, they seem to have suffered attrition, in the plume ravaged regions like the NDVP and the Southern SGT (Singh et al., 2014). We assembled a new massive surface wave database towards obtaining 3D isotropic and anisotropic models for the Indian sub-continent, using surface waves. This necessitated processing of data from more than 500 seismic broadband stations across India and surrounding regions. Surface waves group and phase dispersion measurements are performed in a broad frequency range (16-250s). Our phase velocity anomaly maps recover most of the known geological structures. The cratons are associated with high velocity (4-6%) anomalies till 200 sec, with the WDC being faster than the EDC. Slow velocities in NW India and very high velocity anomalies (6-8%) beneath the central part of the Indo-Gangetic plains are possibly associated with the subducting Indian lithosphere. The LAB depths inferred from

  6. The ribbon continent of northwestern South America

    NASA Astrophysics Data System (ADS)

    Altamira-Areyan, Armando

    The tectonic structure of the Plate Boundary Zone (PBZ) between the Caribbean Plate (CARIB) and the South American Plate (SOAM) is interpreted using models that require CARIB motion from the Pacific into the Atlantic. Those models can be subdivided into: (1) those in which the island arc rocks that are now in the CARIB-SOAM PBZ have collided with the northern South America margin, either obliquely or directly during the Cretaceous or during the Cenozoic, and (2) those in which the island arc rocks now in the CARIB-SOAM PBZ collided with the west coast of South America during the Cretaceous and were transferred to the northern margin by transform motion during the Cenozoic. Magnetic anomalies were first rotated in the Central and South Atlantic, holding Africa fixed to establish how much NOAM had converged on SOAM during the Cenozoic. WSW convergence was discovered to have been accommodated in the northern boundary of the CARIB. There is no evidence of convergence in the form of Cenozoic island arc igneous rocks on the north coast of South America. Those results are consistent only with models of Class (2) that call for transform movement of material that had collided with the west coast of South America along the CARIB-SOAM PBZ on the northern margin of South America. 40Ar/39Ar ages of island arc rocks from northern Venezuela were found to be older than ca 70 Ma, which is consistent with a requirement of models of Class (2) that those rocks are from an island arc which collided with the west coast of South America during Cretaceous times. Testing that conclusion using data from Ecuador, Colombia, Venezuela, the Netherlands Antilles, Trinidad and Tobago has led to the construction of a new ribbon continent model of the northwestern Cordillera of South America. Because the part of the ribbon continent on the north coast of South America has been experiencing substantial deformation in the Maracaibo block during the past 10 m.y., structures in that body have had to be

  7. Young Africans Tackle Their Continent's Environmental Issues

    NASA Astrophysics Data System (ADS)

    Olwoch, Jane Mukarugwiza

    2008-11-01

    Young African Scientists Session at the Fourth International Geosphere-Biosphere Programme Congress; Cape Town, South Africa, 7 May 2008; Africa is often described as a unique and diverse continent. This is reflected in its biodiversity, economic and social circumstances, and diversity in culture and environment. The Young African Scientists (YAS) session at the International Geosphere-Biosphere Programme Congress was one of the congress's highlights. Global environmental change research in Africa was presented to an audience that included visiting international and national scientists, policy makers, and a group of schoolchildren. From the uniqueness of Africa's paleoclimate to the diversity and complexity of current and future impacts of environmental change on Africa, the session not only provided an overview of current projects but also highlighted the problems that are intertwined with poverty. This session was sponsored by the Global Change System for Analysis, Research, and Training (START).

  8. Dynamic Topography of Oceans and Continents

    NASA Astrophysics Data System (ADS)

    Lithgow-Bertelloni, C.; Conrad, C. P.

    2004-05-01

    The large contrasts in surface topography are one of the most striking features of our planet. Contributions to topography range from short-wavelength uncompensated features due to tectonic activity, to variations in crustal thickness and density structure and long-wavelength deflections of the lithosphere caused by mantle dynamics. Upwelling or downwelling flow in Earth's mantle can elevate or depress the earth's surface even if the sources of buoyancy are deep in the mantle. However, direct observation of this ``dynamic topography'' has been elusive, because it is obscured by the isostatic contribution due to crustal and lithospheric structure. Any potential confirmation of the role of dynamic topography, sheds light not only on the impact of mantle dynamics on surface processes, but also on the nature of mantle dynamics itself. For example, we expect dramatically different topographic signals from layered vs. whole mantle convection. We have learned a great deal about the consequences of dynamic topography for continental flooding and the formation of large sedimentary basins since the pioneering work of Mitrovica et al. [1989] and Gurnis [1990]. Recently, unequivocal signals of dynamically supported topography have been found in both continents (Africa [Lithgow-Bertelloni and Silver, 1998] and Arabia [Daradich et al., 2004]) and oceanic basins (North-Atlantic [Conrad et al., 2004]). In all three cases, the identifiable dynamic topography signal results from upwelling mantle. In regions associated with downwellings considerable controversy remains [e.g. Wheeler and White, 2002]. There is a hint in this result that relates to the ability of slabs to penetrate into the lower mantle and of upwellings to reach the surface from great depth. We review in this talk the evidence for dynamic topography in continents and oceans, and present some speculations related to the nature of layering in mantle convection.

  9. OxyContin: Prescription Drug Abuse. CSAT Advisory.

    ERIC Educational Resources Information Center

    Substance Abuse and Mental Health Services Administration (DHHS/PHS), Rockville, MD. Center for Substance Abuse Treatment.

    Recently, the media have issued numerous reports about the apparent increase in OxyContin abuse and addiction. OxyContin has been heralded as a miracle drug that allows patients with chronic pain to resume a normal life. It has also been called pharmaceutical heroin and is thought to have been responsible for a number of deaths and robberies in…

  10. 21 CFR 876.5030 - Continent ileostomy catheter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Continent ileostomy catheter. 876.5030 Section 876.5030 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5030 Continent...

  11. Developing a tool to assess person-centred continence care.

    PubMed

    Wright, Jayne

    2006-07-01

    This article presents an overview of the first phase of a study to determine the contextual indicators that enable or hinder evidence-based continence care and management. The main focus of the article is to provide an insight into the value of understanding practice 'context' and its impact on the provision of person-centred continence care.

  12. Doug Nelson's Contributions to our Understanding of Young Continent-Continent Collisions

    NASA Astrophysics Data System (ADS)

    Klemperer, S. L.; Brown, L. D.; Jones, A. G.

    2002-12-01

    K. Douglas Nelson, Department Chair and Jessie Page Heroy Professor of Earth Sciences at Syracuse University, died suddenly of heart failure on August 17th, 2002, age 49. At the time of his death he was at the heights of an increasingly distinguished career, and had, just prior to his death, agreed to be an invited speaker in this session of the 2002 Fall AGU meeting. Doug began his professional career as a field structural geologist, writing his PhD on the Newfoundland Appalachians, and as a post-doc in South Island, New Zealand. From there he went to Cornell University to join COCORP; he learned to interpret deep seismic reflection data and became hooked on the value of geophysics to the study of large-scale processes in mountain belts. He became one of the proponents of taking the COCORP methodology overseas, to the world's type example of young, continent-continent collisions, the Himalaya. For 10 years from 1992, by now a faculty member at Syracuse, Doug provided operational and intellectual leadership to the INDEPTH program (International Deep Profiling of Tibet and the Himalaya). His talk in this session would undoubtedly have focused on our new understanding of Tibet that resulted in large part from the work that he led and supervised. From the initial conception of INDEPTH as a single reflection profile across Earth's highest mountain range and largest plateau, the program grew through three major stages to encompass a full range of geophysical and geological surveys in a transect that now reaches from the High Himalaya across Tibet. Doug more than anyone was the enthusiastic integrator in the large multi-national group of investigators (from the U.S., China, Canada and Germany), not bound by a single technique, and best able to synthesize the seemingly disparate observations from all the techniques. In recent years he was particularly interested in the combination of magneto-telluric with seismic results to better constrain interpretation of deep geology

  13. Tablet-based screening improves continence management in multiple sclerosis

    PubMed Central

    Beadnall, Heidi N; Kuppanda, Kushi E; O’Connell, Annmaree; Hardy, Todd A; Reddel, Stephen W; Barnett, Michael H

    2015-01-01

    Objective To investigate whether electronic continence questionnaires aid early identification and optimizes management of sphincter dysfunction in a multiple sclerosis clinic. Methods A custom designed, tablet-based cross-platform software tool was designed to capture validated multiple sclerosis (MS) patient-reported outcomes. An unselected cohort of MS patients from a tertiary referral clinic completed electronic tablet-based versions of the Bladder Control Scale (BLCS) and the Bowel Control Scale in the waiting room. Data were captured wirelessly “on-the-fly” and stored in a deidentified, secure database; and individual questionnaire results were immediately available to the treating neurologist in the electronic medical record. Scores of ≥2 on either questionnaire generated an automated electronic referral to the clinic MS continence nurse (MS CN). Results One hundred and fifty-seven MS patients completed a total of 184 electronic continence test sets and on two occasions only the BLCS was completed. An automatic electronic referral for formal continence review was generated 128 times in 108 patients. Fifty-seven formal continence assessments were undertaken by the MS CN following automated referral. All reviews resulted in at least one clinical intervention being made. Interpretation Tablet-based data capture and automated continence referral using this software tool is an efficient, sensitive, and feasible method of screening MS patients for bladder and bowel dysfunction. Concordance with the results of formal continence assessment in this pilot study validates the use of this technology as a screening tool. PMID:26125042

  14. Changing our view of older people's continence care.

    PubMed

    Dennis, Jacqueline

    An assumption is often made that incontinence is inevitable in older people, or those with dementia or other long-term conditions. However, research has highlighted strategies that can help them to remain continent. A working group was established to develop a resource to promote continence for people with dementia and long-term conditions. This article explores the resource's key messages, as well as the importance of changing how incontinence is viewed, and what health professionals and the public expect of continence services. PMID:27386706

  15. Equatorial Electrojet Observations in the African Continent

    NASA Astrophysics Data System (ADS)

    Yizengaw, E.; Moldwin, M. B.; Mebrahtu, A.; Damtie, B.; Pfaff, R.; Zesta, E.

    2008-12-01

    Although Satellite observations in the African sector show unique equatorial ionospheric structures that can severely impact navigation and communication systems, the study of ionospheric disturbances in this region is difficult due to the lack of ground-based instruments. This has created a gap in global understanding of the physics behind the evolution and formation of plasma irregularities in the equatorial region, which imposes limitations on ionospheric density modeling efforts. Therefore, in order to have a more complete global understanding of equatorial ionosphere motion, the international space science community has begun to develop an observational infrastructure in the African sector. This includes the deployment of a number of arrays of small instruments, including the AMBER magnetometer array, through the International Heliophysical Year (IHY) cooperative program with the United Nations Basic Space Science (UNBSS) program. Two AMBER magnetometers have been deployed successfully at Adigrat (~6°N magnetic) in Ethiopia and at Medea in Algeria (28°N magnetic), and became fully operational on 03 August 2008. The remaining two AMBER magnetometers will be deployed soon in Cameroon and Namibia. One of the prime scientific objectives of AMBER is to understand the processes governing electrodynamics of the equatorial ionosphere as a function of latitude, local time, magnetic activity, and season in the African region. The most credible driving mechanism of ionospheric plasma (E × B drift) can be estimated using two magnetometers, one right at the equator and the other about 6 off the equator. Therefore, using the AMBER magnetometer at Adigrat and the INTERMAGNET magnetometer located at Addis Ababa (0.9°N magnetic) in Ethiopia, the equatorial electrojet (E × B drift) activities in that longitudinal sector of the African continent is estimated. The paper also presents the comparison between the estimated vertical drift and the drift values obtained from the

  16. Multimetric Macroinvertebrate Indices for Mid-continent US Great Rivers

    EPA Science Inventory

    We developed a set of great river macroinvertebrate indices of condition (GRMICs) for the mid-continent great rivers. We used a multiscale (site, reach, landscape) multimetric abiotic stressor gradient to select macroinvertebrate assemblage metrics sensitive to human disturbance ...

  17. Improving service provision for patients who are prescribed continence products.

    PubMed

    Mangnall, Joanne; Midgley, Kate; Lakin, Stuart; Beckitt, Liz; Shepherd, Laura

    2010-04-01

    It is estimated that 14 million people experience problems with bladder control and 6.5 million people have a bowel control problem (Bladder and Bowel Foundation, 2008). Many will rely on continence products to manage their problem and as such require products which ensure user dignity and discretion is maintained. Locally, an ever-increasing spend on prescribed continence products promoted a review of current service delivery. The combined results of a clinical audit and patient satisfaction survey highlighted areas in which service delivery needed immediate improvement. Significant service re-design has been undertaken with prescribing responsibility for continence-related products being transferred from GP practices to specialist nurses working within the continence service. Improvements in clinical care have been achieved and cost savings have been re-invested in the service. PMID:20559160

  18. Immediate Continence Rates in RALRP: A Comparison of Three Techniques

    PubMed Central

    Tugcu, Volkan; Sahin, Selcuk; Sevinc, Cuneyd; Eksi, Mithat; Yavuzsan, Abdullah Hizir; Tasci, Ali Ihsan

    2016-01-01

    Background and Objectives: Robot-assisted laparoscopic radical prostatectomy (RALRP) is said to provide excellent long-term continence. In this study, we compared the early incontinence outcomes of our patients, who had undergone no reconstruction, posterior reconstruction only, or total anatomic restoration and posterior reconstruction. Methods: We retrospectively analyzed the patients who underwent RALRP for localized prostate cancer by a single surgeon in our clinic from January 1, 2009–February 1, 2016. Continence was defined as no leakage or use of a safety pad for minimal leakage. The main outcome measure was continence at postoperative week 1 and months 1, 6, and 12. Results: Between 2009 and 2016, 239 patients underwent RALRP for localized prostate disease. Seventy-four patients underwent a standard approach (group 1), 88 had posterior reconstruction (group 2), and 77 had posterior reconstruction with total anatomic restoration (group 3). After 1 week, 24.3% of the patients in group 1 (18/74), 31.8% in group 2 (28/88), and 45.8% in group 3 (33/72) were continent (P = .02). One month after the surgery, continence rates for groups 1, 2, and 3 were 56.7, 67, and 75%, respectively (0.065). After 6 and 12 months, continence rates for groups 1, 2, and 3 were 72.9 and 87.8%, 81.8 and 89.7%, and 84.7 and 91.6%, respectively (P = .178 and .7484). Conclusion: Anatomic restoration improves continence rates in the early period after RALRP. Even though other parameters were higher in the total restoration group, immediate continence (at 1 week) was significantly better. PMID:27777500

  19. Do continence management strategies reduce falls? a systematic review.

    PubMed

    Batchelor, Frances A; Dow, Briony; Low, May-Ann

    2013-12-01

    Urinary incontinence is associated with increased fall risk, and fall prevention programs include recommendations to manage continence as one component of fall reduction. However, the evidence to support this recommendation is unclear. The aim of this study was to identify continence management interventions that are effective in decreasing falls. A systematic review of the literature was conducted. Studies were included if they evaluated the effect of any type of continence management strategy on falls in older adults. The included studies were assessed for quality, and data relating to participants, interventions and outcomes were extracted by two independent reviewers. Four articles met the inclusion criteria. Two studies were randomised controlled trials, one a retrospective cohort study and one an uncontrolled intervention study. Interventions included pharmacological agents, a toileting regime combined with physical activity and an individualised continence program. Only the study evaluating the combination of physical activity and prompted voiding found an effect on falls. It is surprising that there has been so little research into continence management interventions that include fall outcomes. A toileting regime combined with physical activity may reduce falls in residential care. There is a need for further studies investigating the impact of continence management on falls.

  20. The controversy surrounding OxyContin abuse: issues and solutions

    PubMed Central

    Jayawant, Sujata S; Balkrishnan, Rajesh

    2005-01-01

    This paper overviews the controversies surrounding the abuse of prescription analgesic OxyContin® (oxycodone hydrochloride; Purdue Pharma, Stamford, CT, USA). It discusses solutions to this medication-related issue, which has been touted as reaching epidemic proportions. Relevant literature from 1990 to 2004 was identified through a MEDLINE search, and a thorough internet-based search was conducted to obtain the latest updates and government reports. OxyContin became popular as a street drug through its ability to induce a quick heroin-like euphoria. The media hype surrounding OxyContin abuse and the “black box” warning on its label may have added to the abuse and diversion. The US Food and Drug Administration took steps by writing letters to Purdue Pharma, the manufacturers of OxyContin. Purdue Pharma developed a database to identify OxyContin abusers throughout the nation and also launched campaigns to educate patients through the internet. Further suggestions to managing the abuse of OxyContin include: community pharmacists’ assessment of behavioral risk factors that could lead to patient medication abuse; medication abuse risk management courses for physicians; development of a national database linking all pharmacies specifically designed to identify abusers; and tamper-resistant prescription pads for controlled substances, which seems the most plausible and immediate solution to this problem. PMID:18360547

  1. Wrench faulting initiated by continent-continent collision between the Eratosthenes Seamount and Cyprus

    NASA Astrophysics Data System (ADS)

    Ehrhardt, A.; Schnabel, M.; Damm, V.; Huebscher, C. P.

    2010-12-01

    The Eratosthenes Seamount (ESM), located in the Eastern Mediterranean south of Cyprus, is considered to represent a continental fragment originating from the former African-Arabian continental margin. In the late Miocene the subduction of the African-Arabian Plate below the Anatolian Plate turned to continent-continent collision when the ESM collided with the island of Cyprus. This altered the tectonic pattern of the entire Eastern Mediterranean. Since the ESM blocks the northward drift of the African Plate south of Cyprus, the northward motion of the African-Arabian Plate (around 1cm/year) has to be compensated along wrench faults. The Baltim Hecateus Line (BHL) separates the ESM on its eastern side from the deep Levantine Basin. The BHL formed as an extensional fault system during the Triassic formation of the Levatine Basin. During the Upper Cretaceous and Eocene so called Syrian Arc inversion the BHL was reactivated. A set of recent multichannel seismic 2D lines (MCS), acquired with the R/V Maria S. Merian (MSM14-2) in 2010, will be presented here. The NW-SE trending lines show a transformal to transpressional nature of the Baltim Hecateus Line. We propose that the BHL converted to a transform fault during the incipient collision of the ESM with the island of Cyprus in order to compensate the northward motion of the African-Arabian Plate. At the eastern rim of the ESM the BHL continues beneath a prominent bathymetric escarpment. Whereas the escarpment matches the trace of the BHL it is covered below the thick Messinian Evaporites south and north of the ESM. Owing to the ductile properties of salt the Messinian evaporites decouple the sub salt sediments from the supra salt sediments. As a result no direct observations of the BHL are possible. However, seismic imaging reveals thrust folds at the western side of the Levantine Basin pointing to a transpressional nature of the BHL. The overlying sediments are thinned as a reaction to the transform motion. Due to a

  2. Predictors of early continence following robot-assisted radical prostatectomy

    PubMed Central

    Lavigueur-Blouin, Hugo; Noriega, Alina Camacho; Valdivieso, Roger; Hueber, Pierre-Alain; Bienz, Marc; Alhathal, Naif; Latour, Mathieu; Trinh, Quoc-Dien; El-Hakim, Assaad; Zorn, Kevin C.

    2015-01-01

    Introduction: Functional outcomes after robot-assisted radical prostatectomy (RARP) greatly influence patient quality of life. Data regarding predictors of early continence, especially 1 month following RARP, are limited. Previous reports mainly address immediate or 3-month postoperative continence rates. We examine preoperative predictors of pad-free continence recovery at the first follow-up visit 1 month after RARP. Methods: Between January 2007 and January 2013, preoperative and follow-up data were prospectively collected for 327 RARP patients operated on by 2 fellowship-trained surgeons (AEH and KCZ). Patient and operative characteristics included age, body mass index (BMI), staging, preoperative prostate-specific antigen (PSA), prostate weight, International Prostate Symptom Score (IPSS), Sexual Health Inventory for Men (SHIM) score and type of nerve-sparing performed. Continence was defined by 0-pad usage at 1 month follow-up. Univariate and multivariate logistic regression models were used to assess for predictors of early continence. Results: Overall, 44% of patients were pad-free 1 month post-RARP. In multivariate regression analysis, age (odds ratio [OR] 0.946, confidence interval [CI] 95%: 0.91, 0.98) and IPSS (OR: 0.953, CI 95%: 0.92, 0.99) were independent predictors of urinary continence 1 month following RARP. Other variables (BMI, staging, preoperative PSA, SHIM score, prostate weight and type of nerve-sparing) were not statistically significant predictors of early continence. Limitations of this study include missing data for comorbidities, patient use of pelvic floor exercises and patient maximal activity. Moreover, patient-reported continence using a 0-pad usage definition represents a semiquantitative and subjective measurement. Conclusion: In a broad population of patients who underwent RARP at our institution, 44% of patients were pad-free at 1 month. Age and IPSS were independent predictors of early continence after surgery. Men of advanced

  3. Postcollision extension in arc-continent collision zones, eastern Indonesia

    NASA Astrophysics Data System (ADS)

    Charlton, T. R.

    1991-01-01

    Postcollisional extension superimposed on arc-continent collision complexes is a common feature in the orogenic belts of eastern Indonesia. In the southern Banda arc, the arc-continent collision event is essentially a Pliocene and younger feature, but already an element of extension is being superimposed on the compressional structures of the collision complex. It is thus likely that the extension commences within a very short period (<5 m.y.) after the initiation of collision-related compressional deformation. A similar history of fold-belt development immediately followed by extension can be inferred for the Lengguru fold belt and the adjacent Wandamen-Wondiwoi terranes of Irian Jaya and for the Gulf of Bone in Sulawesi. It is suggested that the extension results from decoupling of the subducting oceanic lithosphere from the unsubductable continental lithosphere and that the superimposition of extension is a virtually unavoidable consequence of the arc-continent collision.

  4. Endoscopic treatment for pill bezoars after continent ileostomy.

    PubMed

    Lian, L; Fazio, V; Shen, B

    2009-07-01

    Difficulty intubation is the most common long-term complication after continent ileostomy, which can be associated with nipple valve slippage, parastomal hernia, stenosis. Diagnosis and management of a patient with nipple valve stricture and partial bowel obstruction associated with dietary supplement retention in the pouch reservoir is described. A 50-year-old female patient with ulcerative colitis and a 15-year history of continent ileostomy after total proctocolectomy reported 5-week symptoms of abdominal pain and difficulty in intubating the pouch. Pill bezoar composed of dietary supplement was found in diagnostic pouch endoscopy. Therapeutic pouch endoscopy was performed with balloon dilation of a nipple valve stenosis and retrieval of 224 dietary supplement tablets. Pill bezoar in the pouch is rare. However, patients with continent ileostomy should be advised to avoid taking hard-to-dissolve foods and medications. PMID:18619932

  5. A Geological Model for the Evolution of Early Continents (Invited)

    NASA Astrophysics Data System (ADS)

    Rey, P. F.; Coltice, N.; Flament, N. E.; Thébaud, N.

    2013-12-01

    Geochemical probing of ancient sediments (REE in black shales, strontium composition of carbonates, oxygen isotopes in zircons...) suggests that continents were a late Archean addition at Earth's surface. Yet, geochemical probing of ancient basalts reveals that they were extracted from a mantle depleted of its crustal elements early in the Archean. Considerations on surface geology, the early Earth hypsometry and the rheology and density structure of Archean continents can help solve this paradox. Surface geology: The surface geology of Archean cratons is characterized by thick continental flood basalts (CFBs, including greenstones) emplaced on felsic crusts dominated by Trondhjemite-Tonalite-Granodiorite (TTG) granitoids. This simple geology is peculiar because i/ most CFBs were emplaced below sea level, ii/ after their emplacement, CFBs were deformed into relatively narrow, curviplanar belts (greenstone basins) wrapping around migmatitic TTG domes, and iii/ Archean greenstone belts are richly endowed with gold and other metals deposits. Flat Earth hypothesis: From considerations on early Earth continental geotherm and density structure, Rey and Coltice (2008) propose that, because of the increased ability of the lithosphere to flow laterally, orogenic processes in the Archean produced only subdued topography (continents, Flament et al. (2008) proposed a theory for the hypsometry of the early Earth showing that, until the late Archean, most continents were flooded and Earth was largely a water world. From this, a model consistent with many of the peculiar attributes of Archean geology, can be proposed: 1/ Continents appeared at Earth's surface at an early stage during the Hadean/Archean. However, because they were i/ covered by continental flood basalts, ii/ below sea level, and iii/ deprived of modern-style mountain belts and orogenic plateaux, early felsic

  6. Family Planning in Five Continents: Africa, America, Asia, Europe, Oceania.

    ERIC Educational Resources Information Center

    International Planned Parenthood Federation, London (England).

    Population growth trends and family planning activities in Africa, America, Asia, Europe, and Oceania are summarized in this booklet developed by the International Planned Parenthood Federation. Narrative information for each continent gives a resume of population growth trends, reasons for the trends, population problems, policy formation, family…

  7. Regulating continent growth and composition by chemical weathering

    USGS Publications Warehouse

    Lee, C.-T.A.; Morton, D.M.; Little, M.G.; Kistler, R.; Horodyskyj, U.N.; Leeman, W.P.; Agranier, A.

    2008-01-01

    Continents ride high above the ocean floor because they are underlain by thick, low-density, Si-rich, and Mg-poor crust. However, the parental magmas of continents were basaltic, which means they must have lost Mg relative to Si during their maturation into continents. Igneous differentiation followed by lower crustal delamination and chemical weathering followed by subduction recycling are possible solutions, but the relative magnitudes of each process have never been quantitatively constrained because of the lack of appropriate data. Here, we show that the relative contributions of these processes can be obtained by simultaneous examination of Mg and Li (an analog for Mg) on the regional and global scales in arcs, delaminated lower crust, and river waters. At least 20% of Mg is lost from continents by weathering, which translates into >20% of continental mass lost by weathering (40% by delamination). Chemical weathering leaves behind a more Si-rich and Mg-poor crust, which is less dense and hence decreases the probability of crustal recycling by subduction. Net continental growth is thus modulated by chemical weathering and likely influenced by secular changes in weathering mechanisms. ?? 2008 by The National Academy of Sciences of the USA.

  8. Regulating continent growth and composition by chemical weathering.

    PubMed

    Lee, Cin-Ty Aeolus; Morton, Douglas M; Little, Mark G; Kistler, Ronald; Horodyskyj, Ulyana N; Leeman, William P; Agranier, Arnaud

    2008-04-01

    Continents ride high above the ocean floor because they are underlain by thick, low-density, Si-rich, and Mg-poor crust. However, the parental magmas of continents were basaltic, which means they must have lost Mg relative to Si during their maturation into continents. Igneous differentiation followed by lower crustal delamination and chemical weathering followed by subduction recycling are possible solutions, but the relative magnitudes of each process have never been quantitatively constrained because of the lack of appropriate data. Here, we show that the relative contributions of these processes can be obtained by simultaneous examination of Mg and Li (an analog for Mg) on the regional and global scales in arcs, delaminated lower crust, and river waters. At least 20% of Mg is lost from continents by weathering, which translates into >20% of continental mass lost by weathering (40% by delamination). Chemical weathering leaves behind a more Si-rich and Mg-poor crust, which is less dense and hence decreases the probability of crustal recycling by subduction. Net continental growth is thus modulated by chemical weathering and likely influenced by secular changes in weathering mechanisms.

  9. Petroleum Technology Transfer Council boosts North Mid-continent technology

    SciTech Connect

    Lyle, D.

    1995-10-01

    The Kansas Tertiary Oil Recovery Project served as one of the primary models for the Petroleum Technology Transfer Council, so it`s fitting this series on regional applications should start with the North Mid-Continent organization. The technology transfer program is described.

  10. Choosing and using disposable body-worn continence pads.

    PubMed

    Gilbert, Rachel

    Disposable, body-worn pads are the product most commonly chosen to contain and absorb urine and faeces (Pomfret, 2000). The cost to the NHS of supplying continence pads has been estimated at 80 million pounds per annum (Euromonitor, 1999) and is a huge financial burden on local services. PMID:16052946

  11. Improving continence services--a case study in policy influence.

    PubMed

    Thomas, Sue; Billington, Angela; Getliffe, Kathryn

    2004-07-01

    This article presents a case history of the process followed by a group of nurses who used their power and influence to improve the provision of continence services within the National Health Service in England. The process and outcomes demonstrate how nurses can achieve change using their political influence combined with a planned or evolving strategy. PMID:15209570

  12. 21 CFR 876.5310 - Nonimplanted, peripheral electrical continence device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Nonimplanted, peripheral electrical continence device. 876.5310 Section 876.5310 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices §...

  13. 21 CFR 876.5310 - Nonimplanted, peripheral electrical continence device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Nonimplanted, peripheral electrical continence device. 876.5310 Section 876.5310 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices §...

  14. 21 CFR 876.5270 - Implanted electrical urinary continence device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Implanted electrical urinary continence device. 876.5270 Section 876.5270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices §...

  15. 21 CFR 876.5310 - Nonimplanted, peripheral electrical continence device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Nonimplanted, peripheral electrical continence device. 876.5310 Section 876.5310 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices §...

  16. 21 CFR 876.5270 - Implanted electrical urinary continence device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Implanted electrical urinary continence device. 876.5270 Section 876.5270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices §...

  17. 21 CFR 876.5270 - Implanted electrical urinary continence device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Implanted electrical urinary continence device. 876.5270 Section 876.5270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices §...

  18. 21 CFR 876.5310 - Nonimplanted, peripheral electrical continence device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Nonimplanted, peripheral electrical continence device. 876.5310 Section 876.5310 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices §...

  19. 21 CFR 876.5270 - Implanted electrical urinary continence device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Implanted electrical urinary continence device. 876.5270 Section 876.5270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices §...

  20. 21 CFR 876.5270 - Implanted electrical urinary continence device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Implanted electrical urinary continence device. 876.5270 Section 876.5270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices §...

  1. Regulating continent growth and composition by chemical weathering

    PubMed Central

    Lee, Cin-Ty Aeolus; Morton, Douglas M.; Little, Mark G.; Kistler, Ronald; Horodyskyj, Ulyana N.; Leeman, William P.; Agranier, Arnaud

    2008-01-01

    Continents ride high above the ocean floor because they are underlain by thick, low-density, Si-rich, and Mg-poor crust. However, the parental magmas of continents were basaltic, which means they must have lost Mg relative to Si during their maturation into continents. Igneous differentiation followed by lower crustal delamination and chemical weathering followed by subduction recycling are possible solutions, but the relative magnitudes of each process have never been quantitatively constrained because of the lack of appropriate data. Here, we show that the relative contributions of these processes can be obtained by simultaneous examination of Mg and Li (an analog for Mg) on the regional and global scales in arcs, delaminated lower crust, and river waters. At least 20% of Mg is lost from continents by weathering, which translates into >20% of continental mass lost by weathering (40% by delamination). Chemical weathering leaves behind a more Si-rich and Mg-poor crust, which is less dense and hence decreases the probability of crustal recycling by subduction. Net continental growth is thus modulated by chemical weathering and likely influenced by secular changes in weathering mechanisms. PMID:18362343

  2. Improving continence services--a case study in policy influence.

    PubMed

    Thomas, Sue; Billington, Angela; Getliffe, Kathryn

    2004-07-01

    This article presents a case history of the process followed by a group of nurses who used their power and influence to improve the provision of continence services within the National Health Service in England. The process and outcomes demonstrate how nurses can achieve change using their political influence combined with a planned or evolving strategy.

  3. Oceanic plateaus, the fragmentation of continents, and mountain building

    SciTech Connect

    Nur, A.; Ben-Avraham, Z.

    1982-05-10

    Many anomalous rises in today's oceans may be submerged continental fragments detached from previous continents, ancient island arcs, or basaltic piles formed by hot spots and spreading centers. These rises are embedded in their respective moving oceanic plates and are fated to be consumed at active margins. Where such rises are being consumed at present, e.g., the Nazca Ridge, they cause cessation of volcanism, disruption of the downgoing slab, and possible shifts in plate boundary configuration. Many past rises, including numerous continental fragments have been recognized within mountain belts as allochthonous terranes. They constitute a large portion of the orogenic belts in the North Pacific from Mexico through western North America, Alaska, east Siberia, Japan and in New Zealand. The orogenic deformation in these belts is possibly the result of the accretion of the allochtronous terranes. Many terranes have been accreted with substantial deformation also in the Alpine chain, well before major continent-continent collisions. It is suggested, therefore, that the accretion of fragments may be the common process of the deformation phase of mountain building. Subduction of normal oceanic crust may be insufficient for deformation, whereas full continent-continent collision may be necessary. The general validity of this conclusion depends critically on whether allochthonous terranes caused orogenic deformation in the Andes or not. Most of the accreted fragments with continental affinites in the Mesozoic-Cenozoic orogenic belts of the world can be traced back to the breakup of Gondwana, beginning with a Pacifica domain in the Permian through a larger India domain in the early Mesozoic and continuing through the separation of the Somalia plate in the near future. The reasons for this 250 million year breakup process are not known, but some kind of thermal process, possible of mantle-wide scale, is implied.

  4. Madagascar: Heads It's a Continent, Tails It's an Island

    NASA Astrophysics Data System (ADS)

    de Wit, Maarten J.

    Neither geologists nor biologists have a definition that is capable of classifying Madagascar unambiguously as an island or a continent; nor can they incorporate Malagasy natural history into a single model rooted in Africa or Asia. Madagascar is a microcosm of the larger continents, with a rock record that spans more than 3000 million years (Ma), during which it has been united episodically with, and divorced from, Asian and African connections. This is reflected in its Precambrian history of deep crustal tectonics and a Phanerozoic history of biodiversity that fluctuated between cosmopolitanism and parochialism. Both vicariance and dispersal events over the past 90 Ma have blended a unique endemism on Madagascar, now in decline following rapid extinctions that started about 2000 years ago.

  5. Commissioning continence services--turning policy into action.

    PubMed

    Thomas, Sue

    2004-05-18

    Incontinence of urine and faeces is a major issue in health care today. The financial cost is enormous with the NHS purchasing an annual 80 m Pounds worth of absorbent products alone (Euromonitor, 1999). But the financial cost is only part of the equation. Incontinence also has a considerable impact on the quality of life of those who experience it. The nature and impact on quality of life varies among individuals. However, where expert services are available cure rates can exceed 50 per cent (Royal College of Physicians, 1995). This suggests that specialist continence services have a vital role to play in helping patients improve their incontinence or manage their continence problems more effectively. PMID:15176280

  6. Mid-continent natural gas reservoirs and plays

    SciTech Connect

    Bebout, D.G. )

    1993-09-01

    Natural gas reservoirs of the mid-continent states of Oklahoma, Kansas, and Arkansas (northern part) have produced 103 trillion cubic ft (tcf) of natural gas. Oklahoma has produced the most, having a cumulative production of 71 tcf. The major reservoirs (those that have produced more than 10 billion ft[sup 3]) have been identified and organized into 28 plays based on geologic age, lithology, and depositional environment. The Atlas of Major Midcontinent Gas Reservoirs, published in 1993, provides the documentation for these plays. This atlas was a collaborative effort of the Gas Research Institute; Bureau of Economic Geology. The University of Texas at Austin; Arkansas Geological Commission; Kansas Geological survey; and Oklahoma Geological Survey. Total cumulative production for 530 major reservoirs is 66 tcf associated and nonassociated gas. Oklahoma has the highest production with 39 tcf from 390 major reservoirs, followed by Kansas with 26 tcf from 105 major reservoirs. Most of the mid-continent production is from Pennsylvanian (46%) and Permian (41%) reservoirs; Mississippian reservoirs account for 10% production, and lower Paleozoic reservoirs, 3%. The largest play by far is the Wolfcampian Shallow Shelf Carbonate-Hugoton Embayment play with 25 tcf cumulative production, most of which is from the Hugoton and Panoma fields in Kansas and Guymon-Hugoton gas area in Oklahoma. A total of 53% of the mid-continent gas production is from dolostone and limestone reservoirs; 39% is from sandstone reservoirs. The remaining 8% is from chert conglomerate and granite-wash reservoirs. Geologically based plays established from the distribution of major gas reservoirs provide important support for the extension of productive trends, application of new resource technology to more efficient field development, and further exploration in the mid-continent region.

  7. Durability of the Malone antegrade continence enema in pregnancy.

    PubMed

    Wren, Francis J; Reese, Carl T; Decter, Ross M

    2003-03-01

    The Malone antegrade continence enema (MACE) is a therapeutic option to treat chronic constipation and fecal incontinence in patients with neurogenic bowel. Previous reports have described the short-term success of this procedure, but no report has described the durability of the procedure during pregnancy. We present the case of a spinal cord injury patient who underwent an uncomplicated pregnancy after a MACE procedure with no stomal catheterization difficulties or leakage during or after the pregnancy.

  8. Mid-Continent rift system - a frontier hydrocarbon province

    SciTech Connect

    Lee, C.K.; Kerr, S.D. Jr.

    1983-08-01

    Geophysical evidence in the Mid-Continent has led to delineation of a rift system active during the Proterozoic Y Era. The Mid-Continent rift system can be traced by the Mid-Continent gravity high and corresponding aeromagnetic anomaly signature from the surface exposure of the Keweenawan Supergroup in the Lake Superior basin southwest in the subsurface through Wisconsin, Minnesota, Iowa, Nebraska, and Kansas. The aeromagnetic anomaly signature of the rift trend discloses where these sediments have been preserved. Thick accumulations of upper Proterozoic sediments are indicated by both upward continuation of the aeromagnetic profiles across the rift trend and gravity models which incorporate: 1) a deep mafic body to create the narrow gravity high, 2) anomalously thick crust to account for the more regional gravity low, and 3) sedimentary accumulations on the Precambrian surface to explain the small-scale notches which occur within the narrow gravity high. Reflection seismic data are virtually unknown in the rift area; however, data recently acquired by COCORP across the southern end of the feature in Kansas provide evidence of thick stratified sequences in the rift valley. Studies of the East African rift have revealed that the tropical rift valley is an exceptionally fertile environment for deposition and preservation of kerogenous material. The Sirte, Suez, Viking, Dnieper-Donetz, and Tsaidam basins are just a few of the rift basins currently classed as giant producers. The existence of a rift basin trend with thick accumulations of preserved sediments, demonstrably organic rich, introduces the northern Mid-Continent US as a new frontier for hydrocarbon exploration.

  9. Observational Evidence of Changes in Soil Temperatures across Eurasian Continent

    NASA Astrophysics Data System (ADS)

    Zhang, T.

    2015-12-01

    Soil temperature is one of the key climate change indicators and plays an important role in plant growth, agriculture, carbon cycle and ecosystems as a whole. In this study, variability and changes in ground surface and soil temperatures up to 3.20 m were investigated based on data and information obtained from hydrometeorological stations across Eurasian continent since the early 1950s. Ground surface and soil temperatures were measured daily by using the same standard method and by the trained professionals across Eurasian continent, which makes the dataset unique and comparable over a large study region. Using the daily soil temperature profiles, soil seasonal freeze depth was also obtained through linear interpolation. Preliminary results show that soil temperatures at various depths have increased dramatically, almost twice as much as air temperature increase over the same period. Regionally, soil temperature increase was more dramatically in high northern latitudes than mid/lower latitude regions. Air temperature changes alone may not be able to fully explain the magnitude of changes in soil temperatures. Further study indicates that snow cover establishment started later in autumn and snow cover disappearance occurred earlier in spring, while winter snow depth became thicker with a decreasing trend of snow density. Changes in snow cover conditions may play an important role in changes of soil temperatures over the Eurasian continent.

  10. Mid-Continent rift system: a frontier hydrocarbon province

    SciTech Connect

    Lee, C.K.; Kerr, S.D. Jr.

    1984-04-01

    The Mid-Continent rift system can be traced by the Mid-Continent geophysical anomaly (MGA) from the surface exposure of the Keweenawan Supergroup in the Lake Superior basin southwest in the subsurface through Wisconsin, Minnesota, Iowa, Nebraska, and Kansas. Outcrop and well penetrations of the late rift Keweenawan sedimentary rocks reveal sediments reflecting a characteristic early continental rift clastic sequence, including alluvial fans, deep organic-rich basins, and prograding fluvial plains. Sedimentary basins where these early rift sediments are preserved can be located by upward continuation of the aeromagnetic profiles across the rift trend and by gravity models. Studies of analog continental rifts and aulacogens show that these gravity models should incorporate (1) a deep mafic rift pillow body to create the narrow gravity high of the MGA, and (2) anomalously thick crust to account for the more regional gravity low. Preserved accumulations of rift clastics in central rift positions can then be modeled to explain the small scale notches which are found within the narrow gravity high. Indigenous oil in Keweenawan sediments in the outcrop area and coaly partings in the subsurface penetrations of the Keweenawan clastics support the analogy between these rift sediments and the exceptionally organic-rich sediments of the East African rift. COCORP data across the rift trend in Kansas show layered deep reflectors and large structures. There is demonstrable source, reservoir, and trap potential within the Keweenawan trend, making the Mid-Continent rift system a frontier hydrocarbon province.

  11. Mid-continent rift system: a frontier hydrocarbon province

    SciTech Connect

    Lee, C.K.; Kerr, S.D. Jr.

    1984-04-01

    The Mid-continent rift system can be traced by the Mid-continent geophysical anomaly (MGA) from the surface exposure of the Keweenawan Supergroup in the Lake Superior basin southwest in the subsurface through Wisconsin, Minnesota, Iowa, Nebraska, and Kansas. Outcrop and well penetrations of the late rift Keweenawan sedimentary rocks reveal sediments reflecting a characteristic early continental rift clastic sequence, including alluvial fans, deep organic-rich basins, and prograding fluvial plains. Sedimentary basins where these early rift sediments are preserved can be located by upward continuation of the aeromagnetic profiles across the rift trend and by gravity models. Studies of analog continental rifts and aulacogens show that these gravity models should incorporate (1) a deep mafic rift pillow body to create the narrow gravity high of the MGA, and (2) anomalously thick crust to account for the more regional gravity low. Preserved accumulations of rift clastics in central rift positions can then be modeled to explain the small scale notches which are found within the narrow gravity high. Indigenous oil in Keweenawan sediments in the outcrop area and coaly partings in the subsurface penetrations of the Keweenawan clastics support the analogy between these rift sediments and the exceptionally organic-rich sediments of the East African rift. COCORP data across the rift trend in Kansas show layered deep reflectors and large structures. There is demonstrable source, reservoir, and trap potential within the Keweenawan trend, making the Mid-Continent rift system a frontier hydrocarbon province.

  12. Comparative estimate of volcanism intensity on continents and in oceans

    SciTech Connect

    Ronov, A.B.; Khain, V.E.; Balukhovskii, A.N.

    1980-12-01

    A quantitative estimate of the volume of volcanogenic rocks and the volcanism intensity during different stages in the Earth's development indicates that the total volume of the tholeiitic basalts of Layer II of the oceans exceeds by 20 times that of the synchronous late Mesozoic-Cenozoic volcanics of the continents and is almost 5 times greater than the volume of the volcanogenic rocks of the entire Phanerozoic sequence of the continents. The absolute maxima of volcanism, determined on the basis of the area and volume of the corresponding volcanics, belong to the Late Cretaceous and Miocene intervals. Changes in the volcanic eruption areas took place synchronously in the Pacific, Atlantic, and Indian Oceans. The volcanism intensity, expressed in the volume of its products in km/sup 3/ per m.y., increases in the oceans from Late Jurassic to Pliocene time. During the Riphean and Vendian intervals, the volcanism intensity on the continents remained at an extremely low level, then increased during early Paleozoic time, and underwent a marked jump, beginning in the Devonian Period. Since Late Jurassic time, the intensity of global volcanism increased unusually sharply and reached its culmination during Neogene time.

  13. Continents on the Move or "Where in the World Did Antarctica Come From?"

    ERIC Educational Resources Information Center

    CSTA Journal, 1995

    1995-01-01

    Presents an activity in which students trace the movement of the continents over the past 600 million years to help them understand how the continents' size and position have changed over time. Includes map puzzle pieces. (MKR)

  14. [Surgical therapy of chronic anal fissure--do additional proctologic operations impair continence?].

    PubMed

    Pfeifer, J; Berger, A; Uranüs, S

    1994-07-01

    78 patients with chronic anal fissures have been mainly operated on by lateral internal sphincterotomy (LATS). Continence have been evaluated by questionnaire at least 9 months postoperatively. Patient without any additional proctological operation had minor disturbances of continence in 17%. Patient with additional operations had disturbances of continence in 30%. Especially the subgroup of patients with LATS and haemorrhoidectomy had bad results. In this group only 45% were fully continent.

  15. How Do People Make Continence Care Happen? An Analysis of Organizational Culture in Two Nursing Homes

    ERIC Educational Resources Information Center

    Lyons, Stacie Salsbury

    2010-01-01

    Purpose: Although nursing homes (NHs) are criticized for offering poor quality continence care, little is known about the organizational processes that underlie this care. This study investigated the influence of organizational culture on continence care practices in two NHs. Design and Methods: This ethnographic study explored continence care…

  16. 21 CFR 876.5280 - Implanted mechanical/hydraulic urinary continence device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Implanted mechanical/hydraulic urinary continence....5280 Implanted mechanical/hydraulic urinary continence device. (a) Identification. An implanted mechanical/hydraulic urinary continence device is a device used to treat urinary incontinence by...

  17. 21 CFR 876.5280 - Implanted mechanical/hydraulic urinary continence device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Implanted mechanical/hydraulic urinary continence....5280 Implanted mechanical/hydraulic urinary continence device. (a) Identification. An implanted mechanical/hydraulic urinary continence device is a device used to treat urinary incontinence by...

  18. 21 CFR 876.5280 - Implanted mechanical/hydraulic urinary continence device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Implanted mechanical/hydraulic urinary continence....5280 Implanted mechanical/hydraulic urinary continence device. (a) Identification. An implanted mechanical/hydraulic urinary continence device is a device used to treat urinary incontinence by...

  19. 21 CFR 876.5280 - Implanted mechanical/hydraulic urinary continence device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Implanted mechanical/hydraulic urinary continence....5280 Implanted mechanical/hydraulic urinary continence device. (a) Identification. An implanted mechanical/hydraulic urinary continence device is a device used to treat urinary incontinence by...

  20. 21 CFR 876.5280 - Implanted mechanical/hydraulic urinary continence device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Implanted mechanical/hydraulic urinary continence....5280 Implanted mechanical/hydraulic urinary continence device. (a) Identification. An implanted mechanical/hydraulic urinary continence device is a device used to treat urinary incontinence by...

  1. Currents in the mantle and the geology of continents

    NASA Astrophysics Data System (ADS)

    Wilson, J. Tuzo

    1991-02-01

    This paper is the first of a series which have considered the possible effects of currents in the mantle upon continents. It mentions effects of aging in oceans upon the direction of slope of coastal peneplains. When oceans are young the coasts are cliffs from which peneplains dip downward on the inland side. As the margins separate from the ridge they cool and the slopes reverse. It suggests how Jeffreys' arguments against convection currents breaking the lithosphere can be avoided and discusses the possibility that upwelling has penetrated beneath the southwestern United States.

  2. International Continence Society guidelines on urodynamic equipment performance.

    PubMed

    Gammie, Andrew; Clarkson, Becky; Constantinou, Chris; Damaser, Margot; Drinnan, Michael; Geleijnse, Geert; Griffiths, Derek; Rosier, Peter; Schäfer, Werner; Van Mastrigt, Ron

    2014-04-01

    These guidelines provide benchmarks for the performance of urodynamic equipment, and have been developed by the International Continence Society to assist purchasing decisions, design requirements, and performance checks. The guidelines suggest ranges of specification for uroflowmetry, volume, pressure, and EMG measurement, along with recommendations for user interfaces and performance tests. Factors affecting measurement relating to the different technologies used are also described. Summary tables of essential and desirable features are included for ease of reference. It is emphasized that these guidelines can only contribute to good urodynamics if equipment is used properly, in accordance with good practice.

  3. MAGSAT and aeromagnetic data in the North American continent

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Problems were encountered in deriving a proper reference field to be subtracted from the aeromagnetic data obtained from Project MAGNET. Field models tried thus far do not seem to eliminate properly the main field. The MAGSAT data in the North American continent for the period November 1 to December 22, 1979 are being compiled and compared with MAGNET data. Efforts are being made to eliminate the orbital bias errors. A computer program was developed and successfully tested which computes a topographic profile of the Curie depth isotherm which fits best to the observed vector or scalar field magnetic data.

  4. Savanna vegetation-fire-climate relationships differ among continents.

    PubMed

    Lehmann, Caroline E R; Anderson, T Michael; Sankaran, Mahesh; Higgins, Steven I; Archibald, Sally; Hoffmann, William A; Hanan, Niall P; Williams, Richard J; Fensham, Roderick J; Felfili, Jeanine; Hutley, Lindsay B; Ratnam, Jayashree; San Jose, Jose; Montes, Ruben; Franklin, Don; Russell-Smith, Jeremy; Ryan, Casey M; Durigan, Giselda; Hiernaux, Pierre; Haidar, Ricardo; Bowman, David M J S; Bond, William J

    2014-01-31

    Ecologists have long sought to understand the factors controlling the structure of savanna vegetation. Using data from 2154 sites in savannas across Africa, Australia, and South America, we found that increasing moisture availability drives increases in fire and tree basal area, whereas fire reduces tree basal area. However, among continents, the magnitude of these effects varied substantially, so that a single model cannot adequately represent savanna woody biomass across these regions. Historical and environmental differences drive the regional variation in the functional relationships between woody vegetation, fire, and climate. These same differences will determine the regional responses of vegetation to future climates, with implications for global carbon stocks.

  5. Pressure injury prevention: continence, skin hygiene and nutrition management.

    PubMed

    Roosen, Kerri; Fulbrook, Paul; Nowicki, Tracy

    2010-08-10

    To prevent pressure injuries research indicates the importance of focusing on three key areas of practice: continence, skin hygiene and nutrition. These are a synergistic trio and many patients require considered management in all three areas. In addition to targeting specific aspects of nursing care in these areas, it is also crucial that there is organisational buy-in for strategic initiatives. Some of the ways that we achieved this are outlined below: Support from managerial level by presenting evidence and education to senior nurses and directors. Nurse unit managers completed individual ward action plans outlining their individual commitments to reducing pressure injuries. Providing support and education to staff to choose and use continence products effectively. Support from allied health colleagues in prevention of pressure injuries. After implementing the actions described above, pressure injury prevalence at the Prince Charles Hospital in Brisbane decreased from 13.78% in 2008 to 5.15% in 2010, representing a 62% reduction overall. Of these pressure injuries, 53% were stage one.

  6. Archean komatiite volcanism controlled by the evolution of early continents.

    PubMed

    Mole, David R; Fiorentini, Marco L; Thebaud, Nicolas; Cassidy, Kevin F; McCuaig, T Campbell; Kirkland, Christopher L; Romano, Sandra S; Doublier, Michael P; Belousova, Elena A; Barnes, Stephen J; Miller, John

    2014-07-15

    The generation and evolution of Earth's continental crust has played a fundamental role in the development of the planet. Its formation modified the composition of the mantle, contributed to the establishment of the atmosphere, and led to the creation of ecological niches important for early life. Here we show that in the Archean, the formation and stabilization of continents also controlled the location, geochemistry, and volcanology of the hottest preserved lavas on Earth: komatiites. These magmas typically represent 50-30% partial melting of the mantle and subsequently record important information on the thermal and chemical evolution of the Archean-Proterozoic Earth. As a result, it is vital to constrain and understand the processes that govern their localization and emplacement. Here, we combined Lu-Hf isotopes and U-Pb geochronology to map the four-dimensional evolution of the Yilgarn Craton, Western Australia, and reveal the progressive development of an Archean microcontinent. Our results show that in the early Earth, relatively small crustal blocks, analogous to modern microplates, progressively amalgamated to form larger continental masses, and eventually the first cratons. This cratonization process drove the hottest and most voluminous komatiite eruptions to the edge of established continental blocks. The dynamic evolution of the early continents thus directly influenced the addition of deep mantle material to the Archean crust, oceans, and atmosphere, while also providing a fundamental control on the distribution of major magmatic ore deposits. PMID:24958873

  7. Permo-carboniferous hydrocarbon accumulations, Mid-continent, USA

    SciTech Connect

    Rascoe, B.; Adler, F.J.

    1983-06-01

    Approximately 19.4 billion bbl of oil and 119 tcf of nonassociated gas have been discovered in the Mid-Continent as of January 1, 1978. Although these volumes of hydrocarbons were trapped in thousands of fields throughout the Mid-Continent, the bulk of these resources were emplaced in a relatively few fields about 14.2 billion bbl of oil have been found in 111 significant and giant oil fields, and 103 tcf of nonassociated gas have been discovered in 57 significant and giant gas fields. PermoCarboniferous reservoirs are important in 101 of the large oil fields and 55 of the large gas fields; these fields contained 9.5 billion bbl of oil and 99 tcf of gas, respectively. Our calculations of the total oil and gas accumulations in Permo-Carboniferous reservoirs extrapolated from these data. About 2.1 billion bbl of oil and 5.1 tcf of nonassociated gas accumulated in Lower Carboniferous (Mississippian) reservoirs. Most of this oil and gas was stratigraphically trapped in Upper Mississippian sandstones and carbonates which are truncated at the pre-Pennsylvanian unconformity surface.

  8. Pregnancy and delivery in patients with a continent ileostomy.

    PubMed

    Ojerskog, B; Kock, N G; Philipson, B M; Philipson, M

    1988-07-01

    Patients undergoing surgical treatment for inflammatory disease of the intestine are often in their reproductive years. Therefore, it is highly relevant to study the influence of surgical treatment on later pregnancy and delivery. Reported herein are 28 patients with continent ileostomies who have carried 37 pregnancies to term. An increased urge to empty the ileostomy reservoir, especially in the late period of pregnancy, was noted by the majority of patients. About one-third of the patients reported some difficulties with intubation of the reservoir in late pregnancy but in only a few patients did these disturbances result in a revisional operation after delivery. Pregnancy was normal in most instances and only four premature childbirths occurred. All pregnancies resulted in live birth. Vaginal delivery was successful in the majority of the patients, cesarean section being chosen for obstetric reasons in nine instances. From this study, it is concluded that, in patients with a continent ileostomy, normal pregnancy and delivery can be expected. However, in a few instances, the ileostomy function may be disturbed, necessitating later revisional operations.

  9. Archean komatiite volcanism controlled by the evolution of early continents

    PubMed Central

    Mole, David R.; Fiorentini, Marco L.; Thebaud, Nicolas; Cassidy, Kevin F.; McCuaig, T. Campbell; Kirkland, Christopher L.; Romano, Sandra S.; Doublier, Michael P.; Belousova, Elena A.; Barnes, Stephen J.; Miller, John

    2014-01-01

    The generation and evolution of Earth’s continental crust has played a fundamental role in the development of the planet. Its formation modified the composition of the mantle, contributed to the establishment of the atmosphere, and led to the creation of ecological niches important for early life. Here we show that in the Archean, the formation and stabilization of continents also controlled the location, geochemistry, and volcanology of the hottest preserved lavas on Earth: komatiites. These magmas typically represent 50–30% partial melting of the mantle and subsequently record important information on the thermal and chemical evolution of the Archean–Proterozoic Earth. As a result, it is vital to constrain and understand the processes that govern their localization and emplacement. Here, we combined Lu-Hf isotopes and U-Pb geochronology to map the four-dimensional evolution of the Yilgarn Craton, Western Australia, and reveal the progressive development of an Archean microcontinent. Our results show that in the early Earth, relatively small crustal blocks, analogous to modern microplates, progressively amalgamated to form larger continental masses, and eventually the first cratons. This cratonization process drove the hottest and most voluminous komatiite eruptions to the edge of established continental blocks. The dynamic evolution of the early continents thus directly influenced the addition of deep mantle material to the Archean crust, oceans, and atmosphere, while also providing a fundamental control on the distribution of major magmatic ore deposits. PMID:24958873

  10. Continents as lithological icebergs: The importance of buoyant lithospheric roots

    USGS Publications Warehouse

    Abbott, D.H.; Drury, R.; Mooney, W.D.

    1997-01-01

    An understanding of the formation of new continental crust provides an important guide to locating the oldest terrestrial rocks and minerals. We evaluated the crustal thicknesses of the thinnest stable continental crust and of an unsubductable oceanic plateau and used the resulting data to estimate the amount of mantle melting which produces permanent continental crust. The lithospheric mantle is sufficiently depleted to produce permanent buoyancy (i.e., the crust is unsubductable) at crustal thicknesses greater than 25-27 km. These unsubductable oceanic plateaus and hotspot island chains are important sources of new continental crust. The newest continental crust (e.g., the Ontong Java plateau) has a basaltic composition, not a granitic one. The observed structure and geochemistry of continents are the result of convergent margin magmatism and metamorphism which modify the nascent basaltic crust into a lowermost basaltic layer overlain by a more silicic upper crust. The definition of a continent should imply only that the lithosphere is unsubductable over ??? 0.25 Ga time periods. Therefore, the search for the oldest crustal rocks should include rocks from lower to mid-crustal levels.

  11. Archean komatiite volcanism controlled by the evolution of early continents.

    PubMed

    Mole, David R; Fiorentini, Marco L; Thebaud, Nicolas; Cassidy, Kevin F; McCuaig, T Campbell; Kirkland, Christopher L; Romano, Sandra S; Doublier, Michael P; Belousova, Elena A; Barnes, Stephen J; Miller, John

    2014-07-15

    The generation and evolution of Earth's continental crust has played a fundamental role in the development of the planet. Its formation modified the composition of the mantle, contributed to the establishment of the atmosphere, and led to the creation of ecological niches important for early life. Here we show that in the Archean, the formation and stabilization of continents also controlled the location, geochemistry, and volcanology of the hottest preserved lavas on Earth: komatiites. These magmas typically represent 50-30% partial melting of the mantle and subsequently record important information on the thermal and chemical evolution of the Archean-Proterozoic Earth. As a result, it is vital to constrain and understand the processes that govern their localization and emplacement. Here, we combined Lu-Hf isotopes and U-Pb geochronology to map the four-dimensional evolution of the Yilgarn Craton, Western Australia, and reveal the progressive development of an Archean microcontinent. Our results show that in the early Earth, relatively small crustal blocks, analogous to modern microplates, progressively amalgamated to form larger continental masses, and eventually the first cratons. This cratonization process drove the hottest and most voluminous komatiite eruptions to the edge of established continental blocks. The dynamic evolution of the early continents thus directly influenced the addition of deep mantle material to the Archean crust, oceans, and atmosphere, while also providing a fundamental control on the distribution of major magmatic ore deposits.

  12. Climate control of terrestrial carbon exchange across biomes and continents

    SciTech Connect

    Ricciuto, Daniel M; Gu, Lianhong

    2010-07-01

    Understanding the relationships between climate and carbon exchange by terrestrial ecosystems is critical to predict future levels of atmospheric carbon dioxide because of the potential accelerating effects of positive climate carbon cycle feedbacks. However, directly observed relationships between climate and terrestrial CO2 exchange with the atmosphere across biomes and continents are lacking. Here we present data describing the relationships between net ecosystem exchange of carbon (NEE) and climate factors as measured using the eddy covariance method at 125 unique sites in various ecosystems over six continents with a total of 559 site-years. We find that NEE observed at eddy covariance sites is (1) a strong function of mean annual temperature at mid- and high-latitudes, (2) a strong function of dryness at mid- and low-latitudes, and (3) a function of both temperature and dryness around the mid-latitudinal belt (45 N). The sensitivity of NEE to mean annual temperature breaks down at ~ 16 C (a threshold value of mean annual temperature), above which no further increase of CO2 uptake with temperature was observed and dryness influence overrules temperature influence.

  13. Hydration of the lithospheric mantle by the descending plate in a continent-continent collisional setting and its geodynamic consequences

    NASA Astrophysics Data System (ADS)

    Massonne, Hans-Joachim

    2016-05-01

    At the beginning of continent-continent collision the descending plate dehydrates. The influence of this dehydration on the adjacent lithospheric mantle was studied. For this reason, pressure (P), temperature (T) and T-H2O pseudosections were calculated for an average mantle composition using the computer software PERPLE_X. These pseudosections were contoured by isopleths, for instance, for volumes of amphibole, chlorite, and serpentine. In addition, P-T pseudosections were considered for four psammopelitic rocks, common in the upper portion of the continental crust, in order to quantify the release of H2O in these rocks during prograde metamorphism. At pressures around 1 GPa, a maximum of slightly more than 10 vol.% chlorite, almost 20 vol.% amphibole, and some talc but no serpentine forms when only 1.8 wt.% H2O is added to the dry ultrabasite at temperatures of 600 °C. For example, hydrous phases amount to about 35 vol.% serpentine and 10 vol.% each of chlorite and amphibole at 1 GPa, 550 °C, and 5 wt.% H2O. The modelled psammopelitic rocks can release 0.8-2.5 wt.% H2O between 450 and 650 °C at 0.8-1.4 GPa. On the basis of the above calculations, different collisional scenarios are discussed highlighting the role of hydrated lithospheric mantle. In this context a minimum hydration potential of the front region of the descending continental plate is considered, which amounts to 4.6 × 1016 kg releasable H2O for a 1000 km wide collisional zone, due to a thick sedimentary pile at the continental margin. Further suggestions are that (1) the lower crustal plate in a continent-continent collisional setting penetrates the lithospheric mantle, which is hydrated during the advancement of this plate, (2) the maximum depths of the subduction of upper continental crust is below 70 km and (3) hydrated mantle above the descending crustal plate is thrust onto this continental crust.

  14. The place of science in a continent at the crossroads.

    PubMed

    Koech, D K

    2001-01-01

    I have mentioned it before and I want to repeat it now, that we in Africa share a common history, heritage and basic problems of development. We, therefore, have an inescapable responsibility of pooling our talents and resources in shaping our common destiny. In fulfillment of its mission, AFHES, through its organized con notgresses and this Journal, is an invaluable vessel for enabling us to promote better health for the peoples of this continent. Africa is a continent endowed with great potential that, for one reason or an notother, has been ignored or misused, resulting in the current crisis now enveloping the continent. There is the escalating debt burden, falling agricultural productivity and the ever-increasing population. Efforts to improve the situation are hampered by adverse factors such as malnutrition, HTV/AIDS, malaria and other causes of ill health; wars, poor environmental management and the ever-worrisome problem of refugees. At the sunrise of the 21st Century, we must wake up and reverse the current trend by focusing our resources on priority areas of development. The fight for freedom from the yoke of colonialism and the traumatic experience of apartheid has been won. In some African countries, however, the winning of the fight for freedom has opened up a new fight, a fight that is more fierce and bloody than that which set us free. These include civil strife and internecine wars giving rise to a new black Diaspora, which is far greater than the one experienced during the period of slavery and slave trade. People supposed to build these nations have either been killed or forced into exile. Those intellectually endowed have sought refuge in safer and economically developed countries and, by the same process, also weaken the al notready weak economies of their mother countries. They have, therefore, helped to strengthen the already strong economies of the developed nations. This is indeed, a sad situation that poses a formidable challenge to the

  15. Simulation of active tectonic processes for a convecting mantle with moving continents

    USGS Publications Warehouse

    Trubitsyn, V.; Kaban, M.; Mooney, W.; Reigber, C.; Schwintzer, P.

    2006-01-01

    Numerical models are presented that simulate several active tectonic processes. These models include a continent that is thermally and mechanically coupled with viscous mantle flow. The assumption of rigid continents allows use of solid body equations to describe the continents' motion and to calculate their velocities. The starting point is a quasi-steady state model of mantle convection with temperature/ pressure-dependent viscosity. After placing a continent on top of the mantle, the convection pattern changes. The mantle flow subsequently passes through several stages, eventually resembling the mantle structure under present-day continents: (a) Extension tectonics and marginal basins form on boundary of a continent approaching to subduction zone, roll back of subduction takes place in front of moving continent; (b) The continent reaches the subduction zone, the extension regime at the continental edge is replaced by strong compression. The roll back of the subduction zone still continues after closure of the marginal basin and the continent moves towards the upwelling. As a result the ocean becomes non-symmetric and (c) The continent overrides the upwelling and subduction in its classical form stops. The third stage appears only in the upper mantle model with localized upwellings. ?? 2006 The Authors Journal compilation ?? 2006 RAS.

  16. Does menopausal status impact urinary continence outcomes following abdominal sacrocolpopexy without anti-incontinence procedures in continent women?

    PubMed Central

    Inan, Abdurrahman Hamdi; Toz, Emrah; Beyan, Emrah; Gurbuz, Tutku; Ozcan, Aykut; Oner, Oznur

    2016-01-01

    Objective: We investigated the impact of menopausal status on urinary continence following abdominal sacrocolpopexy (ASC) without an anti-incontinence procedure in continent women. Methods: We conducted a clinical follow-up study of 137 patients diagnosed with stage 3 or higher pelvic organ prolapse (POP) without urinary incontinence between January 2012 and December 2014. Patients were provided with detailed a priori information pertaining to the abdominal sacrocolpopexy procedure and were invited to attend follow-up visits at 1, 3, 12, and 24 months. Follow-up visits included a gynecological examination, cough test, and validated Urinary Distress Inventory-6 (UDI-6) and Incontinence Impact Questionnaire-7 (IIQ-7) questionnaires. Results: The mean follow-up time for the cohort was 16.5±3.45 months. The study group was divided according to menopausal status: premenopausal (Group-1) and postmenopausal women (Group-II). Anatomical recurrence was not detected during the follow-up period in either group, but de novo stress urinary incontinence was seen in 15 of 53 (28.3%) Group-I patients and in 6 of 84 (7.1%; p < 0.01) Group-II patients. Conclusions: The risk of de novo stress urinary incontinence in postmenopausal women after ASC is low. However, premenopausal patients have a higher incidence of de novo stress incontinence which affect quality of life. PMID:27648027

  17. OxyContin® as currency: OxyContin® use and increased social capital among rural Appalachian drug users.

    PubMed

    Jonas, Adam B; Young, April M; Oser, Carrie B; Leukefeld, Carl G; Havens, Jennifer R

    2012-05-01

    Studies have shown that position within networks of social relations can have direct implications on the health behaviors of individuals. The present study examines connections between drug use and individual social capital within social networks of drug users (n = 503) from rural Appalachian Kentucky, U.S.A. Respondent driven sampling was used to recruit individuals age 18 and older who had used one of the following drugs to get high: cocaine, crack, heroin, methamphetamine, or prescription opioids. Substance use was measured via self-report and social network analysis of participants' drug use network was used to compute effective size, a measure of social capital. Drug network ties were based on sociometric data on recent (past 6 month) drug co-usage. Multivariate multi-level ordinal regression was used to model the independent effect of socio-demographic and drug use characteristics on social capital. Adjusting for gender, income, and education, daily OxyContin(®) use was found to be significantly associated with greater social capital, and daily marijuana use was associated with less social capital. These results suggest that in regions with marked economic disparities such as rural Appalachia, OxyContin(®) may serve as a form of currency that is associated with increased social capital among drug users. Interventions focusing on increasing alternate pathways to acquiring social capital may be one way in which to alleviate the burden of drug use in this high-risk population.

  18. OxyContin® as Currency: OxyContin® Use and Increased Social Capital among Rural Appalachian Drug Users

    PubMed Central

    Jonas, Adam B.; Young, April M.; Oser, Carrie B.; Leukefeld, Carl G.; Havens, Jennifer R.

    2012-01-01

    Studies have shown that position within networks of social relations can have direct implications on the health behaviors of individuals. The present study examines connections between drug use and individual social capital within social networks of drug users (n=503) from rural Appalachian Kentucky, U.S.A. Respondent driven sampling was used to recruit individuals age 18 and older who had used one of the following drugs to get high: cocaine, crack, heroin, methamphetamine, or prescription opioids. Substance use was measured via self-report and social network analysis of participants’ drug use network was used to compute effective size, a measure of social capital. Drug network ties were based on sociometric data on recent (past 6 month) drug co-usage. Multivariate multi-level ordinal regression was used to model the independent effect of sociodemographic and drug use characteristics on social capital. Adjusting for gender, income, and education, daily OxyContin® use was found to be significantly associated with greater social capital, and daily marijuana use was associated with less social capital. These results suggest that in regions with marked economic disparities such as rural Appalachia, OxyContin® may serve as a form of currency that is associated with increased social capital among drug users. Interventions focusing on increasing alternate pathways to acquiring social capital may be one way in which to alleviate the burden of drug use in this high-risk population. PMID:22465379

  19. OxyContin® as currency: OxyContin® use and increased social capital among rural Appalachian drug users.

    PubMed

    Jonas, Adam B; Young, April M; Oser, Carrie B; Leukefeld, Carl G; Havens, Jennifer R

    2012-05-01

    Studies have shown that position within networks of social relations can have direct implications on the health behaviors of individuals. The present study examines connections between drug use and individual social capital within social networks of drug users (n = 503) from rural Appalachian Kentucky, U.S.A. Respondent driven sampling was used to recruit individuals age 18 and older who had used one of the following drugs to get high: cocaine, crack, heroin, methamphetamine, or prescription opioids. Substance use was measured via self-report and social network analysis of participants' drug use network was used to compute effective size, a measure of social capital. Drug network ties were based on sociometric data on recent (past 6 month) drug co-usage. Multivariate multi-level ordinal regression was used to model the independent effect of socio-demographic and drug use characteristics on social capital. Adjusting for gender, income, and education, daily OxyContin(®) use was found to be significantly associated with greater social capital, and daily marijuana use was associated with less social capital. These results suggest that in regions with marked economic disparities such as rural Appalachia, OxyContin(®) may serve as a form of currency that is associated with increased social capital among drug users. Interventions focusing on increasing alternate pathways to acquiring social capital may be one way in which to alleviate the burden of drug use in this high-risk population. PMID:22465379

  20. A Zn isotope perspective on the rise of continents.

    PubMed

    Pons, M-L; Fujii, T; Rosing, M; Quitté, G; Télouk, P; Albarède, F

    2013-05-01

    Zinc isotope abundances are fairly constant in igneous rocks and shales and are left unfractionated by hydrothermal processes at pH < 5.5. For that reason, Zn isotopes in sediments can be used to trace the changing chemistry of the hydrosphere. Here, we report Zn isotope compositions in Fe oxides from banded iron formations (BIFs) and iron formations of different ages. Zinc from early Archean samples is isotopically indistinguishable from the igneous average (δ(66) Zn ~0.3‰). At 2.9-2.7 Ga, δ(66) Zn becomes isotopically light (δ(66) Zn < 0‰) and then bounces back to values >1‰ during the ~2.35 Ga Great Oxygenation Event. By 1.8 Ga, BIF δ(66) Zn has settled to the modern value of FeMn nodules and encrustations (~0.9‰). The Zn cycle is largely controlled by two different mechanisms: Zn makes strong complexes with phosphates, and phosphates in turn are strongly adsorbed by Fe hydroxides. We therefore review the evidence that the surface geochemical cycles of Zn and P are closely related. The Zn isotope record echoes Sr isotope evidence, suggesting that erosion starts with the very large continental masses appearing at ~2.7 Ga. The lack of Zn fractionation in pre-2.9 Ga BIFs is argued to reflect the paucity of permanent subaerial continental exposure and consequently the insignificant phosphate input to the oceans and the small output of biochemical sediments. We link the early decline of δ(66) Zn between 3.0 and 2.7 Ga with the low solubility of phosphate in alkaline groundwater. The development of photosynthetic activity at the surface of the newly exposed continents increased the oxygen level in the atmosphere, which in turn triggered acid drainage and stepped up P dissolution and liberation of heavy Zn into the runoff. Zinc isotopes provide a new perspective on the rise of continents, the volume of carbonates on continents, changing weathering conditions, and compositions of the ocean through time. PMID:23421593

  1. A Zn isotope perspective on the rise of continents.

    PubMed

    Pons, M-L; Fujii, T; Rosing, M; Quitté, G; Télouk, P; Albarède, F

    2013-05-01

    Zinc isotope abundances are fairly constant in igneous rocks and shales and are left unfractionated by hydrothermal processes at pH < 5.5. For that reason, Zn isotopes in sediments can be used to trace the changing chemistry of the hydrosphere. Here, we report Zn isotope compositions in Fe oxides from banded iron formations (BIFs) and iron formations of different ages. Zinc from early Archean samples is isotopically indistinguishable from the igneous average (δ(66) Zn ~0.3‰). At 2.9-2.7 Ga, δ(66) Zn becomes isotopically light (δ(66) Zn < 0‰) and then bounces back to values >1‰ during the ~2.35 Ga Great Oxygenation Event. By 1.8 Ga, BIF δ(66) Zn has settled to the modern value of FeMn nodules and encrustations (~0.9‰). The Zn cycle is largely controlled by two different mechanisms: Zn makes strong complexes with phosphates, and phosphates in turn are strongly adsorbed by Fe hydroxides. We therefore review the evidence that the surface geochemical cycles of Zn and P are closely related. The Zn isotope record echoes Sr isotope evidence, suggesting that erosion starts with the very large continental masses appearing at ~2.7 Ga. The lack of Zn fractionation in pre-2.9 Ga BIFs is argued to reflect the paucity of permanent subaerial continental exposure and consequently the insignificant phosphate input to the oceans and the small output of biochemical sediments. We link the early decline of δ(66) Zn between 3.0 and 2.7 Ga with the low solubility of phosphate in alkaline groundwater. The development of photosynthetic activity at the surface of the newly exposed continents increased the oxygen level in the atmosphere, which in turn triggered acid drainage and stepped up P dissolution and liberation of heavy Zn into the runoff. Zinc isotopes provide a new perspective on the rise of continents, the volume of carbonates on continents, changing weathering conditions, and compositions of the ocean through time.

  2. Comparison of different evaporation estimates over the African continent

    NASA Astrophysics Data System (ADS)

    Trambauer, P.; Dutra, E.; Maskey, S.; Werner, M.; Pappenberger, F.; van Beek, L. P. H.; Uhlenbrook, S.

    2014-01-01

    Evaporation is a key process in the water cycle with implications ranging, inter alia, from water management to weather forecast and climate change assessments. The estimation of continental evaporation fluxes is complex and typically relies on continental-scale hydrological models or land-surface models. However, it appears that most global or continental-scale hydrological models underestimate evaporative fluxes in some regions of Africa, and as a result overestimate stream flow. Other studies suggest that land-surface models may overestimate evaporative fluxes. In this study, we computed actual evaporation for the African continent using a continental version of the global hydrological model PCR-GLOBWB, which is based on a water balance approach. Results are compared with other independently computed evaporation products: the evaporation results from the ECMWF reanalysis ERA-Interim and ERA-Land (both based on the energy balance approach), the MOD16 evaporation product, and the GLEAM product. Three other alternative versions of the PCR-GLOBWB hydrological model were also considered. This resulted in eight products of actual evaporation, which were compared in distinct regions of the African continent spanning different climatic regimes. Annual totals, spatial patterns and seasonality were studied and compared through visual inspection and statistical methods. The comparison shows that the representation of irrigation areas has an insignificant contribution to the actual evaporation at a continental scale with a 0.5° spatial resolution when averaged over the defined regions. The choice of meteorological forcing data has a larger effect on the evaporation results, especially in the case of the precipitation input as different precipitation input resulted in significantly different evaporation in some of the studied regions. ERA-Interim evaporation is generally the highest of the selected products followed by ERA-Land evaporation. In some regions, the satellite

  3. Comparison of different evaporation estimates over the African continent

    NASA Astrophysics Data System (ADS)

    Trambauer, P.; Dutra, E.; Maskey, S.; Werner, M.; Pappenberger, F.; van Beek, L. P. H.; Uhlenbrook, S.

    2013-07-01

    Evaporation is a key process in the water cycle, with implications ranging from water management, to weather forecast and climate change assessments. The estimation of continental evaporation fluxes is complex and typically relies on continental-scale hydrological or land-surface models. However, it appears that most global or continental-scale hydrological models underestimate evaporative fluxes in some regions of Africa, and as a result overestimate stream flow. Other studies suggest that land-surface models may overestimate evaporative fluxes. In this study, we computed actual evaporation for the African continent using a continental version of the global hydrological model PCR-GLOBWB, which is based on a water balance approach. Results are compared with other independently computed evaporation products: the evaporation results from the ECMWF reanalysis ERA-Interim and ERA-Land (both based on the energy balance approach), the MOD16 evaporation product, and the GLEAM product. Three other alternative versions of the PCR-GLOBWB hydrological model were also considered. This resulted in eight products of actual evaporation, which were compared in distinct regions of the African continent spanning different climatic regimes. Annual totals, spatial patterns and seasonality were studied and compared through visual inspection and statistical methods. The comparison shows that the representation of irrigation areas has an insignificant contribution to the actual evaporation at a continental scale with a 0.5° spatial resolution. The choice of meteorological forcing data has a larger effect on the evaporation results, especially in the case of the precipitation input as different precipitation input resulted in significantly different evaporation in some of the studied regions. ERA-Interim evaporation is generally the highest of the selected products followed by ERA-Land evaporation. The satellite based products (GLEAM and MOD16) do not show regular behaviour when compared

  4. Assessing the causes of late Pleistocene extinctions on the continents.

    PubMed

    Barnosky, Anthony D; Koch, Paul L; Feranec, Robert S; Wing, Scott L; Shabel, Alan B

    2004-10-01

    One of the great debates about extinction is whether humans or climatic change caused the demise of the Pleistocene megafauna. Evidence from paleontology, climatology, archaeology, and ecology now supports the idea that humans contributed to extinction on some continents, but human hunting was not solely responsible for the pattern of extinction everywhere. Instead, evidence suggests that the intersection of human impacts with pronounced climatic change drove the precise timing and geography of extinction in the Northern Hemisphere. The story from the Southern Hemisphere is still unfolding. New evidence from Australia supports the view that humans helped cause extinctions there, but the correlation with climate is weak or contested. Firmer chronologies, more realistic ecological models, and regional paleoecological insights still are needed to understand details of the worldwide extinction pattern and the population dynamics of the species involved.

  5. Asynchronous extinction of late Quaternary sloths on continents and islands

    PubMed Central

    Steadman, David W.; Martin, Paul S.; MacPhee, Ross D. E.; Jull, A. J. T.; McDonald, H. Gregory; Woods, Charles A.; Iturralde-Vinent, Manuel; Hodgins, Gregory W. L.

    2005-01-01

    Whatever the cause, it is extraordinary that dozens of genera of large mammals became extinct during the late Quaternary throughout the Western Hemisphere, including 90% of the genera of the xenarthran suborder Phyllophaga (sloths). Radiocarbon dates directly on dung, bones, or other tissue of extinct sloths place their “last appearance” datum at ≈11,000 radiocarbon years before present (yr BP) or slightly less in North America, ≈10,500 yr BP in South America, and ≈4,400 yr BP on West Indian islands. This asynchronous situation is not compatible with glacial–interglacial climate change forcing these extinctions, especially given the great elevational, latitudinal, and longitudinal variation of the sloth-bearing continental sites. Instead, the chronology of last appearance of extinct sloths, whether on continents or islands, more closely tracks the first arrival of people. PMID:16085711

  6. Asynchronous extinction of late Quaternary sloths on continents and islands.

    PubMed

    Steadman, David W; Martin, Paul S; MacPhee, Ross D E; Jull, A J T; McDonald, H Gregory; Woods, Charles A; Iturralde-Vinent, Manuel; Hodgins, Gregory W L

    2005-08-16

    Whatever the cause, it is extraordinary that dozens of genera of large mammals became extinct during the late Quaternary throughout the Western Hemisphere, including 90% of the genera of the xenarthran suborder Phyllophaga (sloths). Radiocarbon dates directly on dung, bones, or other tissue of extinct sloths place their "last appearance" datum at approximately 11,000 radiocarbon years before present (yr BP) or slightly less in North America, approximately 10,500 yr BP in South America, and approximately 4,400 yr BP on West Indian islands. This asynchronous situation is not compatible with glacial-interglacial climate change forcing these extinctions, especially given the great elevational, latitudinal, and longitudinal variation of the sloth-bearing continental sites. Instead, the chronology of last appearance of extinct sloths, whether on continents or islands, more closely tracks the first arrival of people.

  7. Convergent structure of multitrophic communities over three continents.

    PubMed

    Segar, Simon T; Pereira, Rodrigo A S; Compton, Steve G; Cook, James M

    2013-12-01

    Ecological theory predicts that communities using the same resources should have similar structure, but evolutionary constraints on colonisation and niche shifts may hamper such convergence. Multitrophic communities of wasps exploiting fig fruits, which first evolved about 75MYA, do not show long-term 'inheritance' of taxonomic (lineage) composition or species diversity. However, communities on three continents have converged ecologically in the presence and relative abundance of five insect guilds that we define. Some taxa fill the same niches in each community (phylogenetic niche conservatism). However, we show that overall convergence in ecological community structure depends also on a combination of niche shifts by resident lineages and local colonisations of figs by other insect lineages. Our study explores new ground, and develops new heuristic tools, in combining ecology and phylogeny to address patterns in the complex multitrophic communities of insect on plants, which comprise a large part of terrestrial biodiversity.

  8. Clustered and transient earthquake sequences in mid-continents

    NASA Astrophysics Data System (ADS)

    Liu, M.; Stein, S. A.; Wang, H.; Luo, G.

    2012-12-01

    Earthquakes result from sudden release of strain energy on faults. On plate boundary faults, strain energy is constantly accumulating from steady and relatively rapid relative plate motion, so large earthquakes continue to occur so long as motion continues on the boundary. In contrast, such steady accumulation of stain energy does not occur on faults in mid-continents, because the far-field tectonic loading is not steadily distributed between faults, and because stress perturbations from complex fault interactions and other stress triggers can be significant relative to the slow tectonic stressing. Consequently, mid-continental earthquakes are often temporally clustered and transient, and spatially migrating. This behavior is well illustrated by large earthquakes in North China in the past two millennia, during which no single large earthquakes repeated on the same fault segments, but moment release between large fault systems was complementary. Slow tectonic loading in mid-continents also causes long aftershock sequences. We show that the recent small earthquakes in the Tangshan region of North China are aftershocks of the 1976 Tangshan earthquake (M 7.5), rather than indicators of a new phase of seismic activity in North China, as many fear. Understanding the transient behavior of mid-continental earthquakes has important implications for assessing earthquake hazards. The sequence of large earthquakes in the New Madrid Seismic Zone (NMSZ) in central US, which includes a cluster of M~7 events in 1811-1812 and perhaps a few similar ones in the past millennium, is likely a transient process, releasing previously accumulated elastic strain on recently activated faults. If so, this earthquake sequence will eventually end. Using simple analysis and numerical modeling, we show that the large NMSZ earthquakes may be ending now or in the near future.

  9. Laparoscopic Mitrofanoff continent catheterisable stoma in children with spina bifida

    PubMed Central

    Reddy, Mallikarjun N.; Nerli, Rajendra B.; Patil, Ranjeet A.; Jali, Sujata M.

    2015-01-01

    Background: In 1980, Mitrofanoff described the creation of an appendicovesicostomy for continent urinary diversion. This procedure greatly facilitates clean intermittent catheterisation in patients with neurogenic bladder. The purpose of our study was to determine the clinical efficacy of the laparoscopic Mitrofanoff catheterisable stoma for children and adolescents with spina bifida. Materials and Methods: Review of hospital records revealed that 11 children with spina bifida underwent a laparoscopic Mitrofanoff procedure with at least 1-year of follow-up. A four-port transperitoneal laparoscopic approach was used to create a Mitrofanoff appendicovesicostomy. The child was followed-up in the urology clinic at 6 weeks, 3 months, 6 months, 1-year, and then semiannually after that. Questionnaires were administered to determine, from the children's perspective, the level of satisfaction with catheterisation and the psychosocial implications of catheterisation before and after the creation of the Mitrofanoff continent catheterisable stoma. Results: Of the 11 children, six were female, and five were male. The mean age at presentation to Paediatric urological services was 11 ± 3.22 years. Overall the mean operative time was 144.09 ± 17.00 min. Mean estimated blood loss was 37.36 ± 11.44 cc. None of the cases needed conversion to open. Patient satisfaction with their catheterisation was measured at 2.18 ± 0.98 preoperatively, Post-operatively, this improved to 4.27 ± 0.46. Statistical analysis using paired t-test showed significance with P < 001. Conclusions: Laparoscopic Mitrofanoff catheterisable stoma is feasible in children with spina bifida and is associated with reasonable outcome with early recovery, resumption of normal activities and excellent cosmesis. PMID:26168751

  10. Plasmodium vivax Diversity and Population Structure across Four Continents

    PubMed Central

    Koepfli, Cristian; Rodrigues, Priscila T.; Antao, Tiago; Orjuela-Sánchez, Pamela; Van den Eede, Peter; Gamboa, Dionicia; van Hong, Nguyen; Bendezu, Jorge; Erhart, Annette; Barnadas, Céline; Ratsimbasoa, Arsène; Menard, Didier; Severini, Carlo; Menegon, Michela; Nour, Bakri Y. M.; Karunaweera, Nadira; Mueller, Ivo; Ferreira, Marcelo U.; Felger, Ingrid

    2015-01-01

    Plasmodium vivax is the geographically most widespread human malaria parasite. To analyze patterns of microsatellite diversity and population structure across countries of different transmission intensity, genotyping data from 11 microsatellite markers was either generated or compiled from 841 isolates from four continents collected in 1999–2008. Diversity was highest in South-East Asia (mean allelic richness 10.0–12.8), intermediate in the South Pacific (8.1–9.9) Madagascar and Sudan (7.9–8.4), and lowest in South America and Central Asia (5.5–7.2). A reduced panel of only 3 markers was sufficient to identify approx. 90% of all haplotypes in South Pacific, African and SE-Asian populations, but only 60–80% in Latin American populations, suggesting that typing of 2–6 markers, depending on the level of endemicity, is sufficient for epidemiological studies. Clustering analysis showed distinct clusters in Peru and Brazil, but little sub-structuring was observed within Africa, SE-Asia or the South Pacific. Isolates from Uzbekistan were exceptional, as a near-clonal parasite population was observed that was clearly separated from all other populations (FST>0.2). Outside Central Asia FST values were highest (0.11–0.16) between South American and all other populations, and lowest (0.04–0.07) between populations from South-East Asia and the South Pacific. These comparisons between P. vivax populations from four continents indicated that not only transmission intensity, but also geographical isolation affect diversity and population structure. However, the high effective population size results in slow changes of these parameters. This persistency must be taken into account when assessing the impact of control programs on the genetic structure of parasite populations. PMID:26125189

  11. Plasmodium vivax Diversity and Population Structure across Four Continents.

    PubMed

    Koepfli, Cristian; Rodrigues, Priscila T; Antao, Tiago; Orjuela-Sánchez, Pamela; Van den Eede, Peter; Gamboa, Dionicia; van Hong, Nguyen; Bendezu, Jorge; Erhart, Annette; Barnadas, Céline; Ratsimbasoa, Arsène; Menard, Didier; Severini, Carlo; Menegon, Michela; Nour, Bakri Y M; Karunaweera, Nadira; Mueller, Ivo; Ferreira, Marcelo U; Felger, Ingrid

    2015-01-01

    Plasmodium vivax is the geographically most widespread human malaria parasite. To analyze patterns of microsatellite diversity and population structure across countries of different transmission intensity, genotyping data from 11 microsatellite markers was either generated or compiled from 841 isolates from four continents collected in 1999-2008. Diversity was highest in South-East Asia (mean allelic richness 10.0-12.8), intermediate in the South Pacific (8.1-9.9) Madagascar and Sudan (7.9-8.4), and lowest in South America and Central Asia (5.5-7.2). A reduced panel of only 3 markers was sufficient to identify approx. 90% of all haplotypes in South Pacific, African and SE-Asian populations, but only 60-80% in Latin American populations, suggesting that typing of 2-6 markers, depending on the level of endemicity, is sufficient for epidemiological studies. Clustering analysis showed distinct clusters in Peru and Brazil, but little sub-structuring was observed within Africa, SE-Asia or the South Pacific. Isolates from Uzbekistan were exceptional, as a near-clonal parasite population was observed that was clearly separated from all other populations (FST>0.2). Outside Central Asia FST values were highest (0.11-0.16) between South American and all other populations, and lowest (0.04-0.07) between populations from South-East Asia and the South Pacific. These comparisons between P. vivax populations from four continents indicated that not only transmission intensity, but also geographical isolation affect diversity and population structure. However, the high effective population size results in slow changes of these parameters. This persistency must be taken into account when assessing the impact of control programs on the genetic structure of parasite populations.

  12. GOCE observations for Mineral exploration in Africa and across continents

    NASA Astrophysics Data System (ADS)

    Braitenberg, Carla

    2014-05-01

    The gravity anomaly field over the whole Earth obtained by the GOCE satellite is a revolutionary tool to reveal geologic information on a continental scale for the large areas where conventional gravity measurements have yet to be made (e.g. Alvarez et al., 2012). It is, however, necessary to isolate the near-surface geologic signal from the contributions of thickness variations in the crust and lithosphere and the isostatic compensation of surface relief (e.g. Mariani et al., 2013) . Here Africa is studied with particular emphasis on selected geological features which are expected to appear as density inhomogeneities. These include cratons and fold belts in the Precambrian basement, the overlying sedimentary basins and magmatism, as well as the continental margins. Regression analysis between gravity and topography shows coefficients that are consistently positive for the free air gravity anomaly and negative for the Bouguer gravity anomaly (Braitenberg et al., 2013; 2014). The error and scatter on the regression is smallest in oceanic areas, where it is a possible tool for identifying changes in crustal type. The regression analysis allows the large gradient in the Bouguer anomaly signal across continental margins to be removed. After subtracting the predicted effect of known topography from the original Bouguer anomaly field, the residual field shows a continent-wide pattern of anomalies that can be attributed to regional geological structures. A few of these are highlighted, such as those representing Karoo magmatism, the Kibalian foldbelt, the Zimbabwe Craton, the Cameroon and Tibesti volcanic deposits, the Benue Trough and the Luangwa Rift. A reconstruction of the pre-break up position of Africa, South and North America is made for the residual GOCE gravity field obtaining today's gravity field of the plates forming West Gondwana. The reconstruction allows the positive and negative anomalies to be compared across the continental fragments, and so helps

  13. Recent Aeromagnetic Anomaly views of the Antarctic continent

    NASA Astrophysics Data System (ADS)

    Ferraccioli, F.

    2012-04-01

    Antarctica is a keystone within the Gondwana and Rodinia supercontinents. However, despite intense geological research along the coastal fringes of Antarctica, the interior of the continent remains one of the most poorly understood regions on Earth. Aeromagnetic investigations are a useful tool to help disclose the structure and the evolution of continents from the Precambrian to the Cenozoic and Antarctica is no exception. Here I review a variety of aeromagnetic studies in East and West Antarctica performed since the completion of the first generation ADMAP -Antarctic Digital Magnetic Anomaly Project- in 2001. In western Dronning Maud, in East Antarctica, aeromagnetic data help delineate the extent of the Jurassic Jutulstraumen subglacial rift that is flanked by remnants of a Grenvillian-age (ca 1.1. Ga) igneous province and magmatic arc. Different magnetic signatures appear to characterize the Coats Land block but reconnaissance surveys are insufficient to fully delineate the extent and significance of the Coats Land block, a possible tectonic tracer of Laurentia within Rodinia (Loewy et al., 2011). Further in the interior of East Antarctica, a mosaic of distinct and hitherto largely unknown Precambrian provinces has recently been revealed by combining aeromagnetic and satellite magnetic data with models of crustal thickness constrained by gravity modeling and seismology (Ferraccioli et al., 2011, Nature). A major collisional suture may lie between the Archean Ruker Province and an inferred Proterozoic Gamburtsev Province but the age of final assembly of central East Antarctica remains uncertain and controversial. I favour a Grenville-age collisional event (linked to Rodinia assembly) or possibly older Paleoproteroic collision, followed by intraplate reactivation, as opposed to Neoproterozoic or Early Cambrian collision linked to East-West Gondwana assembly (Boger, 2011). New aerogeophysical surveys over Prince Elizabeth and Queen Mary Land could test this

  14. A model of weathering intensity for the Australian continent

    NASA Astrophysics Data System (ADS)

    Wilford, J.

    2013-12-01

    Regolith encompasses all weathered materials in the zone between the Earth's surface and fresh bedrock at depth. This weathered zone includes the soil, which may constitute the whole of the regolith profile or represent only its upper part. Important hydrological and biogeochemical processes operate within the regolith, including the infiltration and storage of near-surface water and nutrients, which sustain agricultural productivity. The degree to which the regolith is weathered (or its weathering intensity) is intrinsically linked to the factors involved in soil formation including parent material, climate, topography, biota and time. The degree to which the bedrock or sediments are weathered has a significant effect on the nature and distribution of regolith materials. There is commonly a strong correlation between weathering intensity and the degree of soil development as well as the depth of the weathering front. Changes in weathering intensity correspond to changes in the geochemical and physical properties of bedrock, ranging from essentially unweathered parent materials through to intensely weathered and leached regolith where all traits of the original protolith (original unweathered rock) are overprinted or lost altogether. With increasing weathering intensity we see mineral and geochemical convergence to more resistant secondary weathered materials including clay, silica, and various oxides. A weathering intensity index (WII) over the Australian continent has been developed at a 100 m resolution using two regression models based on airborne gamma-ray spectrometry imagery and the Shuttle Radar Topography Mission (SRTM) elevation data. Airborne gamma-ray spectrometry measures the concentration of three radioelements -- potassium (K), thorium (Th) and uranium (U) at the Earth's surface. The total gamma-ray flux (dose) is also calculated based on the weighted additions of the three radioelements. In general K is leached with increasing weathering whereas Th

  15. Volcanic passive margins: another way to break up continents

    PubMed Central

    Geoffroy, L.; Burov, E. B.; Werner, P.

    2015-01-01

    Two major types of passive margins are recognized, i.e. volcanic and non-volcanic, without proposing distinctive mechanisms for their formation. Volcanic passive margins are associated with the extrusion and intrusion of large volumes of magma, predominantly mafic, and represent distinctive features of Larges Igneous Provinces, in which regional fissural volcanism predates localized syn-magmatic break-up of the lithosphere. In contrast with non-volcanic margins, continentward-dipping detachment faults accommodate crustal necking at both conjugate volcanic margins. These faults root on a two-layer deformed ductile crust that appears to be partly of igneous nature. This lower crust is exhumed up to the bottom of the syn-extension extrusives at the outer parts of the margin. Our numerical modelling suggests that strengthening of deep continental crust during early magmatic stages provokes a divergent flow of the ductile lithosphere away from a central continental block, which becomes thinner with time due to the flow-induced mechanical erosion acting at its base. Crustal-scale faults dipping continentward are rooted over this flowing material, thus isolating micro-continents within the future oceanic domain. Pure-shear type deformation affects the bulk lithosphere at VPMs until continental breakup, and the geometry of the margin is closely related to the dynamics of an active and melting mantle. PMID:26442807

  16. Convective Transport of Trace Gases in the Maritime Continent

    NASA Astrophysics Data System (ADS)

    Harris, Neil

    2015-04-01

    Passage of air through the Tropical Tropopause Layer (TTL) is the major route for troposphere to stratosphere transport. The UK CAST (Co-ordinated Airborne Studies in the Tropics) campaign took place in the West Pacific in January/February 2014. The field campaign was based mainly in Guam (13.5oN, 144.8oE) and had three components: CAST with the NERC FAAM BAe-146 research aircraft; the NASA ATTREX project based around the Global Hawk; the NCAR-led CONTRAST campaign based around the Gulfstream V (HIAPER) aircraft. Together, these aircraft were able to make detailed measurements of atmospheric structure and composition from the ocean surface to 20 km. The CAST team also made ground-based and ozonesonde measurements at the ARM site on Manus Island in Papua New Guinea during February 2014, and halocarbon measurements were made at several West Pacific sites. I will present an overview of the CAST campaign along with the results of high resolution global Unified Model studies and NAME (Numerical Atmospheric-dispersion Modelling Environment) trajectory calculations to look at the transport of air into the TTL in convective systems over the Maritime continent and West Pacific. I will focus on the transport of air from in and around the boundary layer and will assess the possible importance of natural and anthropogenic emissions for TTL composition.

  17. Genetic characteristics of infectious bursal disease viruses from four continents.

    PubMed

    Jackwood, Daral J; Sommer-Wagner, Susan

    2007-09-01

    Following the initial discovery of very virulent infectious bursal disease virus (vvIBDV) strains in Europe, these viruses spread to many parts of the world. In this study, we examined the phylogenetic relationship of never-before-published IBDV from 18 countries on four continents. All the samples were collected between 1997 and 2005 and were reported to be from broiler flocks experiencing higher than expected mortality which is often associated with acute very virulent infectious bursal disease. A total of 113 samples were imported into the U.S. and viral genetic material was used to determine the nucleotide sequence of the VP2 gene hypervariable region. Although all the samples were reported to be associated clinically with high mortality, genetic analysis suggests that some were not vvIBDV strains. Two viruses from South Africa were genetically similar to U.S. variant viruses. A majority (71/113) of the viruses examined had the amino acid Alanine at position 222 and sixty-seven of these suspect vvIBDV also had amino acids I242, I256, I294 and S299 which are highly conserved among vvIBDV strains. Phylogenetic analysis placed putative vvIBDV strains from many different countries and geographic regions in a single clade with some minor non-significant branching.

  18. Volcanic passive margins: another way to break up continents.

    PubMed

    Geoffroy, L; Burov, E B; Werner, P

    2015-10-07

    Two major types of passive margins are recognized, i.e. volcanic and non-volcanic, without proposing distinctive mechanisms for their formation. Volcanic passive margins are associated with the extrusion and intrusion of large volumes of magma, predominantly mafic, and represent distinctive features of Larges Igneous Provinces, in which regional fissural volcanism predates localized syn-magmatic break-up of the lithosphere. In contrast with non-volcanic margins, continentward-dipping detachment faults accommodate crustal necking at both conjugate volcanic margins. These faults root on a two-layer deformed ductile crust that appears to be partly of igneous nature. This lower crust is exhumed up to the bottom of the syn-extension extrusives at the outer parts of the margin. Our numerical modelling suggests that strengthening of deep continental crust during early magmatic stages provokes a divergent flow of the ductile lithosphere away from a central continental block, which becomes thinner with time due to the flow-induced mechanical erosion acting at its base. Crustal-scale faults dipping continentward are rooted over this flowing material, thus isolating micro-continents within the future oceanic domain. Pure-shear type deformation affects the bulk lithosphere at VPMs until continental breakup, and the geometry of the margin is closely related to the dynamics of an active and melting mantle.

  19. Volcanic passive margins: another way to break up continents.

    PubMed

    Geoffroy, L; Burov, E B; Werner, P

    2015-01-01

    Two major types of passive margins are recognized, i.e. volcanic and non-volcanic, without proposing distinctive mechanisms for their formation. Volcanic passive margins are associated with the extrusion and intrusion of large volumes of magma, predominantly mafic, and represent distinctive features of Larges Igneous Provinces, in which regional fissural volcanism predates localized syn-magmatic break-up of the lithosphere. In contrast with non-volcanic margins, continentward-dipping detachment faults accommodate crustal necking at both conjugate volcanic margins. These faults root on a two-layer deformed ductile crust that appears to be partly of igneous nature. This lower crust is exhumed up to the bottom of the syn-extension extrusives at the outer parts of the margin. Our numerical modelling suggests that strengthening of deep continental crust during early magmatic stages provokes a divergent flow of the ductile lithosphere away from a central continental block, which becomes thinner with time due to the flow-induced mechanical erosion acting at its base. Crustal-scale faults dipping continentward are rooted over this flowing material, thus isolating micro-continents within the future oceanic domain. Pure-shear type deformation affects the bulk lithosphere at VPMs until continental breakup, and the geometry of the margin is closely related to the dynamics of an active and melting mantle. PMID:26442807

  20. The antegrade continence enema procedure and total anorectal reconstruction

    PubMed Central

    Zbar, Andrew P.

    2014-01-01

    Patients may present with anal incontinence (AI) following repair of a congenital anorectal anomaly years previously, or require total anorectal reconstruction (TAR) following radical rectal extirpation, most commonly for rectal cancer. Others may require removal of their colostomy following sphincter excision for Fournier's gangrene, or in cases of severe perineal trauma. Most of the data pertaining to antegrade continence enema (the ACE or Malone procedure) comes from the pediatric literature in the management of children with AI, but also with supervening chronic constipation, where the quality of life and compliance with this technique appears superior to retrograde colonic washouts. Total anorectal reconstruction requires an anatomical or physical supplement to the performance of a perineal colostomy, which may include an extrinsic muscle interposition (which may or may not be ‘dynamized'), construction of a neorectal reservoir, implantation of an incremental artificial bowel sphincter or creation of a terminal, smooth-muscle neosphincter. The advantages and disadvantages of these techniques and their outcome are presented here. PMID:24759342

  1. The ocean-continent transition of western Iberia

    SciTech Connect

    Whitmarsh, R.B.; Miles, P.R.; Pinheiro, L.M. ); Boillot, G. ); Recq, M. )

    1991-08-01

    The western continental margin of the Iberian peninsular has the characteristic of a rifted non-volcanic continental margin with half-graben and tilted fault blocks seen in several places on multichannel seismic reflection profiles. The ocean-continent transition (OCT) is therefore expected to be where thinned continental crust and oceanic crust are juxtaposed, as elsewhere. The authors located the OCT off western Iberia in order to constrain the pre-lift fit of Iberia to North America. This fit is only marginally constrained by sea-floor spreading magnetic anomalies because the Cretaceous constant polarity interval is adjacent to the OCT. Thinned continental crust can be distinguished from oceanic crust by the nature of the lower crustal velocity structure. In 1986-1987, a series of seismic refraction profiles was shot across three parts of the Iberian Abyssal Plain, the OCT can be detected not only from seismic velocities but also by modeling magnetic anomalies. The chosen location of the OCT is consistent with the interpretation of subsequently acquired multichannel profiles. Off Galicia Bank, the OCT, recognized from seismic velocities and multichannel profiles, corresponds to a seabed peridotite ridge, which has been extensively sampled. In the Tagus Abyssal Plain, limited seismic data gives a less clear picture of the OCT.

  2. Quantification of neurological and other contributors to continence in female rats

    PubMed Central

    Jiang, Hai-Hong; Salcedo, Levilester B.; Damaser, Margot S.

    2011-01-01

    Smooth muscle, striated muscle, their central and peripheral innervations and control, and mucosal coaptation contribute to maintenance of continence. We used manual leak point pressure (mLPP) testing and electrical stimulation LPP (eLPP) testing in female rats to quantify the contribution of these factors to urethral resistance, a measure of continence. Abdominal muscles were electrically stimulated to induce leakage for eLPP. A Crede maneuver was applied for mLPP. These were repeated after complete T8 spinal cord injury (SCI) and/or bilateral pudendal nerve transection (PNT). After euthanasia, mLPP was repeated. MLPP was not significantly affected by opening the abdomen, suggesting that intra-abdominal pressure transmission contributes little to continence during slow pressure changes. ELPP was significantly higher than mLPP in intact rats, after PNT, and after SCI+PNT, suggesting that abdominal pressure transmission contributes to continence during rapid increases in intra-abdominal pressure. MLPP decreased significantly after PNT, indicating that urethral striated muscles contribute significantly to continence. ELPP decreased significantly after PNT with and without SCI, suggesting that supraspinal control significantly affects continence during rapid pressure changes, but not during slow pressure changes. MLPP after euthanasia was significantly decreased compared to mLPP after SCI+PNT, suggesting that urethral mucosal seal coaptation and tissue elasticity also contribute to continence. The urethra is a complex organ that maintains continence via a highly organized and hierarchical system involving both the central and peripheral nervous systems. PMID:21295013

  3. Thermomechanical consequences of Cretaceous continent-continent collision in the eastern Alps (Austria): Insights from two-dimensional modeling

    NASA Astrophysics Data System (ADS)

    Willingshofer, Ernst; van Wees, J. D.; Cloetingh, S. A. P. L.; Neubauer, F.

    1999-10-01

    We use two-dimensional numerical modeling techniques to investigate the thermomechanical consequences of closure of the Meliata-Hallstatt ocean and consequent Cretaceous continent-continent collision in the eastern Alps (Austria). In the modeling a lower plate position of the Austro-Alpine (AA) continental block is adopted during collision with the Upper Juvavic-Silice block. The thermal structure of the lithosphere was calculated for major AA tectonic units (Upper, Middle, and Lower Austro-Alpine) by integration of the transient heat flow equation along an approximately NW-SE cross section east of the Tauern Window. Indications of the rheological evolution of the AA were determined by calculating strength profiles at key stages of the Cretaceous orogeny, making use of the thermal modeling predictions combined with rock mechanics data. Cooling in the upper plate and lower greenschist facies metamorphism within footwall parts of the lower Upper Austro-Alpine (UA) plate, related to SE directed underthrusting of the UA beneath the Upper Juvavic-Silice block at circa 100 Ma, were predicted by the numerical model. The observed pressure-temperature path for deeply buried Middle Austro-Alpine (MA) upper crustal units and their subsequent isothermal exhumation are best reproduced assuming a pressure peak at 95 Ma and exhumation rates ranging between 4 and 7.5 mm yr-1. From the modeling results, we deduce that the temperature evolution during eclogite exhumation is primarily dependent on rates of tectonic movements and largely independent of the mode of exhumation (thrusting versus erosion). Furthermore, very rapid postmetamorphic exhumation of southern Lower Austro-Alpine (LA) units is predicted in order to account for subsequent cooling. This is constrained by 40Ar/39Ar data. The cooling paths of MA and LA rocks appear to be primarily controlled by their near-surface positions at the end of the Cretaceous rather than by other processes such as concurrent underthrusting

  4. Wetland dynamics influence mid-continent duck recruitment

    USGS Publications Warehouse

    Anteau, Michael J.; Pearse, Aaron T.; Szymankski, Michael L.

    2013-01-01

    Recruitment is a key factor influencing duck population dynamics. Understanding what regulates recruitment of ducks is a prerequisite to informed habitat and harvest management. Quantity of May ponds (MP) has been linked to recruitment and population size (Kaminski and Gluesing 1987, Raveling and Heitmeyer 1989). However, wetland productivity (quality) is driven by inter-annual hydrological fluctuations. Periodic drying of wetlands due to wet-dry climate cycles releases nutrients and increases invertebrate populations when wet conditions return (Euliss et al. 1999). Wetlands may also become wet or dry within a breeding season. Accordingly, inter-annual and intra-seasonal hydrologic variation potentially influence duck recruitment. Here, we examined influences of wetland quantity, quality, and intra-seasonal dynamics on recruitment of ducks. We indexed duck recruitment by vulnerability-corrected age ratios (juveniles/adult females) for mid-continent Gadwall (Anas strepera). We chose Gadwall because the majority of the continental population breeds in the Prairie Pothole Region (PPR), where annual estimates of MP exist since 1974. We indexed wetland quality by calculating change in MP (?MP) over the past two years (?MP = 0.6[MPt – MPt-1] + 0.4[MPt – MPt-2]). We indexed intra-seasonal change in number of ponds by dividing the PPR mean standardized precipitation index for July by MP (hereafter summer index). MP and ?MP were positively correlated (r = 0.65); therefore, we calculated residual ?MP (?MPr) with a simple linear regression using MP, creating orthogonal variables. Finally, we conducted a multiple regression to examine how MP, ?MPr, and summer index explained variation in recruitment of Gadwall from 1976–2010. Our model explained 67% of the variation in mid-continent Gadwall recruitment and all three hydrologic indices were positively correlated with recruitment (Figure 1). Type II semi-partial R2 estimates indicated that MP accounted for 41%, ?MPr

  5. Stratigraphy, structure, and extent of the East Continent Rift Basin

    SciTech Connect

    Wickstrom, L.H. )

    1992-01-01

    The proven existence of pre-Mt. Simon sedimentary rocks named the Middle Run Formation in southwestern Ohio led to the establishment of the Cincinnati Arch Consortium, a joint industry-government partnership to investigate the areal extent, nature, and origin of this new unit. Utilizing available well, seismic, and potential-field data, the consortium has shown that the Middle Run was deposited in a Precambrian rift basin, named the East Continent Rift Basin (ECRB). These data indicate the ECRB assemblage consists of a large folded and faulted wedge of interlayered volcanic and sedimentary rocks, unconformably overlain by Cambrian strata. This wedge is estimated to be thickest (up to about 22,000 feet) on the western edge, where it is in fault contact with Grenville Province rocks. To the west, the ECRB may extend as far as central Illinois and postdates the Precambrian Granite-Rhyolite Province rocks. The contact between the ECRB and this older province appears to be in part an angular unconformity and in part block faulted. The northern limit of this basin was not encountered in the study area; this may indicate a connection with the Midcontinent Rift in Michigan. In central Kentucky, the boundary conditions are more complex. It appears that the ECRB is constricted between a large block of the Granite-Rhyolite Province to the west and the Grenville Front on the east. Large Cambrian extensional structures (Rough Creek Graben and Rome Trough) were overprinted on the Granite-Rhyolite and Grenville Provinces. The ECRB may have acted as a stable block between these Cambrian features. The relationships of the ECRB to overlying Paleozoic features may be profound. Indeed, the ECRB may prove to be the reason for the very existence of the Cincinnati and Kankakee Arches.

  6. Intraplate termination of transform faulting within the Antarctic continent

    NASA Astrophysics Data System (ADS)

    Storti, F.; Salvini, F.; Rossetti, F.; Phipps Morgan, J.

    2007-08-01

    The sector of Antarctica facing Australia east of 139 °E is characterized by the abundance of exceptionally long oceanic fracture zones that are collinear to post-rift right-lateral strike-slip fault systems developed at the northeastern edge of the Antarctic continent. High-resolution reflection seismic profiles indicate recent strike-slip activity at the southeastern edge of the Balleny Fracture Zone, similar to what is observed onshore in North Victoria Land. The architecture, kinematics, and timing of this intraplate deformation at the northeastern edge of Antarctica cannot be reconciled with typical plate tectonic kinematics, in particular, with a classical divergent plate boundary environment. Here we show that combined geological and geophysical data in northeastern Antarctica support the post-rift southeastward reactivation of the passive margin east of 139 °E along intraplate right-lateral strike-slip deformation belts. These deformation belts include oceanic transform faults and their collinear oceanic fracture zone and continental shear zone extensions. A striking consequence is that there is intraplate accommodation of transform fault slip in this region of Earth's surface along fracture zones and a long-active region of intracontinental deformation that is 'reusing' prior plate boundary fault zones. As the intraplate termination of plate boundary transform faulting is not predicted by classical plate tectonic theory; this region is one of the most clear examples of the transition from rigid to semi-rigid plate tectonic deformation during the formation and long-lived incubation of a potential new plate boundary.

  7. Northern and eastern margins of the Siberian continent in Triassic

    SciTech Connect

    Egorov, A.Yu. )

    1993-09-01

    Siliciclastic sedimentation has been predominant on the northern and eastern margins of the Siberian continent since the Triassic period. Seven transgression-regression cycles can be recognized in the Triassic succession: Griesbachien-Dienerian, Smithian-Low Spathian, Upper Spathian, Anissian (with subcycles), Ladian, Carnian, and Norlan (with subcycles). All zonal units were distinguished within transgressive portions of the cycles. Regressive portions of the cycles formed practically instantaneously. Very high sedimentation rate (300-3000 mm/1000 yr), specific structures of sedimentary rocks, and distribution of unconformities led to the conclusion that active avalanche sedimentation at the basin margins was of major significance. six facies regions are recognized in the sedimentation area: Taimyr, Kotuy-Anabar, Leno-Anabar, Bur-Olenek, Verkhoyansk, and Novosibirsk (New Siberian Islands). The main source areas were located at the Patoma Mountains for the eastern margin and at the Anabar anticline and Olenek uplift for the northern margin. Most sediments were transported to the eastern margin by a large river with a huge delta which was similar in size to the modern Lena's delta. Sediments were further distributed by contour streams. Local synsedimentary structures controlled the paleogeography of the entire area. The paleogeographical evolution of the eastern margin is the history of this delta development. The rifting activities with the trappean magmatism were the main events at the northern margin, especially in the Talmyr area. The pelagic sedimentation has been predominant in the New Siberian Islands area and most of the Laptev Sea aquatoria. The organic-rich sediments have been distinguished in Low Olenekian (Smithian), Low Anissian, Low Ladinian, and Low Carnian substages. Most of them could be hydrocarbon source rocks. Triassic oil and gas seeps have been discovered at the northern portion of the Vilyui syncline, near the Lena's delta and the Nordvic Bay.

  8. Drifting continents and endemic goitre in northern Pakistan.

    PubMed Central

    Stewart, A G

    1990-01-01

    Although Baltistan, north east Pakistan, is in a region of iodine deficiency disorders, the distribution of goitre within the district, according to age and sex, has not been clearly defined. To establish the prevalence of the condition and to measure the reported difference in prevalence in the north and south of the district thyroid size was assessed in new patients attending the Aman clinic, Khapalu, and outlying areas between April and September from 1981 to 1986. Samples of potable water collected from villages were analysed for iodine (as iodide) concentrations in Britain. Population weighted prevalences were: in the north in males 20.4%, in females 28.1% and in the south in males 13.9%, in females 21.2%. There was an overall deficiency of iodine in the water (mean iodine (as iodide) concentrations (north) 11.0 nmol/l (1.4 micrograms/l), (south) 11.8 nmol/l (1.5 micrograms/l) (95% confidence interval -0.7 to 0.9). The differences followed the Main Karakoram Thrust, suggesting a geological goitrogen in the north, which might be minerals containing ions such as BF4- and SO3F-, and molybdenite and calcium, which are present in rocks in Baltistan. A new hypothesis for the genesis of endemic goitre is proposed--that is, that continents on crustal plates drift across the earth and collide, one plate sliding under the other and melting, giving rise to characteristic mineral assemblages in the overlying rocks. As the minerals weather out they enter the diet of the local population, where in the presence of iodine deficiency they produce or enhance iodine deficiency disorders. Despite the current iodised oil campaign by the Pakistani government with Unicef a long term working iodisation programme is still urgently needed. PMID:2372605

  9. Antarctica and IGY: New Frontiers in "A Continent for Science"

    NASA Astrophysics Data System (ADS)

    Wilson, T.; Anandakrishnan, S.; Deconto, R.; Finn, C.; Harwood, D.; Leventer, A.; Ritzwoller, M.; Tulaczyk, S.

    2002-12-01

    Antarctica was established as a laboratory for cooperative international science during the last IGY, and remains an unparalleled model of successful international research. The scientific foundations established in the IGY have led to significant advances in understanding processes in the solid earth, the atmosphere, the oceans, the cryosphere and the global climate system. It is increasingly clear that deciphering the feedbacks and interactions between these spheres is required to comprehend the earth system as a whole, hence understanding the unique Antarctic geodynamic environment is imperative. Yet, in many respects, Antarctica remains an unexplored frontier of the earth system. The Antarctic geoscience community has begun planning a new era of earth science exploration projected to reach fruition at the time of the IGY golden jubilee (see: http://www.geology.ohio-state.edu/agg-group/). International cooperation will be organized through SCAR (Scientific Committee on Antarctic Research). An `Antarctic Geophysical Decade' will include experiments at unprecedented scales across the continent, enabled by new technologies. Coordinated airborne and marine geophysical surveys, drilling (offshore and through the ice sheet to bedrock), deployment of GPS and seismic arrays, topical geological studies, and modeling studies, integrated with the wealth of new and upcoming satellite-derived data, will allow us to make the next leaps forward in understanding questions such as: 1) how changing ice mass loads influence lithospheric stress/strain regimes; 2) how glacial isostatic adjustment and the tectono-thermal structure of the lithosphere control modern ice sheet dynamics; 3) inception, growth and fluctuations of Antarctic ice sheets and interhemispheric a/synchroneity; 4) climate sensitivity to forcing factors such as continental-scale paleogeography, volcanism, erosion/sedimentation; 5) the origin and evolution of subglacial lakes and their life forms; and 6) the mode

  10. Smoke aerosol transport patterns over the Maritime Continent

    NASA Astrophysics Data System (ADS)

    Xian, Peng; Reid, Jeffrey S.; Atwood, Samuel A.; Johnson, Randall S.; Hyer, Edward J.; Westphal, Douglas L.; Sessions, Walter

    2013-03-01

    Smoke transport patterns over the Maritime Continent (MC) are studied through a combination of approaches, including a) analyzing AODs obtained from satellite products; b) aerosol transport modeling with AOD assimilation along with the atmospheric flow patterns; c) analyzing smoke wet deposition distributions; and d) examining forward trajectories for smoke events defined in this study. It is shown that smoke transport pathways are closely related to the low-level atmospheric flow, i.e., during June-Sept, smoke originating from the MC islands with a dominant source over central and southern Sumatra, and southern and western Borneo, is generally transported northwestward south of the equator and northeastward north of the equator with the cross-equatorial flow, to the South China Sea (SCS), the Philippines and even further to the western Pacific. During the October-November transitional period, smoke transport paths are more zonally oriented compared to June-September. Smoke originating from Java, Bali, Timor etc, and southern New Guinea, which are in the domain of easterlies and southeasterlies during the boreal summer (June-November), is generally transported westward. It is also found that smoke transport over the MC exhibits multi-scale variability. Smoke typically lives longer and can be transported farther in El Niño years and later MJO phases compared with non El Niño years and earlier MJO phases. During El Niño periods there is much stronger westward transport to the east tropical Indian Ocean. Finally, orographic effect on smoke transport over the MC is also clearly discernable.

  11. National Instrument Facility for Electromagnetic Studies of the Continents (EMSOC)

    NASA Astrophysics Data System (ADS)

    Wannamaker, P. E.; Park, S. K.; Booker, J. R.; Egbert, G. D.; Jiracek, G. R.; Chave, A. D.

    2002-12-01

    EMSOC (Electromagnetic Studies of the Continents) is an NSF-supported, multi-institutional consortium that fosters research in electromagnetic (EM) studies of the Earth by maintaining and providing magnetotelluric (MT) equipment to U.S. institutions and their co-workers. The MT method measures electrical resistivity (or its inverse conductivity), which is one of only a handful of physical properties with which we can understand dynamic Earth processes. EMSOC-supported experiments, often a component of multidisciplinary studies, have mapped fluids and domains of probable weakness within the San Andreas fault zone, orogen-wide partial melting and mobility beneath the Tibetan Plateau, buoyant mantle supporting the High Sierra, and prograde fluid generation and rheological controls beneath the Southern Alps orogen of New Zealand. The EMSOC National Instrument Facility is a collaborative venture by the Universities of Washington, Utah, and California at Riverside formed in response to rising costs to NSF for rental of modern MT systems for experiments and the lack of commercial availability of long period (1-30,000 s) instruments. Starting in 1998, this facility has supported 27 projects by 10 institutions. EMSOC equipment has also allowed the exposure of the MT method to nonspecialists at the NSF-supported field geophysical education and research program SAGE (Summer of Applied Geophysical Experience). Allocation of the instruments is determined by a steering committee with representatives from six institutions, which convenes formally at every fall AGU meeting. Currently, EMSOC intends to modernize the existing pool of long period instruments, add magnetic sensors capable of recording at higher frequencies (>1000 Hz), and complete the establishment of an archive for all data collected with the EMSOC instruments in collaboration with the IRIS-DMC. Information about facility activities is available on the EMSOC web site vortex.ucr.edu/emsoc/index.html.

  12. Preparation of northern mid-continent petroleum atlas

    SciTech Connect

    Gerhard, L.C.; Carr, T.R.; Watney, W.L.

    1997-02-13

    The prototype Digital Petroleum Atlas (DPA) Project is part of a long-term effort to develop a new methodology to provide efficient and timely access to the latest petroleum data and technology for the domestic oil and gas industry, public sector research organizations and local governmental units. The DPA provides real-time access through the Internet using widely available tools such as World-Wide-Web browsers. The latest technologies and information are published electronically when individual project components are completed removing the lag and expense of transferring technology using traditional paper publication. Active links, graphical user interfaces and database search mechanisms of the DPA provide a product with which the operator can interact in ways that are impossible in the paper publication. Contained in the DPA are forms of publication that can only be displayed in an electronic environment (for example, animated exploration histories through time). Improvement in data and technology access for the domestic petroleum industry represents one of the best and cost-effective options that is available for mitigating the continued decline in domestic production. The prototype DPA concentrated on developing methodologies and computerized procedures to generate and to publish a limited set of field and play studies concentrated in Kansas and to a lesser extent the Northern Mid-continent. Access is provided through the DPA to previously existing and new regional, play, field and individual well information. Methodologies, developed in year one of the prototype DPA Project, provide a published product and ongoing technology transfer activity that is continuously updated with the latest information and technology.

  13. Organic geochemistry of mid-continent Ordovician oils

    SciTech Connect

    Palmer, S.E.

    1985-01-01

    Early Paleozoic oils retain the biochemical imprint of oceanic life prior to evolution of land plants and vertebrates. Thus, these oils have geochemical features which make them unique with respect to younger oils, but also share some common properties with the latter. Characteristic mid-continent Ordovician oil features include predominance of n-C/sub 14/ to n-C/sub 19/ over n-C/sub 20/+ alkanes in the C/sub 15/+ saturate hydrocarbon fraction, low amounts of isoprenoids and abundant C/sub 27/ and C/sub 29/ diasteranes relative to normal steranes. Properties common to both Ordovician and younger oils are: nearly equal amounts of C/sub 15/+ n-alkanes, cycloalkanes, and aromatics and pristane/phytane ratios of 0.7 to 1.6. Collectively, these Ordovician oils have a relatively negative stable carbon isotopic composition but are not unique with respect to other marine oils. Although terpane distributions are generally similar to geologically-younger oils, the Ordovician oils contain significant amounts of C/sub 19/, C/sub 20/, and C/sub 21/ tricyclic diterpanes relative to the C/sub 23/ homolog as well as large contributions by C/sub 31/+ pentacyclic triterpanes. Presence of long-chained n-alkanes, C/sub 29/ steranes, and C/sub 24/ tetracyclic terpanes, which are generally accepted as input from land plants in, e.g., Tertiary deposits, are also present in Ordovician oils. The characteristics listed above describe oils from the Williston and Michigan basins as well as Ordovician oils from Kansas and Oklahoma.

  14. Improving continence services for older people from the service-providers’ perspective: a qualitative interview study

    PubMed Central

    Orrell, Alison; McKee, Kevin; Dahlberg, Lena; Gilhooly, Mary; Parker, Stuart

    2013-01-01

    Objective To examine in depth the views and experiences of continence service leads in England on key service and continence management characteristics in order to identify and to improve our understanding of barriers to a good-quality service and potential facilitators to develop and to improve services for older people with urinary incontinence (UI). Design Qualitative semistructured interviews using a purposive sample recruited across 16 continence services. Setting 3 acute and 13 primary care National Health Service Trusts in England. Participants 16 continence service leads in England actively treating and managing older people with UI. Results In terms of barriers to a good-quality service, participants highlighted a failure on the part of commissioners, managers and other health professionals in recognising the problem of UI and in acknowledging the importance of continence for older people and prevalent negative attitudes towards continence and older people. Patient assessment and continence promotion regardless of age, rather than pad provision, were identified as important steps for a good-quality service for older people with UI. More rapid and appropriate patient referral pathways, investment in service capacity, for example, more trained staff and strengthened interservice collaborations and a higher profile within medical and nurse training were specified as being important facilitators for delivering an equitable and high-quality continence service. There is a need, however, to consider the accounts given by our participants as perhaps serving the interests of their professional group within the context of interprofessional work. Conclusions Our data point to important barriers and facilitators of a good-quality service for older people with UI, from the perspective of continence service leads. Further research should address the views of other stakeholders, and explore options for the empirical evaluation of the effectiveness of identified service

  15. Continent-continent collision at the Pacific/Australian plate boundary: Lithospheric deformation, mountain building, and subsequent scientific endeavors

    NASA Astrophysics Data System (ADS)

    Okaya, D. A.; Stern, T. A.; Davey, F. J.

    2012-12-01

    Continental collision occurs at strike-slip plate boundaries where transform motion and oblique convergence create processes of surficial mountain building and deformation within the deeper crust and lithospheric mantle. The Pacific/Australian transform plate boundary in South Island, New Zealand, is characterized by active oblique continent-continent collision with an associated Southern Alps orogen that exhibits both high exhumation rates and rapid strike-slip movement. Beginning in the 1990s, this system was the focus of a decade-long collaborative USA-New Zealand multi-disciplinary study to understand lithospheric structure and processes involved in this transpression. Funded primarily by the NSF Continental Dynamics program and the New Zealand Science Foundation, this project known as SIGHT (South Island Geophysical Transect) with its companion SAPSE (Southern Alps Passive Seismic Experiment) included the following disciplines that involved substantial field observation experiments: seismic reflection, explosion refraction, onshore-offshore wide-angle reflection/refraction, regional and teleseismic passive seismology, magnetotellurics, laboratory petrophysics, gravity, regional geological investigations, and rheological analyses. More than fifty scientists and students from both nations participated in the combined set of studies that have led to over forty-five journal publications, an AGU Monograph, and a dozen graduate theses. Primary results of the project indicate the Pacific-Australian strike-slip plate boundary (Alpine fault) is not vertical but is eastward dipping and rheologically weak based on diverse geophysical data. Most deformation is within the Pacific plate that hosts the Southern Alps orogen. High mantle seismic velocities vertically disposed beneath the orogen suggest Pacific and perhaps Australian mantle lithosphere contribute to a zone of plate-boundary-parallel distributed mantle shortening. The crustal root of the overlying Southern Alps

  16. The thermal influence of continents on a model-generated January climate

    NASA Technical Reports Server (NTRS)

    Spar, J.; Cohen, C.; Wu, P.

    1981-01-01

    Two climate simulations were compared. Both climate computations were initialized with the same horizontally uniform state of rest. However, one is carried out on a water planet (without continents), while the second is repeated on a planet with geographically realistic but flat (sea level) continents. The continents in this experiment have a uniform albedo of 0.14, except where snow accumulates, a uniform roughness height of 0.3 m, and zero water storage capacity. Both runs were carried out for a 'perpetual January' with solar declination fixed at January 15.

  17. Correlation between mobile continents and elevated temperatures in the subcontinental mantle

    NASA Astrophysics Data System (ADS)

    Jain, Charitra; Rozel, Antoine; Tackley, Paul

    2016-04-01

    Rolf et al. (EPSL, 2012) and Coltice et al. (Science, 2012) have previously shown that continents exert a first order influence on Earth's mantle flow by affecting convective wavelength and surface heat flow. With stationary continents, Heron and Lowman (JGR, 2014) highlighted the decreasing role of continental insulation on subcontinental temperatures with higher Rayleigh number (Ra). However, the question whether there exists a correlation between mobile continents and elevated temperatures in the subcontinental mantle or not remains to be answered. By systematically varying parameters like core-mantle boundary (CMB) temperature, continental size, and mantle heating modes (basal and internal); we model thermo-chemical mantle convection with 2D spherical annulus geometry (Hernlund and Tackley, PEPI 2008) using StagYY (Tackley, PEPI 2008). Starting with a simple incompressible model having mobile continents, we observe this correlation. Furthermore, this correlation still holds when the model complexity is gradually increased by introducing internal heating, compressibility, and melting. In general, downwellings reduce the mantle temperature away from the continents, thereby resulting in correlation between mobile continents and elevated temperatures in the subcontinental mantle. For incompressible models (Boussinesq approximation), correlation exists and the dominant degree of convection varies with the continental distribution. When internal heating is switched on, correlation is observed but it is reduced as there are less cold regions in the mantle. Even for compressible models with melting, big continents are able to focus the heat underneath them. The dominant degree of convection changes with continental breakup. Additionally, correlation is observed to be higher in the upper mantle (300 - 1000 km) compared to the lower mantle (1000 - 2890 km). At present, mobile continents in StagYY are simplified into a compositionally distinct field drifting at the top of

  18. Effect of Nerve-Sparing Radical Prostatectomy on Urinary Continence in Patients With Preoperative Erectile Dysfunction

    PubMed Central

    2016-01-01

    Purpose: We aimed to assess whether nerve-sparing radical prostatectomy (nsRP) is associated with improved recovery of urinary continence compared to non–nerve-sparing radical prostatectomy (nnsRP) in patients with localized prostate cancer and preoperative erectile dysfunction. Methods: A total of 360 patients with organ-confined prostate cancer and an International Index of Erectile Function score of less than 17 were treated with nsRP or nnsRP in Seoul St. Mary’s Hospital. Patients who received neoadjuvant or adjuvant androgen deprivation therapy or had a history of prostate-related surgery were excluded. Recovery of urinary continence was assessed at 0, 1, 3, 6, and 12 months. Postoperative recovery of continence was defined as zero pad usage. The association between nerve-sparing status and urinary continence was assessed by using univariate and multivariate Cox regression analyses after controlling for known predictive factors. Results: Urinary continence recovered in 279 patients (77.5%) within the mean follow-up period of 22.5 months (range, 6–123 months). Recovery of urinary continence was reported in 74.6% and 86.4% of patients after nnsRP and nsRP, respectively, at 12 months (P=0.022). All groups had comparable perioperative criteria and had no significant preoperative morbidities. Age, American Society of Anesthesiologists score, and nerve-sparing status were significantly associated with recovery of urinary continence on univariate analysis. On multivariate analysis, age (hazard ratio [HR], 1.254; 95% confidence interval [CI], 1.002–1.478; P=0.026) and nerve-sparing status (HR, 0.713; 95% CI, 0.548–0.929; P=0.012) were independently associated with recovery of urinary continence. Conclusions: nsRP, as compared to nnsRP, improves recovery rates of urinary incontinence and decreases surgical morbidity without compromising pathologic outcomes. PMID:27032560

  19. Radical urethrectomy with bladder preservation and continent catheterizable stoma (Yang-Monti tecnique)

    PubMed Central

    Maestro, Mario Alvarez; Martinez-Piñeiro, Luis; Gonzalez, Emilio Rios

    2012-01-01

    Malignant melanoma originating in the urethra is considered extremely rare and has a very poor prognosis. Consequently, therapeutic reviews are retrospective describing assorted treatments. We report how to perform a radical urethrectomy with bladder preservation and a continent catheterizable stoma (Yang-Monti technique) Radical urethrectomy with bladder preservation and a continent catheterizable stoma may be appropriate in selected patients with tumours that do not invade the bladder neck. PMID:22557732

  20. Flexural Tectonics in Continents: Critical Stress amid Immeasurable Strain

    NASA Astrophysics Data System (ADS)

    Bilham, R. G.

    2012-12-01

    With a few notable exceptions, most fatalities from earthquakes in the past millennium have occurred in mid-continent regions along the southern edge of the Eurasian plate where earthquakes are not expected due to their infrequency, or absence, in local historical records. Although the spatial density geodetic measurement in many parts of the Indo-Eurasian collision zone is currently poor, geodetically estimated strain rates where these are sufficiently dense (e.g. North America) are now being considered an important option to quantify the stressing rate of regions where seismic productivity is low. Certain assumptions attend the use of surface strain as a measure of seismic productivity: that the observed surface strain rate provides a measure of strain at seismogeninc depths, that none of the observed strain is dissipated in aseismic processes, that currently measured rates are uniform in time, and perhaps most importantly, whether regional strain rate alone is an adequate measure of the failure process. The first of these assumptions can be violated in locations in continental collisional settings, such as India, where flexural stresses prevail. The minimum in-plane northerly directed compressional stress in the Indian plate required to support the Tibetan Plateau is overwhelmed by the flexural stresses caused by the depression of its northern edge. Flexure results in static stresses that vary with depth and latitude, but which, averaged over the entire plate vary negligibly with time, because the rocks of India stream through the >600 km wavelength flexural stress-field at rates of only 2 cm/yr. This theoretical result is consistent with India's mean north-south strain rate observed geodetically, which is less than a few nanostrain each year. The spatial distribution of flexural stress, however, varies spatially as a function of distance from the Himalayan front. Strain rates exceed 2 bars/km in a flexural trough between 1000-1800 km south of the Himalaya, and

  1. Heat Flow Partitioning Between Continents and Oceans - from 2D to 3D

    NASA Astrophysics Data System (ADS)

    Moresi, L. N.; Cooper, C. M.; Lenardic, A.

    2010-12-01

    Scalings derived from thermal network theory explain how the presence of continents can influence the Earth’s overall heat loss. Intuitively, it may seem that increasing the proportion of a planet’s surface area covered by continents would decrease the efficiency of heat transfer given that continents do not participate in convective overturn. However, this ignores the potential feedback between the insulating effect of continents and the temperature-dependent viscosity of the mantle (Lenardic et al, 2005, Cooper et al, 2007). When this feedback is considered, a clear regime exists in which the partial stagnation and insulation of the surface by buoyant continental crust can lead to an increase in heat flow compared to the uninsulated case. The numerical results used to verify the scalings have mostly been conducted in two dimensions in order to cover a very wide range of Rayleigh number, fraction of continental coverage, and continental thickness. However as more recent results show that the configuration of the crust also plays a role in determining the heat flow partitioning and global heat flow (See Lenardic et al, “Continents, Super-Continents, Mantle Thermal Mixing, and Mantle Thermal Isolation” in this session), we have begun to repeat this exhaustive and exhausting 2D study in 3D. Cooper, C.M., A. Lenardic, and L.-N. Moresi "Effects of continental insulation and the partioning of heat producing elements on the Earth's heat loss." Geophys. Res. Lett., 33 ,10.1029, 2006. Lenardic, A., L.-N. Moresi, A.M. Jellinek, and M. Manga "Continental insulation, mantle cooling, and the surface area of oceans and continents." Earth Planet. Sci. Lett., 234 ,317-333, 2005.

  2. A unified model of avian species richness on islands and continents.

    PubMed

    Kalmar, Attila; Currie, David J

    2007-05-01

    How many species in a given taxon should be found in a delimited area in a specified place in the world? Some recent literature suggests that the answer to this question depends strongly on the geographical, evolutionary, and ecological context. For example, current theory suggests that species accumulate as a function of area differently on continents and islands. Species richness-climate relationships have been examined separately on continents and on islands. This study tests the hypotheses that (1) the functional relationship between richness and climate is the same on continents and islands; (2) the species-area slope depends on distance-based isolation; (3) species-area relationships differ among land bridge islands, oceanic islands, and continents; (4) richness differs among biogeographic regions independently of climate and isolation. We related bird species numbers in a worldwide sample of 240 continental parcels and 346 islands to several environmental variables. We found that breeding bird richness varies similarly on islands and on continents as a function of mean annual temperature, an area x precipitation interaction, and the distance separating insular samples from the nearest continent (R2 = 0.86). Most studies to date have postulated that the slope of the species-area relationship depends upon isolation. In contrast, we found no such interaction. A richness-environment relationship derived using Old World sites accurately predicts patterns of richness in the New World and vice versa (R2 = 0.85). Our results suggest that most of the global variation in richness is not strongly context-specific; rather, it reflects a small number of general environmental constraints operating on both continents and islands.

  3. The Ocean-Continent Boundary Effect on Seismic Noise Recorded on Land

    NASA Astrophysics Data System (ADS)

    Stutzmann, E.; Gualtieri, L.; Capdeville, Y.; Farra, V.; Mangeney, A.

    2014-12-01

    Seismic noise in the period band 3-10s is generated at the surface of the ocean by the interaction of ocean gravity waves. Noise signal is dominated by Rayleigh waves and is recorded worldwide, both on the ocean seafloor and on continent. Microseismic Rayleigh waves, like any other elastic wave, loose energy when traveling from the ocean to the continent. Thus, the noise records on continent are affected by the propagation of microseismic waves, especially across the boundary between the ocean and the continent, the main structural boundary along the source-receiver path. At the ocean-continent boundary, Rayleigh waves dissipate a significant amount of energy (e.g. McGarr, 1969) and noise Love waves may be generated (e.g. Gregersen, 1977). In order to investigate the effect of the ocean-continent boundary on seismic noise records, we simulate the propagation of the seismic wavefield across the seafloor using the spectral-element method in the secondary microseismic period band (3-10s). A single noise source is located at the surface of the ocean and the signal is recorded at the seafloor, both in deep and shallow ocean regions and on continent. The seismograms computed in a model with continental slope are compared to those computed in a model with flat seafloor, for varying periods and slopes. In the presence of the continental slope, the seismic records are affected by a secondary virtual source, generated by the seafloor topography. The effect of the spatial distribution of noise sources is also investigated.

  4. Quality audit--a review of the literature concerning delivery of continence care.

    PubMed

    Swaffield, J

    1995-09-01

    This paper outlines the role of quality audit within the framework of quality assurance, presenting the concurrent and retrospective approaches available. The literature survey provides a review of the limited audit tools available and their application to continence services and care delivery, as well as attempts to produce tools from national and local standard setting. Audit is part of a process; it can involve staff, patients and their relatives and the team of professionals providing care, as well as focusing on organizational and management levels. In an era of market delivery of services there is a need to justify why audit is important to continence advisors and managers. Effectiveness, efficiency and economics may drive the National Health Service, but quality assurance, which includes standards and audit tools, offers the means to ensure the quality of continence services and care to patients and auditing is also required in the purchaser/provider contracts for patient services. An overview and progress to date of published and other a projects in auditing continence care and service is presented. By outlining and highlighting the audit of continence service delivery and care as a basis on which to build quality assurance programmes, it is hoped that this knowledge will be shared through the setting up of a central auditing clearing project. PMID:7551434

  5. The Interaction of Eastward Propagating Equatorial Modes with the Maritime Continent

    NASA Astrophysics Data System (ADS)

    Flatau, M. K.

    2015-12-01

    We examine the processes that contribute to blocking of the eastward propagating equatorial modes by the Maritime Continent. The recent study by Baranowski at al (2015) have shown that the propgation of Kelvin waves through the Maritime Continent is strongly influenced by the interaction of the waves with the diurnnal cycle of convection over the land which can either amplify or supress the convective forcing of the wave. This suggests that inorder for the wave to cross the Maritime Continent it has to be in phase with local convection. Another possible mechanism through which the Maritime Continent can influence approaching Kelvin waves and MJO's is their interacton with cyclonic disturbances generated by the lee vortices at the tips of Sumatra. Both of these mechanisms can be misrepresented by dynamic models and contribute to predictability barrier in this region These equatorial modes ate examined in Navy models forecasts of DYNAMO MJOs and n idealized experiments. While the models appear to predict the MJO and Kelvin wave approach to the Maritime continent their propagation is too slowa andn westward propagating disturbance are often too strong. We examine the contribution of lee vortices and local diurnal convection variability to this process

  6. How Do People Make Continence Care Happen? An Analysis of Organizational Culture in Two Nursing Homes

    PubMed Central

    Lyons, Stacie Salsbury

    2010-01-01

    Purpose: Although nursing homes (NHs) are criticized for offering poor quality continence care, little is known about the organizational processes that underlie this care. This study investigated the influence of organizational culture on continence care practices in two NHs. Design and Methods: This ethnographic study explored continence care from the perspectives of NH stakeholders, including residents and interdisciplinary team members. Data were collected through participant observation, interviews, and archival records. Results: Human relations dimensions of organizational culture influenced continence care by affecting institutional missions, admissions and hiring practices, employee tenure, treatment strategies, interdisciplinary teamwork, and group decision making. Closed system approaches, parochial identity, and an employee focus stabilized staff turnover, fostered evidence-based practice, and supported hierarchical toileting programs in one facility. Within a more dynamic environment, open system approaches, professional identity, and job focus allowed flexible care practices during periods of staff turnover. Neither organizational culture fully supported interdisciplinary team efforts to maximize the bladder and bowel health of residents. Implications: Organizational culture varies in NHs, shaping the continence care practices of interdisciplinary teams and leading to the selective use of treatments across facilities. Human relations dimensions of organizational culture, including open or closed systems, professional or parochial identity, and employee or job focus are critical to the success of quality improvement initiatives. Evidence-based interventions should be tailored to organizational culture to promote adoption and sustainability of resident care programs. PMID:20008040

  7. Cecal rupture after continent ileocecal urinary diversion during total pelvic exenteration

    SciTech Connect

    Brand, E. )

    1991-09-01

    Continent ureteral diversion at the time of pelvic exenteration avoids an external appliance and allows patients to retain bladder reservoir function. The technical difficulty of this procedure requires meticulous attention to operative and perioperative care, particularly after pelvic irradiation. A patient with recurrent stage IIIB carcinoma of the cervix underwent total pelvic exenteration with reconstructive procedures including low rectal anastomosis, neovagina formation, and ileocecal (Indiana) continent diversion. Early catheterization of the reservoir began 2 weeks postoperatively. One week later cecal rupture occurred, not related to suture line (technical) failure. Because of the high wall tension and reduced compliance in the irradiated cecum, the authors do not recommend catheterization of the urinary reservoir before 4-6 weeks. In order for continent diversion to become the standard diversion in exenteration patients, the major complication rate must remain comparable to that of noncontinent diversion.

  8. What caused the recent ``Warm Arctic, Cold Continents'' trend pattern in winter temperatures?

    NASA Astrophysics Data System (ADS)

    Sun, Lantao; Perlwitz, Judith; Hoerling, Martin

    2016-05-01

    The emergence of rapid Arctic warming in recent decades has coincided with unusually cold winters over Northern Hemisphere continents. It has been speculated that this "Warm Arctic, Cold Continents" trend pattern is due to sea ice loss. Here we use multiple models to examine whether such a pattern is indeed forced by sea ice loss specifically and by anthropogenic forcing in general. While we show much of Arctic amplification in surface warming to result from sea ice loss, we find that neither sea ice loss nor anthropogenic forcing overall yield trends toward colder continental temperatures. An alternate explanation of the cooling is that it represents a strong articulation of internal atmospheric variability, evidence for which is derived from model data, and physical considerations. Sea ice loss impact on weather variability over the high-latitude continents is found, however, to be characterized by reduced daily temperature variability and fewer cold extremes.

  9. Growth of the Maritime Continent and its possible contribution to recurring Ice Ages

    NASA Astrophysics Data System (ADS)

    Molnar, Peter; Cronin, Timothy W.

    2015-03-01

    The areal extent of the Maritime Continent (the islands of Indonesia and surrounding region) has grown larger by ~60% since 5 Ma. We argue that this growth might have altered global climate in two ways that would have contributed to making recurring Ice Ages possible. First, because rainfall over the islands of the Maritime Continent not only is heavier than that over the adjacent ocean but also correlates with the strength of the Walker Circulation, the growth of the Maritime Continent since 5 Ma may have contributed to the cooling of the eastern tropical Pacific since that time. Scaling relationships between the strength of the Walker Circulation and rainfall over the islands of the Maritime Continent and between sea surface temperature (SST) of the eastern tropical Pacific and the strength of easterly wind stress suggest that the increase in areal extent of islands would lead to a drop in that SST of 0.75°C. Although only a fraction of the 3-4°C decrease in SSTs between the eastern and western tropical Pacific, the growth of the Maritime Continent may have strengthened the Walker Circulation, increased the east-west temperature gradient across the Pacific and thereby enabled ice sheets to wax and wane over Canada since 3 Ma. Second, because the weathering of basaltic rock under warm, moist conditions extracts CO2 from the atmosphere more rapidly than weathering of other rock or of basalt under cooler or drier conditions, the increase in weathering due to increasing area of basalt in the Maritime Continent may have drawn down enough CO2 from the atmosphere to affect global temperatures. Simple calculations suggest that increased weathering of basalt might have lowered global temperatures by 0.25°C, possibly important for the overall cooling.

  10. Does previous transurethral prostate surgery affect oncologic and continence outcomes after RARP?

    PubMed

    Su, Yu-Kai; Katz, Benjamin F; Sehgal, Shailen S; Yu, Sue-Jean S; Su, Yu-Chen; Lightfoot, Andrew; Lee, Ziho; Llukani, Elton; Monahan, Kelly; Lee, David I

    2015-12-01

    We examined the effect of previous transurethral resection of the prostate (TURP) on multiple oncologic and continence outcomes after robotic-assisted radical prostatectomy (RARP). We performed a retrospective cohort study of a total of 2693 patients from 2007 to 2014 who underwent RARP. Patients were stratified into 49 patients who had previous TURP prior to RARP (group 1) and 2644 patients who had no TURP prior to RARP (group 2). We collected operative variables including estimated blood loss, operative time, and positive surgical margin (PSM) rates. Urinary continence, defined as 0 pads per day (PPD), and social continence, defined as 1-PPD, were also assessed. American Urological Association Symptoms Score (AUASS), overall ability to function sexually, and Expanded Prostate Cancer Index Composite (EPIC) questionnaire were evaluated at 3 and 12 months after RARP. Weakness of urinary stream (EPIC #4d) at 12 months imposed a greater problem for group 1 patients with prior TURP compared to group 2 patients without prior TURP (p = 0.012). PSM was not statistically significant between the two groups (p = 0.110). Group 1 patients had a greater PSM rate (30.61 %) as compared to group 2 (20.95 %). PSM locations in group 1 patients showed the most common locations at the posterior and apex. The difference between the two groups for AUASS, overall sexual function, estimated blood loss, operative time, urinary continence, and social continence was not statistically significant. We examined the effect of previous TURP on postoperative RARP continence and oncologic outcomes. This data can be used to counsel those with prior TURP before RARP. PMID:26530840

  11. Urinary Continence after Robot-Assisted Laparoscopic Radical Prostatectomy: The Impact of Intravesical Prostatic Protrusion

    PubMed Central

    Jo, Jung Ki; Hong, Sung Kyu; Byun, Seok-Soo; Zargar, Homayoun; Autorino, Riccardo

    2016-01-01

    Purpose To assess the impact of intravesical prostatic protrusion (IPP) on the outcomes of robot-assisted laparoscopic prostatectomy (RALP). Materials and Methods The medical records of 1094 men who underwent RALP from January 2007 to March 2013 were analyzed using our database to identify 641 additional men without IPP (non-IPP group). We excluded 259 patients who presented insufficient data and 14 patients who did not have an MRI image. We compared the following parameters: preoperative transrectal ultrasound, prostate specific antigen (PSA), clinicopathologic characteristics, intraoperative characteristics, postoperative oncologic characteristics, minor and major postoperative complications, and continence until postoperative 1 year. IPP grade was stratified by grade into three groups: Grade 1 (IPP≤5 mm), Grade 2 (5 mm10 mm). Results Of the 821 patients who underwent RALP, 557 (67.8%) experienced continence at postoperative 3 months, 681 (82.9%) at 6 months, and 757 (92.2%) at 12 months. According to IPP grade, there were significant differences in recovering full continence at postoperative 3 months, 6 months, and 12 months (p<0.001). On multivariate analysis, IPP was the most powerful predictor of postoperative continence in patients who underwent RALP (p<0.001). Using a generalized estimating equation model, IPP also was shown to be the most powerful independent variable for postoperative continence in patients who underwent RALP (p<0.001). Conclusion Patients with low-grade IPP have significantly higher chances of recovering full continence. Therefore, the known IPP grade will be helpful during consultations with patients before RALP. PMID:27401645

  12. Correlation Between Mobile Continents and Elevated Temperatures in the Subcontinental Mantle

    NASA Astrophysics Data System (ADS)

    Jain, C.; Rozel, A. B.; Tackley, P.

    2015-12-01

    Rolf et al. (EPSL, 2012) and Coltice et al. (Science, 2012) have previously shown that continents exert a first order influence on Earth's mantle flow by affecting convective wavelength and surface heat flow. With stationary continents, Heron and Lowman (JGR, 2014) highlighted the decreasing role of continental insulation on subcontinental temperatures with higher Rayleigh number (Ra). However, the question whether there exists a correlation between mobile continents and elevated temperatures in the subcontinental mantle or not remains to be answered. Continental motion is attributed to the viscous stresses imparted by the convecting mantle and the extent of this motion depends on the heat budget of the mantle. Core-mantle boundary (CMB) heat flux, internal heating from decay of radioactive elements, and mantle cooling contribute to this heat budget. Out of these sources, CMB heat flux is not well defined. However, the recent determination of core's high thermal conductivity requires a CMB heat flow of at least 12 TW (de Koker et al., PNAS 2012; Pozzo et al., Nature 2012; Gomi et al., PEPI 2013). Thus it is necessary to characterize the impact of basal heating on mantle dynamics with mobile continents and self-consistent plate tectonics. By systematically varying parameters such as CMB temperature, continental size, mantle heating modes, and Rayleigh number; we model Boussinesq, incompressible, thermo-chemical mantle convection with 2D spherical annulus geometry using StagYY (Tackley, PEPI 2008). We observe the aforementioned correlation irrespective of the variations in basal heating and continental size (except for very small continents). Moreover, we see episodicity between correlation-anticorrelation with increasing convective vigour. Furthermore, the effect of radioactivity in the continental crust on this correlation is investigated. At present, mobile continents in StagYY are simplified into a compositionally distinct field drifting at the top of the mantle

  13. The effects of size, configuration and distribution of continents on the efficiency of heat transport

    NASA Astrophysics Data System (ADS)

    Cooper, C. M.; Moresi, L. N.; Lenardic, A.

    2011-12-01

    The addition of continents to the surface of a planet alters its interior dynamics; understanding this alteration is critical to understanding the thermal evolution of the Earth. Specifically, the increase in temperature induced by continental insulation can be compensated by an increase in the heat loss through the overturn of the oceanic lithosphere, thus contradicting the predicted reduction of global heat loss due to presence of continents (e.g., Lenardic et al, 2005; Cooper et al, 2006; Lenardic et al, 2011). We reconfirm this counterintuitive result with three-dimensional simulations. In addition, we explore variations in the configuration of continents on the surface. Within simulations with equivalent continental coverage, but varying configuration, there is a competition between the lateral size of the blocks and the natural horizontal scale of the convection pattern which influences the stability of the models over time, and the efficiency of heat transport. Smaller continental blocks tend to induce a stable planform with upwellings permanently avoiding the blocks. However, in cases with larger continental blocks, the imposed scale is larger than the preferred scale of the convection pattern and upwellings are unable to avoid the blocks altogether. The dependency on stability and efficiency of heat transport within the Earth on continental coverage and configuration suggests continents can play a significant role in the Earth's heat budget and thermal history. Cooper, C.M., A. Lenardic, and L.-N. Moresi "Effects of continental insulation and the partioning of heat producing elements on the Earth's heat loss." Geophys. Res. Lett., 33 ,10.1029, 2006; Lenardic, A., C.M. Cooper, and L.-N. Moresi "A note on continents and the Earth's Urey ratio", Physics of the Earth and Planetary Interiors, 2011; Lenardic, A., L.-N. Moresi, A.M. Jellinek, and M. Manga "Continental insulation, mantle cooling, and the surface area of oceans and continents." Earth Planet. Sci

  14. Feldspar basalts in lunar soil and the nature of the lunar continents

    NASA Technical Reports Server (NTRS)

    Reid, A. M.; Ridley, W. I.; Harmon, R. S.; Warner, J.; Brett, R.; Jakes, P.; Brown, R. W.

    1974-01-01

    It is found that 25% on the Apollo-14 glasses have the same composition as the glasses in two samples taken from the Luna-16 column. The compositions are equivalent to feldspar basalt and anorthosite gabbro, and are similar to the feldspar basalts identified from Surveyor-7 analysis for lunar continents.

  15. Rotational Inerfia of Continents: A Proposed Link between Polar Wandering and Plate Tectonics.

    PubMed

    Kane, M F

    1972-03-24

    A mechanism is proposed whereby displacement between continents and the earth's pole of rotation (polar wandering) gives rise to latitudinal transport of continental plates (continental drift) because of their relatively greater rotational inertia. When extended to short-term polar wobble, the hypothesis predicts an energy change nearly equivalent to the seismic energy rate. PMID:17813830

  16. Meteor Shower observations from the Indian Sub-Continent (Visual Photographic and Radio)

    NASA Astrophysics Data System (ADS)

    Dabhade, R.; Savant, V.; Belapure, J.

    2011-01-01

    We review the present status of meteor shower observing from the Indian sub-continent. Some amateur groups are active in visual observations, although they are restricted by the lack of good observing sites. Ham radio appears to be promising as a technique to monitor the major meteor showers in this region. We present radio observations of the 2006 Quadrantids.

  17. Family Planning Services Available to Migratory Farm Workers in the Mid-Continent Streams.

    ERIC Educational Resources Information Center

    Planned Parenthood--World Population, Austin, TX. Southwest Region.

    The information in this directory is designed to promote continuity in family planning services for migrant families in mid-continent streams. It provides professional personnel with a new tool to help meet the distinctive needs of individual migrants. Names, addresses, schedules, methods, and fee information of service agencies (health…

  18. Family Planning in Five Continents: Africa, America, Asia, Europe, Oceania. October 1973 Update.

    ERIC Educational Resources Information Center

    International Planned Parenthood Federation, London (England).

    Population growth trends and family planning activities in Africa, America, Asia, Europe, and Oceania are summarized in this booklet developed by the International Planned Parenthood Federation. Narrative information for each continent gives a resume of population growth trends, reasons for the trends, population problems, policy formation, family…

  19. Listening to carers talking about the subjects of continence and toileting.

    PubMed

    Forbat, Liz

    Toilets and continence play critical roles in the lives of people who care for a relative at home. Issues around toileting are central to the relationship between the carer and the person being cared for, with the bathroom often becoming the most important place in the house. PMID:14768154

  20. Extended Diaper Wearing: Effects on Continence in and out of the Diaper

    ERIC Educational Resources Information Center

    Tarbox, Rachel S. F.; Williams, W. Larry; Friman, Patrick C.

    2004-01-01

    Diaper use is widespread and possibly even increasing across diverse populations in the United States, ranging from infants to very old adults. We found no reports of an experimental analysis of the effect of wearing diapers on the frequency of urinary accidents and the attainment of continence skills (e.g., urinating in the toilet). In this…

  1. Can individualized health care plans help increase continence in children with dysfunctional elimination syndrome?

    PubMed

    Boisclair-Fahey, Anne

    2009-10-01

    School-age children with dysfunctional elimination syndrome (DES) do not always have school support for their treatment plans, including an every 2-hr voiding schedule. The objective of this study was to increase school support of treatment plans by allowing access to bathrooms, thereby improving continence. An eight-question survey about bathroom access at schools was given to parents at baseline. The author contacted school nurses requesting that treatment plans be incorporated into individual health plans (IHPs) with teacher support of the IHP. Six weeks later, school nurses were contacted and parents completed a postintervention survey to determine whether IHPs were supported by teachers. Voiding diaries were used to document continence. Seventeen parents completed the survey at baseline, and 13 children were enrolled in the intervention. After the intervention, 100% of the children had IHPs and teacher support of treatment plans. Ninety-two percent had increased continence. IHPs improved teacher support of children's treatment plans and improved their continence. PMID:19342536

  2. Can Individualized Health Care Plans Help Increase Continence in Children with Dysfunctional Elimination Syndrome?

    ERIC Educational Resources Information Center

    Boisclair-Fahey, Anne

    2009-01-01

    School-age children with dysfunctional elimination syndrome (DES) do not always have school support for their treatment plans, including an every 2-hr voiding schedule. The objective of this study was to increase school support of treatment plans by allowing access to bathrooms, thereby improving continence. An eight-question survey about bathroom…

  3. Rotational inertia of continents: A proposed link between polar wandering and plate tectonics

    USGS Publications Warehouse

    Kane, M.F.

    1972-01-01

    A mechanism is proposed whereby displacement between continents and the earth's pole of rotation (polar wandering) gives rise to latitudinal transport of continental plates (continental drift) because of their relatively greater rotational inertia. When extended to short-term polar wobble, the hypothesis predicts an energy change nearly equivalent to the seismic energy rate.

  4. Manipulation of the Family Photo Album: Esther Parada's Transplant--A Tale of Three Continents

    ERIC Educational Resources Information Center

    Eggemeyer, Valerie

    2004-01-01

    In this article, the author focuses on Esther Parada's non-traditional use of the Web to communicate her art, and offers a critique of Parada's work, "Transplant: A Tale of Three Continents," and suggestions for critiquing Web art in the school classroom. Parada creates an intersection between this new medium and the more traditional medium of…

  5. Evaluation Plan of the Mid-continent Research for Education and Learning, FY1996-FY2000.

    ERIC Educational Resources Information Center

    Barley, Zoe

    This evaluation plan, which is updated annually, provides a synthesis of the various evaluation activities of Mid-continent Research for Education and Learning (McREL). During 1999, the fourth year of the Laboratory's contract period with the Office of Educational Research and Improvement, special studies and integrated studies were designed to…

  6. Littoral and Shoreline Wood in Mid-continent Great Rivers (USA)

    EPA Science Inventory

    Less is known about the ecology of wood in great rivers than in smaller lotic systems. We used a probability survey to estimate the abundance of littoral and shoreline wood along the mid-continent great rivers of the United States: the Missouri, Upper Mississippi, and the Ohio Ri...

  7. Lost Continents? Children's Understanding of the Location and Orientation of the Earth's Land Masses.

    ERIC Educational Resources Information Center

    Wiegand, Patrick; Stiell, Bernadette

    1996-01-01

    Presents the results of an experiment that asked 53 middle school children to identify continent shapes and to arrange them to form a map of the world. Australia, Europe, and Asia were the most recognized. Misidentified and misaligned most consistently were Africa and Antarctica. Discusses possible reasons and teachers' responses. (MJP)

  8. Papers presented to the Conference on Heat and Detachment in Crustal Extension on Continents and Planets

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Several topics relative to heat and detachment in crustal extension on continents and planets are discussed. Rifting on Venus, heat flow and continental breakup, magnetism, the mountains and tectonic processes of Io, and the ductile extension of planetary lithospheres are among the topics covered.

  9. Rotational Inerfia of Continents: A Proposed Link between Polar Wandering and Plate Tectonics.

    PubMed

    Kane, M F

    1972-03-24

    A mechanism is proposed whereby displacement between continents and the earth's pole of rotation (polar wandering) gives rise to latitudinal transport of continental plates (continental drift) because of their relatively greater rotational inertia. When extended to short-term polar wobble, the hypothesis predicts an energy change nearly equivalent to the seismic energy rate.

  10. A northern Cordilleran ocean-continent transect: Sitka Sound, Alaska, to Atlin Lake, British Columbia

    USGS Publications Warehouse

    Brew, D.A.; Karl, S.M.; Barnes, D.F.; Jachens, R.C.; Ford, A.B.; Horner, R.

    1991-01-01

    The 155 km wide, 310 km long Sitka Sound - Atlin Lake continent-ocean transect includes almost all the geologic, geophysical, and geotectonic elements of the Canadian Cordillera. It crosses the Chugach, Wrangellia, Alexander, Stikine, and Cache Creek terranes, the Gravina and Laberge overlap assemblages, intrusive and metamorphic belts, and neotectonic faults that bound major blocks. -from Authors

  11. Multiscale Interactions over the Maritime Continent: Feedbacks between Atmospheric Convectively Coupled Kelvin Waves and Diurnal Cycle

    NASA Astrophysics Data System (ADS)

    Baranowski, D.

    2015-12-01

    Interactions between atmospheric convectively coupled Kelvin waves (CCKW), initiated over the Indian Ocean, and the diurnally varying convection over the Maritime Continent are primary interest of this presentation. Mutliscale interactions between local and propagating convection lead to substantial enhancement of the local diurnal cycle over that region. CCKW activity strongly modulates magnitude of the diurnal cycle of precipitation over the Maritime Continent, but not its temporal evolution, which maintains characteristics of a diurnal cycle. The impact is such that precipitation is highly increased during convective part of the CCKW and little suppressed during its non-convective part. Timing of the increase in diurnal cycle magnitude strongly depends on the time of the day of the CCKW approach to the Maritime Continent. It is shown that precipitation anomaly associated with CCKW is phase locked with local diurnal cycle of precipitation over the Maritime Continent and that has implications for CCKW ability to propagate across that region. The composite daily-zonal evolution of the precipitation anomaly associated with CCKW is such that it is "in-phase" with local diurnal cycle over Sumatra, Borneo and surrounding seas. This presentation is based on analysis of TRMM precipitation data and newly developed CCKW trajectories database.

  12. Modeled summer background concentration nutrients and suspended sediment in the mid-continent (USA) great rivers

    EPA Science Inventory

    We used regression models to predict background concentration of four water quality indictors: total nitrogen (N), total phosphorus (P), chloride, and total suspended solids (TSS), in the mid-continent (USA) great rivers, the Upper Mississippi, the Lower Missouri, and the Ohio. F...

  13. Developing Your Own Continent--A Teaching Unit for World Geography.

    ERIC Educational Resources Information Center

    Richburg, Robert W.; Dornan, David Lynn

    1980-01-01

    Describes a six-week seventh-grade project in which students create their own continent. The project helps students learn about weather and climatic patterns, use map scales and legends, describe relationships between natural resources and human activities, solve problems, and work effectively in groups. (Author/KC)

  14. Vas deferens urethral support improves early post-prostatectomy urine continence.

    PubMed

    van der Poel, H G; De Blok, W; Van Muilekom, H A M

    2012-12-01

    Urine continence is often impaired after radical prostatectomy. Few randomized studies prove the efficacy of novel surgical approaches. Vas deferens urethral support (VDUS) during robot-assisted laparoscopic prostatectomy (RALP) was studied for improvement of early postoperative urine continence in a single-centre prospective double-blind randomized study with a power of 90% to detect a 30% decrease in early incontinence. 112 men were randomized, and 108 could be analyzed (VDUS n = 54, noVDUS n = 54). VDUS improved early continence by 40% at 1 month (59% vs. 35%, P = 0.02); 6 months postoperatively this was 72% vs. 62%, P = 0.41. A 24-h pad test at 1 day, 3 days, and 1 week showed decreased amounts of urine loss in the VDUS group. The ICIQ-SF score was significantly lower for the VDUS group within the first month after surgery. VDUS had no impact upon quality of life questionnaire analyses for overall and lower urinary tract symptom-related quality of life but showed a significant improvement in the social domain of the EORTC-QLQ-C30 questionnaire. VDUS moderately improved early urine continence within 1 month after RALP. PMID:27628467

  15. Moving Target: ENSO and Seasonal Forecasting for the Winter Monsoon over the Western Maritime Continent

    NASA Astrophysics Data System (ADS)

    Lee, S. Y.

    2014-12-01

    The El Niño-Southern Oscillation (ENSO) is the dominant mode of interannual variability over most of the tropics, and the performance of seasonal forecast models over such region is often related to how well they capture the regional teleconnection with ENSO. During the boreal winter monsoon, mean precipitation over much of the Maritime Continent is strongly correlated with ENSO phase. Over these regions, the prospect of accurate seasonal precipitation forecast is optimistic. Unfortunately, the ENSO signal in precipitation is known to be much weaker over the western Maritime Continent, which covers the Malay Peninsula, Borneo, Sumatra, and west Java. We investigate the ENSO teleconnection with mean precipitation using simple statistics on merged observation-remote sensing and model hindcast products. These diagnostics suggest an additional reason for why the winter monsoon mean precipitation over the western Maritime Continent is poorly correlated with the ENSO phase, and why some forecast models may not reflect this observed situation. We make recommendations for some process-based forecast products that are desirable for the Western Maritime Continent.

  16. Educational Visions from Two Continents: What Tagore Adds to the Deweyan Perspective

    ERIC Educational Resources Information Center

    Samuel, Francis A.

    2011-01-01

    In this global village, it is relevant to look at two educational visionaries from two continents, John Dewey and Rabindranath Tagore. Dewey observed that the modern individual was depersonalized by the industrial and commercial culture. He, thus, envisioned a new individual who would find fulfillment in maximum individuality within maximum…

  17. Is "Warm Arctic, Cold Continent" A Fingerprint Pattern of Climate Change?

    NASA Astrophysics Data System (ADS)

    Hoerling, M. P.; Sun, L.; Perlwitz, J.

    2015-12-01

    Cold winters and cold waves have recently occurred in Europe, central Asia and the Midwest to eastern United States, even as global mean temperatures set record highs and Arctic amplification of surface warming continued. Since 1979, Central Asia winter temperatures have in fact declined. Conjecture has it that more cold extremes over the mid-latitude continents should occur due to global warming and the impacts of Arctic sea ice loss. A Northern Hemisphere temperature signal termed the "Warm Arctic, Cold Continent" pattern has thus been surmised. Here we use a multi-model approach to test the hypothesis that such a pattern is indeed symptomatic of climate change. Diagnosis of a large model ensemble of historical climate simulations shows some individual realizations to yield cooling trends over Central Asia, but importantly the vast majority show warming. The observed cooling has thus likely been a low probability state of internal variability, not a fingerprint of forced climate change. We show that daily temperature variations over continents decline in winter due to global warming, and cold waves become less likely. This is partly related to diminution of Arctic cold air reservoirs due to warming-induced sea ice loss. Nonetheless, we find some evidence and present a physical basis that Arctic sea ice loss alone can induce a winter cooling over Central Asia, though with a magnitude that is appreciably smaller than the overall radiative-forced warming signal. Our results support the argument that recent cooling trends over central Asia, and cold extreme events over the winter continents, have principally resulted from atmospheric internal variability and have been neither a forced response to Arctic seas ice loss nor a symptom of global warming. The paradigm of climate change is thus better expressed as "Warm Arctic, Warm Continent" for the NH winter.

  18. Oceans and continents: Similarities and differences in the mechanisms of heat loss

    SciTech Connect

    Sclater, J.G.; Parsons, B.; Jaupart, C.

    1981-12-10

    The principal objective of this paper is to present a simple and self-consistent review of the basic physical processes controlling heat loss from the earth. To accomplish this objective, we give a short summary of the oceanic and continental data and compare and contrast the respective mechanisms of heat loss . In the oceans we concentrate on the effect of hydrothermal circulation, and on the continents we consider in some detail a model relating surface heat flow to varying depth scales for the distribution of potassium, thorium, and uranium. From this comparison we conclude that the range in possible geotherms at depths below 100 to 150 km under continents and oceans overlaps and the thermal structure beneath an old stable continent is indistinguishable from that beneath an ocean were it at equilibrium. Oceans and continents are part of the same thermal system. Both have an upper rigid mechanical layer where heat loss is by conduction and a lower thermal boundary layer where convection is dominant. The simple conductive definition of the plate thickness is an oversimplification. The observed distribution of area versus age in the ocean allows us to investigate the dominant mechanism of heat loss which is plate creation. This distribution and an understanding of the heat flow through oceans and continents can be used to calculate the heat loss of the earth. This heat loss is 10/sup 13/ cal/s (4.2 x 10/sup 13/W) of which more than 60% results from the creation of oceanic plate. The relation between area and age of the oceans is coupled to the ridge and subducting slab forces that contribute to the driving mechanism for plate motions. These forces are self-regulating and maintain the rate of plate generation required to achieve a balance between heat loss and heat generation.

  19. Relationship of multispectral satellite data to land surface evaporation from the Australian continent

    NASA Technical Reports Server (NTRS)

    Smith, R. C. G.; Choudhury, B. J.

    1990-01-01

    Based on NOAA-9 AVHRR and Nimbus-7 SMMR satellite data, satellite indices of vegetation from the Australian continent are calculated for the period of May 1986 to April 1987. Visible (VIS) and near infrared (NIR) reflectances and the normalized difference (ND) vegetation index are calculated from the AVHRR sensor. The microwave polarization difference (PD) is also calculated as the difference between the vertically and horizontally polarized brightness temperatures at 37 GHz. ND, PD, VIS, and NIR indices were plotted against rainfall and water balance estimates of evaporation. It is concluded that direct satellite monitoring of annual evaporation across the Australian continent using PD or VIS satellite indices of vegetation biomass appears possible for areas with evaporation less than 600 mm/y and that use of the ND relationship at continental scale may underpredict monthly evaporation of forests relative to agriculture.

  20. Ophiolites in ocean-continent transitions: From the Steinmann Trinity to sea-floor spreading

    NASA Astrophysics Data System (ADS)

    Bernoulli, Daniel; Jenkyns, Hugh C.

    2009-05-01

    Before the theory of plate tectonics took hold, there was no coherent model for ocean-continent transitions that included both extant continental margins and fragmentary ancient examples preserved in orogenic belts. Indeed, during the early 1900, two strands of thought developed, one relying on the antiquity and permanence of continents and oceans, advocated by the mainstream of the scientific community and one following mobilist concepts derived from Wegener's hypothesis (1915) of continental drift. As an illustration of the prevailing North-American view, the different composition and thickness of continental and oceanic crust and the resulting isostatic response showed "how improbable it would be to suppose that a continent could founder or go to oceanic depth or that ocean floor at ± 3000 fathoms could ever have been a stable land area since the birth of the oceans" [H.H. Hess, Trans. R. Soc. London, A 222 (1954) 341-348]. Because of the perceived permanence of oceans and continents, mountain chains were thought to originate from narrow, elongated, unstable belts, the geosynclines, circling the continents or following "zones of crustal weakness" within them, from which geanticlines and finally mountain belts would develop. This teleological concept, whereby a geosyncline would inevitably evolve into a mountain chain, dominated geological interpretations of orogenic belts for several decades in the mid-twentieth century. However, the concept of permanence of oceans and continents and the concept of the geosyncline had already met with the critiques of Suess and others. As early as 1905, Steinmann considered the association of peridotite, "diabase" (basalt/dolerite) and radiolarite (a typical ocean-continent transition assemblage), present in the Alps and Apennines, as characteristic of the deep-ocean floor and Bailey (1936) placed Steinmann's interpretation into the context of continental drift and orogeny. Indeed, in both authors' writings, the concept of

  1. A staff management system for maintaining improvements in continence with elderly nursing home residents.

    PubMed Central

    Burgio, L D; Engel, B T; Hawkins, A; McCormick, K; Scheve, A; Jones, L T

    1990-01-01

    We developed a staff management system for maintaining treatment gains achieved on a specialized continence unit located in a geriatric nursing home. Geriatric assistants learned to use a prompted voiding procedure to maintain improved dryness for 4 elderly residents. The staff management system included self-monitoring and recording of prompted voiding activities and supervisory monitoring and feedback based on group performance of these activities. Results show that the system was effective in maintaining prompted voiding activities with corresponding maintenance of improved patient continence. However, a gradual decline in staff performance was noted 4 to 5 months after the initiation of the system. During a subsequent phase of the study, provision of individual feedback restored staff performance to previous levels. Results are discussed in relation to the practicality of prompted voiding interventions in nursing home environments and the applicability of staff management systems in this setting. PMID:2335482

  2. Image of the Moho across the continent-ocean transition, US east coast

    SciTech Connect

    Holbrook, W.S.; Purdy, G.M. ); Reiter, E.C.; Toksoez, M.N. )

    1992-03-01

    Strong wide-angle reflections from the Moho were recorded by ocean-bottom seismic instruments during the 1988 Carolina Trough multichannel seismic experiment, in an area where the Moho is difficult to detect with vertical-incidence seismic data. Prestack depth migration of these reflections has enabled the construction of a seismic image of the Moho across the continent-ocean transition of a sedimented passive margin. The Moho rises across the margin at a slope of 10{degree}-12{degree}, from a depth of about 33 km beneath the continental shelf to 20 km beneath the outer rise. This zone of crustal thinning defines a distinct, 60-70-km-wide continent-ocean transition zone. The authors interpret the Moho in the Carolina Trough as a Jurassic feature, formed by magmatic intrusion and underplating during the rifting of Pangea.

  3. An exhumation history of continents over billion-year time scales.

    PubMed

    Blackburn, Terrence J; Bowring, Samuel A; Perron, J Taylor; Mahan, Kevin H; Dudas, Francis O; Barnhart, Katherine R

    2012-01-01

    The continental lithosphere contains the oldest and most stable structures on Earth, where fragments of ancient material have eluded destruction by tectonic and surface processes operating over billions of years. Although present-day erosion of these remnants is slow, a record of how they have uplifted, eroded, and cooled over Earth's history can provide insight into the physical properties of the continents and the forces operating to exhume them over geologic time. We constructed a continuous record of ancient lithosphere cooling with the use of uranium-lead (U-Pb) thermochronology on volcanically exhumed lower crustal fragments. Combining these measurements with thermal and Pb-diffusion models constrains the range of possible erosion histories. Measured U-Pb data are consistent with extremely low erosion rates persisting over time scales approaching the age of the continents themselves.

  4. Cold cratonic roots and thermal blankets: How continents affect mantle convection

    USGS Publications Warehouse

    Trubitsyn, V.P.; Mooney, W.D.; Abbott, D.H.

    2003-01-01

    Two-dimensional convection models with moving continents show that continents profoundly affect the pattern of mantle convection. If the continents are wider than the wavelength of the convection cells (???3000 km, the thickness of the mantle), they cause neighboring deep mantle thermal upwellings to coalesce into a single focused upwelling. This focused upwelling zone will have a potential temperature anomaly of about 200??C, much higher than the 100??C temperature anomaly of upwelling zones generated beneath typical oceanic lithosphere. Extensive high-temperature melts (including flood basalts and late potassic granites) will be produced, and the excess temperature anomaly will induce continental uplift (as revealed in sea level changes) and the eventual breakup of the supercontinent. The mantle thermal anomaly will persist for several hundred million years after such a breakup. In contrast, small continental blocks (<1000 km diameter) do not induce focused mantle upwelling zones. Instead, small continental blocks are dragged to mantle downwelling zones, where they spend most of their time, and will migrate laterally with the downwelling. As a result of sitting over relatively cold mantle (downwellings), small continental blocks are favored to keep their cratonic roots. This may explain the long-term survival of small cratonic blocks (e.g., the Yilgarn and Pilbara cratons of western Australia, and the West African craton). The optimum size for long-term stability of a continental block is <3000 km. These results show that continents profoundly affect the pattern of mantle convection. These effects are illustrated in terms of the timing and history of supercontinent breakup, the production of high-temperature melts, and sea level changes. Such two-dimensional calculations can be further refined and tested by three-dimensional numerical simulations of mantle convection with moving continental and oceanic plates.

  5. The Diurnal Cycle over the Maritime Continent and its Interaction with the MJO

    NASA Astrophysics Data System (ADS)

    Matthews, A. J.; Peatman, S.; Baranowski, D. B.; Stevens, D. P.; Heywood, K. J.; Flatau, P. J.; Schmidtko, S.

    2014-12-01

    The complex land-sea distribution and topography of the maritime continent acts to disrupt or even completely block the eastward propagation of the Madden-Julian Oscillation (MJO) from the Indian Ocean to the western Pacific. This leads to changes in tropical latent heat release and subsequent impacts on global circulation. Convection over the maritime continent is dominated by the diurnal cycle. Where the mean diurnal cycle is strong (over the islands and surrounding seas), 80% of the MJO precipitation signal in the maritime continent is accounted for by changes in the amplitude of the diurnal cycle. The canonical view of the MJO as the smooth eastward propagation of a large-scale precipitation envelope also breaks down over the islands of the Maritime Continent. Instead, a vanguard of precipitation jumps ahead of the main body by approximately 6 days or 2000 km. Hence, there can be enhanced precipitation over Sumatra, Borneo or New Guinea when the large-scale MJO envelope over the surrounding ocean is one of suppressed precipitation. This behaviour is discussed in terms of an interaction between the diurnal cycle and the MJO circulation. The diurnal cycle is also strong in the ocean. Seaglider measurements taken during the CINDY/DYNAMO campaign show the existence of a diurnal warm layer in the upper few metres of the ocean. This has a significant effect on the surface fluxes, of an order of Watts per square metre. The diurnal warm layer is favoured during the inactive phase of the MJO and may act to help precondition the atmosphere to convection. The activities of the MJO Task Force and Subseasonal to Seasonal Prediction project will be discussed in this context.

  6. Redi award lecture: clinical studies of snake-bite in four tropical continents.

    PubMed

    Warrell, David A

    2013-07-01

    Research is discussed in the areas of venomous snake taxonomy, epidemiology, species diagnosis, defining the clinical phenotype of human envenoming, pathophysiological mechanisms of envenoming, clinical testing of antivenoms and prevention of snake-bite through community education. This work was carried out over the past 40 years in many countries in four tropical continents. The help and friendship of a large number of collaborators is gratefully acknowledged.

  7. Intraplate mountain building in response to continent continent collision—the Ancestral Rocky Mountains (North America) and inferences drawn from the Tien Shan (Central Asia)

    NASA Astrophysics Data System (ADS)

    Dickerson, Patricia Wood

    2003-04-01

    The intraplate Ancestral Rocky Mountains of western North America extend from British Columbia, Canada, to Chihuahua, Mexico, and formed during Early Carboniferous through Early Permian time in response to continent-continent collision of Laurentia with Gondwana—the conjoined masses of Africa and South America, including Yucatán and Florida. Uplifts and flanking basins also formed within the Laurentian Midcontinent. On the Gondwanan continent, well inboard from the marginal fold belts, a counterpart structural array developed during the same period. Intraplate deformation began when full collisional plate coupling had been achieved along the continental margin; the intervening ocean had been closed and subduction had ceased—that is, the distinction between upper versus lower plates became moot. Ancestral Rockies deformation was not accompanied by volcanism. Basement shear zones that formed during Mesoproterozoic rifting of Laurentia were reactivated and exerted significant control on the locations, orientations, and modes of displacement on late Paleozoic faults. Ancestral Rocky Mountain uplifts extend as far south as Chihuahua and west Texas (28° to 33°N, 102° to 109°W) and include the Florida-Moyotes, Placer de Guadalupe-Carrizalillo, Ojinaga-Tascotal and Hueco Mountain blocks, as well as the Diablo and Central Basin Platforms. All are cored with Laurentian Proterozoic crystalline basement rocks and host correlative Paleozoic stratigraphic successions. Pre-late Paleozoic deformational, thermal, and metamorphic histories are similar as well. Southern Ancestral Rocky Mountain structures terminate along a line that trends approximately N 40°E (present coordinates), a common orientation for Mesoproterozoic extensional structures throughout southern to central North America. Continuing Tien Shan intraplate deformation (Central Asia) has created an analogous array of uplifts and basins in response to the collision of India with Eurasia, beginning in late

  8. Two-step rise of atmospheric oxygen linked to the growth of continents

    NASA Astrophysics Data System (ADS)

    Lee, Cin-Ty A.; Yeung, Laurence Y.; McKenzie, N. Ryan; Yokoyama, Yusuke; Ozaki, Kazumi; Lenardic, Adrian

    2016-06-01

    Earth owes its oxygenated atmosphere to its unique claim on life, but how the atmosphere evolved from an initially oxygen-free state remains unresolved. The rise of atmospheric oxygen occurred in two stages: approximately 2.5 to 2.0 billion years ago during the Great Oxidation Event and roughly 2 billion years later during the Neoproterozoic Oxygenation Event. We propose that the formation of continents about 2.7 to 2.5 billion years ago, perhaps due to the initiation of plate tectonics, may have led to oxygenation by the following mechanisms. In the first stage, the change in composition of Earth's crust from iron- and magnesium-rich mafic rocks to feldspar- and quartz-rich felsic rocks could have caused a decrease in the oxidative efficiency of the Earth's surface, allowing atmospheric O2 to rise. Over the next billion years, as carbon steadily accumulated on the continents, metamorphic and magmatic reactions within this growing continental carbon reservoir facilitated a gradual increase in the total long-term input of CO2 to the ocean-atmosphere system. Given that O2 is produced during organic carbon burial, the increased CO2 input may have triggered a second rise in O2. A two-step rise in atmospheric O2 may therefore be a natural consequence of plate tectonics, continent formation and the growth of a crustal carbon reservoir.

  9. Transport and scavenging of biomass burning aerosols in the maritime continent

    NASA Astrophysics Data System (ADS)

    Lee, H. H.; Wang, C.

    2014-12-01

    Biomass burning frequently occurs in summertime over the maritime continent, especially in Malaysia peninsula, Sumatra, and Borneo. Under certain weather conditions, particulate matters emitted from such fires cause degrade of air quality and thus occurrence of often weekly long haze in downwind locations such as Singapore. It is possible that these biomass burning aerosols may have influenced convective clouds in the maritime continent though such cases have not been well simulated and understood. In order to improve understanding of the spatiotemporal coverage and influence of biomass burning aerosols in the maritime continent, we have used the Weather Research and Forecasting (WRF) model to study the transport of biomass burning aerosols from Malaysia peninsula, Sumatra, and Borneo, using biomass burning emissions from the Fire INventory from NCAR (FINN) version 1.0. We choose to use emissions from the month of August because the annual emissions peak often occurs within this month. Based on a multi-year ensemble simulation, we have examined the influences of various meteorological regimes on the aerosol transport and wet removal.

  10. A study on the birth and globalization of sports originated from each continent

    PubMed Central

    Lee, Byung Jin; Kim, Tae Young

    2016-01-01

    The purpose of this research is to see how continent specific sports rose to its modern-day status through globalization. This research focuses on the historical background of how England’s football, America’s national pastime, baseball, Japan’s Judo, and Korea’s Taekwondo developed into sports in addition to the reasoning behind its globalization. Promoted by England and the rest of the European continent, Soccer is considered to be one of the world’s most popular sports and has served its function as a form of cultural imperialism. It has also advanced alongside commerce, missionary work and other types of cultural clashes. In America, baseball was used to integrate its multicultural society and developed so that the team captain leads the rest of his team. The sports of Oriental countries were reborn through modernization that was influenced by the modern rationality, education etc. of its Western counterparts. Judo and Taekwondo were introduced globally through the Olympic Games. As mentioned above the birth of sporting events has a close connection to a nation’s cultural background and globalization has taken different forms depending on which continent it originated from. PMID:26933653

  11. Longitudinal Study of Intestinal Symptoms and Fecal Continence in Patients With Conformal Radiotherapy for Prostate Cancer

    SciTech Connect

    Geinitz, Hans; Thamm, Reinhard; Keller, Monika; Astner, Sabrina T.; Heinrich, Christine; Scholz, Christian; Pehl, Christian; Kerndl, Simone; Prause, Nina; Busch, Raymonde; Molls, Michael; Zimmermann, Frank B.

    2011-04-01

    Purpose: To prospectively assess the intestinal symptoms and fecal continence in patients who had undergone conformal radiotherapy (CRT) for prostate cancer. Methods and Materials: A total of 78 men who had undergone definitive CRT for prostate cancer were evaluated. The patients were assessed before, during (treatment Weeks 4 and 6), and 2, 12, and 24 months after CRT completion. The intestinal symptoms and fecal continence were evaluated with comprehensive standardized questionnaires. Results: The intestinal symptoms were mostly intermittent, with only a small minority of patients affected daily. Defecation pain, fecal urge, and rectal mucous discharge increased significantly during therapy. Defecation pain and rectal mucous discharge had returned to baseline levels within 8 weeks and 1 year after CRT, respectively. However, fecal urge remained significantly elevated for {<=}1 year and then returned toward the pretreatment values. The prevalence of rectal bleeding was significantly elevated 2 years after CRT. Fecal continence deteriorated during CRT and remained impaired at 1 year after treatment. Incontinence was mostly minor, occurring less than once per week and predominantly affecting incontinence for gas. Conclusion: Intestinal symptoms and fecal incontinence increased during prostate CRT. Except for rectal bleeding, the intestinal symptoms, including fecal incontinence, returned to baseline levels within 1-2 years after CRT. Thus, the rate of long-term late radiation-related intestinal toxicity was low.

  12. Integrated Mid-Continent Carbon Capture, Sequestration & Enhanced Oil Recovery Project

    SciTech Connect

    Brian McPherson

    2010-08-31

    A consortium of research partners led by the Southwest Regional Partnership on Carbon Sequestration and industry partners, including CAP CO2 LLC, Blue Source LLC, Coffeyville Resources, Nitrogen Fertilizers LLC, Ash Grove Cement Company, Kansas Ethanol LLC, Headwaters Clean Carbon Services, Black & Veatch, and Schlumberger Carbon Services, conducted a feasibility study of a large-scale CCS commercialization project that included large-scale CO{sub 2} sources. The overall objective of this project, entitled the 'Integrated Mid-Continent Carbon Capture, Sequestration and Enhanced Oil Recovery Project' was to design an integrated system of US mid-continent industrial CO{sub 2} sources with CO{sub 2} capture, and geologic sequestration in deep saline formations and in oil field reservoirs with concomitant EOR. Findings of this project suggest that deep saline sequestration in the mid-continent region is not feasible without major financial incentives, such as tax credits or otherwise, that do not exist at this time. However, results of the analysis suggest that enhanced oil recovery with carbon sequestration is indeed feasible and practical for specific types of geologic settings in the Midwestern U.S.

  13. A study on the birth and globalization of sports originated from each continent.

    PubMed

    Lee, Byung Jin; Kim, Tae Young

    2016-02-01

    The purpose of this research is to see how continent specific sports rose to its modern-day status through globalization. This research focuses on the historical background of how England's football, America's national pastime, baseball, Japan's Judo, and Korea's Taekwondo developed into sports in addition to the reasoning behind its globalization. Promoted by England and the rest of the European continent, Soccer is considered to be one of the world's most popular sports and has served its function as a form of cultural imperialism. It has also advanced alongside commerce, missionary work and other types of cultural clashes. In America, baseball was used to integrate its multicultural society and developed so that the team captain leads the rest of his team. The sports of Oriental countries were reborn through modernization that was influenced by the modern rationality, education etc. of its Western counterparts. Judo and Taekwondo were introduced globally through the Olympic Games. As mentioned above the birth of sporting events has a close connection to a nation's cultural background and globalization has taken different forms depending on which continent it originated from.

  14. Hypothesis That Urethral Bulb (Corpus Spongiosum) Plays an Active Role in Male Urinary Continence

    PubMed Central

    Rehder, Peter; Staudacher, Nina M.; Schachtner, Joerg; Berger, Maria E.; Schillfahrt, Florian; Hauser, Verena; Mueller, Raphael; Skradski, Viktor; Horninger, Wolfgang; Glodny, Bernhard

    2016-01-01

    The proximal urethral bulb in men is enlarged, surrounds the bulbous urethra, and extends dorsally towards the perineum. During intercourse engorgement takes place due to increased blood flow through the corpus spongiosum. Antegrade ejaculation is facilitated by contraction of the bulbospongiosus muscles during climax. Micturition during sexual stimulation is functionally inhibited. Supporting the bulb may indirectly facilitate continence in a certain subset of patients with postprostatectomy incontinence. During physical activity with increased abdominal pressure, reflex contraction of the pelvic floor muscles as well as the bulbospongiosus muscles occurs to support sphincter function and limit urinary incontinence. Operations to the prostate may weaken urinary sphincter function. It is hypothesized that the distal urinary sphincter may be supported indirectly by placing a hammock underneath the urethral bulb. During moments of physical stress the “cushion” of blood within the supported corpus spongiosum helps to increase the zone of coaptation within the sphincteric (membranous) urethra. This may lead to urinary continence in patients treated by a transobturator repositioning sling in patients with postprostatectomy incontinence. This paper describes the possible role of the urethral bulb in male urinary continence, including its function after retroluminal sling placement (AdVance, AdVance XP® Male Sling System, Minnetonka, USA). PMID:27022393

  15. A study on the birth and globalization of sports originated from each continent.

    PubMed

    Lee, Byung Jin; Kim, Tae Young

    2016-02-01

    The purpose of this research is to see how continent specific sports rose to its modern-day status through globalization. This research focuses on the historical background of how England's football, America's national pastime, baseball, Japan's Judo, and Korea's Taekwondo developed into sports in addition to the reasoning behind its globalization. Promoted by England and the rest of the European continent, Soccer is considered to be one of the world's most popular sports and has served its function as a form of cultural imperialism. It has also advanced alongside commerce, missionary work and other types of cultural clashes. In America, baseball was used to integrate its multicultural society and developed so that the team captain leads the rest of his team. The sports of Oriental countries were reborn through modernization that was influenced by the modern rationality, education etc. of its Western counterparts. Judo and Taekwondo were introduced globally through the Olympic Games. As mentioned above the birth of sporting events has a close connection to a nation's cultural background and globalization has taken different forms depending on which continent it originated from. PMID:26933653

  16. Contrasting introduction scenarios among continents in the worldwide invasion of the banana fungal pathogen Mycosphaerella fijiensis.

    PubMed

    Robert, S; Ravigne, V; Zapater, M-F; Abadie, C; Carlier, J

    2012-03-01

    Reconstructing and characterizing introduction routes is a key step towards understanding the ecological and evolutionary factors underlying successful invasions and disease emergence. Here, we aimed to decipher scenarios of introduction and stochastic demographic events associated with the global spread of an emerging disease of bananas caused by the destructive fungal pathogen Mycosphaerella fijiensis. We analysed the worldwide population structure of this fungus using 21 microsatellites and 8 sequence-based markers on 735 individuals from 37 countries. Our analyses designated South-East Asia as the source of the global invasion and supported the location of the centre of origin of M. fijiensis within this area. We confirmed the occurrence of bottlenecks upon introduction into other continents followed by widespread founder events within continents. Furthermore, this study suggested contrasting introduction scenarios of the pathogen between the African and American continents. While potential signatures of admixture resulting from multiple introductions were detected in America, all the African samples examined seem to descend from a single successful founder event. In combination with historical information, our study reveals an original and unprecedented global scenario of invasion for this recently emerging disease caused by a wind-dispersed pathogen.

  17. Parallel Evolution of Copy-Number Variation across Continents in Drosophila melanogaster.

    PubMed

    Schrider, Daniel R; Hahn, Matthew W; Begun, David J

    2016-05-01

    Genetic differentiation across populations that is maintained in the presence of gene flow is a hallmark of spatially varying selection. In Drosophila melanogaster, the latitudinal clines across the eastern coasts of Australia and North America appear to be examples of this type of selection, with recent studies showing that a substantial portion of the D. melanogaster genome exhibits allele frequency differentiation with respect to latitude on both continents. As of yet there has been no genome-wide examination of differentiated copy-number variants (CNVs) in these geographic regions, despite their potential importance for phenotypic variation in Drosophila and other taxa. Here, we present an analysis of geographic variation in CNVs in D. melanogaster. We also present the first genomic analysis of geographic variation for copy-number variation in the sister species, D. simulans, in order to investigate patterns of parallel evolution in these close relatives. In D. melanogaster we find hundreds of CNVs, many of which show parallel patterns of geographic variation on both continents, lending support to the idea that they are influenced by spatially varying selection. These findings support the idea that polymorphic CNVs contribute to local adaptation in D. melanogaster In contrast, we find very few CNVs in D. simulans that are geographically differentiated in parallel on both continents, consistent with earlier work suggesting that clinal patterns are weaker in this species.

  18. MONTI as continent catheterized stoma using serosal-lined trough “Ghoneim Abolenin” technique in ileocystoplasty

    PubMed Central

    Sammour, Mohammed T.; Ajjaj, Abdulbari Bin

    2011-01-01

    It is a great challenge to select and perform continent mechanism in a stoma for urinary reservoir. A new technique by combining MONTI ileal conduit with the serosal lined trough in order to achieve continent catheterizable stoma to the umbilicus as a part of augmentation ileocystoplasty. We applied serosal-lined trough as a continent mechanism with MONTI ileal tube in 12 years smart girl underwent ileocystoplasty for neuropathic bladder due to meylomeningocele in whom continence failed to be achieved by using Mitrofanoff with submucosal tunnel of the bladder as continent mechanism before, also the previous operation included left to right transuretero-ureterostomy, ureterocystoplasty and reimplantation of the right ureter. The patient became completely continent; she was able to do self-catheterization easily through the umbilical stoma using 16-French catheter and was able to wash the mucous easily. The capacity of the augmented bladder was 300ccs. She became independent from her mother and stopped using diapers, anticholinergic and antibiotics. Combining MONTI conduit with serosal-lined extramural valve trough (The Ghoneim technique) is an effective continent technique and gives wider channel for catheterization and washing out the mucous. PMID:21346831

  19. Seismotectonic features of the African plate: the possible dislocation of a continent

    NASA Astrophysics Data System (ADS)

    Meghraoui, Mustapha

    2014-05-01

    The African continent is made of seismically active structures with active deformation in between main substratum shields considered as stable continental interiors. Seismically active regions are primarily located along rift zones, thrust and fold mountain belts, transform faults and volcanic fields. The active tectonic structures generated large and destructive earthquakes in the past with significant damage and economic losses in Africa. Although some regions of the continent show a low-level of seismic activity, several large earthquakes (with M > 7) have occurred in the past. The presence of major active faults that generate destructive earthquakes is among the most important geological and geophysical hazards for the continent. National and International scientific projects dealing with the seismic hazards assessment are increasing in seismically active regions in Africa. The UNESCO-SIDA/IGCP (Project 601 http://eost.u-strasbg.fr/~igcp601/) support the preparation and implementation of the "Seismotectonic Map of Africa". Therefore, new seismotectonic data with the regional analysis of earthquake hazards became necessary as a basis for a mitigation of the earthquake damage. A database in historical and instrumental seismicity, active tectonics, stress tensor distribution, earthquake geology and paleoseismology, active deformation, earthquake geodesy (GPS) and gravity, crustal structure studies, magnetic and structural segmentation, volcanic fields, collision tectonics and rifting processes is prepared to constrain the geodynamic evolution of the continent. Taking into account the geological, tectonic and geophysical characteristics, we define six seismotectonic provinces that characterize the crustal deformation. With the previously identified Somalia tectonic block, the seismotectonic and geophysical framework of the continent reveal the existence of the Cameroon volcanic line, the South African tectonic block with transform faulting and Cape folding system

  20. Effectiveness of continence promotion for older women via community organisations: a cluster randomised trial

    PubMed Central

    Tannenbaum, Cara; Agnew, Rona; Benedetti, Andrea; Thomas, Doneal; van den Heuvel, Eleanor

    2013-01-01

    Objectives The primary objective of this cluster randomised controlled trial was to compare the effectiveness of the three experimental continence promotion interventions against a control intervention on urinary symptom improvement in older women with untreated incontinence recruited from community organisations. A second objective was to determine whether changes in incontinence-related knowledge and new uptake of risk-modifying behaviours explain these improvements. Setting 71 community organisations across the UK. Participants 259 women aged 60 years and older with untreated incontinence entered the trial; 88% completed the 3-month follow-up. Interventions The three active interventions consisted of a single 60 min group workshop on (1) continence education (20 clusters, 64 women); (2) evidence-based self-management (17 clusters, 70 women); or (3) combined continence education and self-management (17 clusters, 61 women). The control intervention was a single 60 min educational group workshop on memory loss, polypharmacy and osteoporosis (17 clusters, 64 women). Primary and secondary outcome measures The primary outcome was self-reported improvement in incontinence 3 months postintervention at the level of the individual. The secondary outcome was change in the International Consultation on Incontinence Questionnaire (ICIQ) from baseline to 3-month follow-up. Changes in incontinence-related knowledge and behaviours were also assessed. Results The highest rate of urinary symptom improvement occurred in the combined intervention group (66% vs 11% of the control group, prevalence difference 55%, 95% CI 43% to 67%, intracluster correlation 0). 30% versus 6% of participants reported significant improvement respectively (prevalence difference 23%, 95% CI 10% to 36%, intracluster correlation 0). The number-needed-to-treat was 2 to achieve any improvement in incontinence symptoms, and 5 to attain significant improvement. Compared to controls, participants in the

  1. Mesohabitat-specific Macroinvertebrate Assemblage Responses to Water Quality Variation in Mid-continent (North America) Great Rivers

    EPA Science Inventory

    We compared the responsiveness of macroinvertebrate assemblages to water quality stressors (ions, nutrients, dissolved metals and suspended sediment) in two mesohabitats within the main-channel macrohabitat of three mid-continent North American rivers, the Upper Mississippi, Miss...

  2. Refertilization-driven destabilization of subcontinental mantle and the importance of initial lithospheric thickness for the fate of continents

    NASA Astrophysics Data System (ADS)

    Zheng, J. P.; Lee, C.-T. A.; Lu, J. G.; Zhao, J. H.; Wu, Y. B.; Xia, B.; Li, X. Y.; Zhang, J. F.; Liu, Y. S.

    2015-01-01

    Continents are underlain by thick, cold thermal boundary layers. Thermal contraction should render these boundary layers negatively buoyant and unstable; this is why old, cold oceanic lithospheres subduct. However, the ancient lithospheric roots of many continents appear to have existed for billions of years. In the common view, this preservation is due to the fact that the thermal boundary layers are compositionally distinct from the ambient mantle in that they are highly melt-depleted and dehydrated; the former provides positive buoyancy and the latter provides strength. Here, we show using mantle xenoliths that the Precambrian South China Block originally was underlain by highly depleted mantle, but has been refertilized via silicate melts generated from the asthenosphere. It is now more fertile than the ambient convecting mantle and is intrinsically denser by more than 1.5%. Achieving sufficient melt generation for refertilization is only possible if the lithosphere is thin enough to provide "headspace" for decompression melting. Thus, continental boundary layers thinner than the maximum depth of melting should experience refertilization, whereas thicker continents would altogether suppress melting and hence the potential for refertilization. We propose that refertilization, once initiated, will destabilize the base of the continent; this in turn will increase the amount of "headspace" and promote further refertilization, resulting in a positive feedback that could culminate in lithospheric destruction. By contrast, continents that are thick enough may not experience significant refertilization. This suggests that initial lithospheric thickness, as well as lithospheric composition, may be important for defining the fate of continents.

  3. The progression of the boreal winter monsoon through the western Maritime Continent as differentiated by ENSO phase

    NASA Astrophysics Data System (ADS)

    Lee, Shao-Yi; McBride, John L.

    2016-08-01

    The impact of global ENSO on the regional monsoon onset over the Maritime Continent is examined, using satellite-derived scatterometer surface winds over the sea channel from the South China Sea, through the Karimata Strait into the Java Sea. An index of monsoon onset, fracsign, is defined based on a positive dot-product between the monthly wind at each gridpoint and the "basis-wind" or climatological wind at the peak of the relevant monsoon season.Rather than being delayed throughout the Maritime Continent during El Niño years, the monsoon is seen to arrive faster at and remain longer over the western Maritime Continent, and therefore delayed for the eastern Maritime Continent. The wind-based diagnostic can be further decomposed into two components that reflect the monsoon wind strength and the location of the wind convergence zone, respectively. During El Niño years, the monsoon strength post-onset is weaker than normal over the eastern maritime continent. However, there is no ENSO-related differentiation in monsoon strength post-onset over the western Maritime Continent.

  4. Regional climate projection of the Maritime Continent using the MIT Regional Climate Model

    NASA Astrophysics Data System (ADS)

    IM, E. S.; Eltahir, E. A. B.

    2014-12-01

    Given that warming of the climate system is unequivocal (IPCC AR5), accurate assessment of future climate is essential to understand the impact of climate change due to global warming. Modelling the climate change of the Maritime Continent is particularly challenge, showing a high degree of uncertainty. Compared to other regions, model agreement of future projections in response to anthropogenic emission forcings is much less. Furthermore, the spatial and temporal behaviors of climate projections seem to vary significantly due to a complex geographical condition and a wide range of scale interactions. For the fine-scale climate information (27 km) suitable for representing the complexity of climate change over the Maritime Continent, dynamical downscaling is performed using the MIT regional climate model (MRCM) during two thirty-year period for reference (1970-1999) and future (2070-2099) climate. Initial and boundary conditions are provided by Community Earth System Model (CESM) simulations under the emission scenarios projected by MIT Integrated Global System Model (IGSM). Changes in mean climate as well as the frequency and intensity of extreme climate events are investigated at various temporal and spatial scales. Our analysis is primarily centered on the different behavior of changes in convective and large-scale precipitation over land vs. ocean during dry vs. wet season. In addition, we attempt to find the added value to downscaled results over the Maritime Continent through the comparison between MRCM and CESM projection. Acknowledgements.This research was supported by the National Research Foundation Singapore through the Singapore MIT Alliance for Research and Technology's Center for Environmental Sensing and Modeling interdisciplinary research program.

  5. The Emerging Legacy of USArray: New Views of the Architecture of the North American Continent

    NASA Astrophysics Data System (ADS)

    Ritzwoller, M. H.

    2013-12-01

    In the decade that preceded the new millennium, seismologists on several continents dared to think big: envisioning, designing, and then building seismic arrays of unprecedented quality, resolution, and scale. In the US, their vision became USArray: thousands of broadband seismometers spanning the continent, professionally deployed, superbly maintained, with data ready in realtime quite literally at one's fingertips. For many young (and not so young) seismologists the building of USArray, particularly the Transportable Array, marks the crucial event of their scientific careers. An important part of the legacy of USArray will be an improved understanding of the architecture of the North American continent - one of its seminal motivations. A more dimly perceived motivation, but perhaps more important aspect of its legacy, will be its impact on the discipline of seismology. The impacts are profound and broad, but I will speak only about one small area: the transformation of array-based surface wave seismology. Innovations stimulated by USArray include the creation of ambient noise tomography, the reformulation of the tomographic inverse problem in terms of local differential filters applied to observed travel time and amplitude fields, the extrication of subtle signals that reveal robust and independent information about anisotropy in the crust and mantle, and the joint interpretation with other kinds of geophysical data. Interpreting the results of these innovations in a Bayesian framework helps to define another legacy of USArray, the replacement of single models with statistical distributions of model variables that can be assimilated by researchers in other fields or by seismologists in the future. As we transition to considering the scientific legacy of USArray, it is important to remember Beno Gutenberg's faith in the power of data to resolve scientific dispute. As he stated in the next to last sentence of his remarkable book Physics of the Earth's Interior

  6. Methane over the North American Continent - INTEX-NA, Summer 2004

    NASA Astrophysics Data System (ADS)

    Karen, B.; Blake, D.; Meinardi, S.; Blake, N.; Sachse, G.; Slate, T.

    2005-12-01

    During July and August of 2004, the INTEX-NA mission was flown over the North American continent as a part of the integrated ICARTT campaign. Its primary focus was to examine the intercontinental transport and transformation of chemically and radiatively important trace gases and aerosols across the region. As a part of the mission, methane (CH4) was sampled using both canisters and a fast response tunable diode laser, the DACOM instrument. Agreement between the two techniques was excellent. Sources of methane are both natural (wetlands, wildfires) and anthropogenically controlled (landfills, ruminants, petroleum production and use, coal mining). Although natural biogenic emissions would be expected to be near seasonal maximums, the majority of North American wetlands are located in Canada and Alaska, and were difficult to isolate during the mission. Overall distributions were well correlated with C2Cl4, a tracer of industrial and urban activity, and reflect the widespread impact of anthropogenic emissions. As expected for a gas with surface continental sources, variability was greatest in the near-surface atmosphere and decreased with increasing altitude and distance from the continent. Summer convective activity over the region resulted in elevated concentrations measured at altitudes above 6 km. Enhanced levels with distinctive trace gas signatures were observed for a variety of sources, including petroleum mining and distribution, coal mining, Canadian wildfires, and aged Asian plumes advected across the Pacific. Several flights during the mission were flown along the U.S. east coast to sample air masses transported off the continent to the Atlantic. In the near-surface over the ocean, clean boundary layer air with mixing ratios comparable to background CMDL levels at this time were encountered. At altitudes above about 4 km, CH4 was enhanced by roughly 20-50 ppb.

  7. The Feedback Between Continents and Compositional Anomalies in the Deep Mantle

    NASA Astrophysics Data System (ADS)

    Lowman, J. P.; Trim, S. J.

    2014-12-01

    Findings from global seismic tomography studies suggest that the deep mantle may harbor a pair of broad, steep-sided, relatively dense compositionally anomalous provinces. The longevity and stability of these Large Low Shear-Wave Velocity Provinces (LLSVPs) has received considerable interest but their possible influence on surface motion has drawn lesser attention. Recent work using numerical mantle convection models investigated the feedback between oceanic plate motion and high density compositional anomalies. It was found that surface mobility is affected by the presence of compositional anomalies such that critical density contrasts and volumes of the enriched material produce a transition to stagnant-lid convection. For lesser volumes and density contrast (for example, volumes that are representative of the concentrations in the Earth's mantle) the presence of the compositional anomalies affects mean plate velocity and size when compared to the characteristics of systems in which the enriched material is absent. In addition, numerous studies and lines of evidence in the geologic record suggest that the presence of the density anomalies plays a role in determining the location of mantle upwellings, which in turn influence surface dynamics. In this study, we present the results from a study implementing a two-dimensional mantle convection model featuring an anomalously dense component and distinct continental and oceanic lithosphere. The mass, momentum, and energy conservation equations are solved using a hybrid spectral-finite difference code. Compositional variations are tracked using Lagrangian tracer particles. Mobile tectonic plates are modeled using a force-balance method and plate boundary locations evolve in response to interior stresses, plate velocity, age and lithospheric chemistry (i.e., oceanic versus continental). We examine the influence of continents on compositional anomaly morphology and longevity and the influence of compositional anomalies on

  8. Continent-wide distribution in mycorrhizal fungi: implications for the biogeography of specialized orchids

    PubMed Central

    Davis, Belinda J.; Phillips, Ryan D.; Wright, Magali; Linde, Celeste C.; Dixon, Kingsley W.

    2015-01-01

    Background and Aims Although mycorrhizal associations are predominantly generalist, specialized mycorrhizal interactions have repeatedly evolved in Orchidaceae, suggesting a potential role in limiting the geographical range of orchid species. In particular, the Australian orchid flora is characterized by high mycorrhizal specialization and short-range endemism. This study investigates the mycorrhizae used by Pheladenia deformis, one of the few orchid species to occur across the Australian continent. Specifically, it examines whether P. deformis is widely distributed through using multiple fungi or a single widespread fungus, and if the fungi used by Australian orchids are widespread at the continental scale. Methods Mycorrhizal fungi were isolated from P. deformis populations in eastern and western Australia. Germination trials using seed from western Australian populations were conducted to test if these fungi supported germination, regardless of the region in which they occurred. A phylogenetic analysis was undertaken using isolates from P. deformis and other Australian orchids that use the genus Sebacina to test for the occurrence of operational taxonomic units (OTUs) in eastern and western Australia. Key Results With the exception of one isolate, all fungi used by P. deformis belonged to a single fungal OTU of Sebacina. Fungal isolates from eastern and western Australia supported germination of P. deformis. A phylogenetic analysis of Australian Sebacina revealed that all of the OTUs that had been well sampled occurred on both sides of the continent. Conclusions The use of a widespread fungal OTU in P. deformis enables a broad distribution despite high mycorrhizal specificity. The Sebacina OTUs that are used by a range of Australian orchids occur on both sides of the continent, demonstrating that the short-range endemism prevalent in the orchids is not driven by fungal species with narrow distributions. Alternatively, a combination of specific edaphic

  9. Moisture transport by Atlantic tropical cyclones onto the North American continent

    NASA Astrophysics Data System (ADS)

    Xu, Guangzhi; Osborn, Timothy J.; Matthews, Adrian J.

    2016-07-01

    Tropical Cyclones (TCs) are an important source of freshwater for the North American continent. Many studies have tried to estimate this contribution by identifying TC-induced precipitation events, but few have explicitly diagnosed the moisture fluxes across continental boundaries. We design a set of attribution schemes to isolate the column-integrated moisture fluxes that are directly associated with TCs and to quantify the flux onto the North American Continent due to TCs. Averaged over the 2004-2012 hurricane seasons and integrated over the western, southern and eastern coasts of North America, the seven schemes attribute 7-18 % (mean 14 % ) of total net onshore flux to Atlantic TCs. A reduced contribution of 10 % (range 9-11 % ) was found for the 1980-2003 period, though only two schemes could be applied to this earlier period. Over the whole 1980-2012 period, a further 8 % (range 6-9 % from two schemes) was attributed to East Pacific TCs, resulting in a total TC contribution of 19 % (range 17-22 % ) to the ocean-to-land moisture transport onto the North American continent between May and November. Analysis of the attribution uncertainties suggests that incorporating details of individual TC size and shape adds limited value to a fixed radius approach and TC positional errors in the ERA-Interim reanalysis do not affect the results significantly, but biases in peak wind speeds and TC sizes may lead to underestimates of moisture transport. The interannual variability does not appear to be strongly related to the El Niño-Southern Oscillation phenomenon.

  10. A satellite-based perspective of convective systems over the Maritime Continent

    NASA Astrophysics Data System (ADS)

    Rowe, A.; Houze, R.; Virts, K.; Zuluaga, M. D.

    2014-12-01

    Data from TRMM, the A-Train satellites, and the Worldwide Lightning Location Network (WWLLN) have been used to study extreme weather throughout low latitudes, from deep convection over the Himalayas to oceanic mesoscale systems associated with the MJO. This study presents a more in-depth examination of convection over the Maritime Continent (Indonesia and Malaysia). During November to February, this area is the rainiest regional climate on Earth, thus constituting one of the atmosphere's primary heat sources. On multiple temporal and spatial scales, it is a complex region with clouds and precipitation having both oceanic and orographic influence. The November-February season encompasses both the eastward propagation of the MJO through this region and rainfall associated with the Asian-Australian monsoon. More specifically, the precipitation in this region is strongly modulated by MJO phases, pulsations of the monsoon, and the powerful diurnal effects of the islands and ocean. Through a feature-based analysis of convective and stratiform components of storms, the evolution of precipitating clouds in this region will be described using data from the November-February time period over multiple years. This analysis leads to an increased understanding of the characteristics of convection associated with the intraseasonal and diurnal variability during these months over the Maritime Continent. Previous work using A-Train data noted the prevalence of smaller separated MCSs over the region during the locally active phase of the MJO, and WWLLN data have shown a peak in lightning density as convection becomes deeper and more numerous leading up to this active period. By applying the analysis of the TRMM data in addition to the A-Train and WWLLN datasets, the relative roles of convective and stratiform components of MCSs to the behavior of convection can be determined during the MJO and monsoonal maxima of rainfall over the Maritime Continent.

  11. Analysis of positron annihilation lifetime data by numerical laplace inversion with the program CONTIN

    NASA Astrophysics Data System (ADS)

    Gregory, Roger B.; Zhu, Yongkang

    1990-05-01

    The performance of the program CONTIN [Stephen W. Provencher, Comput. Phys. Commun. 27 (1982) 229], modified to solve Fredholm integral equations with convoluted kernels of the type that occur in the deconvolution and analysis of positron annihilation lifetime data, is investigated with computer-simulated test data. The method avoids direct determination of the instrument resolution function by employing the decay curve of a reference material with a well-known single lifetime. CONTIN employs a constrained, regularized least-squares analysis to calculate a continuous annihilation-rate probability density function (pdf) which is the most parsimonious solution that is consistent with the experimental data and prior knowledge. The performance of the algorithm for extracting positron annihilation lifetime information was evaluated by using several measures of the information content of the data described by Schrader and Usmar [in: Positron Annihilation Studies of Fluids, ed. S. Sharma (World Scientific, Singapore, 1988) p. 215]. The quality of the CONTIN reconstruction of the annihilation-rate pdf is strongly dependent on the information content of the data and is greatly improved as the total number of counts in the data set is increased. Nevertheless, the method provides excellent estimates of the intensities and mean lifetimes of peaks in the annihilation-rate pdf, even when the total counts in the data set are relatively low (10 5-10 6). The sensitivity of the algorithm to systematic errors in the data, including errors in the instrument resolution function, shifts in the positron of the zero-time channel of the sample and reference data and contamination of the reference decay by additional lifetime components was also evaluated. Errors in the FWHM of the instrument resolution function and shifts in the zero time channel as small as {1}/{10}to{1}/{5} of the channel width of the instrument generate additional spurious peaks in the annihilation-rate pdf and

  12. Scale interaction between the MJO and the diurnal cycle of precipitation over the Maritime Continent

    NASA Astrophysics Data System (ADS)

    Peatman, Simon; Matthews, Adrian; Stevens, David

    2013-04-01

    The Maritime Continent is a highly-populated region of many islands and shallow oceans, located in the oceanic warm pool, between the Indian and Pacific Oceans. A strong diurnal cycle of precipitation exists due to onshore breezes causing strong convergence of moist air - enhanced by topographic effects - over the land during the day time, peaking during afternoon-evening. The respective diurnal cycle over the ocean is far weaker and does not peak until early in the morning. On intra-seasonal time-scales the greatest source of variability in the tropics is the Madden-Julian Oscillation (MJO). The convectively active part of the MJO propagates slowly (~5 ms-1) eastward through the warm pool from the Indian Ocean to the western Pacific, followed by the convectively suppressed part. The complex topography of the Maritime Continent means the exact nature of the propagation through this region is unclear. Model simulations of the MJO are often poor over the region, leading to errors in latent heat release and, subsequently, global errors in medium-range weather prediction and climate simulation. Using 14 northern hemisphere winters of high-resolution satellite data it is shown that, over regions where the diurnal cycle is strong, more than 80% of the variance in precipitation during an MJO cycle is accounted for by changes in the amplitude of the diurnal cycle. A canonical view of the MJO is of smooth eastward progression of a large-scale precipitation envelope over the warm pool. However, by computing "MJO harmonics" it is shown that the leading edge of the precipitation envelope advances over the islands of the Maritime Continent approximately 6 days or 2000 km ahead of the main body. This behaviour can be accommodated within existing theories of MJO propagation. When the active convective MJO envelope is over the eastern Indian Ocean, frictional moisture convergence and topographic blocking in the easterlies of the equatorial Kelvin wave response supply moisture to

  13. Stability, continence and breathing: the role of fascia following pregnancy and delivery.

    PubMed

    Lee, D G; Lee, L J; McLaughlin, L

    2008-10-01

    Pregnancy-related pelvic girdle pain (PRPGP) has a prevalence of approximately 45% during pregnancy and 20-25% in the early postpartum period. Most women become pain free in the first 12 weeks after delivery, however, 5-7% do not. In a large postpartum study of prevalence for urinary incontinence (UI) [Wilson, P.D., Herbison, P., Glazener, C., McGee, M., MacArthur, C., 2002. Obstetric practice and urinary incontinence 5-7 years after delivery. ICS Proceedings of the Neurourology and Urodynamics, vol. 21(4), pp. 284-300] found that 45% of women experienced UI at 7 years postpartum and that 27% who were initially incontinent in the early postpartum period regained continence, while 31% who were continent became incontinent. It is apparent that for some women, something happens during pregnancy and delivery that impacts the function of the abdominal canister either immediately, or over time. Current evidence suggests that the muscles and fascia of the lumbopelvic region play a significant role in musculoskeletal function as well as continence and respiration. The combined prevalence of lumbopelvic pain, incontinence and breathing disorders is slowly being understood. It is also clear that synergistic function of all trunk muscles is required for loads to be transferred effectively through the lumbopelvic region during multiple tasks of varying load, predictability and perceived threat. Optimal strategies for transferring loads will balance control of movement while maintaining optimal joint axes, maintain sufficient intra-abdominal pressure without compromising the organs (preserve continence, prevent prolapse or herniation) and support efficient respiration. Non-optimal strategies for posture, movement and/or breathing create failed load transfer which can lead to pain, incontinence and/or breathing disorders. Individual or combined impairments in multiple systems including the articular, neural, myofascial and/or visceral can lead to non-optimal strategies during

  14. The integrated continence system: a manual therapy approach to the treatment of stress urinary incontinence.

    PubMed

    Grewar, Heather; McLean, Linda

    2008-10-01

    Stress urinary incontinence (SUI) constitutes a large-scale public health concern. The integrated continence system (ICS) developed by the authors is an evidence-based model that demonstrates how urinary incontinence is maintained through the interaction of three structural systems (intrinsic urethral closure, urethral support and lumbopelvic stability) and three modifiable factors (motor control, musculoskeletal and behavioural). The purpose of the ICS is first, to demonstrate the important role that manual physiotherapists can play in the treatment of SUI and second, to guide clinical practice decisions in order to improve clinical outcomes among women with SUI.

  15. The CONTIN algorithm and its application to determine the size distribution of microgel suspensions

    SciTech Connect

    Scotti, A.; Liu, W.; Hyatt, J. S.; Fernandez-Nieves, A.; Herman, E. S.; Lyon, L. A.; Choi, H. S.; Kim, J. W.; Gasser, U.

    2015-06-21

    We review a powerful regularization method, known as CONTIN, for obtaining the size distribution of colloidal suspensions from dynamic light scattering data. We show that together with the so-called L-curve criterion for selecting the optimal regularization parameter, the method correctly describes the average size and size distribution of microgel suspensions independently characterized using small-angle neutron scattering. In contrast, we find that when using the default regularization process, where the regularizer is selected via the “probability to reject” method, the results are not as satisfactory.

  16. The Promotion and Marketing of OxyContin: Commercial Triumph, Public Health Tragedy

    PubMed Central

    2009-01-01

    I focus on issues surrounding the promotion and marketing of controlled drugs and their regulatory oversight. Compared with noncontrolled drugs, controlled drugs, with their potential for abuse and diversion, pose different public health risks when they are overpromoted and highly prescribed. An in-depth analysis of the promotion and marketing of OxyContin illustrates some of the associated issues. Modifications of the promotion and marketing of controlled drugs by the pharmaceutical industry and an enhanced capacity of the Food and Drug Administration to regulate and monitor such promotion can have a positive impact on the public health. PMID:18799767

  17. Evaluating mid-Holocene precipitation over Australasia and the Maritime Continent in climate models

    NASA Astrophysics Data System (ADS)

    Ackerley, Duncan; Reeves, Jessica

    2015-04-01

    The Australasian INTIMATE (INTegration of Ice-core, Marine and Terrestrial records) initiative (INQUA project #0809) was undertaken to develop a consistent chronological assessment of the climate of the past 30000 years over Australia, New Zealand and the Maritime Continent. Work has continued as part of SHAPE initiative (INQUA project #1302), but there has currently been little use of this comprehensive resource for evaluating the available climate model data. Therefore, this work presents the initial assessment of model simulations of the mid-Holocene over the Australasian and Maritime Continents (taken from the Paleoclimate Modelling Intercomparison Project, PMIP) in relation to those available data. The mid-Holocene (6 ka) encompasses a period after sea level stabilisation (around 8-7.5 ka) and before the onset of strong ENSO-related variability (post 4 ka). There is some evidence of possibly drier conditions over northern Australia with increased coastal dune activity, along with slightly wetter conditions over Borneo and Papua New Guinea. Weakening of the Southern Hemisphere mid-latitude westerlies (relative to the early Holocene) is also likely to have occurred, as evidenced by drier conditions in Western Tasmania and Victoria. The modelled results from the mid-Holocene simulations indicate that conditions were approximately 1-6% drier over much of continental Australia than at present. There is also evidence of slightly wetter conditions (1-3%) over the northern tip of Australia and parts of Papua New Guinea and Borneo. The Southern Hemisphere westerlies in the mid-latitudes (around 50S) are also weaker by 1-2 m s-1 in the model simulations. There are also differences in the seasonal cycle of precipitation and circulation in these models in response to the changes in the orbital parameters in the mid-Holocene relative to present day. The precipitation in the early half of the monsoon season (October, November and December-OND) is typically 10% higher in the

  18. The CONTIN algorithm and its application to determine the size distribution of microgel suspensions.

    PubMed

    Scotti, A; Liu, W; Hyatt, J S; Herman, E S; Choi, H S; Kim, J W; Lyon, L A; Gasser, U; Fernandez-Nieves, A

    2015-06-21

    We review a powerful regularization method, known as CONTIN, for obtaining the size distribution of colloidal suspensions from dynamic light scattering data. We show that together with the so-called L-curve criterion for selecting the optimal regularization parameter, the method correctly describes the average size and size distribution of microgel suspensions independently characterized using small-angle neutron scattering. In contrast, we find that when using the default regularization process, where the regularizer is selected via the "probability to reject" method, the results are not as satisfactory.

  19. Strain-specific and pooled genome sequences for populations of Drosophila melanogaster from three continents.

    PubMed

    Bergman, Casey M; Haddrill, Penelope R

    2015-01-01

    To contribute to our general understanding of the evolutionary forces that shape variation in genome sequences in nature, we have sequenced genomes from 50 isofemale lines and six pooled samples from populations of Drosophila melanogaster on three continents. Analysis of raw and reference-mapped reads indicates the quality of these genomic sequence data is very high. Comparison of the predicted and experimentally-determined Wolbachia infection status of these samples suggests that strain or sample swaps are unlikely to have occurred in the generation of these data. Genome sequences are freely available in the European Nucleotide Archive under accession ERP009059. Isofemale lines can be obtained from the Drosophila Species Stock Center.

  20. Macroecology: The division of food and space among species on continents

    SciTech Connect

    Brown, J.H. ); Maurer, B.A. )

    1989-03-03

    Analyses of statistical distributions of body mass, population density, and size and shape of geographic range offer insights into the empirical patterns and causal mechanisms that characterize the allocation of food and space among the diverse species in continental biotas. These analyses also provide evidence of the processes that couple ecological phenomena that occur on disparate spatial and temporal scales - from the activities of individual organisms within local populations to the dynamics of continent-wide speciation, colonization, and extinction events. 26 refs., 6 figs.

  1. Evolution of female urinary continence after physical therapy and associated factors

    PubMed Central

    2014-01-01

    Background Urinary incontinence (UI) is defined as any involuntary loss of urine that can influence the quality of life, personal hygiene and social interaction. The types of UI that most affect women are stress urinary incontinence, urge incontinence and mixed urinary incontinence. There are several risk factors that result in specific treatments. We aimed to investigate the evolution of female urinary continence after physical therapy intervention and its associated factors. Method A retrospective cross-sectional study was conducted with 71 participants who were discharged from physiotherapy sector from August 2006 to April 2012 and met the inclusion criteria. Results Among the studied variables, the number of sessions and completion of home pelvic floor exercises showed a significant association. The urinary continence appeared in 43.7% of the cases, and factors, performance of home exercises, and number of sessions showed a significant association. Conclusion The number of sessions and completion of home pelvic floor exercises showed a significant relationship with each other. PMID:24839462

  2. Phylogeography of the Microcoleus vaginatus (Cyanobacteria) from Three Continents – A Spatial and Temporal Characterization

    PubMed Central

    Dvořák, Petr; Hašler, Petr; Poulíčková, Aloisie

    2012-01-01

    It has long been assumed that cyanobacteria have, as with other free-living microorganisms, a ubiquitous occurrence. Neither the geographical dispersal barriers nor allopatric speciation has been taken into account. We endeavoured to examine the spatial and temporal patterns of global distribution within populations of the cyanobacterium Microcoleus vaginatus, originated from three continents, and to evaluate the role of dispersal barriers in the evolution of free-living cyanobacteria. Complex phylogeographical approach was applied to assess the dispersal and evolutionary patterns in the cyanobacterium Microcoleus vaginatus (Oscillatoriales). We compared the 16S rRNA and 16S-23S ITS sequences of strains which had originated from three continents (North America, Europe, and Asia). The spatial distribution was investigated using a phylogenetic tree, network, as well as principal coordinate analysis (PCoA). A temporal characterization was inferred using molecular clocks, calibrated from fossil DNA. Data analysis revealed broad genetic diversity within M. vaginatus. Based on the phylogenetic tree, network, and PCoA analysis, the strains isolated in Europe were spatially separated from those which originated from Asia and North America. A chronogram showed a temporal limitation of dispersal barriers on the continental scale. Dispersal barriers and allopatric speciation had an important role in the evolution of M. vaginatus. However, these dispersal barriers did not have a permanent character; therefore, the genetic flow among populations on a continental scale was only temporarily present. Furthermore, M. vaginatus is a recently evolved species, which has been going through substantial evolutionary changes. PMID:22761955

  3. Attractiveness of reformulated OxyContin(R) tablets: assessing comparative preferences and tampering potential.

    PubMed

    Sellers, Edward M; Perrino, Peter J; Colucci, Salvatore V; Harris, Stephen C

    2013-09-01

    Reformulated OxyContin® (oxycodone HCl controlled-release or ORF) was developed as a tamper and abuse-deterrent product, to reduce the risk of product abuse, misuse and their consequences. This noninterventional single-session study asked participants who were medically-healthy recreational opioid users, aged 18 years and older, to consider how they would use commonly available supplies to tamper with placebo ORF and placebo original OxyContin (OC) tablets, and how they would assess the attractiveness of tampering and abusing ORF tablets, as compared with other opioid formulations. Participants provided information on past opioid use, and they assessed the properties of five nonhypothetical oxycodone products and two hypothetical oxycodone products. Participants provided feedback on tampering preferences, preferred tamper methods for each product, overall tampering potential and product preferences. We had 30 participants (27 males and 3 females; mean age 35 years, range 18-51) complete both the interview and tampering sessions. Participants judged OC as the most attractive, valuable, desirable and most likely to be tampered with, from among all opioid products studied. By contrast, they rated ORF as the least attractive, least valuable, least desirable, and least likely to be tampered with among all the nonhypothetical opioid products studied. These results suggested that recreational drug abusers view ORF tablets as tamper-deterrent products.

  4. American Exceptionalism: Population Trends and Flight Initiation Distances in Birds from Three Continents

    PubMed Central

    Møller, Anders Pape; Samia, Diogo S. M.; Weston, Mike A.; Guay, Patrick-Jean; Blumstein, Daniel T.

    2014-01-01

    Background All organisms may be affected by humans' increasing impact on Earth, but there are many potential drivers of population trends and the relative importance of each remains largely unknown. The causes of spatial patterns in population trends and their relationship with animal responses to human proximity are even less known. Methodology/Principal Finding We investigated the relationship between population trends of 193 species of bird in North America, Australia and Europe and flight initiation distance (FID); the distance at which birds take flight when approached by a human. While there is an expected negative relationship between population trend and FID in Australia and Europe, we found the inverse relationship for North American birds; thus FID cannot be used as a universal predictor of vulnerability of birds. However, the analysis of the joint explanatory ability of multiple drivers (farmland breeding habitat, pole-most breeding latitude, migratory habit, FID) effects on population status replicated previously reported strong effects of farmland breeding habitat (an effect apparently driven mostly by European birds), as well as strong effects of FID, body size, migratory habit and continent. Farmland birds are generally declining. Conclusions/Significance Flight initiation distance is related to population trends in a way that differs among continents opening new research possibilities concerning the causes of geographic differences in patterns of anti-predator behavior. PMID:25226165

  5. Tectonic evolution of Late Cenozoic arc-continent collision in Taiwan

    SciTech Connect

    Teng, L.S. )

    1990-06-01

    The island of Taiwan is an active orogen formed by the collision between the Luzon arc and the Asian continent. The kinematic progression of the arc-continent collision can be reconstructed by superimposing the restored paleopositions of Luzon arc upon the precollisional Asian continental margin. The geological history of the collision can be interpreted from the rock records of the mountain ranges of Taiwan. By incorporating geological information into plate kinematics, the collision can be attributed to the northwesterly impingement of the Luzon arc upon the continental margin in the last 12 million years. During the initial stage of the collision, some of the continental materials might have been metamorphosed in the deep subduction zone, but no distinct effects can be perceived in the sedimentary record. In the Mio-Pliocene time (about 5 Ma), the accretionary wedge grew large enough to become a sediment source for the Luzon forearc basin and to induce foreland subsidence on the continental margin. In the early late Pliocene (about 3 Ma), drastic collision caused rapid uplift of the collision orogen that shed voluminous orogenic sediments into the forearc and foreland basins. Continued collision progressively accreted the forearc and foreland basins to the collision orogen from north to south to the present configuration.

  6. Continent-wide survey reveals massive decline in African savannah elephants.

    PubMed

    Chase, Michael J; Schlossberg, Scott; Griffin, Curtice R; Bouché, Philippe J C; Djene, Sintayehu W; Elkan, Paul W; Ferreira, Sam; Grossman, Falk; Kohi, Edward Mtarima; Landen, Kelly; Omondi, Patrick; Peltier, Alexis; Selier, S A Jeanetta; Sutcliffe, Robert

    2016-01-01

    African elephants (Loxodonta africana) are imperiled by poaching and habitat loss. Despite global attention to the plight of elephants, their population sizes and trends are uncertain or unknown over much of Africa. To conserve this iconic species, conservationists need timely, accurate data on elephant populations. Here, we report the results of the Great Elephant Census (GEC), the first continent-wide, standardized survey of African savannah elephants. We also provide the first quantitative model of elephant population trends across Africa. We estimated a population of 352,271 savannah elephants on study sites in 18 countries, representing approximately 93% of all savannah elephants in those countries. Elephant populations in survey areas with historical data decreased by an estimated 144,000 from 2007 to 2014, and populations are currently shrinking by 8% per year continent-wide, primarily due to poaching. Though 84% of elephants occurred in protected areas, many protected areas had carcass ratios that indicated high levels of elephant mortality. Results of the GEC show the necessity of action to end the African elephants' downward trajectory by preventing poaching and protecting habitat. PMID:27635327

  7. [The 4-stage continence-micturition cycle. The presentation of a urodynamic, diagnostic and therapeutic abacus].

    PubMed

    Lardennois, B; Clément, T; Coulon, J M; Brandt, B

    1990-01-01

    The complexity of the mode of operation of the bladder and urinary sphincter has led to the development of a number of temporospatial physiologic models that divide the process of micturition into several stages in order to facilitate investigations. Ten years ago, the authors described a two-stage continence-micturition model intended to improve the accuracy of studies of urodynamic disorders and thus contribute to the development of more effective and more rational therapeutic solutions. A large number of diseases can affect the distal urinary tract and recent advances in neurophysiology [10] have made the selection of the appropriate therapy extremely complex. Consequently, the authors have developed a decision analysis system that simultaneously confronts diseases, urodynamic manifestations, risks for the patient, and the main therapeutic approaches available. In 1985, they increased the number of stages in their continence-micturition model from two the four. This four-stage model has provided satisfactory result when used with an abacus for modeling observed biologic phenomena. In addition to offering simulation exercises for teaching purposes, this abacus provides the means for studying the instantaneous urodynamic situation (correspondences between cycle time points, symptoms, and effects of treatments) and determining the effect of various medicosocial events on the course of the bladder and sphincter dysfunction. The authors hope this abacus will be an attractive aide to the understanding of the complex function of the distal urinary tract.

  8. Continent-wide survey reveals massive decline in African savannah elephants.

    PubMed

    Chase, Michael J; Schlossberg, Scott; Griffin, Curtice R; Bouché, Philippe J C; Djene, Sintayehu W; Elkan, Paul W; Ferreira, Sam; Grossman, Falk; Kohi, Edward Mtarima; Landen, Kelly; Omondi, Patrick; Peltier, Alexis; Selier, S A Jeanetta; Sutcliffe, Robert

    2016-01-01

    African elephants (Loxodonta africana) are imperiled by poaching and habitat loss. Despite global attention to the plight of elephants, their population sizes and trends are uncertain or unknown over much of Africa. To conserve this iconic species, conservationists need timely, accurate data on elephant populations. Here, we report the results of the Great Elephant Census (GEC), the first continent-wide, standardized survey of African savannah elephants. We also provide the first quantitative model of elephant population trends across Africa. We estimated a population of 352,271 savannah elephants on study sites in 18 countries, representing approximately 93% of all savannah elephants in those countries. Elephant populations in survey areas with historical data decreased by an estimated 144,000 from 2007 to 2014, and populations are currently shrinking by 8% per year continent-wide, primarily due to poaching. Though 84% of elephants occurred in protected areas, many protected areas had carcass ratios that indicated high levels of elephant mortality. Results of the GEC show the necessity of action to end the African elephants' downward trajectory by preventing poaching and protecting habitat.

  9. Paleokarst and fracture overprints in Mid-Continent carbonates in evaluation of horizontal drilling potential

    SciTech Connect

    Fritz, R.D.; Shelton, J.W. ); Esteban, M. ); Wilson, J.L.

    1991-03-01

    The Mid-Continent region, especially in Oklahoma and Arkansas, contains thick Paleozoic carbonate sections that are dolomitic and karstic in character. These sections commonly exhibit strong structural overprints, including intense fracturing, due primarily to Pennsylvanian orogenies. Because of their rather wide association with source rocks, these carbonates are thought to represent good potential targets for horizontal drilling. The Cambro-Ordovician Arbuckle Group, the Ordovician Viola Group, the Siluro-Devonian Hunton Group, and the Mississippian Limestone all contain zones that are locally productive. These stratigraphic units are either uniformly tight or they are heterogeneous with complex porosity profiles. In karst terranes both types commonly occur together; both require fracturing to increase porosity and permeability. Both youthful and mature stages of paleokarst are observed in the Arbuckle Group; the best porosity is developed in the youthful stage. These stages can develop microporous, planar porous, or macroporous types of reservoir geometry. All of these may be heterogeneous in nature, requiring fractures to interconnect porous intervals. Horizontal drilling is yet to be proved as a reliable method for increasing production efficiency in Mid-Continent carbonates. An evaluation of diagenetic history, especially karst processes, along with local and regional structural settings, may provide a key for improved understanding of the horizontal drilling potential in these carbonates.

  10. Comparing determinants of alien bird impacts across two continents: implications for risk assessment and management.

    PubMed

    Evans, Thomas; Kumschick, Sabrina; Dyer, Ellie; Blackburn, Tim

    2014-07-01

    Invasive alien species can have serious adverse impacts on both the environment and the economy. Being able to predict the impacts of an alien species could assist in preventing or reducing these impacts. This study aimed to establish whether there are any life history traits consistently correlated with the impacts of alien birds across two continents, Europe and Australia, as a first step toward identifying life history traits that may have the potential to be adopted as predictors of alien bird impacts. A recently established impact scoring system was used in combination with a literature review to allocate impact scores to alien bird species with self-sustaining populations in Australia. These scores were then tested for correlation with a series of life history traits. The results were compared to data from a previous study in Europe, undertaken using the same methodology, in order to establish whether there are any life history traits consistently correlated with impact across both continents. Habitat generalism was the only life history trait found to be consistently correlated with impact in both Europe and Australia. This trait shows promise as a potential predictor of alien bird impacts. The results support the findings of previous studies in this field, and could be used to inform decisions regarding the prevention and management of future invasions. PMID:25165531

  11. Continent-wide survey reveals massive decline in African savannah elephants

    PubMed Central

    Schlossberg, Scott; Griffin, Curtice R.; Bouché, Philippe J.C.; Djene, Sintayehu W.; Elkan, Paul W.; Ferreira, Sam; Grossman, Falk; Kohi, Edward Mtarima; Landen, Kelly; Omondi, Patrick; Peltier, Alexis; Selier, S.A. Jeanetta; Sutcliffe, Robert

    2016-01-01

    African elephants (Loxodonta africana) are imperiled by poaching and habitat loss. Despite global attention to the plight of elephants, their population sizes and trends are uncertain or unknown over much of Africa. To conserve this iconic species, conservationists need timely, accurate data on elephant populations. Here, we report the results of the Great Elephant Census (GEC), the first continent-wide, standardized survey of African savannah elephants. We also provide the first quantitative model of elephant population trends across Africa. We estimated a population of 352,271 savannah elephants on study sites in 18 countries, representing approximately 93% of all savannah elephants in those countries. Elephant populations in survey areas with historical data decreased by an estimated 144,000 from 2007 to 2014, and populations are currently shrinking by 8% per year continent-wide, primarily due to poaching. Though 84% of elephants occurred in protected areas, many protected areas had carcass ratios that indicated high levels of elephant mortality. Results of the GEC show the necessity of action to end the African elephants’ downward trajectory by preventing poaching and protecting habitat.

  12. Convergence across a continent: adaptive diversification in a recent radiation of Australian lizards.

    PubMed

    Blom, Mozes P K; Horner, Paul; Moritz, Craig

    2016-06-15

    Recent radiations are important to evolutionary biologists, because they provide an opportunity to study the mechanisms that link micro- and macroevolution. The role of ecological speciation during adaptive radiation has been intensively studied, but radiations can arise from a diversity of evolutionary processes; in particular, on large continental landmasses where allopatric speciation might frequently precede ecological differentiation. It is therefore important to establish a phylogenetic and ecological framework for recent continental-scale radiations that are species-rich and ecologically diverse. Here, we use a genomic (approx. 1 200 loci, exon capture) approach to fit branch lengths on a summary-coalescent species tree and generate a time-calibrated phylogeny for a recent and ecologically diverse radiation of Australian scincid lizards; the genus Cryptoblepharus We then combine the phylogeny with a comprehensive phenotypic dataset for over 800 individuals across the 26 species, and use comparative methods to test whether habitat specialization can explain current patterns of phenotypic variation in ecologically relevant traits. We find significant differences in morphology between species that occur in distinct environments and convergence in ecomorphology with repeated habitat shifts across the continent. These results suggest that isolated analogous habitats have provided parallel ecological opportunity and have repeatedly promoted adaptive diversification. By contrast, speciation processes within the same habitat have resulted in distinct lineages with relatively limited morphological variation. Overall, our study illustrates how alternative diversification processes might have jointly stimulated species proliferation across the continent and generated a remarkably diverse group of Australian lizards. PMID:27306048

  13. Circumpolar oil-and-gas-bearing basins of the arctic part of the North American continent

    NASA Astrophysics Data System (ADS)

    Zabanbark, A.; Lobkovsky, L. I.

    2015-09-01

    Major geotectonic elements of the reviewed territory of the Arctic part of the North American continent are the Hyperborean Precambrian Platform, the Franklin folding belt, the northern part of the Precambrian Canadian platform, and the Mesozoic folding belt of Canada and Alaska. The rise of the Arctic slope of Alaska, the Beaufort Sea, and the Sverdrup basin are located in the southern margins of the Hyperborean Platform. The structure and peculiarities of development of these structural elements are genetically related to the evolution of this platform, as well as the current state of petroleum potential of the most promising exploration region of Arctic in the 21st century. The forced exploration of the Arctic regions of the United States and Canada has become an important milestone in the current development of the world energetics. Up to 100 oil, gas, and gas condensate fields have been discovered as a result of violent studies, and the potential oil and gas reserves in the Arctic part of the North American continent have been estimated to 30 billiion t and 50 trillion cubic meters, respectively. Many prospects are related to the continental slopes of all three above-mentioned basins; the total potential reserves of slopes are estimated as 10-12 billion t of oil and 20-25 trillion cubic meters of gas.

  14. Continent-wide survey reveals massive decline in African savannah elephants

    PubMed Central

    Schlossberg, Scott; Griffin, Curtice R.; Bouché, Philippe J.C.; Djene, Sintayehu W.; Elkan, Paul W.; Ferreira, Sam; Grossman, Falk; Kohi, Edward Mtarima; Landen, Kelly; Omondi, Patrick; Peltier, Alexis; Selier, S.A. Jeanetta; Sutcliffe, Robert

    2016-01-01

    African elephants (Loxodonta africana) are imperiled by poaching and habitat loss. Despite global attention to the plight of elephants, their population sizes and trends are uncertain or unknown over much of Africa. To conserve this iconic species, conservationists need timely, accurate data on elephant populations. Here, we report the results of the Great Elephant Census (GEC), the first continent-wide, standardized survey of African savannah elephants. We also provide the first quantitative model of elephant population trends across Africa. We estimated a population of 352,271 savannah elephants on study sites in 18 countries, representing approximately 93% of all savannah elephants in those countries. Elephant populations in survey areas with historical data decreased by an estimated 144,000 from 2007 to 2014, and populations are currently shrinking by 8% per year continent-wide, primarily due to poaching. Though 84% of elephants occurred in protected areas, many protected areas had carcass ratios that indicated high levels of elephant mortality. Results of the GEC show the necessity of action to end the African elephants’ downward trajectory by preventing poaching and protecting habitat. PMID:27635327

  15. Onset of oxidative weathering of continents recorded in the geochemistry of ancient glacial diamictites

    NASA Astrophysics Data System (ADS)

    Gaschnig, Richard M.; Rudnick, Roberta L.; McDonough, William F.; Kaufman, Alan J.; Hu, Zhaochu; Gao, Shan

    2014-12-01

    Glacial diamictites deposited in the Mesoarchean, Paleoproterozoic, Neoproterozoic, and Paleozoic eras record temporal variations in their average compositions that reflect the changing composition of the upper continental crust (UCC). Twenty six of the 27 units studied show elevated chemical index of alternation (CIA) and low Sr abundances, regardless of their age, documenting pervasive weathering of the average UCC. Lower abundances of transition metals reflect a shift towards more felsic crustal compositions after the Archean. Superimposed on this chemical difference is the signal of the rise of oxidative weathering of the continents, recorded by changes in the absolute and relative abundances of the redox sensitive elements Mo and V. Neoproterozoic and Paleozoic diamictites show pervasive depletion in Mo and V, reflecting their loss from the continents due to increasing intensity of oxidative weathering, as also recorded in some of the Paleoproterozoic diamictites. A few of the Paleoproterozoic diamictites deposited after the Great Oxidation Event show no depletion in Mo and V (e.g., Gowganda), but such signatures could be inherited from their provenance. In contrast, the pre-GOE Duitschland diamictite (ca. 2.3-2.5 Ga) from South Africa reveals evidence of intense oxidative weathering (i.e., large depletions in Mo), supporting a growing body of observations showing the presence of measurable atmospheric oxygen prior to permanent loss of the mass independent fractionation signal in sulfur isotopes.

  16. Comparing determinants of alien bird impacts across two continents: implications for risk assessment and management

    PubMed Central

    Evans, Thomas; Kumschick, Sabrina; Dyer, Ellie; Blackburn, Tim

    2014-01-01

    Invasive alien species can have serious adverse impacts on both the environment and the economy. Being able to predict the impacts of an alien species could assist in preventing or reducing these impacts. This study aimed to establish whether there are any life history traits consistently correlated with the impacts of alien birds across two continents, Europe and Australia, as a first step toward identifying life history traits that may have the potential to be adopted as predictors of alien bird impacts. A recently established impact scoring system was used in combination with a literature review to allocate impact scores to alien bird species with self-sustaining populations in Australia. These scores were then tested for correlation with a series of life history traits. The results were compared to data from a previous study in Europe, undertaken using the same methodology, in order to establish whether there are any life history traits consistently correlated with impact across both continents. Habitat generalism was the only life history trait found to be consistently correlated with impact in both Europe and Australia. This trait shows promise as a potential predictor of alien bird impacts. The results support the findings of previous studies in this field, and could be used to inform decisions regarding the prevention and management of future invasions. PMID:25165531

  17. Implications of the Projected Future Climate on Water Resources in the Indian Sub-continent Basins

    NASA Astrophysics Data System (ADS)

    Shah, H. L.; Mishra, V.

    2014-12-01

    Sustainability of water resources is vital for agricultural and socio-economic development in India. In the recent few decades, India has been witnessing erratic nature of the Indian summer monsoon, which accounts for about 80% of the total annual rainfall. While there is a large uncertainty in the precipitation projections during the summer monsoon from the regional and global climate models, we need to understand sensitivity of water resources in the Indian sub-continental river basins under the projected future climate. This is particularly important as the Indian sub-continent is one of the most populated regions of the world. We evaluated changes in water budget in the 18 Indian sub-continental basins under the projected future climate using the Variable Infiltration Capacity (VIC) model. The VIC model was calibrated and evaluated using the observed streamflow as well as satellite derived evapotranspiration and soil moisture. After the successful calibration and evaluation, we performed a sensitivity analysis for the water balance variables. Finally, we used downscaled and bias corrected climate forcings to develop scenarios of changes in water balance under the future climate. Despite the intermodal variation, Indian basins are projected to experience wetter and warmer climate in future. Results indicate positive changes in evapotranspiration and runoff under the projected future climate; however, increases in total runoff are projected to be significant in most of the basins in the sub-continent.

  18. Polychlorinated terphenyl patterns and levels in selected marine mammals and a river fish from different continents.

    PubMed

    Rosenfelder, Natalie; Vetter, Walter

    2014-01-01

    Polychlorinated terphenyls (PCTs) are a class of persistent organic pollutants which have been used from the 1920s to the 1980s for similar purposes as polychlorinated biphenyls (PCBs). Comparably little data was available on the PCT distribution in the environment mainly due to analytical difficulties in their determination. By means of a calculation algorithm recently developed we now studied the PCT pattern in individual marine mammal samples and one fish sample from different continents. Altogether, 97 PCTs were detected in eight samples and twelve to 66 tetra- to nonachloroterphenyl (tetra- to nonaCT) congeners were detected in individual samples. PCTs were present in all marine mammal samples which originated from four continents, but the PCT pattern was varied. TetraCTs were dominant in the sample from Africa, Australia, Spitsbergen (European Arctic) and in a sample from the Baltic Sea, heptaCTs in samples from the North Sea and octaCTs in a sample from Iceland. The abundance of sumPCTs relative to PCB 153, estimated from the GC/ECNI-MS response corrected for the degree of chlorination, ranged from 0.9 to 8.8%, corresponding with ~0.22-2.2% of the total PCB content. The highest PCT level detected was 980 mg/kg lipid in a harbour seal from the North Sea, Germany. The results from this study indicated that samples from certain areas, e.g. the North Sea may still be polluted with PCTs.

  19. Phylogeography of the Microcoleus vaginatus (Cyanobacteria) from three continents--a spatial and temporal characterization.

    PubMed

    Dvořák, Petr; Hašler, Petr; Poulíčková, Aloisie

    2012-01-01

    It has long been assumed that cyanobacteria have, as with other free-living microorganisms, a ubiquitous occurrence. Neither the geographical dispersal barriers nor allopatric speciation has been taken into account. We endeavoured to examine the spatial and temporal patterns of global distribution within populations of the cyanobacterium Microcoleus vaginatus, originated from three continents, and to evaluate the role of dispersal barriers in the evolution of free-living cyanobacteria. Complex phylogeographical approach was applied to assess the dispersal and evolutionary patterns in the cyanobacterium Microcoleus vaginatus (Oscillatoriales). We compared the 16S rRNA and 16S-23S ITS sequences of strains which had originated from three continents (North America, Europe, and Asia). The spatial distribution was investigated using a phylogenetic tree, network, as well as principal coordinate analysis (PCoA). A temporal characterization was inferred using molecular clocks, calibrated from fossil DNA. Data analysis revealed broad genetic diversity within M. vaginatus. Based on the phylogenetic tree, network, and PCoA analysis, the strains isolated in Europe were spatially separated from those which originated from Asia and North America. A chronogram showed a temporal limitation of dispersal barriers on the continental scale. Dispersal barriers and allopatric speciation had an important role in the evolution of M. vaginatus. However, these dispersal barriers did not have a permanent character; therefore, the genetic flow among populations on a continental scale was only temporarily present. Furthermore, M. vaginatus is a recently evolved species, which has been going through substantial evolutionary changes.

  20. Does structural complexity determine the morphology of assemblages? An experimental test on three continents.

    PubMed

    Gibb, Heloise; Parr, Catherine L

    2013-01-01

    Understanding how species will respond to global change depends on our ability to distinguish generalities from idiosyncrasies. For diverse, but poorly known taxa, such as insects, species traits may provide a short-cut to predicting species turnover. We tested whether ant traits respond consistently to habitat complexity across geographically independent ant assemblages, using an experimental approach and baits. We repeated our study in six paired simple and complex habitats on three continents with distinct ant faunas. We also compared traits amongst ants with different foraging strategies. We hypothesised that ants would be larger, broader, have longer legs and more dorsally positioned eyes in simpler habitats. In agreement with predictions, ants had longer femurs and dorsally positioned eyes in simple habitats. This pattern was most pronounced for ants that discovered resources. Body size and pronotum width responded as predicted for experimental treatments, but were inconsistent across continents. Monopolising ants were smaller, with shorter femurs than those that occupied or discovered resources. Consistent responses for several traits suggest that many, but not all, aspects of morphology respond predictably to habitat complexity, and that foraging strategy is linked with morphology. Some traits thus have the potential to be used to predict the direction of species turnover, changes in foraging strategy and, potentially, evolution in response to changes in habitat structure.

  1. Comparing determinants of alien bird impacts across two continents: implications for risk assessment and management.

    PubMed

    Evans, Thomas; Kumschick, Sabrina; Dyer, Ellie; Blackburn, Tim

    2014-07-01

    Invasive alien species can have serious adverse impacts on both the environment and the economy. Being able to predict the impacts of an alien species could assist in preventing or reducing these impacts. This study aimed to establish whether there are any life history traits consistently correlated with the impacts of alien birds across two continents, Europe and Australia, as a first step toward identifying life history traits that may have the potential to be adopted as predictors of alien bird impacts. A recently established impact scoring system was used in combination with a literature review to allocate impact scores to alien bird species with self-sustaining populations in Australia. These scores were then tested for correlation with a series of life history traits. The results were compared to data from a previous study in Europe, undertaken using the same methodology, in order to establish whether there are any life history traits consistently correlated with impact across both continents. Habitat generalism was the only life history trait found to be consistently correlated with impact in both Europe and Australia. This trait shows promise as a potential predictor of alien bird impacts. The results support the findings of previous studies in this field, and could be used to inform decisions regarding the prevention and management of future invasions.

  2. Organic geochemistry of Mid-Continent middle and Late Ordovician oils

    SciTech Connect

    Longman, M.W.; Palmer, S.E.

    1987-08-01

    Ordovician oils in Mohawkian and Cincinnatian reservoirs of the US Mid-Continent retain the biochemical imprint of Middle and Upper Ordovician oceanic life before the evolution of land plants and most vertebrates. Thus, these oils have some geochemical features that distinguish them from younger oils. These features include (1) a predominance of n-C/sub 15/, n-C/sub 17/, and n-C/sub 19/ alkanes in the saturated hydrocarbon fraction, (2) relatively low amounts of longer chain n-alkanes, (3) low amounts of chlorophyll-derived isoprenoids, such as pristane and phytane, and (4) abundant C/sub 29/ sterane relative to C/sub 27/ with rearranged forms (diasteranes) predominant over normal steranes. Ordovician oils also generally contain little sulfur and have a somewhat variable light stable carbon isotopic composition with delta/sup 13/C/sub sat/ and delta/sup 13/C/sub aro/ values of -28 to -31 per thousand (PDB), but these features are typical of many marine oils. The unusual chemistry of these Ordovician oils supports the interpretation of Reed, Illich, and Horsfield (1986) that prokaryotic organisms provided the organic matter for most Ordovician oils. Although their claim for Gloeocapsamorpha (a problematic unicellular prokaryote, possibly a blue-green alga or an unusually large bacterium) cannot be proven from oil chemistry alone, knowing that indigenous Mid-Continent Ordovician oils were derived from prokaryotic organisms may aid in future exploration for these reservoirs. 7 figures, 3 tables.

  3. Afriflu2--second international workshop on influenza vaccination in the African continent--8 November 2012, Cape Town (South Africa).

    PubMed

    Schoub, Barry D; Gessner, Bradford D; Ampofo, William; Cohen, Adam L; Steffen, Christoph A

    2013-08-01

    The second meeting of the Afriflu conferences took place in Cape Town, South Africa, with over 60 participants from 15 countries in Africa and also outside the continent. Significant progress in surveillance has been made in better understanding the illness burden of influenza on the continent, which limited evidence suggests is greater than that in the developed world. In southern Africa HIV and TB coinfections play a major role in increasing hospitalisation and mortality, while elsewhere in Africa other cofactors still need to be determined. There is currently no indigenous vaccine production in sub-Saharan Africa and only one facility, based in South Africa, capable of filling imported bulk. Innovative vaccine strategies will need to be explored, such as maternal immunisation, and also the possibility of other influenza vaccine options, such as live attenuated influenza vaccine for young children. Sustained indigenous vaccine production is essential for the continent to have vaccine security in the event of a pandemic even though establishing local production faces considerable challenges especially ensuring adequate markets on the continent. There is an urgent need to develop effective communication messages for decision makers as well as healthcare workers addressing the importance of influenza even in the face of the major competing health burdens of the continent.

  4. Evolutionary conservatism and convergence both lead to striking similarity in ecology, morphology and performance across continents in frogs.

    PubMed

    Moen, Daniel S; Irschick, Duncan J; Wiens, John J

    2013-12-22

    Many clades contain ecologically and phenotypically similar species across continents, yet the processes generating this similarity are largely unstudied, leaving fundamental questions unanswered. Is similarity in morphology and performance across assemblages caused by evolutionary convergence or by biogeographic dispersal of evolutionarily conserved ecotypes? Does convergence to new ecological conditions erase evidence of past adaptation? Here, we analyse ecology, morphology and performance in frog assemblages from three continents (Asia, Australia and South America), assessing the importance of dispersal and convergent evolution in explaining similarity across regions. We find three striking results. First, species using the same microhabitat type are highly similar in morphology and performance across both clades and continents. Second, some species on different continents owe their similarity to dispersal and evolutionary conservatism (rather than evolutionary convergence), even over vast temporal and spatial scales. Third, in one case, an ecologically specialized ancestor radiated into diverse ecotypes that have converged with those on other continents, largely erasing traces of past adaptation to their ancestral ecology. Overall, our study highlights the roles of both evolutionary conservatism and convergence in explaining similarity in species traits over large spatial and temporal scales and demonstrates a statistical framework for addressing these questions in other systems.

  5. Intermediate crust (IC); its construction at continent edges, distinctive epeirogenic behaviour and identification as sedimentary basins within continents: new light on pre-oceanic plate motions

    NASA Astrophysics Data System (ADS)

    Osmaston, Miles F.

    2014-05-01

    Introduction. The plate tectonics paradigm currently posits that the Earth has only two kinds of crust - continental and oceanic - and that the former may be stretched to form sedimentary basins or the latter may be modified by arc or collision until it looks continental. But global analysis of the dynamics of actual plate motions for the past 150 Ma indicates [1 - 3] that continental tectospheres must be immensely thicker and rheologically stiffer than previously thought; almost certainly too thick to be stretched with the forces available. In the extreme case of cratons, these tectospheric keels evidently extend to 600 km or more [2, 3]. This thick-plate behaviour is attributable, not to cooling but to a petrological 'stiffening' effect, associated with a loss of water-weakening of the mineral crystals, which also applies to the hitherto supposedly mobile LVZ below MORs [4, 5]. The corresponding thick-plate version of the mid-ocean ridge (MOR) process [6 - 8], replacing the divergent mantle flow model, has a deep, narrow wall-accreting axial crack which not only provides the seismic anisotropy beneath the flanks but also brings two outstanding additional benefits:- (i) why, at medium to fast spreading rates, MOR axes become straight and orthogonally segmented [6], (ii) not being driven by body forces, it can achieve the sudden jumps of axis, spreading-rate and direction widely present in the ocean-floor record. Furthermore, as we will illustrate, the crack walls push themselves apart at depth by a thermodynamic mechanism, so the plates are not being pulled apart. So the presence of this process at a continental edge would not imply the application of extensional force to the margin. Intermediate Crust (IC). In seeking to resolve the paradox that superficially extensional structures are often seen at margins we will first consider how this MOR process would be affected by the heavy concurrent sedimentation to be expected when splitting a mature continent. I reason

  6. Pandemic Vibrio parahaemolyticus O3:K6 on the American continent

    PubMed Central

    Velazquez-Roman, Jorge; León-Sicairos, Nidia; de Jesus Hernández-Díaz, Lucio; Canizalez-Roman, Adrian

    2014-01-01

    Vibrio parahaemolyticus is one of the most important seafood-borne bacterial in recent years and is the leading causal agent of human acute gastroenteritis, primarily following the consumption of raw, undercooked or mishandled marine products. Until 1996, infections caused by V. parahaemolyticus were generally associated with diverse serovars. However, in February 1996, a unique serovar (O3:K6) of V. parahaemolyticus with specific genetic markers (tdh, toxRS/New and/or orf8) appeared abruptly in Kolkata, India. In subsequent years, O3:K6 isolates similar to those isolated in Kolkata have been reported from food borne outbreaks in Southeast Asia, as well as in the Atlantic and Gulf coasts of the United States (U.S). More recently, there have been reports in Europe, Africa and Central and South America. Specifically, in the American continent, some countries have reported cases of gastroenteritis due to the pandemic O3:K6 strain and its serovariants; the pandemic strain was first detected in Peru (1996, >100 cases), subsequently spreading to Chile in 1998 (>16,804 human cases), to the U.S. in 1998 (>700 cases), to Brazil in 2001 (>18 cases) and to Mexico in 2004 (>1200 cases). The arrival of the pandemic clone on the American continent may have resulted in a significant shift on the epidemic dynamics of V. parahaemolyticus. However, although O3:K6 is the predominant serovar of the recognized clinical strains in some countries in the Americas, a decrease in clinical cases caused by O3:K6 and an increase in cases associated with a new serotype (O3:K59, Chile) have been recently reported. The emergence and worldwide dissemination of O3:K6 and other pandemic strains since 1996 have come to represent a threat to public health and should concern health authorities. This review focuses on the presence, distribution and virulence factors of the V. parahaemolyticus O3:K6 pandemic clone and its serovariants in clinical and environmental strains on the American continent. PMID

  7. Force Required to Breakup a Continent: Implications on Rifting Localization and Migration

    NASA Astrophysics Data System (ADS)

    Svartman Dias, A. E.; Lavier, L. L.; Hayman, N. W.

    2014-12-01

    The maximum force from ridge push available is about 5 TN/m, lower than that required by 2D and 3D numerical experiments to rift the lithosphere in the absence of magmatic input. We carry out 2D numerical experiments without any magmatic input to study the extensional force necessary to start a rift basin and to breakup a continent. We assume a range of initial temperature structure, crust and mantle initial thicknesses and composition. In a first step, we use velocity boundary conditions (1cm/yr) and we monitor the force necessary to breakup the continent. Results can be classified in two groups according to the amount of force needed to rift through time: (1) The initial force builds up rapidly to 12-20 TN/m within 0.4-1.0 Myr. This is followed by an exponential decrease due to early strain localization and lithospheric weakening. The force is < 5TN/m after 4.4-7.0 Myr of extension. Continental breakup occurs approximately 10 Myr after the onset of extension forming narrow conjugate margins. This group encompasses experiments with initial Tmoho < 650oC and crustal thicknesses ≤ 35 km, where crust and mantle deformation are coupled from the early stages of rifting. (2) The initial build-up is more discrete, from < 3 TN/m to 4-6.5 TN/m in the first 0.1 Myr, followed by a decrease to a nearly constant value of 3-5 TN/m from 0.4 Myr to 10 Myr, when strain starts localizing. The constant force through time reflects lithosphere strengthening and migration of the deformation. This rift migration forms a wide basin (> 250 km wide) that may evolve to form very asymmetric conjugate margins. Breakup occurs 18 Myr after the onset of rifting or later. This second group corresponds to experiments with initial Tmoho > 650 km and crustal thicknesses ≥ 35 km. High bending stresses result in upper crust brittle failure and on enhancement of lower crust lateral flow. Interaction between ductile failure in the lower crust and brittle failure in the upper crust controls the

  8. Consistent response of bird populations to climate change on two continents

    USGS Publications Warehouse

    Stephens, Philip A.; Mason, Lucy R.; Green, Rhys E.; Gregory, Richard D.; Sauer, John R.; Alison, Jamie; Aunins, Ainars; Brotons, Lluís; Butchart, Stuart H.M.; Campedelli, Tommaso; Chodkiewicz, Tomasz; Chylarecki, Przemyslaw; Crowe, Olivia; Elts, Jaanus; Escandell, Virginia; Foppen, Ruud P.B.; Heldbjerg, Henning; Herrando, Sergi; Husby, Magne; Jiguet, Frédéric; Lehikoinen, Aleksi; Lindström, Åke; Noble, David G.; Paquet, Jean-Yves; Reif, Jiri; Sattler, Thomas; Szép, Tibor; Teufelbauer, Norbert; Trautmann, Sven; Van Strien, Arco; van Turnhout, Chris A.M.; Vorisek, Petr; Willis, Stephen G.

    2016-01-01

    Global climate change is a major threat to biodiversity. Large-scale analyses have generally focused on the impacts of climate change on the geographic ranges of species and on phenology, the timing of ecological phenomena. We used long-term monitoring of the abundance of breeding birds across Europe and the United States to produce, for both regions, composite population indices for two groups of species: those for which climate suitability has been either improving or declining since 1980. The ratio of these composite indices, the climate impact indicator (CII), reflects the divergent fates of species favored or disadvantaged by climate change. The trend in CII is positive and similar in the two regions. On both continents, interspecific and spatial variation in population abundance trends are well predicted by climate suitability trends.

  9. Crustal volumes of the continents and of oceanic and continental submarine plateaus

    NASA Technical Reports Server (NTRS)

    Schubert, G.; Sandwell, D.

    1989-01-01

    Using global topographic data and the assumption of Airy isostasy, it is estimated that the crustal volume of the continents is 7182 X 10 to the 6th cu km. The crustal volumes of the oceanic and continental submarine plateaus are calculated at 369 X 10 to the 6th cu km and 242 X 10 to the 6th cu km, respectively. The total continental crustal volume is found to be 7581 X 10 to the 6th cu km, 3.2 percent of which is comprised of continental submarine plateaus on the seafloor. An upper bound on the contintental crust addition rate by the accretion of oceanic plateaus is set at 3.7 cu km/yr. Subduction of continental submarine plateaus with the oceanic lithosphere on a 100 Myr time scale yields an upper bound to the continental crustal subtraction rate of 2.4 cu km/yr.

  10. The lithosphere-asthenosphere transition and radial anisotropy beneath the Australian continent

    NASA Astrophysics Data System (ADS)

    Yoshizawa, K.; Kennett, B. L. N.

    2015-05-01

    A new 3-D S wave speed model for the Australian region derived from multimode surface waves allows us to examine the nature of the lithosphere-asthenosphere transition (LAT) and its relation to radial anisotropy. In eastern Phanerozoic Australia the estimated depths of the LAT tie well with those from receiver functions. However, in the Archean and Proterozoic lithosphere in western and central Australia, the LAT derived from the surface wave model is generally much deeper than the discontinuities recognized from receiver functions and shows a smooth transition. There is significant radial anisotropy (SH > SV) in the upper lithosphere as well as in the LAT and the underlying asthenosphere. Strong anisotropy in the asthenosphere reflects the effects of present shear flow in the mantle beneath the continent. The lateral variation of lithospheric anisotropy correlates well with the suture zones between cratonic blocks, representing frozen anisotropy associated with the ancient tectonics of Australia.

  11. Consistent response of bird populations to climate change on two continents.

    PubMed

    Stephens, Philip A; Mason, Lucy R; Green, Rhys E; Gregory, Richard D; Sauer, John R; Alison, Jamie; Aunins, Ainars; Brotons, Lluís; Butchart, Stuart H M; Campedelli, Tommaso; Chodkiewicz, Tomasz; Chylarecki, Przemysław; Crowe, Olivia; Elts, Jaanus; Escandell, Virginia; Foppen, Ruud P B; Heldbjerg, Henning; Herrando, Sergi; Husby, Magne; Jiguet, Frédéric; Lehikoinen, Aleksi; Lindström, Åke; Noble, David G; Paquet, Jean-Yves; Reif, Jiri; Sattler, Thomas; Szép, Tibor; Teufelbauer, Norbert; Trautmann, Sven; van Strien, Arco J; van Turnhout, Chris A M; Vorisek, Petr; Willis, Stephen G

    2016-04-01

    Global climate change is a major threat to biodiversity. Large-scale analyses have generally focused on the impacts of climate change on the geographic ranges of species and on phenology, the timing of ecological phenomena. We used long-term monitoring of the abundance of breeding birds across Europe and the United States to produce, for both regions, composite population indices for two groups of species: those for which climate suitability has been either improving or declining since 1980. The ratio of these composite indices, the climate impact indicator (CII), reflects the divergent fates of species favored or disadvantaged by climate change. The trend in CII is positive and similar in the two regions. On both continents, interspecific and spatial variation in population abundance trends are well predicted by climate suitability trends. PMID:27034371

  12. Global change research for protecting resources in the Crown of the continent Ecosystem

    SciTech Connect

    Fagre, D.B. )

    1993-06-01

    A multi-faceted, long-term research program has been initiated by the National Park Service to evaluate the potential effects of climatic changes on natural resources of parks. Glacier National Park is centrally located in a mountainous wilderness complex along the continental divide which was described early in the century as the [open quotes]Crown of the Continent[close quotes]. A central component of the program is a regional ecosystem simulation system. This system acts as an interface for a number of ecological models which collectively provide spatially explicit, mechanistically-derived predictions of microclimate, hydrological output, and forest biophysical processes within the park. Validation of the system is being carried out over the next 5 years with associated studies on glacier dynamics, stream hydrology, lake chemistry, forest landscape classification, remote sensing, and others.

  13. Major influences on buying decision processes by international university students. Differences by continent of origin.

    PubMed

    Tirelli, Christian; Pilar Martínez-Ruiz, María; Gómez-Ladrón-De-Guevara, Ricardo

    2013-12-01

    To analyze how food values and other variables related to dietary acculturation affect international university students' food buying decisions, this article provides an in-depth review of relevant literature related to the food buying decisions of groups of sojourners, which suggest several research hypotheses. The data collection targeted international university students in Spain and used factorial analysis of the main components together with linear parametric regressions. The resulting findings offer distinct insights, according to sojourners' continent of origin. Specifically, whereas European students exhibit a higher propensity to value sustainable production practices in the food choices, American students emphasize flavor and exhibit a greater degree of adaptation. These findings in turn suggest some key managerial recommendations and research guidelines for both private and public operators in related fields.

  14. A complex empirical orthogonal function for combining two different variables over Indonesian maritime continent

    NASA Astrophysics Data System (ADS)

    Nuryanto, Danang Eko

    2016-02-01

    The spatiotemporal patterns of Indonesian Maritime Continent (IMC) convective activity was documented by using two different variables i.e. cloud and wind datasets. In this study, a Complex Empirical Orthogonal Function (CEOF) was used to combining that variables. This method was applied to representing the land-sea-atmosphere interaction of diurnal convective activity in IMC. This study used pseudo-vector to define complex signals from convective index (cloud) as complex part and convergence (wind) as real part. The results showed that the phase patterns of CEOF were more consistent than those of pseudo-vector. Both CEOF1 and CEOF2 have shown semi-annual and annual cycles, respectively. Spatially, CEOF1 represents common patterns, whereas CEOF2 was more toward local patterns and tends to be in random.

  15. The changing role of mammal life histories in Late Quaternary extinction vulnerability on continents and islands.

    PubMed

    Lyons, S Kathleen; Miller, Joshua H; Fraser, Danielle; Smith, Felisa A; Boyer, Alison; Lindsey, Emily; Mychajliw, Alexis M

    2016-06-01

    Understanding extinction drivers in a human-dominated world is necessary to preserve biodiversity. We provide an overview of Quaternary extinctions and compare mammalian extinction events on continents and islands after human arrival in system-specific prehistoric and historic contexts. We highlight the role of body size and life-history traits in these extinctions. We find a significant size-bias except for extinctions on small islands in historic times. Using phylogenetic regression and classification trees, we find that while life-history traits are poor predictors of historic extinctions, those associated with difficulty in responding quickly to perturbations, such as small litter size, are good predictors of prehistoric extinctions. Our results are consistent with the idea that prehistoric and historic extinctions form a single continuing event with the same likely primary driver, humans, but the diversity of impacts and affected faunas is much greater in historic extinctions. PMID:27330176

  16. Multiple broadly synchronous km-scale exhumation episodes on different continents: implications for controlling processes

    NASA Astrophysics Data System (ADS)

    Green, Paul; Duddy, Ian; Japsen, Peter

    2015-04-01

    Numerous low temperature thermochronology studies have defined regional cooling episodes which imply removal of several km of section over areas of several 104 km2. The origin of such events has long been the subject of debate, while their reality has sometimes been questioned because of the lack of a viable mechanism. Kilometre-scale denudation at rifted margins has traditionally been interpreted as related to rifting and breakup, magnified by the flexural response to denudation of the uplifted rift flanks. But it is now clear that at many margins the post-breakup history is more complex, with km-scale uplift and erosion commonly post-dating breakup by 10s of Myr and often affecting regions many 100s of kilometres inland of the margins (Green et al., 2013; Brown et al., 2014). Numerous examples around the world of km-scale exhumation affecting regions distant from continental margins, including cratonic regions traditionally regarded as stable over Phanerozoic time (e.g. Ault et al., 2009; Flowers & Kelley, 2011), cannot be explained by margin-related mechanisms. It has also become clear that periods of exhumation are separated by episodes of burial, defining a series of positive and negative vertical movements. Previous studies have defined a broad synchroneity of Early, Middle and Late Cenozoic exhumation events in regions from Alaska to Greenland, Norway and Svalbard (Green and Duddy, 2010). New results from SE Australia define a series of exhumation episodes ranging in time from Carboniferous to Cenozoic which are broadly synchronous with similar events previously defined in Brazil and South Africa (Green et al. 2013). While estimates of the timing of exhumation in different areas are subject to some uncertainty, data across three southern hemisphere continents show a broad synchronicity in similar fashion to the northern hemisphere examples cited above. Dynamic topography has been invoked as a possible mechanism for producing uplift, the effects of which

  17. Consistent response of bird populations to climate change on two continents.

    PubMed

    Stephens, Philip A; Mason, Lucy R; Green, Rhys E; Gregory, Richard D; Sauer, John R; Alison, Jamie; Aunins, Ainars; Brotons, Lluís; Butchart, Stuart H M; Campedelli, Tommaso; Chodkiewicz, Tomasz; Chylarecki, Przemysław; Crowe, Olivia; Elts, Jaanus; Escandell, Virginia; Foppen, Ruud P B; Heldbjerg, Henning; Herrando, Sergi; Husby, Magne; Jiguet, Frédéric; Lehikoinen, Aleksi; Lindström, Åke; Noble, David G; Paquet, Jean-Yves; Reif, Jiri; Sattler, Thomas; Szép, Tibor; Teufelbauer, Norbert; Trautmann, Sven; van Strien, Arco J; van Turnhout, Chris A M; Vorisek, Petr; Willis, Stephen G

    2016-04-01

    Global climate change is a major threat to biodiversity. Large-scale analyses have generally focused on the impacts of climate change on the geographic ranges of species and on phenology, the timing of ecological phenomena. We used long-term monitoring of the abundance of breeding birds across Europe and the United States to produce, for both regions, composite population indices for two groups of species: those for which climate suitability has been either improving or declining since 1980. The ratio of these composite indices, the climate impact indicator (CII), reflects the divergent fates of species favored or disadvantaged by climate change. The trend in CII is positive and similar in the two regions. On both continents, interspecific and spatial variation in population abundance trends are well predicted by climate suitability trends.

  18. The changing role of mammal life histories in Late Quaternary extinction vulnerability on continents and islands.

    PubMed

    Lyons, S Kathleen; Miller, Joshua H; Fraser, Danielle; Smith, Felisa A; Boyer, Alison; Lindsey, Emily; Mychajliw, Alexis M

    2016-06-01

    Understanding extinction drivers in a human-dominated world is necessary to preserve biodiversity. We provide an overview of Quaternary extinctions and compare mammalian extinction events on continents and islands after human arrival in system-specific prehistoric and historic contexts. We highlight the role of body size and life-history traits in these extinctions. We find a significant size-bias except for extinctions on small islands in historic times. Using phylogenetic regression and classification trees, we find that while life-history traits are poor predictors of historic extinctions, those associated with difficulty in responding quickly to perturbations, such as small litter size, are good predictors of prehistoric extinctions. Our results are consistent with the idea that prehistoric and historic extinctions form a single continuing event with the same likely primary driver, humans, but the diversity of impacts and affected faunas is much greater in historic extinctions.

  19. The peopling of the African continent and the diaspora into the new world

    PubMed Central

    Campbell, Michael C; Hirbo, Jibril B; Townsend, Jeffrey P; Tishkoff, Sarah A

    2014-01-01

    Africa is the birthplace of anatomically modern humans, and is the geographic origin of human migration across the globe within the last 100,000 years. The history of African populations has consisted of a number of demographic events that have influenced patterns of genetic and phenotypic variation across the continent. With the increasing amount of genomic data and corresponding developments in computational methods, researchers are able to explore long-standing evolutionary questions, expanding our understanding of human history within and outside of Africa. This review will summarize some of the recent findings regarding African demographic history, including the African Diaspora, and will briefly explore their implications for disease susceptibility in populations of African descent. PMID:25461616

  20. [Hypotheses on the origin of certain parasites on the Latin American continent].

    PubMed

    Nozais, J P

    1985-01-01

    The South American continent has been connected to Africa over millions of centuries. In prehistorical time, the filling of the Bering strait allowed passage on firm ground between Asia and North America. South American peopling has thus occurred from North America, through the Pacific sea and, from the 15th century A.C., through the Atlantic. Necator americanus was present in South America prior to the arrival of black slaves and its African origin is probably related to contacts between Africa and South America; the same applies to Leishmania donovani and Biom-Phalaria glabrata. Ankylostoma duodenale originates from Asia as well as Plasmodium falciparum which was brought by man at time of his migration. To the contrary, muco-cutaneous Leishmaniasis stem (or have a South American origin) from South America. Finally, it is difficult to understand for which reasons Loa loa has not established itself in South America as did Schistosoma mansoni. PMID:3928184

  1. Hierarchical Genetic Analysis of German Cockroach (Blattella germanica) Populations from within Buildings to across Continents

    PubMed Central

    Vargo, Edward L.; Crissman, Jonathan R.; Booth, Warren; Santangelo, Richard G.; Mukha, Dmitry V.; Schal, Coby

    2014-01-01

    Understanding the population structure of species that disperse primarily by human transport is essential to predicting and controlling human-mediated spread of invasive species. The German cockroach (Blattella germanica) is a widespread urban invader that can actively disperse within buildings but is spread solely by human-mediated dispersal over longer distances; however, its population structure is poorly understood. Using microsatellite markers we investigated population structure at several spatial scales, from populations within single apartment buildings to populations from several cities across the U.S. and Eurasia. Both traditional measures of genetic differentiation and Bayesian clustering methods revealed increasing levels of genetic differentiation at greater geographic scales. Our results are consistent with active dispersal of cockroaches largely limited to movement within a building. Their low levels of genetic differentiation, yet limited active spread between buildings, suggests a greater likelihood of human-mediated dispersal at more local scales (within a city) than at larger spatial scales (within and between continents). About half the populations from across the U.S. clustered together with other U.S. populations, and isolation by distance was evident across the U.S. Levels of genetic differentiation among Eurasian cities were greater than those in the U.S. and greater than those between the U.S. and Eurasia, but no clear pattern of structure at the continent level was detected. MtDNA sequence variation was low and failed to reveal any geographical structure. The weak genetic structure detected here is likely due to a combination of historical admixture among populations and periodic population bottlenecks and founder events, but more extensive studies are needed to determine whether signatures of global movement may be present in this species. PMID:25020136

  2. Destruction of Luzon forearc basin from subduction to Taiwan arc-continent collision

    NASA Astrophysics Data System (ADS)

    Hirtzel, Justin; Chi, Wu-Cheng; Reed, Donald; Chen, Liwen; Liu, Char-Shine; Lundberg, Neil

    2009-12-01

    Along offshore to the east of southern Taiwan, different stages of subduction and collision occur simultaneously along strike of the convergent boundary. As a result, the evolution of the Luzon arc and its forearc basin can be studied from the younger subduction zone to the south to the collision zone to the north. Examining more than 8000 km of seismic lines, we analyzed the seismic stratigraphy of strata in a forearc basin and its successive basins in the collision zone, to study the processes related to arc collapse and forearc basin closure. The study area presents three evolutional stages: intra-oceanic subduction, initial arc-continent collision, and arc-continent collision. We divided 9 seismic sequences in the forearc basin and found older, sub-parallel basin-fill sequences (4-9) and younger, divergent sequences (1-3). Isochron maps of the sequences were used to interpret different deformation modes and their areal extends. On the arc side of the basin of the subduction and initial collision zones, we found relatively undisturbed strata, showing little arc deformation. On the trench side, the growth strata in sequences 1 through 3 are the result of recent tectonic wedging along the rear of the accretionary prism. Tectonic wedging and back-thrusts incorporate the forearc strata into the rear of the accretionary prism until they close the forearc basin at a region with a 2200 m basement relief. This relief is not caused by active deformation, as young flat forearc strata lap onto it and mark the transition from initial collision to collision where many growth strata to the north suggest abrupt increase in active arc basement deformation. The (1) deforming basement, (2) back-thrusts, and (3) other sedimentary processes affect the architecture of the successive basins in the collision zone until the arc is juxtaposed to the rear of the fold and thrust belt on land.

  3. Exploration of tectonic structures with GOCE in Africa and across-continents

    NASA Astrophysics Data System (ADS)

    Braitenberg, Carla

    2015-03-01

    The gravity anomaly field over the whole Earth obtained by the GOCE satellite is a revolutionary tool to reveal geologic information on a continental scale for the large areas where conventional gravity measurements have yet to be made. It is, however, necessary to isolate the near-surface geologic signal from the contributions of thickness variations in the crust and lithosphere and the isostatic compensation of surface relief. Here Africa is studied with particular emphasis on selected geological features which are expected to appear as density inhomogeneities. These include cratons and fold belts in the Precambrian basement, the overlying sedimentary basins and magmatism, as well as the continental margins. Regression analysis between gravity and topography shows coefficients that are consistently positive for the free air gravity anomaly and negative for the Bouguer gravity anomaly. The error and scatter on the regression are smallest in oceanic areas, where it is a possible tool for identifying changes in crustal type. The regression analysis allows the large gradient in the Bouguer anomaly signal across continental margins to be removed. After subtracting the predicted effect of known topography from the original Bouguer anomaly field, the residual field shows a continent-wide pattern of anomalies that could be attributed to regional geological structures. A few of these are highlighted, such as those representing Karoo magmatism, the Kibalian foldbelt, the Zimbabwe Craton, the Cameroon and Tibesti volcanic deposits, the Benue Trough and the Luangwa Rift. A reconstruction of the pre-break up position of Africa and South America (the plates forming West Gondwana) is made for the residual GOCE gravity field. The reconstruction allows the positive and negative anomalies to be compared across the continental fragments, and so helps identify common geologic units that extend across both the now-separate continents.

  4. Seismic investigation of an ocean-continent transition zone in the northern South China Sea

    NASA Astrophysics Data System (ADS)

    Zhu, J.; Qiu, X.; Xu, H.; Zhan, W.; Sun, Z.

    2011-12-01

    Rifted continental margins and basins are mainly formed by the lithospheric extension. Thined lithosphere of passive continental margins results in decompression melt of magma and created oceanic crust and thined ocean-continent transition (OCT) zone. Two refraction profiles used ocean bottom seismometers deployed in the broad continental shelf and three multi-channel seismic reflection lines in the northern South China Sea, acquired by the ship "Shiyan 2" of the South China Sea Institute of Oceanology, Chinese Academy of Sciences in 2010, are processed and interpreted in this study. Seismic reflection lines cut through the Dongsha rise, Zhu-1 and Zhu-2 depression within a Tertiary basin, Pear River Mouth basin (called as Zhujiangkou basin). These tectonic features are clear imaged in the seismic reflection records. Numerous normal faults, cutted through the basement and related to the stretch of the northern South China Sea margin, are imaged and interpreted. Reflection characteristics of the ocean-continent transition (OCT) zone are summaried and outlined. The COT zone is mainly divided into the northern syn-rift subsidence zone, central volcano or buried volcano uplift zone and tilt faulted block near the South Chia Sea basin. Compared to the previous seismic reflection data and refraction velocity models, the segmentation range of the OCT zone is outlined, from width of about 225 km in the northeastern South China Sea , of 160 km in the central to of 110 km in the north-central South China Sea. Based on the epicenter distribution of sporadic and large than 6 magnitude earthquakes, it suggests the OCT zone in the northern South China Sea at present is still an active seismic zone.

  5. Continent-wide risk assessment for the establishment of nonindigenous species in Antarctica

    PubMed Central

    Chown, Steven L.; Huiskes, Ad H. L.; Gremmen, Niek J. M.; Lee, Jennifer E.; Terauds, Aleks; Crosbie, Kim; Frenot, Yves; Hughes, Kevin A.; Imura, Satoshi; Kiefer, Kate; Lebouvier, Marc; Raymond, Ben; Tsujimoto, Megumu; Ware, Chris; Van de Vijver, Bart; Bergstrom, Dana Michelle

    2012-01-01

    Invasive alien species are among the primary causes of biodiversity change globally, with the risks thereof broadly understood for most regions of the world. They are similarly thought to be among the most significant conservation threats to Antarctica, especially as climate change proceeds in the region. However, no comprehensive, continent-wide evaluation of the risks to Antarctica posed by such species has been undertaken. Here we do so by sampling, identifying, and mapping the vascular plant propagules carried by all categories of visitors to Antarctica during the International Polar Year's first season (2007–2008) and assessing propagule establishment likelihood based on their identity and origins and on spatial variation in Antarctica's climate. For an evaluation of the situation in 2100, we use modeled climates based on the Intergovernmental Panel on Climate Change's Special Report on Emissions Scenarios Scenario A1B [Nakićenović N, Swart R, eds (2000) Special Report on Emissions Scenarios: A Special Report of Working Group III of the Intergovernmental Panel on Climate Change (Cambridge University Press, Cambridge, UK)]. Visitors carrying seeds average 9.5 seeds per person, although as vectors, scientists carry greater propagule loads than tourists. Annual tourist numbers (∼33,054) are higher than those of scientists (∼7,085), thus tempering these differences in propagule load. Alien species establishment is currently most likely for the Western Antarctic Peninsula. Recent founder populations of several alien species in this area corroborate these findings. With climate change, risks will grow in the Antarctic Peninsula, Ross Sea, and East Antarctic coastal regions. Our evidence-based assessment demonstrates which parts of Antarctica are at growing risk from alien species that may become invasive and provides the means to mitigate this threat now and into the future as the continent's climate changes. PMID:22393003

  6. Continent-wide risk assessment for the establishment of nonindigenous species in Antarctica.

    PubMed

    Chown, Steven L; Huiskes, Ad H L; Gremmen, Niek J M; Lee, Jennifer E; Terauds, Aleks; Crosbie, Kim; Frenot, Yves; Hughes, Kevin A; Imura, Satoshi; Kiefer, Kate; Lebouvier, Marc; Raymond, Ben; Tsujimoto, Megumu; Ware, Chris; Van de Vijver, Bart; Bergstrom, Dana Michelle

    2012-03-27

    Invasive alien species are among the primary causes of biodiversity change globally, with the risks thereof broadly understood for most regions of the world. They are similarly thought to be among the most significant conservation threats to Antarctica, especially as climate change proceeds in the region. However, no comprehensive, continent-wide evaluation of the risks to Antarctica posed by such species has been undertaken. Here we do so by sampling, identifying, and mapping the vascular plant propagules carried by all categories of visitors to Antarctica during the International Polar Year's first season (2007-2008) and assessing propagule establishment likelihood based on their identity and origins and on spatial variation in Antarctica's climate. For an evaluation of the situation in 2100, we use modeled climates based on the Intergovernmental Panel on Climate Change's Special Report on Emissions Scenarios Scenario A1B [Nakićenović N, Swart R, eds (2000) Special Report on Emissions Scenarios: A Special Report of Working Group III of the Intergovernmental Panel on Climate Change (Cambridge University Press, Cambridge, UK)]. Visitors carrying seeds average 9.5 seeds per person, although as vectors, scientists carry greater propagule loads than tourists. Annual tourist numbers (∼33,054) are higher than those of scientists (∼7,085), thus tempering these differences in propagule load. Alien species establishment is currently most likely for the Western Antarctic Peninsula. Recent founder populations of several alien species in this area corroborate these findings. With climate change, risks will grow in the Antarctic Peninsula, Ross Sea, and East Antarctic coastal regions. Our evidence-based assessment demonstrates which parts of Antarctica are at growing risk from alien species that may become invasive and provides the means to mitigate this threat now and into the future as the continent's climate changes.

  7. The connectivity of Mytilus galloprovincialis in northern Morocco: A gene flow crossroads between continents

    NASA Astrophysics Data System (ADS)

    Ouagajjou, Yassine; Presa, Pablo

    2015-01-01

    Previous population genetic studies on the Mediterranean mussel Mytilus galloprovincialis have shown the existence of two well differentiated sets of populations around Southern European coasts, one Atlantic and another Mediterranean. Those two population pools are kept apart by the Almería - Oran Oceanographic Front (AOOF), an oceanographic discontinuity acting either as a cause of such differentiation or simply as a means of maintaining two historically differentiated gene pools. The role of the Gibraltar Strait at shaping mussel larval flow entering the Alboran Sea has been much less addressed, especially regarding mussel swarms inhabiting the northern coast of Morocco. The present study applies seven microsatellite markers to describing the genetic status of northern Moroccan populations of M. galloprovincialis and their relationship with the two well-characterized mussel gene pools from southern Europe. We show that the Atlantic Iberia gene pool extending continuously from the Cantabrian Sea (NE Iberia) to the Alboran Sea (SE Iberia) up to the AOOF is well differentiated from the Atlantic Moroccan mussel. Either an oceanographic barrier or a limited larval dispersal or both, are required to explain this unexpected intercontinental differentiation regarding previous studies on this species. Populations from Atlantic Morocco conformed to a single gene pool (FST ± SD = 0.012 ± 0.007) as opposed to the reported latitudinal barrier to gene flow at Cape Ghir in western Morocco. Additionally, a significant restriction to gene flow was observed between Atlantic Morocco and Alboran Morocco (FST ± SD = 0.038 ± 0.010) in contrast to the reported mussel genetic continuity along the Iberian coast up to AOOF. Three major mussel gene pools appear to meet at this crossroads between continents and between seas, namely, a Mediterranean European subpopulation, an Atlantic Iberia subpopulation including the Alboran Sea, and an Atlantic Morocco subpopulation. Knowledge on

  8. Assessing Microseismicity of the Northern Mid-Continent Rift Zone and Surrounding Regions

    NASA Astrophysics Data System (ADS)

    Bartz, D.; Wysession, M. E.; Wiens, D. A.; Aleqabi, G. I.; Shore, P.; van der Lee, S.; Jurdy, D. M.; Stein, S. A.; Revenaugh, J.; Wolin, E.; Bollmann, T. A.; Frederiksen, A. W.; Darbyshire, F. A.

    2014-12-01

    SPREE is a flexible array (FA) deployment associated with the EarthScope project with the aim of better understanding the Mid-Continent Rift Zone (MCRZ). We have used data from SPREE FA and TA stations to detect and locate small earthquakes in the vicinity of the northwestern arm of the Mid-Continent Rift Zone, covering Minnesota, Wisconsin, and parts of Iowa, Michigan, and Ontario. This region, now stable craton, is a failed Precambrian rift marked by low levels of recorded seismicity, perhaps resulting in part from a historic dearth of stations deployed in the region. We assessed this possibility by taking advantage of the densest array that has been deployed in the region. Processing has allowed for regional stress constraints and a means of distinguishing earthquakes from mine blasts, and a quantitative method to differentiate natural earthquakes from mine blasting events, frequent here. After automated event identification, a manual review confirmed 14 earthquakes and several hundred blasting events with magnitudes ranging from M1 - M3. Observed seismicity is in reasonable agreement with available historical data. We use these earthquakes in conjunction with historical catalogs to estimate regional recurrence intervals for events of greater magnitudes. While initial earthquake/blast discrimination was done manually, the ratio of Rayleigh to P-wave amplitude appears to be a reliable discriminant for distinguishing between earthquakes and mine blasting in this region in a systematic way, with earthquakes displaying a systematically depressed ratio. Additionally, P-wave first-motion data and S/P amplitude ratios from natural events constrain focal mechanisms and regional stresses. These methods indicate roughly WSW-ENE compression, consistent with other determinations and absolute plate motion. The majority of events detected lie some distance from the actual rift; we thus conclude current seismicity bears no preferred association with the MCR.

  9. Petroleum potential of lower and middle Paleozoic rocks in Nebraska portion of Mid-Continent

    SciTech Connect

    Carlson, M.P. )

    1989-08-01

    Central North America during the Paleozoic was characterized by northern (Williston) and southern (Anadarko) depositional regimes separated by a stable Transcontinental arch. Nebraska lies on the southern flank of this arch and contains the northern zero edges of the lower and middle Paleozoic rocks of the southern regime. Most of these rocks are secondary dolomites with zones of excellent intercrystalline porosity. The Reagan-LaMotte Sandstones and the overlying Arbuckle dolomites are overlapped by Middle Ordovician rocks toward the Transcontinental arch. Rocks equivalent to the Simpson consist of a basal sand (St. Peter) and overlying interbedded gray-green shales and dolomitic limestones. An uppermost shale facies is present in the Upper Ordovician (Viola-Maquoketa) eastward and southward across Nebraska. The dolomite facies extends northward into the Williston basin. The Silurian dolomites, originally more widely deposited, are overlapped by Devonian dolomites in southeastern Nebraska. Upper Devonian rocks exhibit a regional facies change from carbonate to green-gray shale to black shale southeastward across the Mid-Continent. Mississippian carbonates overlap the Devonian westward and northward across the Transcontinental arch. Pennsylvanian uplift and erosion were widespread, producing numerous stratigraphic traps. Sands related to the basal Pennsylvanian unconformity produce along the Cambridge arch. Arbuckle, Simpson, Viola, and Hunton production is present in the Forest City basin and along the Central Kansas uplift. Although source rocks are scarce and the maturation is marginal, current theories of long-distance oil migration encourage exploration in the extensive lower and middle Paleozoic reservoirs in this portion of the Mid-Continent.

  10. Hierarchical genetic analysis of German cockroach (Blattella germanica) populations from within buildings to across continents.

    PubMed

    Vargo, Edward L; Crissman, Jonathan R; Booth, Warren; Santangelo, Richard G; Mukha, Dmitry V; Schal, Coby

    2014-01-01

    Understanding the population structure of species that disperse primarily by human transport is essential to predicting and controlling human-mediated spread of invasive species. The German cockroach (Blattella germanica) is a widespread urban invader that can actively disperse within buildings but is spread solely by human-mediated dispersal over longer distances; however, its population structure is poorly understood. Using microsatellite markers we investigated population structure at several spatial scales, from populations within single apartment buildings to populations from several cities across the U.S. and Eurasia. Both traditional measures of genetic differentiation and Bayesian clustering methods revealed increasing levels of genetic differentiation at greater geographic scales. Our results are consistent with active dispersal of cockroaches largely limited to movement within a building. Their low levels of genetic differentiation, yet limited active spread between buildings, suggests a greater likelihood of human-mediated dispersal at more local scales (within a city) than at larger spatial scales (within and between continents). About half the populations from across the U.S. clustered together with other U.S. populations, and isolation by distance was evident across the U.S. Levels of genetic differentiation among Eurasian cities were greater than those in the U.S. and greater than those between the U.S. and Eurasia, but no clear pattern of structure at the continent level was detected. MtDNA sequence variation was low and failed to reveal any geographical structure. The weak genetic structure detected here is likely due to a combination of historical admixture among populations and periodic population bottlenecks and founder events, but more extensive studies are needed to determine whether signatures of global movement may be present in this species.

  11. Patterns of Human Diversity, within and among Continents, Inferred from Biallelic DNA Polymorphisms

    PubMed Central

    Romualdi, Chiara; Balding, David; Nasidze, Ivane S.; Risch, Gregory; Robichaux, Myles; Sherry, Stephen T.; Stoneking, Mark; Batzer, Mark A.; Barbujani, Guido

    2002-01-01

    Previous studies have reported that about 85% of human diversity at Short Tandem Repeat (STR) and Restriction Fragment Length Polymorphism (RFLP) autosomal loci is due to differences between individuals of the same population, whereas differences among continental groups account for only 10% of the overall genetic variance. These findings conflict with popular notions of distinct and relatively homogeneous human races, and may also call into question the apparent usefulness of ethnic classification in, for example, medical diagnostics. Here, we present new data on 21 Alu insertions in 32 populations. We analyze these data along with three other large, globally dispersed data sets consisting of apparently neutral biallelic nuclear markers, as well as with a β-globin data set possibly subject to selection. We confirm the previous results for the autosomal data, and find a higher diversity among continents for Y-chromosome loci. We also extend the analyses to address two questions: (1) whether differences between continental groups, although small, are nevertheless large enough to confidently assign individuals to their continent on the basis of their genotypes; (2) whether the observed genotypes naturally cluster into continental or population groups when the sample source location is ignored. Using a range of statistical methods, we show that classification errors are at best around 30% for autosomal biallelic polymorphisms and 27% for the Y chromosome. Two data sets suggest the existence of three and four major groups of genotypes worldwide, respectively, and the two groupings are inconsistent. These results suggest that, at random biallelic loci, there is little evidence, if any, of a clear subdivision of humans into biologically defined groups. PMID:11932244

  12. “Total reconstruction” of the urethrovesical anastomosis contributes to early urinary continence in laparoscopic radical prostatectomy

    PubMed Central

    Liao, Xiaoxing; Qiao, Peng; Tan, Zhaohui; Shi, Hongbin; Xing, Nianzeng

    2016-01-01

    ABSTRACT Purpose: To demonstrate the effect of total reconstruction technique on postoperative urinary continence after laparoscopic radical prostatectomy (LRP). Material and Methods: LRP was performed using a standard urethrovesical anastomosis in 79 consecutive patients (Group-A) from June 2011 to October 2012, and a total reconstruction procedure in 82 consecutive patients (Group-B) from June 2012 to June 2013. The primary outcome measurement was urinary continence assessed at 1, 2, 4, 12, 24 and 52 weeks after catheter removal. Other data recorded were patient age, body mass index, International Prostate Symptoms Score, prostate volume, preoperative PSA, Gleason score, neurovascular bundle preservation, operation time, estimated blood loss, complications and pathology results. Results: In Group-A, the continence rates at 1, 2, 4, 12, 24 and 52 weeks were 7.59%, 20.25%, 37.97%, 58.22%, 81.01% and 89.87% respectively. In Group-B, the continence rates were 13.41%, 32.92%, 65.85%, 81.71%, 90.24% and 95.12% respectively. Group––B had significantly higher continence rates at 4 and 12 weeks after surgery (P<0.001 and P=0.001). There were no significant differences between the groups with respect to patient's age, body mass index, prostate-specific antigen level, prostate volume, IPSS, estimated blood loss, number of nerve-sparing procedures and postoperative complications. Conclusions: Total reconstruction technique in the procedure of urethrovesical anastomosis during LRP improved early recovery of continence. PMID:27256174

  13. Warming increases plant biomass and reduces diversity across continents, latitudes, and species migration scenarios in experimental wetland communities.

    PubMed

    Baldwin, Andrew H; Jensen, Kai; Schönfeldt, Marisa

    2014-03-01

    Atmospheric warming may influence plant productivity and diversity and induce poleward migration of species, altering communities across latitudes. Complicating the picture is that communities from different continents deviate in evolutionary histories, which may modify responses to warming and migration. We used experimental wetland plant communities grown from seed banks as model systems to determine whether effects of warming on biomass production and species richness are consistent across continents, latitudes, and migration scenarios. We collected soil samples from each of three tidal freshwater marshes in estuaries at three latitudes (north, middle, south) on the Atlantic coasts of Europe and North America. In one experiment, we exposed soil seed bank communities from each latitude and continent to ambient and elevated (+2.8 °C) temperatures in the greenhouse. In a second experiment, soil samples were mixed either within each estuary (limited migration) or among estuaries from different latitudes in each continent (complete migration). Seed bank communities of these migration scenarios were also exposed to ambient and elevated temperatures and contrasted with a no-migration treatment. In the first experiment, warming overall increased biomass (+16%) and decreased species richness (-14%) across latitudes in Europe and North America. Species richness and evenness of south-latitude communities were less affected by warming than those of middle and north latitudes. In the second experiment, warming also stimulated biomass and lowered species richness. In addition, complete migration led to increased species richness (+60% in North America, + 100% in Europe), but this higher diversity did not translate into increased biomass. Species responded idiosyncratically to warming, but Lythrum salicaria and Bidens sp. increased significantly in response to warming in both continents. These results reveal for the first time consistent impacts of warming on biomass and

  14. Intermediate crust (IC); its construction at continent edges, distinctive epeirogenic behaviour and identification as sedimentary basins within continents: new light on pre-oceanic plate motions

    NASA Astrophysics Data System (ADS)

    Osmaston, Miles F.

    2014-05-01

    Introduction. The plate tectonics paradigm currently posits that the Earth has only two kinds of crust - continental and oceanic - and that the former may be stretched to form sedimentary basins or the latter may be modified by arc or collision until it looks continental. But global analysis of the dynamics of actual plate motions for the past 150 Ma indicates [1 - 3] that continental tectospheres must be immensely thicker and rheologically stiffer than previously thought; almost certainly too thick to be stretched with the forces available. In the extreme case of cratons, these tectospheric keels evidently extend to 600 km or more [2, 3]. This thick-plate behaviour is attributable, not to cooling but to a petrological 'stiffening' effect, associated with a loss of water-weakening of the mineral crystals, which also applies to the hitherto supposedly mobile LVZ below MORs [4, 5]. The corresponding thick-plate version of the mid-ocean ridge (MOR) process [6 - 8], replacing the divergent mantle flow model, has a deep, narrow wall-accreting axial crack which not only provides the seismic anisotropy beneath the flanks but also brings two outstanding additional benefits:- (i) why, at medium to fast spreading rates, MOR axes become straight and orthogonally segmented [6], (ii) not being driven by body forces, it can achieve the sudden jumps of axis, spreading-rate and direction widely present in the ocean-floor record. Furthermore, as we will illustrate, the crack walls push themselves apart at depth by a thermodynamic mechanism, so the plates are not being pulled apart. So the presence of this process at a continental edge would not imply the application of extensional force to the margin. Intermediate Crust (IC). In seeking to resolve the paradox that superficially extensional structures are often seen at margins we will first consider how this MOR process would be affected by the heavy concurrent sedimentation to be expected when splitting a mature continent. I reason

  15. 77 FR 35959 - Atlas Pipeline Mid-Continent WestTex, LLC; Pioneer Natural Resources USA, Inc.; Notice of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-15

    ... Federal Energy Regulatory Commission Atlas Pipeline Mid-Continent WestTex, LLC; Pioneer Natural Resources...Tex, LLC (Atlas) and Pioneer Natural Resources USA, Inc. (Pioneer), filed in the above referenced..., Pioneer Natural Resources USA, Inc., 5205 North O'Connor Blvd., Suite 200, Irving, TX 75039, by...

  16. An Assessment of Stressor Extent and Biological Condition in the North American Mid-continent Great Rivers (USA)

    EPA Science Inventory

    We assessed the North American mid-continent great rivers (Upper Mississippi, Missouri, and Ohio). We estimated the extent of each river in most- (MDC) or least-disturbed condition (LDC) based on multiple biological response indicators: fi sh and macroinvertebrate, trophic stat...

  17. Globalization and Multilingualism: Case Studies of Indigenous Culture-Based Education from the Indian Sub-Continent and Their Implications

    ERIC Educational Resources Information Center

    Singh, Navin Kumar

    2013-01-01

    This paper presents some of the major program initiatives honoring Indigenous knowledge, culture, heritage, arts, and skills through curricular reforms and culturally appropriate educational practices on the Indian sub-continent. It presents case studies of Indigenous culture-based education, with reference to mother tongue and multicultural…

  18. Taking the pulse of a continent: Expanding site-based research infrastructure for regional- to continental-scale ecology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many of the most dramatic and surprising effects of global change on ecological systems will occur across large spatial extents, from regions to continents. Multiple ecosystem types will be impacted across a range of interacting spatial and temporal scales. The ability of ecologists to understand an...

  19. High-resolution mapping of biomass burning emissions in tropical regions across three continents

    NASA Astrophysics Data System (ADS)

    Shi, Yusheng; Matsunaga, Tsuneo; Saito, Makoto

    2015-04-01

    Biomass burning emissions from open vegetation fires (forest fires, savanna fires, agricultural waste burning), human waste and biofuel combustion contain large amounts of trace gases (e.g., CO2, CH4, and N2O) and aerosols (BC and OC), which significantly impact ecosystem productivity, global atmospheric chemistry, and climate . With the help of recently released satellite products, biomass density based on satellite and ground-based observation data, and spatial variable combustion factors, this study developed a new high-resolution emissions inventory for biomass burning in tropical regions across three continents in 2010. Emissions of trace gases and aerosols from open vegetation burning are estimated from burned areas, fuel loads, combustion factors, and emission factors. Burned areas were derived from MODIS MCD64A1 burned area product, fuel loads were mapped from biomass density data sets for herbaceous and tree-covered land based on satellite and ground-based observation data. To account for spatial heterogeneity in combustion factors, global fractional tree cover (MOD44B) and vegetation cover maps (MCD12Q1) were introduced to estimate the combustion factors in different regions by using their relationship with tree cover under less than 40%, between 40-60% and above 60% conditions. For emission factors, the average values for each fuel type from field measurements are used. In addition to biomass burning from open vegetation fires, the emissions from human waste (residential and dump) burning and biofuel burning in 2010 were also estimated for 76 countries in tropical regions across the three continents and then allocated into each pixel with 1 km grid based on the population density (Gridded Population of the World v3). Our total estimates for the tropical regions across the three continents in 2010 were 17744.5 Tg CO2, 730.3 Tg CO, 32.0 Tg CH4, 31.6 Tg NOx, 119.2 Tg NMOC, 6.3 Tg SO2, 9.8 NH3 Tg, 81.8 Tg PM2.5, 48.0 Tg OC, and 5.7 Tg BC, respectively. Open

  20. SELECTION AND TREATMENT OF STRIPPER GAS WELLS FOR PRODUCTION ENHANCEMENT IN THE MID-CONTINENT

    SciTech Connect

    Scott Reeves

    2003-03-01

    Stripper gas wells are an important source of domestic energy supply and under constant threat of permanent loss (shut-in) due to marginal economics. In 1998, 192 thousand stripper gas wells produced over a Tcf of gas, at an average rate of less than 16 Mcfd. This represents about 57% of all producing gas wells in the onshore lower-48 states, yet only 8% of production. Reserves of stripper gas wells are estimated to be only 1.6 Tcf, or slightly over 1% of the onshore lower-48 total (end of year 1996 data). Obviously, stripper gas wells are at the very margin of economic sustenance. As the demand for natural gas in the U.S. grows to the forecasted estimate of over 30 Tcf annually by the year 2010, supply from current conventional sources is expected to decline. Therefore, an important need exists to fully exploit known domestic resources of natural gas, including those represented by stripper gas wells. The overall objectives of this project are to develop an efficient and low-cost methodology to broadly categorize the well performance characteristics for a stripper gas field, identify the high-potential candidate wells for remediation, and diagnose the specific causes for well underperformance. With this capability, stripper gas well operators can more efficiently and economically produce these resources and maximize these gas reserves. A further objective is to identify/develop, evaluate and test ''new and novel,'' economically viable remediation options. Finally, it is the objective of this project that all the methods and technologies developed in this project, while being tested in the Mid-Continent, be widely applicable to stripper gas wells of all types across the country. The project activities during the reporting period were: (1) Continued to solicit industry research partners to provide test sites. A Cooperative Research Agreement has been signed with Oneok, for a test site in the Mocane-Laverne field in the Anadarko basin (Oklahoma). The site consists of

  1. Tag team tectonics: mantle upwelling and lithospheric heterogeneity ally to rift continents (Invited)

    NASA Astrophysics Data System (ADS)

    Nelson, W. R.; Furman, T.

    2013-12-01

    The configuration of continents we know today is the result of several billion years of active Wilson Cycle tectonics. The rifting of continents and subsequent development of ocean basins is an integral part of long-term planetary-scale recycling processes. The products of this process can be seen globally, and the East African Rift System (EARS) provides a unique view of extensional processes that actively divide a continent. Taken together with the adjoining Red Sea and Gulf of Aden, the EARS has experienced over 40 Ma of volcanism and ~30 Ma of extension. While early (pre-rift) volcanism in the region is attributed to mantle plume activity, much of the subsequent volcanism occurs synchronously with continental rifting. Numerous studies indicate that extension and magmatism are correlated: extension leads to decompression melting while magmatism accommodates further extension (e.g. Stein et al., 1997; Buck 2004; Corti 2012). Evaluation of the entire EARS reveals significant geochemical patterns - both spatial and temporal - in the volcanic products. Compositional variations are tied directly to the melt source(s), which changes over time. These variations can be characterized broadly by region: the Ethiopian plateau and Turkana Depression, the Kenya Rift, and the Western Rift. In the Ethiopian plateau, early flood basalt volcanism is dominated by mantle plume contributions with variable input from lherzolitic mantle lithosphere. Subsequent alkaline shield volcanism flanking the juvenile Main Ethiopian Rift records the same plume component as well as contributions from a hydrous peridotitic lithosphere. The hydrous lithosphere does not contribute indefinitely. Instead, young (< 2 Ma) volcanism taps a combination of the mantle plume and anhydrous depleted lithospheric mantle. In contrast, volcanism in the Kenya Rift and the Western Rift are derived dominantly from metasomatized lithospheric mantle rather than mantle plume material. These rifts lie in the mobile

  2. An Analysis of Surface and Subsurface Lineaments and Fractures for Oil and Gas Exploration in the Mid-Continent Region

    SciTech Connect

    Guo, Genliang; and George, S.A.

    1999-04-08

    An extensive literature search was conducted and geological and mathematical analyses were performed to investigate the significance of using surface lineaments and fractures for delineating oil and gas reservoirs in the Mid-Continent region. Tremendous amount of data were acquired including surface lineaments, surface major fracture zones, surface fracture traces, gravity and magnetic lineaments, and Precambrian basement fault systems. An orientation analysis of these surface and subsurface linear features was performed to detect the basic structural grains of the region. The correlation between surface linear features and subsurface oil and gas traps was assessed, and the implication of using surface lineament and fracture analysis for delineating hydrocarbon reservoirs in the Mid-Continent region discussed. It was observed that the surface linear features were extremely consistent in orientation with the gravity and magnetic lineaments and the basement faults in the Mid-Continent region. They all consist of two major sets bending northeast and northwest, representing, therefore, the basic structural grains of the region. This consistency in orientation between the surface and subsurface linear features suggests that the systematic fault systems at the basement in the Mid-Continent region have probably been reactivated many times and have propagated upward all the way to the surface. They may have acted as the loci for the development of other geological structures, including oil and gas traps. Also observed was a strong association both in orientation and position between the surface linear features and the subsurface reservoirs in various parts of the region. As a result, surface lineament and fracture analysis can be used for delineating additional oil and gas reserves in the Mid-Continent region. The results presented in this paper prove the validity and indicate the significance of using surface linear features for inferring subsurface oil and gas reservoirs

  3. 3D Geometry and Kinematics of the Taiwan Arc-continent Collision

    NASA Astrophysics Data System (ADS)

    Carena, S.; Suppe, J.; Wu, Y. M.

    2015-12-01

    In Taiwan two subduction zones (Manila trench and Ryukyu trench) come together in a quasi-orthogonal, kinematically stable configuration. Subduction is ongoing in both trenches, even though the tectonic setting in the Manila trench is that of an arc-continent collision. The upper crust of Eurasia (EU) is decoupled from the rest of the lithosphere by a detachment horizon, which is the main subduction interface between EU and Philippine Sea plate (PSP). The interface is visible in both seismicity and crustal tomography at shallow depths, and it can be followed into the mantle to 450-500 km depth with global tomography. Shortening across the plate boundary is accomplished by a combination of subduction of EU lithosphere, folding and thrusting in the Eurasian upper crust, and a secondary subduction zone within the PSP. We hypothesize that: (1) once arc-continent collision occurs, subduction of Eurasian continental lower crust and upper mantle can continue by lithospheric delamination and by continuity with the much larger Eurasian slab to the south; (2) the upper crust of EU deforms by faulting and folding; (3) the present convergence rate of about 90 mm/yr is limited at most to the last 2 Ma, whereas the long-term rate is about 30 mm/yr and in Taiwan the difference is being taken up by secondary subduction within the PSP margin; (4) a margin-parallel STEP (Subduction-Transform-Edge-Propagator) fault forms the northern limit of Eurasian subduction, which allows the whole system to propagate self-similarly southwestward. No slab breakoff is required for the kinematics of the margin, and none is observed in geophysical or geological data either. This kinematics is consistent with geologic observations: from timing of opening of the southern Okinawa trough, to geometry of geologic boundaries within the Taiwan mountain belt, to geographic distribution, geochemical character, and timing of Quaternary volcanism in the northern Taiwan volcanic zone. We constrained the long

  4. Suicidal behaviour across the African continent: a review of the literature

    PubMed Central

    2014-01-01

    Background Suicide is a major cause of premature mortality worldwide, but data on its epidemiology in Africa, the world’s second most populous continent, are limited. Methods We systematically reviewed published literature on suicidal behaviour in African countries. We searched PubMed, Web of Knowledge, PsycINFO, African Index Medicus, Eastern Mediterranean Index Medicus and African Journals OnLine and carried out citation searches of key articles. We crudely estimated the incidence of suicide and suicide attempts in Africa based on country-specific data and compared these with published estimates. We also describe common features of suicide and suicide attempts across the studies, including information related to age, sex, methods used and risk factors. Results Regional or national suicide incidence data were available for less than one third (16/53) of African countries containing approximately 60% of Africa’s population; suicide attempt data were available for <20% of countries (7/53). Crude estimates suggest there are over 34,000 (inter-quartile range 13,141 to 63,757) suicides per year in Africa, with an overall incidence rate of 3.2 per 100,000 population. The recent Global Burden of Disease (GBD) estimate of 49,558 deaths is somewhat higher, but falls within the inter-quartile range of our estimate. Suicide rates in men are typically at least three times higher than in women. The most frequently used methods of suicide are hanging and pesticide poisoning. Reported risk factors are similar for suicide and suicide attempts and include interpersonal difficulties, mental and physical health problems, socioeconomic problems and drug and alcohol use/abuse. Qualitative studies are needed to identify additional culturally relevant risk factors and to understand how risk factors may be connected to suicidal behaviour in different socio-cultural contexts. Conclusions Our estimate is somewhat lower than GBD, but still clearly indicates suicidal behaviour is an

  5. Lithospheric Structure of the North American Continent from Ambient Noise Tomography And Wave Gradiometry

    NASA Astrophysics Data System (ADS)

    Porter, R. C.; Liu, Y.; Holt, W. E.

    2015-12-01

    In order to better understand the formation and tectonic evolution of the North American continent we utilize data from the EarthScope Transportable Array network to calculate a 3D shear-velocity model for the continental United States. This model was produced through the inversion of Rayleigh wave phase velocities calculated using ambient noise tomography and wave gradiometry, which allows for sensitivity to a broad depth range. Seismic velocities within this model highlight the diverse lithospheric character across the continent and preliminary results are consistent with potential active tectonics within the eastern US. Preliminary observations show that seismic velocities in the shallow crust correlate with sediment thickness, as the slowest velocities are observed along the Gulf Coast where thick sediment is found and the fastest velocities are observed in the cratonic north-central United States. Mid-crustal velocities appear to largely correlate with regions of active tectonics with slow velocities observed in the Basin and Range province, the Rio Grande Rift, and along the Pacific Coast. However, anomalous low velocity regions are observed in Iowa, Indiana, and West Virginia that warrant further investigation. Velocities between 30-40 km depth appear to be largely controlled by crustal thickness with fast velocities observed in regions of thinner crust and slower velocities in thick crustal regions. In the upper mantle there is a sharp contrast between relatively slow seismic velocities in the western US and fast velocities in the eastern US that correlates well with the eastern limit of Laramide deformation. However, there are several pockets of low velocities in the upper mantle beneath western Virginia and New England that may suggest active tectonic processes in the mantle beneath these regions. Finally, within the deeper mantle (>100 km depth) the fastest velocities are observed beneath the cratonic regions of the north central US and slower velocities

  6. Evaluation of the Interplate and Intraplate Deformations of the African Continent Using cGNSS Data

    NASA Astrophysics Data System (ADS)

    Apolinário, J. P.; Fernandes, R. M. S.; Bos, M. S.; Meghraoui, M.; Miranda, J. M. A.

    2014-12-01

    Two main plates, Nubia and Somalia, plus some few more tectonic blocks in the East African Rift System (EARS) delimit the African continent. The major part of the external plate boundaries of Africa is well defined by oceanic ridge systems with the exception of the Nubia-Eurasia complex convergence-collision tectonic zone. In addition, the number and distribution of the tectonic blocks along the EARS region is a major scientific issue that has not been completely answered so far. Nevertheless, the increased number of cGNSS (continuous Global Navigation Satellite Systems) stations in Africa with sufficient long data span is helping to better understand and constrain the complex sub-plate distribution in the EARS as well as in the other plate boundaries of Africa. This work is the geodetic contribution for the IGCP-Project 601 - "Seismotectonics and Seismic Hazards in Africa". It presents the current tectonic relative motions of the African continent based on the analysis of the estimated velocity field derived from the existing network of cGNSS stations in Africa and bordering plate tectonics. For the majority of the plate pairs, we present the most recent estimation of their relative velocity using a dedicated processing. The velocity solutions are computed using HECTOR, a software that takes into account the existing temporal correlations between the daily solutions of the stations. It allows to properly estimate the velocity uncertainties and to detect any artifacts in the time-series. For some of the plate pairs, we compare our solutions of the angular velocities with other geodetic and geophysical models. In addition, we also study the sensitivity of the derived angular velocity to changes in the data (longer data-span for some stations) for tectonic units with few stations, and in particular for the Victoria and Rovuma blocks of the EARS. Finally, we compute estimates of velocity fields for several sub-regions correlated with the seismotectonic provinces and

  7. Ecosystem modelling, scaling, benchmarking and data assimilation for the Australian continent

    NASA Astrophysics Data System (ADS)

    Evans, B. J.

    2013-12-01

    Modelling terrestrial biosphere processes in the world's driest inhabited continent presents some unique challenges, but also excellent opportunities to capitalize on major data infrastructure projects led by the Terrestrial Ecosystem Research Network (TERN). TERN, Australia's counterpart to NEON, has charged its ecosystem Modelling And Scaling InfrasTructure facility (e-MAST) with enhancing the national capacity for model benchmarking, data assimilation and data-model integration. e-MAST models the Australian terrestrial biosphere in space and time from various disciplinary perspectives. The foundation for all e-MAST modelling is ANUCLIMATE, a set of well-founded, high-resolution estimates of key climate variables (minimum and maximum temperature, precipitation, vapour pressure) from the 1970s up to near the present. Using all reliable meteorological measurements, we have enhanced the standard (ANUSPLIN) approach to allow interpolation of all variables at daily time resolution to a common 0.01 degree grid. Satellite data assimilation is used to provide continent-wide fields of derived variables including stomatal conductance, evapotranspiration and soil moisture. Plant productivity has been modelled by fusion of eddy-covariance CO2 flux measurements with satellite reflectance data, exploiting the well-tested light-use-efficiency modelling approach. Working towards the next generation of robust, process-based ecosystem models, we are synthesizing observations of plant biophysical and physiological traits; developing gridded surfaces of these traits; and working with TERN's MultiScale Plot Network to improve national coverage of trait measurements. Evaluation and benchmarking of models is based on the Protocol for the Analysis of Land Surface Models (PALS), which is being extended from its original core of flux data-model comparison ';experiments' to encompass more data types, including remote atmospheric CO2¬ concentrations and streamflow measurements, which (when

  8. Efficacy of Duloxetine in the Early Management of Urinary Continence after Radical Prostatectomy

    PubMed Central

    Alan, Cabir; Eren, Ali E.; Ersay, Ahmet R.; Kocoglu, Hasan; Basturk, Gokhan; Demirci, Emrah

    2015-01-01

    Aim To evaluate the efficacy of early duloxetine therapy in stress urinary incontinence occurring after radical prostatectomy (RP). Material and Method Patients that had RP were randomly divided into 2 groups following the removal of the urinary catheter. Group A patients (n = 28) had pelvic floor exercise and duloxetine therapy. Group B patients (n = 30) had only pelvic floor exercise. The incontinence status of the patients and number of pads were recorded and 1-hour pad test and Turkish validation of International Consultation on Incontinence Questionnaire-Short Form test were applied to the patients at the follow-up. Results When the dry state of the patients was evaluated, 5, 17, 3, and 2 of 28 Group A patients stated that they were completely dry in the 3rd, 6th, 9th and 12th month respectively and pad use was stopped. There was no continence in 30 Group B in the first 3 months. Twelve, 6, and 8 patients stated that they were completely dry in the 6th, 9th and 12th month, respectively. But 3 of 4 patients in whom dryness could not be provided were using a mean of 7.6 pads in the first day and a mean of 1.3 pads after 1 year. When pad use of the patients was evaluated, the mean monthly number of pad use was determined to be 6.2 (4-8) in the initial evaluation, 2.7 (0-5) in the in 3rd month, 2 (0-3) in the 6th month and 1.6 (0-2) pad/d in the 9th month in the group taking medicine. The mean monthly number of pads used was determined to be 5.8 (4-8) in the initial evaluation, 4.3 (3-8) in the 3rd month, 3 (0-6) in the 6th month and 1.6 (0-6) pad/d in the 9th month in the group not taking medicine. Conclusion According to the results, early duloxetine therapy in stress urinary incontinence that occurred after RP provided early continence. PMID:26195963

  9. Convective Cloud and Rainfall Processes Over the Maritime Continent: Simulation and Analysis of the Diurnal Cycle

    NASA Astrophysics Data System (ADS)

    Gianotti, Rebecca L.

    The Maritime Continent experiences strong moist convection, which produces significant rainfall and drives large fluxes of heat and moisture to the upper troposphere. Despite the importance of these processes to global circulations, current predictions of climate change over this region are still highly uncertain, largely due to inadequate representation of the diurnally-varying processes related to convection. In this work, a coupled numerical model of the land-atmosphere system (RegCM3-IBIS) is used to investigate how more physically-realistic representations of these processes can be incorporated into large-scale climate models. In particular, this work improves simulations of convective-radiative feedbacks and the role of cumulus clouds in mediating the diurnal cycle of rainfall. Three key contributions are made to the development of RegCM3-IBIS. Two pieces of work relate directly to the formation and dissipation of convective clouds: a new representation of convective cloud cover, and a new parameterization of convective rainfall production. These formulations only contain parameters that can be directly quantified from observational data, are independent of model user choices such as domain size or resolution, and explicitly account for subgrid variability in cloud water content and nonlinearities in rainfall production. The third key piece of work introduces a new method for representation of cloud formation within the boundary layer. A comprehensive evaluation of the improved model was undertaken using a range of satellite-derived and ground-based datasets, including a new dataset from Singapore's Changi airport that documents diurnal variation of the local boundary layer height. The performance of RegCM3-IBIS with the new formulations is greatly improved across all evaluation metrics, including cloud cover, cloud liquid water, radiative fluxes and rainfall, indicating consistent improvement in physical realism throughout the simulation. This work

  10. Intraseasonal Variability of δ18O of Precipitation in The Indonesia Maritime Continent

    NASA Astrophysics Data System (ADS)

    Belgaman, H. A.; Ichiyanagi, K.; Tanoue, M.; Suwarman, R.; Yoshimura, K.; Mori, S.; Yamanaka, M. D.; Kurita, N.; Syamsudin, F.

    2014-12-01

    The Indonesian maritime continent (IMC) consists of many islands in a warm pool of sea water and is located between two great oceans—the Pacific Ocean and Indian Ocean, and two major continents—the Asian and Australian continents. This tropical region also influenced by many regional and local climate and weather phenomenon which causes high spatial and temporal rainfall variability. These factors may produce unique variability of isotopic precipitation. The isotopic content (d18O and dD) in precipitation have been known to have important role for reconstructing the atmospheric circulation, hydrological cycle, and paleoclimate. Using daily data from six observation station across the IMC (Bukit tinggi, Jambi, Denpasar, Makasar, Manado, and Palau Island), the variability of δ18O was explored. Observation times for each station were different. Bukit Tinggi (GAW) was from Jan. 2001 - Mar. 2010, Jambi (JMB) was from Apr. 2001 - Dec. 2005, Denpasar (DPS), Makassar (MKS), Manado (MND) were from Nov. 2002 - Mar. 2010, and Palau Island (PLL) was from Dec. 2001 - May 2007. Daily average value of δ18O were -7.57‰, -5.41‰, -3.15‰, -6.12‰, -5.49‰ and -4.26‰ for GAW, JMB, DPS, MKS, MND and PLL respectively. Daily value of δ18O in GAW has the lowest value compare with the other station was because the location of GAW station located at high altitude. High correlation of variability of δ18O and Madden-Julian Oscillation (MJO) was observed at western part of the IMC (GAW and JMB), and northern part of the IMC (MKS, MND, and PLL), meanwhile δ18O variability at DPS was less correlated with MJO compare with other stations. Preliminary result from Color Moisture Analysis (CMA) model revealed that precipitable water at GAW and JMB stations was mostly occupied by water vapor evaporated from the Indian Ocean. However, precipitable water at other stations was mostly composed of water vapor evaporated from the Java Sea and the Pacific Ocean. These findings indicate

  11. A Geophysical Overview of the Structure and Evolution of the Crust of the Mid-Continent Region of North America

    NASA Astrophysics Data System (ADS)

    Keller, G. R., Jr.

    2015-12-01

    A variety of geophysical data, including newly released 3-D seismic reflection data, show us that the crustal structure of the Mid-Continent region of North America is very complex. The dimensions of many of the crustal structures is very large by global standards, and thus, they are a tectonic puzzle because of their size, structural complexity, and distance from active plate margins that usually create the driving mechanisms for intraplate deformation evident. The crust of the Mid-Continent region formed during a period of continental growth that extended from about 1.8 to 0.9 Ga. The impressive Mid-Continent rift system (MCRS) tried to interrupt this period of continental growth at about 1.1 Ga but it its western arm failed even though it modified the crust massively. However, the supercontinent resulting from this growth did not survive long and began to break up by ~700 Ma. This period of rifting established the structural framework of the southern Mid-Continent region, subsequent Early Paleozoic basin development, and at least partly, the formation of the Ancestral Rocky Mountains in the late Paleozoic. The Southern Oklahoma aulacogen (SOA) is an impressive example of this rifting event. The deformation that formed the Ancestral Rocky Mountains resulted in massive inversion of SOA rift structures and is due to a plate collision in the late Paleozoic whose origin is under debate. There has been increased emphasis on the use of gravity, magnetic, seismic, drilling, and remote sensing data in studies of the Mid-Continent region. For example, the MCRS is traditionally viewed as ending in central Kansas and the SOA can be interpreted as ending in the Texas panhandle. However, we used enhancement of gravity and magnetic data, seismic data, geologic mapping, and deep-drilling data to study its southern extent, and it appears that the MCRS could extend further southward beneath the much younger Anadarko basin of Oklahoma to abut the SOA.

  12. Maritime Continent rainfall variability during the TRMM era: The role of monsoon, topography and El Niño Modoki

    NASA Astrophysics Data System (ADS)

    As-syakur, Abd. Rahman; Osawa, Takahiro; Miura, Fusanori; Nuarsa, I. Wayan; Ekayanti, Ni Wayan; Dharma, I. Gusti Bagus Sila; Adnyana, I. Wayan Sandi; Arthana, I. Wayan; Tanaka, Tasuku

    2016-09-01

    Rainfall is among the most important climatic elements of the Maritime Continent. The Maritime Continent rainfall climate is uniquely located in the world's most active convective area. Satellite data measured by the Tropical Rainfall Measuring Mission (TRMM) 3B43 based high-resolution rainfall products represent monthly Maritime Continent rainfall characteristics over 16 years. Several statistical scores were employed to analyse annual means, linear trends, seasonal means, and anomalous Maritime Continent rainfall characteristic percentages. The effects of land and topography on rainfall quantities were also studied and compared with the Global Precipitation Climatology Project (GPCP) gridded precipitation estimates which has low-resolution. Comparison also applied on linear correlation and partial correlation techniques to determine the relationship between rainfall and the El Niño Modoki and El Niño-Southern Oscillation (ENSO; hereafter conventional El Niño). The results show that north-south Maritime Continent precipitation is associated with and generated by the northwest and southeast monsoon patterns. In addition, the large-scale circulations are linked with heavy rainfall over this land-ocean region due to large-scale island-topography-induced convective organization. The rainfall responses to El Niño Modoki and conventional El Niño clearly indicated the times at which the conventional El Niño had a higher impact than El Niño Modoki, especially during northern winter and spring, and vice versa during northern fall, and similarly affect during northern summer. Furthermore, the dynamic movements of rainfall anomaly that are caused by El Niño Modoki and the conventional El Niño events spanned from the southwest during June-July-August (JJA) to throughout the northeast ending in March-April-May (MAM).

  13. Spatial and temporal snowpack variation in the crown of the continent ecosystem

    USGS Publications Warehouse

    Selkowitz, D.J.; Fagre, D.B.; Reardon, B.A.

    2002-01-01

    Snowpack related ecosystem changes such as glacier recession and alpine treeline advance have been documented in the Crown of the Continent Ecosystem (CCE) over the course of the previous 150 years. Using data from the Natural Resource Conservation Service's SNOTEL sites and snow course surveys, we examined the spatial and temporal variation in snowpack in the region. SNOTEL data suggest CCE snowpacks are larger and more persistent than in most regions of the Western U.S., and that water year precipitation, rather than mean temperature, is the primary control on April 1 snow water equivalent (SWE). Snow course data indicate a statistically significant downward trend in mean April 1 SWE for the period 1950-2001 but no statistically significant trend in mean May 1 SWE for the longer period 1922-2001. Further analysis reveals that variations in both April 1 and May 1 mean SWE are closely tied to the Pacific Decadal Oscillation, an ENSO-like interdecadal pattern of Pacific Ocean climate variability. Despite no significant trend in mean May 1 SWE between 1922-2001, glaciers in Glacier National Park receded steadily during this period, implying changing climatic conditions crossed a threshold for glacier mass balance maintenace sometime between the Little Ice Age glacial maxima and 1922.

  14. The origin and geologic evolution of the East Continent Rift Basin

    SciTech Connect

    Drahovzal, J.A. . Kentucky Geological Survey)

    1992-01-01

    The East Continent Rift Basin (ECRB) is a newly recognized, dominantly sedimentary-volcanic Proterozoic rift basin that apparently represents the southern extension of the Keweenawan Midcontinent Rift. The ECRB extends from central Michigan at least as far south as south-central Kentucky. The inferred age of the rift fill is approximately 1,000 Ma. Evidence supporting a rift origin for the ECRB includes: interbedding of continental flood basalts and felsic volcanics with siliciclastics; sedimentary fill consisting of distal, arid-climate alluvial fan sediments that lack metamorphic lithologies; close proximity and similar lithologic succession to the Keweenawan rift-fill rocks of the Michigan Basin; and inferred marginal block faulting of Granite-Rhyolite Province rocks near the western edge of the ECRB. ECRB evolution is interpreted as follows: (1) formation of Granite-Rhyolite Province rocks (1,500--1,340 Ma); (2) Keweenawan crustal extension and rifting with development of central mafic complexes, emplacement of volcanic rocks, and deposition of siliciclastic fill from eroded marginal Granite-Rhyolite Province tilted fault blocks (ca 1,000 Ma); (3) overthrusting of the Grenville allochthon and associated foreland thrusting and folding of the rift sequence rocks together with deposition of foreland basin sediments (975---890 Ma); (4) Late Proterozoic erosional removal of the foreland basin sediments and interpreted wrench faulting along the Grenville Front (post-975 to pre-570 Ma); and (5) tectonic inversion, with the ECRB area remaining relatively high during major cambrian subsidence in central Kentucky (590--510 Ma).

  15. High diversity of picornaviruses in rats from different continents revealed by deep sequencing.

    PubMed

    Hansen, Thomas Arn; Mollerup, Sarah; Nguyen, Nam-Phuong; White, Nicole E; Coghlan, Megan; Alquezar-Planas, David E; Joshi, Tejal; Jensen, Randi Holm; Fridholm, Helena; Kjartansdóttir, Kristín Rós; Mourier, Tobias; Warnow, Tandy; Belsham, Graham J; Bunce, Michael; Willerslev, Eske; Nielsen, Lars Peter; Vinner, Lasse; Hansen, Anders Johannes

    2016-08-17

    Outbreaks of zoonotic diseases in humans and livestock are not uncommon, and an important component in containment of such emerging viral diseases is rapid and reliable diagnostics. Such methods are often PCR-based and hence require the availability of sequence data from the pathogen. Rattus norvegicus (R. norvegicus) is a known reservoir for important zoonotic pathogens. Transmission may be direct via contact with the animal, for example, through exposure to its faecal matter, or indirectly mediated by arthropod vectors. Here we investigated the viral content in rat faecal matter (n=29) collected from two continents by analyzing 2.2 billion next-generation sequencing reads derived from both DNA and RNA. Among other virus families, we found sequences from members of the Picornaviridae to be abundant in the microbiome of all the samples. Here we describe the diversity of the picornavirus-like contigs including near-full-length genomes closely related to the Boone cardiovirus and Theiler's encephalomyelitis virus. From this study, we conclude that picornaviruses within R. norvegicus are more diverse than previously recognized. The virome of R. norvegicus should be investigated further to assess the full potential for zoonotic virus transmission.

  16. High diversity of picornaviruses in rats from different continents revealed by deep sequencing

    PubMed Central

    Hansen, Thomas Arn; Mollerup, Sarah; Nguyen, Nam-phuong; White, Nicole E; Coghlan, Megan; Alquezar-Planas, David E; Joshi, Tejal; Jensen, Randi Holm; Fridholm, Helena; Kjartansdóttir, Kristín Rós; Mourier, Tobias; Warnow, Tandy; Belsham, Graham J; Bunce, Michael; Willerslev, Eske; Nielsen, Lars Peter; Vinner, Lasse; Hansen, Anders Johannes

    2016-01-01

    Outbreaks of zoonotic diseases in humans and livestock are not uncommon, and an important component in containment of such emerging viral diseases is rapid and reliable diagnostics. Such methods are often PCR-based and hence require the availability of sequence data from the pathogen. Rattus norvegicus (R. norvegicus) is a known reservoir for important zoonotic pathogens. Transmission may be direct via contact with the animal, for example, through exposure to its faecal matter, or indirectly mediated by arthropod vectors. Here we investigated the viral content in rat faecal matter (n=29) collected from two continents by analyzing 2.2 billion next-generation sequencing reads derived from both DNA and RNA. Among other virus families, we found sequences from members of the Picornaviridae to be abundant in the microbiome of all the samples. Here we describe the diversity of the picornavirus-like contigs including near-full-length genomes closely related to the Boone cardiovirus and Theiler's encephalomyelitis virus. From this study, we conclude that picornaviruses within R. norvegicus are more diverse than previously recognized. The virome of R. norvegicus should be investigated further to assess the full potential for zoonotic virus transmission. PMID:27530749

  17. Conservation education in Madagascar: three case studies in the biologically diverse island-continent.

    PubMed

    Dolins, Francine L; Jolly, Alison; Rasamimanana, Hantanirina; Ratsimbazafy, Jonah; Feistner, Anna T C; Ravoavy, Florent

    2010-05-01

    Few Malagasy children and adults are aware of the rare and unique fauna and flora indigenous to their island-continent, including flagship lemur species. Even the Malagasy ancestral proverbs never mentioned lemurs, but these same proverbs talked about the now extinct hippopotamus. Madagascar's geography, history, and economic constraints contribute to severe biodiversity loss. Deforestation on Madagascar is reported to be over 100,000 ha/year, with only 10-15% of the island retaining natural forest [Green & Sussman, 1990]. Educating children, teacher-training, and community projects about environmental and conservation efforts to protect the remaining natural habitats of endangered lemur species provide a basis for long-term changes in attitudes and practices. Case studies of three conservation education projects located in different geographical regions of Madagascar, Centre ValBio, Madagacar Wildlife Conservation Alaotra Comic Book Project, and The Ako Book Project, are presented together with their ongoing stages of development, assessment, and outcomes. We argue that while nongovernmental organizational efforts are and will be very important, the Ministry of Education urgently needs to incorporate biodiversity education in the curriculum at all levels, from primary school to university. PMID:20039330

  18. Biogeochemistry of Hypersaline Springs Supporting a Mid-Continent Marine Ecosystem: An Analogue for Martian Springs?

    NASA Astrophysics Data System (ADS)

    Grasby, Stephen E.; Londry, Kathleen L.

    2007-08-01

    Hypersaline springs that host unique mid-continent marine ecosystems were examined in central Manitoba, Canada. The springs originate from a reflux of glacial meltwater that intrudes into underlying bedrock and dissolved buried salt beds. Two spring types were distinguished based both on flow rate and geochemistry. High flow springs (greater than 10 L/s) hosted extensive marine microbial mats, which were dominated by algae but also included diverse microbes. These varied somewhat between springs as indicated by changes in profiles of fatty acid methyl esters. Culture studies confirmed the presence of sulfate-reducing bacteria in sediments at the high flow sites. In contrast, low flow springs were affected by solar evaporation, increasing salinity, and temperature. These low flow springs behaved more like closed nutrient-limited systems and did not support microbial mats. Direct comparison of the high and low flow springs revealed interesting implications for the potential to record biosignatures in the rock record. High flow springs have abundant, well-developed microbial mats, which desiccate and are cemented along the edges of the spring pools; however, the high mass flux overwhelms any geochemical signature of microbial activity. In contrast, the nutrient-limited low flow sites develop strong geochemical signatures of sulfate reduction, even in the absence of microbial mats, due to less dilution with the lower flows. Geochemical and physical evidence for life did not correlate with the abundance of microbial life but, rather, with the extent to which the biological system formed a closed ecosystem.

  19. Long aftershock sequences within continents and implications for earthquake hazard assessment.

    PubMed

    Stein, Seth; Liu, Mian

    2009-11-01

    One of the most powerful features of plate tectonics is that the known plate motions give insight into both the locations and average recurrence interval of future large earthquakes on plate boundaries. Plate tectonics gives no insight, however, into where and when earthquakes will occur within plates, because the interiors of ideal plates should not deform. As a result, within plate interiors, assessments of earthquake hazards rely heavily on the assumption that the locations of small earthquakes shown by the short historical record reflect continuing deformation that will cause future large earthquakes. Here, however, we show that many of these recent earthquakes are probably aftershocks of large earthquakes that occurred hundreds of years ago. We present a simple model predicting that the length of aftershock sequences varies inversely with the rate at which faults are loaded. Aftershock sequences within the slowly deforming continents are predicted to be significantly longer than the decade typically observed at rapidly loaded plate boundaries. These predictions are in accord with observations. So the common practice of treating continental earthquakes as steady-state seismicity overestimates the hazard in presently active areas and underestimates it elsewhere. PMID:19890328

  20. SELECTION AND TREATMENT OF STRIPPER GAS WELLS FOR PRODUCTION ENHANCEMENT IN THE MID-CONTINENT

    SciTech Connect

    Scott Reeves

    2003-03-01

    Stripper gas wells are an important source of domestic energy supply and under constant threat of permanent loss (shut-in) due to marginal economics. In 1998, 192 thousand stripper gas wells produced over a Tcf of gas, at an average rate of less than 16 Mcfd. This represents about 57% of all producing gas wells in the onshore lower-48 states, yet only 8% of production. Reserves of stripper gas wells are estimated to be only 1.6 Tcf, or slightly over 1% of the onshore lower-48 total (end of year 1996 data). Obviously, stripper gas wells are at the very margin of economic sustenance. As the demand for natural gas in the U.S. grows to the forecasted estimate of over 30 Tcf annually by the year 2010, supply from current conventional sources is expected to decline. Therefore, an important need exists to fully exploit known domestic resources of natural gas, including those represented by stripper gas wells. The overall objectives of this project are to develop an efficient and low-cost methodology to broadly categorize the well performance characteristics for a stripper gas field, identify the high-potential candidate wells for remediation, and diagnose the specific causes for well underperformance. With this capability, stripper gas well operators can more efficiently and economically produce these resources and maximize these gas reserves. A further objective is to identify/develop, evaluate and test ''new and novel,'' economically viable remediation options. Finally, it is the objective of this project that all the methods and technologies developed in this project, while being tested in the Mid-Continent, be widely applicable to stripper gas wells of all types across the country. The project activities during the reporting period were: (1) Prepared various materials to describe the project for promotional purposes and to attract potential industry partners. Materials included slides for DOE's displays at the SPE Eastern Regional and Annual Technical Conference, and

  1. The likelihood of observing dust-stimulated phytoplankton growth in waters proximal to the Australian continent

    NASA Astrophysics Data System (ADS)

    Cropp, R. A.; Gabric, A. J.; Levasseur, M.; McTainsh, G. H.; Bowie, A.; Hassler, C. S.; Law, C. S.; McGowan, H.; Tindale, N.; Viscarra Rossel, R.

    2013-05-01

    We develop a tool to assist in identifying a link between naturally occurring aeolian dust deposition and phytoplankton response in the ocean. Rather than examining a single, or small number of dust deposition events, we take a climatological approach to estimate the likelihood of observing a definitive link between dust deposition and a phytoplankton bloom for the oceans proximal to the Australian continent. We use a dust storm index (DSI) to determine dust entrainment in the Lake Eyre Basin (LEB) and an ensemble of modelled atmospheric trajectories of dust transport from the basin, the major dust source in Australia. Deposition into the ocean is computed as a function of distance from the LEB source and the local over-ocean precipitation. The upper ocean's receptivity to nutrients, including dust-borne iron, is defined in terms of time-dependent, monthly climatological fields for light, mixed layer depth and chlorophyll concentration relative to the climatological monthly maximum. The resultant likelihood of a dust-phytoplankton link being observed is then mapped as a function of space and time. Our results suggest that the Southern Ocean (north of 45°S), the North West Shelf, and Great Barrier Reef are ocean regions where a rapid biological response to dust inputs is most likely to be observed. Conversely, due to asynchrony between deposition and ocean receptivity, direct causal links appear unlikely to be observed in the Tasman Sea and Southern Ocean south of 45°S.

  2. Geomorphologic Indices for Transition from Subduction to Arc-Continent Collision in Sumba Island, Indonesia

    NASA Astrophysics Data System (ADS)

    Authemayou, C.; Delcaillau, B.; Brocard, G. Y.; Molliex, S.; Nexer, M.; Pedoja, K.

    2014-12-01

    The Sumba Island lies in a key area to study the eastern Indonesia geodynamics. It is located in the Sunda-Banda fore-arc in the area of transition from subduction of the Indian oceanic lithosphere (W) beneath the Sunda-Banda arc to arc-continent collision between the Australian continental margin and the Sunda-Banda arc (E). East of the Sumba Island, the western boundary of the Savu basin originated during Middle Miocene by the southeastward slab retreat below the Sunda-Banda arc (Rigg and Hall, 2001). Previous studies has detected a global uplift of the island accommodating the Australian plate - South West Banda Arc convergence (Fleury et al., 2009). This uplift is associated with northeastward tilting and gravitational collapse to the South. Analyses of various geomorphic markers (perched low relief landscapes, rockyshore platform, coral reef terraces, drainages) and of morphometric indices allowed us to localise new structures (faults and folds), to determine the chronology of their activation and to better constraint the uplift history of Sumba Island. These results aim to understand the evolution of the deformation in Sumba Island in regard with its geodynamic context from Middle Miocene to present-day.

  3. A VLBI baseline post-adjustment approach for station velocity estimation in Eurasian continent

    NASA Astrophysics Data System (ADS)

    Zhang, Zhibin; Liu, Xiang

    2014-10-01

    Baseline lengths and their time-derivatives among 58 geodetic VLBI stations were fitted by using 4439 observing sessions from the International VLBI Service for Geodesy and Astrometry (IVS). First, the velocities of eight stations in Eurasian continent were set as unknown quantities. Then, two standard global solutions from 3523 IVS sessions and 1110 sessions from database code XA, respectively, were applied prior to all-station coordinates and the non-estimated station velocities. Finally, from the relations among the coordinates, velocities, baseline length and its time-derivative, two types of baseline post-adjustment (BPA) were used to estimate the velocities of the eight stations. We discuss the data processing details, including the effect of different prior values for the stations and the optimal solution. The results suggest that the precision of the station velocities based on the proposed approach is comparable to that of the global solution of the XA sessions. The baseline structure and the prior values of the stations affect the velocity estimates. Compared to the standard method of velocity estimation, there are no external constrains and conditions used in the proposed method.

  4. Climate as a driver of continent-wide irruptions in boreal seed-eating birds (Invited)

    NASA Astrophysics Data System (ADS)

    Strong, C.; Zuckerberg, B.; Betancourt, J. L.

    2013-12-01

    Boreal seed-eating birds regularly breed and overwinter throughout Canada and Alaska, but every few years these species demonstrate impressive irruptive migrations out of the boreal forest and into more southerly regions. It is thought that irruptive migrations are inversely dependent on a circumboreally synchronized pattern of seed crop fluctuations in boreal trees; seed-eating boreal birds stay in the north when food is plentiful, but sojourn south when food is scarce. Because both seed production and bird irruptions are characterized by periodicity ranging from biennial to decadal cycles, there is a strong possibility that these ecological phenomena are driven by climate variability. Using over twenty years of data from Project FeederWatch (a national citizen science project), we found that 'super irruptions' are correlated with continent-wide irruptive events in pine siskin population, and that these irruptions are associated with multi-decadal climate variability of Pacific origin. We also investigate how climate variability may influence the distribution of boreal bird species across different regions of North America during winter, and evaluate results in the context of limited banding data to assess possible geographic pathways of irruptions.

  5. Environmental character and history of the Lake Eyre Basin, one seventh of the Australian continent

    NASA Astrophysics Data System (ADS)

    Habeck-Fardy, Anna; Nanson, Gerald C.

    2014-05-01

    One of the world's largest internally drained (endorheic) basins, the 1.14 million km2 Lake Eyre (hydrological) Basin (LEB), covers nearly 15% of the Australian continent. Palaeoclimatic and associated flow regime variations are recorded in an archive of fluvial, aeolian and lacustrine sediments that are particularly accessible for deposits from the past ~ 300 ka, and are especially relevant for the past ~ 50 ka during which humans have inhabited Australia. Due to its great size, economic resources and diverse latitudinal extent, it has for over six decades been the focus of environmental, scientific and resource-based studies across numerous disciplines. With an emphasis on assessing the scientific and environmental research over this period, this paper is divided into four parts: Part A provides an introduction and background. Part B provides the geological history, including evidence of substantial Tertiary and Quaternary climate change. Part C covers the contemporary environmental conditions, and Part D presents a conclusion and summary. This not only represents the first comprehensive review of current knowledge of any of the world's truly large dryland drainage basins, but also highlights how more multi-disciplinary research is required. Key remaining questions revolve around the impact of global weather systems on the LEB; the lake-level story in relation to a more precise picture of Late Quaternary climate change; the role of humans and climate in the demise of the megafauna; modern hydrological changes; the role of vegetation in altering channel morphology and flow efficiencies; and nature of flood transmissions.

  6. Genetically similar isolates of Klebsiella pneumoniae serotype K1 causing liver abscesses in three continents.

    PubMed

    Turton, Jane F; Englender, Hilary; Gabriel, Samantha N; Turton, Sarah E; Kaufmann, Mary E; Pitt, Tyrone L

    2007-05-01

    The magA gene was sought in hypermucoviscous isolates of Klebsiella spp., the Klebsiella K serotype reference strains and in isolates of the K1 serotype of Klebsiella pneumoniae from the UK, Hong Kong, Israel, Taiwan and Australia. Only K1 isolates were PCR positive for magA; this gene was found in all such isolates tested. Hypermucoviscosity was not confined to magA positive isolates, nor was it found in all magA positive isolates. Comparison of XbaI PFGE profiles revealed that most (19/23) of the magA positive isolates clustered within 72 % similarity, with a further subcluster of isolates, from three different continents, clustering within >80 %. All of the 16 isolates tested within the main cluster had the same sequence type (ST 23) by multilocus sequence typing, with the exception of one isolate, which had a single nucleotide difference at one of the seven loci. This study indicates that a genotype strongly associated with highly invasive disease in Taiwan, where large numbers of cases have been reported, is geographically very widespread.

  7. Continent catheterizable conduit for urinary diversion in children: Applicability and acceptability

    PubMed Central

    Solanki, Shailesh; Babu, Muniamjanappa Narendra; Jadhav, Vinay; Shankar, Gowri; Ramesh, Santhanakrishnan

    2015-01-01

    Background: Continent catheterizable conduit (CCC) has made clean intermittent catheterization (CIC) painless and easy. It is applicable in diverse clinical conditions. Nonetheless, convincing the parents for the need of conduit procedure is still difficult. Materials and Methods: A prospective study, included children who underwent CCC procedure from March 2008 to February 2013. The data were assessed for; diagnosis, type of conduit, number of preoperative counselling sessions before acceptance, role of “self-help group” in decision making, parental concern and satisfaction for the procedure. Results: Twenty-nine patients (males; 24, females; 5) underwent CCC procedure for various clinical conditions. The multiple preoperative counselling sessions and creation of “self-help groups” were helped them for decision making. The main concerns among parents were: (1) Impact of procedure on future fertility and sexual life. (2) Patency of native urethral channel. (3) Permanent urinary stoma over the abdomen. Conclusion: CCC procedures are applicable to a wide array of clinical situations with a good outcome. The acceptability of the CCC procedure improves with preoperative counselling of parent/child, initiation of preoperative per urethral CIC and creation of self-help groups. PMID:25659547

  8. Stratigraphy of Mid-Continent rift system in Kansas as revealed by recent exploration wells

    SciTech Connect

    Newell, K.D.; Berendsen, P.; Watney, W.L.; Doveton, J.H.; Steeples, D.

    1989-03-01

    The Texaco 1 Poersch well in Kansas (11,300 ft TD) was the first significant exploration test of the Mid-Continent Rift System (MRS). An upper succession of rift-related rocks (2846-7429 ft) contains approximately 90% mafic igneous rocks with minor pegmatites and 10% oxidized siltstone and arkose. Arkose and subarkose with minor siltstone and shale make up 90% of a lower succession (7429 ft to TD). The remaining lower succession is composed of mafic igneous rocks. Mafic rocks are typically alkali basalts. Individual flows (detected by presence of amygdules, interflow sediments, compositional differences, and oxidized zones) range in thickness from 20 to 250 ft. Sedimentary rocks in the lower succession are divided into three sequences, each 1000-2000 ft thick. The sequences overlie relatively thin mafic flows or intrusives. Each sequence is generally composed of fining-upward units (50-150 ft thick) attributed to episodic movement and erosion of fault blocks in alluvial fan-dominated sedimentary environments. Shales and siltstones are too oxidized to be viable petroleum source rocks, but gray shale with approximately 0.5% total organic carbon was found in the MRS by the 1-4 Finn well, 21 mi to the northeast. Geologic examination of several shallower Precambrian tests holes near 1 Poersch shows considerable variability in sedimentary and tectonic settings along the MRS. Correlation between wells in Kansas and exposed areas of the MRS is still problematic. Additional wells will be necessary to better understand its hydrocarbon potential.

  9. The newfoundland basin - Ocean-continent boundary and Mesozoic seafloor spreading history

    NASA Technical Reports Server (NTRS)

    Sullivan, K. D.

    1983-01-01

    It is pointed out that over the past 15 years there has been considerable progress in the refinement of predrift fits and seafloor spreading models of the North Atlantic. With the widespread acceptance of these basic models has come increasing interest in resolution of specific paleogeographic and kinematic problems. Two such problems are the initial position of Iberia with respect to North America and the geometry and chronology of early (pre-80 m.y.) relative motions between these two plates. The present investigation is concerned with geophysical data from numerous Bedford Institute/Dalhousie University cruises to the Newfoundland Basin which were undrtaken to determine the location of the ocean-continent boundary (OCB) and the Mesozoic spreading history on the western side. From the examination of magnetic data in the Newfoundland Basin, the OCB east of the Grand Banks is defined as the seaward limit of the 'smooth' magnetic domain which characterizes the surrounding continental shelves. A substantial improvement in Iberia-North America paleographic reconstructions is achieved.

  10. Biogeochemistry of hypersaline springs supporting a mid-continent marine ecosystem: an analogue for martian springs?

    PubMed

    Grasby, Stephen E; Londry, Kathleen L

    2007-08-01

    Hypersaline springs that host unique mid-continent marine ecosystems were examined in central Manitoba, Canada. The springs originate from a reflux of glacial meltwater that intrudes into underlying bedrock and dissolved buried salt beds. Two spring types were distinguished based both on flow rate and geochemistry. High flow springs (greater than 10 L/s) hosted extensive marine microbial mats, which were dominated by algae but also included diverse microbes. These varied somewhat between springs as indicated by changes in profiles of fatty acid methyl esters. Culture studies confirmed the presence of sulfate-reducing bacteria in sediments at the high flow sites. In contrast, low flow springs were affected by solar evaporation, increasing salinity, and temperature. These low flow springs behaved more like closed nutrient-limited systems and did not support microbial mats. Direct comparison of the high and low flow springs revealed interesting implications for the potential to record biosignatures in the rock record. High flow springs have abundant, well-developed microbial mats, which desiccate and are cemented along the edges of the spring pools; however, the high mass flux overwhelms any geochemical signature of microbial activity. In contrast, the nutrient-limited low flow sites develop strong geochemical signatures of sulfate reduction, even in the absence of microbial mats, due to less dilution with the lower flows. Geochemical and physical evidence for life did not correlate with the abundance of microbial life but, rather, with the extent to which the biological system formed a closed ecosystem.

  11. High diversity of picornaviruses in rats from different continents revealed by deep sequencing.

    PubMed

    Hansen, Thomas Arn; Mollerup, Sarah; Nguyen, Nam-Phuong; White, Nicole E; Coghlan, Megan; Alquezar-Planas, David E; Joshi, Tejal; Jensen, Randi Holm; Fridholm, Helena; Kjartansdóttir, Kristín Rós; Mourier, Tobias; Warnow, Tandy; Belsham, Graham J; Bunce, Michael; Willerslev, Eske; Nielsen, Lars Peter; Vinner, Lasse; Hansen, Anders Johannes

    2016-01-01

    Outbreaks of zoonotic diseases in humans and livestock are not uncommon, and an important component in containment of such emerging viral diseases is rapid and reliable diagnostics. Such methods are often PCR-based and hence require the availability of sequence data from the pathogen. Rattus norvegicus (R. norvegicus) is a known reservoir for important zoonotic pathogens. Transmission may be direct via contact with the animal, for example, through exposure to its faecal matter, or indirectly mediated by arthropod vectors. Here we investigated the viral content in rat faecal matter (n=29) collected from two continents by analyzing 2.2 billion next-generation sequencing reads derived from both DNA and RNA. Among other virus families, we found sequences from members of the Picornaviridae to be abundant in the microbiome of all the samples. Here we describe the diversity of the picornavirus-like contigs including near-full-length genomes closely related to the Boone cardiovirus and Theiler's encephalomyelitis virus. From this study, we conclude that picornaviruses within R. norvegicus are more diverse than previously recognized. The virome of R. norvegicus should be investigated further to assess the full potential for zoonotic virus transmission. PMID:27530749

  12. FROM MICROCONTINENTS TO EXTENSIONAL ALLOCHTHONS: WITNESSES OF HOW CONTINENTS BREAK APART? (Invited)

    NASA Astrophysics Data System (ADS)

    Peron-Pinvidic, G.; Manatschal, G.

    2009-12-01

    It is well known that extensional processes can lead to different crustal configurations, depending notably on lithospheric composition, thermal structure and extension rate. Thereby, rifted margins are characterized, worldwide, by distinct tectonic, geological and magmatic contexts. Direct comparisons are not straightforward. However, even if different, these margins also present a limited number of crustal features that are regularly observed and described such as micro-continents, continental ribbons, H blocks, extensional allochthons and outer highs. If some of these structures have been proposed to be issued from plume-related events and strength differences between oceanic and continental lithosphere, it is still unclear how these different types of crustal bodies are generated and consequently what they may tell us about the underlying processes and associated tectonic evolution. However, we believe each of these features, by their similarities and differences, point to distinct processes (stretching, thinning, exhumation, magmatism, spreading). The aim of this contribution is to present these different "building stones", describe their characteristics and positions within the margins, and discuss the underlying tectonic processes and stratigraphic relationships related to their formation. We propose, using the example of the North Atlantic, that the superposition of specific deformation modes may explain the various types of crustal blocks and, as a consequence, that the occurrence of these various blocks are the witnesses of particular rifting processes.

  13. Long aftershock sequences within continents and implications for earthquake hazard assessment.

    PubMed

    Stein, Seth; Liu, Mian

    2009-11-01

    One of the most powerful features of plate tectonics is that the known plate motions give insight into both the locations and average recurrence interval of future large earthquakes on plate boundaries. Plate tectonics gives no insight, however, into where and when earthquakes will occur within plates, because the interiors of ideal plates should not deform. As a result, within plate interiors, assessments of earthquake hazards rely heavily on the assumption that the locations of small earthquakes shown by the short historical record reflect continuing deformation that will cause future large earthquakes. Here, however, we show that many of these recent earthquakes are probably aftershocks of large earthquakes that occurred hundreds of years ago. We present a simple model predicting that the length of aftershock sequences varies inversely with the rate at which faults are loaded. Aftershock sequences within the slowly deforming continents are predicted to be significantly longer than the decade typically observed at rapidly loaded plate boundaries. These predictions are in accord with observations. So the common practice of treating continental earthquakes as steady-state seismicity overestimates the hazard in presently active areas and underestimates it elsewhere.

  14. Spatial patterns in the evolution of Cenozoic dynamic topography and its influence on the Antarctic continent

    NASA Astrophysics Data System (ADS)

    Anderson, Lester; Ferraccioli, Fausto; Eagles, Graeme; Steinberger, Bernhard; Ritsema, Jeroen

    2013-04-01

    Our knowledge of dynamic topography in Antarctica remains in an infancy stage compared to other continents. We assess the space-time variability in dynamic topography in Antarctica by analysing grids of global dynamic topography in the Cenozoic (and late Cretaceous) based on the tomographic model S40RTS. Our model reveals that the Gamburtsev Province and Dronning Maud Land, two of the major nucleation sites for the East Antarctic Ice Sheet (EAIS) were ~500 m higher 60 Ma ago. The increased elevation may have facilitated ephemeral ice cap development in the early Cenozoic. Between ca 25 and 50 Ma the northern Wilkes Subglacial Basin was ca 200 m higher than today and a major increase in regional elevation (>600 m) occurred over the last 20-15 Ma over the northern and southern Victoria Land in the Transantarctic Mountains (TAM). The most prominent signal is observed over the Ross Sea Rift (RSR) where predicted Neogene dynamic topography exceeds 1,000 m. The flow of warm mantle from the West Antarctic Rift System (WARS)may have driven these dynamic topography effects over the TAM and RSR. However, we found that these effects are comparatively less significant over the Marie Byrd Land Dome and the interior of the WARS. If these contrasting dynamic topography effects are included, then the predicted elevations of the Ross Sea Embayment ca 20 Ma ago are more similar to the interior of the WARS, with significant implications for the early development of the West Antarctic Ice Sheet.

  15. Early onset of industrial-era warming across the oceans and continents.

    PubMed

    Abram, Nerilie J; McGregor, Helen V; Tierney, Jessica E; Evans, Michael N; McKay, Nicholas P; Kaufman, Darrell S

    2016-08-25

    The evolution of industrial-era warming across the continents and oceans provides a context for future climate change and is important for determining climate sensitivity and the processes that control regional warming. Here we use post-ad 1500 palaeoclimate records to show that sustained industrial-era warming of the tropical oceans first developed during the mid-nineteenth century and was nearly synchronous with Northern Hemisphere continental warming. The early onset of sustained, significant warming in palaeoclimate records and model simulations suggests that greenhouse forcing of industrial-era warming commenced as early as the mid-nineteenth century and included an enhanced equatorial ocean response mechanism. The development of Southern Hemisphere warming is delayed in reconstructions, but this apparent delay is not reproduced in climate simulations. Our findings imply that instrumental records are too short to comprehensively assess anthropogenic climate change and that, in some regions, about 180 years of industrial-era warming has already caused surface temperatures to emerge above pre-industrial values, even when taking natural variability into account. PMID:27558063

  16. Clostridium difficile Infection Seasonality: Patterns across Hemispheres and Continents – A Systematic Review

    PubMed Central

    Furuya-Kanamori, Luis; McKenzie, Samantha J.; Yakob, Laith; Clark, Justin; Paterson, David L.; Riley, Thomas V.; Clements, Archie C.

    2015-01-01

    Background Studies have demonstrated seasonal variability in rates of Clostridium difficile infection (CDI). Synthesising all available information on seasonality is a necessary step in identifying large-scale epidemiological patterns and elucidating underlying causes. Methods Three medical and life sciences publication databases were searched from inception to October 2014 for longitudinal epidemiological studies written in English, Spanish or Portuguese that reported the incidence of CDI. The monthly frequency of CDI were extracted, standardized and weighted according to the number of follow-up months. Cross correlation coefficients (XCORR) were calculated to examine the correlation and lag between the year-month frequencies of reported CDI across hemispheres and continents. Results The search identified 13, 5 and 2 studies from North America, Europe, and Oceania, respectively that met the inclusion criteria. CDI had a similar seasonal pattern in the Northern and Southern Hemisphere characterized by a peak in spring and lower frequencies of CDI in summer/autumn with a lag of 8 months (XCORR = 0.60) between hemispheres. There was no difference between the seasonal patterns across European and North American countries. Conclusion CDI demonstrates a distinct seasonal pattern that is consistent across North America, Europe and Oceania. Further studies are required to identify the driving factors of the observed seasonality. PMID:25775463

  17. Land-Use Change and Emerging Infectious Disease on an Island Continent

    PubMed Central

    McFarlane, Rosemary A.; Sleigh, Adrian C.; McMichael, Anthony J.

    2013-01-01

    A more rigorous and nuanced understanding of land-use change (LUC) as a driver of emerging infectious disease (EID) is required. Here we examine post hunter-gatherer LUC as a driver of infectious disease in one biogeographical region with a compressed and documented history—continental Australia. We do this by examining land-use and native vegetation change (LUCC) associations with infectious disease emergence identified through a systematic (1973–2010) and historical (1788–1973) review of infectious disease literature of humans and animals. We find that 22% (20) of the systematically reviewed EIDs are associated with LUCC, most frequently where natural landscapes have been removed or replaced with agriculture, plantations, livestock or urban development. Historical clustering of vector-borne, zoonotic and environmental disease emergence also follows major periods of extensive land clearing. These advanced stages of LUCC are accompanied by changes in the distribution and density of hosts and vectors, at varying scales and chronology. This review of infectious disease emergence in one continent provides valuable insight into the association between accelerated global LUC and concurrent accelerated infectious disease emergence. PMID:23812027

  18. Comparison of unilateral spinal and continous spinal anesthesia for hip surgery in elderly patients

    PubMed Central

    Kilinc, Leyla T.; Sivrikaya, G. Ulufer; Eksioglu, Birsen; Hanci, Ayse; Dobrucali, Hale

    2013-01-01

    Background: Continous spinal anesthesia (CSA) and frequently unilateral spinal anesthesia (USpA) are usually preferred for lower extremity surgeries. In this study, we aimed to compare the effects of these anesthetic techniques, on hemodynamic parameters, quality of anesthesia and complications in elderly patients undergoing hip surgeries. Methods: Forty patients aged 65 years and older, assigned to receive either CSA or USpA with 7.5 mg (1.5 cc) 0.5% hyperbaric bupivacaine initially. In CSA group, additional doses of 2.5 mg bupivacaine were applied until sensory block reach to T10. Maximum sensorial block level, time to reach the level of T10 (defined as onset time) and to regress to T12, hemodynamic parameters and ephedrine requirements were recorded peroperatively and during 2 h postoperatively. Results: Hemodynamic parameters, ephedrine requirements and regression of sensory block by two levels were similar in two groups. The onset time of anesthesia was significantly longer in USpA group than CSA group. Neuraxial anesthesia had to be converted to general anesthesia in 5 patients (25%) in CSA group and 1 patient (5%) in USpA group. Conclusions: We conclude that both USpA and CSA techniques have similar effects in elderly high risk patients. On the other hand, USpA is more preferable for surgeries with shorter durations due to its low cost and high success rate. PMID:24348291

  19. A correlation between mid-ocean-ridge basalt chemistry and distance to continents.

    PubMed

    Humler, Eric; Besse, Jean

    2002-10-10

    To fully understand the structure and dynamics of the Earth's convecting mantle, the origins of temperature variations within the mantle need to be resolved. Different hypotheses have been proposed to account for these temperature variations: for example, heat coming from the decay of radioactive elements or heat flowing out of the Earth's core. In addition, theoretical studies suggest that the thermal properties of continental masses can affect mantle convection, but quantitative data that could allow us to test these models are scarce. To address this latter problem, we have examined the chemistry of mid-ocean-ridge basalt--which reflects the temperature of the source mantle--as a function of the distance of the ridge from the closest continental margin. No correlation is observed for oceanic ridges close to subduction zones or hotspots; subduction zones probably inhibit thermal transfer between the mantle beneath continents and ocean, whereas hotspots influence the major-element chemistry of ridge basalts, which makes their interpretation with respect to mantle temperature more difficult. However, we do observe a significant correlation for mid-oceanic basalts from the Atlantic and Indian oceans. From this, we conclude that the location of continental masses relative to active ridges influences the large-scale thermal structure of the mantle and we estimate that the mantle cools by 0.05 to 0.1 degrees C per kilometre from the continental margins.

  20. Early onset of industrial-era warming across the oceans and continents

    NASA Astrophysics Data System (ADS)

    2016-08-01

    The evolution of industrial-era warming across the continents and oceans provides a context for future climate change and is important for determining climate sensitivity and the processes that control regional warming. Here we use post-AD 1500 palaeoclimate records to show that sustained industrial-era warming of the tropical oceans first developed during the mid-nineteenth century and was nearly synchronous with Northern Hemisphere continental warming. The early onset of sustained, significant warming in palaeoclimate records and model simulations suggests that greenhouse forcing of industrial-era warming commenced as early as the mid-nineteenth century and included an enhanced equatorial ocean response mechanism. The development of Southern Hemisphere warming is delayed in reconstructions, but this apparent delay is not reproduced in climate simulations. Our findings imply that instrumental records are too short to comprehensively assess anthropogenic climate change and that, in some regions, about 180 years of industrial-era warming has already caused surface temperatures to emerge above pre-industrial values, even when taking natural variability into account.

  1. The growth of continents and some consequences since 1.5 Ga

    NASA Technical Reports Server (NTRS)

    Howell, David G.

    1988-01-01

    The budget of Earth's oceanic sediment masses was discussed in terms of crustal growth and recycling. Based on estimates of the volume of oceanic sediments and the average age of oceanic crust, a continental denudation rate of 1.65 cu km/yr was computed. This crudely balances estimated crustal production rates of about 1 cu km/yr, but the efficiency of sediment loss via subduction, for example, must be considered. It was argued, on the basis of earthquake focal solutions, imagery of subduction zones, and plate kinematic reconstructions that little, if any, sediment was lost in this way. This yields a present day crustal growth rate of about 1 cu km/yr. The volume of continents to 1.5 Ga ago was discussed, assuming constant continental thickness and freeboard, and a constant hydrosphere volume. It was concluded that ocean ridge length was a factor of about 1.75 greater 1.5 Ga ago, but a major uncertainty is the average spreading rate in the past.

  2. Sensitivity of the Maritime Continent precipitation to horizontal resolution in a coupled regional model

    NASA Astrophysics Data System (ADS)

    Li, Yue; Jourdain, Nicolas; Taschetto, Andréa; Gupta, Alex Sen; Masson, Sébastien; Cai, Wenju

    2015-04-01

    The Maritime Continent (MC) is centred at one of the major monsoon systems in the world. Characterized by massive tropical heating and precipitation, it is strongly influencing both the Hadley and Walker circulations. However, there are significant challenges in correctly represent climate of this region because of the complex topography and the arrangement of lands and seas. It is often argued that improved representation of the diurnal cycle over islands and the complex mesoscale circulation associated with land-sea contrast is important to energy and hydrological cycles of this region. To investigate the sensitivity of precipitation over the MC to model horizontal resolution, we perform three regional numerical experiments using the coupled NEMO-OASIS-WRF model at different horizontal resolutions of 3/4°, 1/4° and 1/12° in both atmosphere and ocean components. The 3/4° and 1/4° experiments are run on a large MC domain for 21 years (1989 to 2009), and the 1/12° experiment is nested within the 1/4° domain using two-way interactive nesting over 5 years. Increasing the resolution reduces biases in mean SST and mean precipitation. The precipitation distribution is also improved at higher resolution, particularly in coastal areas. A part of these improvements are related to different behaviours of the model physical schemes across the three resolutions. Other changes are interpreted in terms of land-sea breeze, that we describe through a new comprehensive method.

  3. Early onset of industrial-era warming across the oceans and continents.

    PubMed

    Abram, Nerilie J; McGregor, Helen V; Tierney, Jessica E; Evans, Michael N; McKay, Nicholas P; Kaufman, Darrell S

    2016-08-24

    The evolution of industrial-era warming across the continents and oceans provides a context for future climate change and is important for determining climate sensitivity and the processes that control regional warming. Here we use post-ad 1500 palaeoclimate records to show that sustained industrial-era warming of the tropical oceans first developed during the mid-nineteenth century and was nearly synchronous with Northern Hemisphere continental warming. The early onset of sustained, significant warming in palaeoclimate records and model simulations suggests that greenhouse forcing of industrial-era warming commenced as early as the mid-nineteenth century and included an enhanced equatorial ocean response mechanism. The development of Southern Hemisphere warming is delayed in reconstructions, but this apparent delay is not reproduced in climate simulations. Our findings imply that instrumental records are too short to comprehensively assess anthropogenic climate change and that, in some regions, about 180 years of industrial-era warming has already caused surface temperatures to emerge above pre-industrial values, even when taking natural variability into account.

  4. Analysis of metagenomic data reveals common features of halophilic viral communities across continents.

    PubMed

    Roux, Simon; Enault, Francois; Ravet, Viviane; Colombet, Jonathan; Bettarel, Yvan; Auguet, Jean-Christophe; Bouvier, Thierry; Lucas-Staat, Soizick; Vellet, Agnès; Prangishvili, David; Forterre, Patrick; Debroas, Didier; Sime-Ngando, Telesphore

    2016-03-01

    Microbial communities from hypersaline ponds, dominated by halophilic archaea, are considered specific of such extreme conditions. The associated viral communities have accordingly been shown to display specific features, such as similar morphologies among different sites. However, little is known about the genetic diversity of these halophilic viral communities across the Earth. Here, we studied viral communities in hypersaline ponds sampled on the coast of Senegal (8-36% of salinity) using metagenomics approach, and compared them with hypersaline viromes from Australia and Spain. The specificity of hyperhalophilic viruses could first be demonstrated at a community scale, salinity being a strong discriminating factor between communities. For the major viral group detected in all samples (Caudovirales), only a limited number of halophilic Caudovirales clades were highlighted. These clades gather viruses from different continents and display consistent genetic composition, indicating that they represent related lineages with a worldwide distribution. Non-tailed hyperhalophilic viruses display a greater rate of gene transfer and recombination, with uncharacterized genes conserved across different kind of viruses and plasmids. Thus, hypersaline viral communities around the world appear to form a genetically consistent community that are likely to harbour new genes coding for enzymes specifically adapted to these environments.

  5. An interlaboratory transfer of a multi-analyte assay between continents.

    PubMed

    Georgiou, Alexandra; Dong, Kelly; Hughes, Stephen; Barfield, Matthew

    2015-01-01

    Alex has worked at GlaxoSmithKline for the past 15 years and currently works within the bioanalytical and toxicokinetic group in the United Kingdom. Alex's role in previous years has been the in-house support of preclinical and clinical bioanalysis, from method development through to sample analysis activities as well as acting as PI for GLP bioanalysis and toxicokinetics. For the past two years, Alex has applied this analytical and regulatory experience to focus on the outsourcing of preclinical bioanalysis, toxicokinetics and clinical bioanalysis, working closely with multiple bioanalytical and in-life CRO partners worldwide. Alex works to support DMPK and Safety Assessment outsourcing activities for GSK across multiple therapeutic areas, from the first GLP study through to late stage clinical PK studies. Transfer and cross-validation of an existing analytical assay between a laboratory providing current analytical support, and a laboratory needed for new or additional support, can present the bioanalyst with numerous challenges. These challenges can be technical or logistical in nature and may prove to be significant when transferring an assay between laboratories in different continents. Part of GlaxoSmithKline's strategy to improve confidence in providing quality data, is to cross-validate between laboratories. If the cross-validation fails predefined acceptance criteria, then a subsequent investigation would follow. This may also prove to be challenging. The importance of thorough planning and good communication throughout assay transfer, cross-validation and any subsequent investigations is illustrated in this case study.

  6. Crustal recycling at active convergent margins and growth of the continents

    SciTech Connect

    Morris, J. . Dept. of Earth and Planetary Sciences Carnegie Institution of Washington, DC ); Zheng, S.H. . Dept. of Geological Sciences)

    1993-03-01

    Subduction of continental materials at active convergent margins provides an opportunity to evaluate mechanisms and magnitude of subduction-driven crustal recycling and its potential role in continental growth. Continental materials, in the form of detrital sediments and elements adsorbed out of seawater onto settling sediment particles, are continuously supplied to subduction trenches. The sediments may be accreted and re-attached to the continental crust through collisional processes subducted to depth and subsequently involved in arc magma generation (magmatic recycling) or subducted past the arc into the deep mantle. Cosmogenic 10Be, which is strongly adsorbed onto settling sediment particles, may be used to investigate all aspects of sediment recycling. Because of its atmospheric source and short half-life, the high 10Be concentrations observed in many volcanic arc magmas require that the uppermost part of the sediment column be subducted to depth and some part of it returned to the surface in arc magmas within the measurable 10Be lifetime, effectively a few million years. In the Aleutians, Middle America and Marianas, 10Be is present only in the upper 12m, 100m and 25m, respectively of the subducting oceanic sediment column. Using von Huene and Scholl's 1991 estimate of oceanic sediment supply to trenches, the authors evidence for sediment bypassing of accretionary margins, and the limited recycling of most major elements in arc volcanism, estimates of sediment subduction are nearly equal to those required in a steady-state, recycling model for growth of the continents through time.

  7. Petrology and tectonics of Phanerozoic continent formation: From island arcs to accretion and continental arc magmatism

    USGS Publications Warehouse

    Lee, C.-T.A.; Morton, D.M.; Kistler, R.W.; Baird, A.K.

    2007-01-01

    Mesozoic continental arcs in the North American Cordillera were examined here to establish a baseline model for Phanerozoic continent formation. We combine new trace-element data on lower crustal xenoliths from the Mesozoic Sierra Nevada Batholith with an extensive grid-based geochemical map of the Peninsular Ranges Batholith, the southern equivalent of the Sierras. Collectively, these observations give a three-dimensional view of the crust, which permits the petrogenesis and tectonics of Phanerozoic crust formation to be linked in space and time. Subduction of the Farallon plate beneath North America during the Triassic to early Cretaceous was characterized by trench retreat and slab rollback because old and cold oceanic lithosphere was being subducted. This generated an extensional subduction zone, which created fringing island arcs just off the Paleozoic continental margin. However, as the age of the Farallon plate at the time of subduction decreased, the extensional environment waned, allowing the fringing island arc to accrete onto the continental margin. With continued subduction, a continental arc was born and a progressively more compressional environment developed as the age of subducting slab continued to young. Refinement into a felsic crust occurred after accretion, that is, during the continental arc stage, wherein a thickened crustal and lithospheric column permitted a longer differentiation column. New basaltic arc magmas underplate and intrude the accreted terrane, suture, and former continental margin. Interaction of these basaltic magmas with pre-existing crust and lithospheric mantle created garnet pyroxenitic mafic cumulates by fractional crystallization at depth as well as gabbroic and garnet pyroxenitic restites at shallower levels by melting of pre-existing lower crust. The complementary felsic plutons formed by these deep-seated differentiation processes rose into the upper crust, stitching together the accreted terrane, suture and former

  8. A new theory of micturition and urinary continence based on histomorphological studies. 3. The two parts of the musculus sphincter urethrae: physiological importance for continence in rest and stress.

    PubMed

    Dorschner, W; Stolzenburg, J U

    1994-01-01

    The urethral component of continence is the object of a lively discussion. A large number of the examiners interpret the external striated urethral muscle as part of the muscular pelvic diaphragm, formed partially or completely by the so-called musculus transversus perinei profundus. About 30,000 histological sections have been examined by light microscopy in a systematical manner. In contrast to numerous suggestions in the literature the musculus sphincter urethrae has been found to be an independent morphological unit in our investigation. It is separated from the surroundings by a segment of connective tissue. Furthermore, with the help of transversal, sagittal and frontal serial sections it was possible to show that the musculus transversus perinei profundus does not exist. In the female as well as in the male in the direction of the urethra the outer sphincter always borders on a layer of smooth muscle cells. In order to distinguish both parts the terms musculus sphincter urethrae transversostriatus and musculus sphincter urethrae glaber are introduced. In the context of a new continence theory three structures capable of occluding the urinary bladder will be discussed. It should be emphasized that the musculus sphincter urethrae glaber makes long-term continence possible.

  9. A bioassessment approach for mid-continent great rivers: the Upper Mississippi, Missouri, and Ohio (USA).

    PubMed

    Angradi, T R; Bolgrien, D W; Jicha, T M; Pearson, M S; Hill, B H; Taylor, D L; Schweiger, E W; Shepard, L; Batterman, A R; Moffett, M F; Elonen, C M; Anderson, L E

    2009-05-01

    The objectives of the Environmental Monitoring and Assessment Program for Great River Ecosystems (EMAP-GRE) are to (1) develop and demonstrate, in collaboration with states, an assessment program yielding spatially unbiased estimates of the condition of mid-continent great rivers; (2) evaluate environmental indicators for assessing great rivers; and (3) assess the current condition of selected great river resources. The purpose of this paper is to describe EMAP-GRE using examples based on data collected in 2004-2006 with emphasis on an approach to determining reference conditions. EMAP-GRE includes the Upper Mississippi River, the Missouri River, and the Ohio River. Indicators include biotic assemblages (fish, macroinvertebrates, plankton, algae), water chemistry, and aquatic and riparian physical habitat. Reference strata (river reaches for which a single reference expectation is appropriate) were determined by ordination of the fish assemblage and examination of spatial variation in environmental variables. Least disturbed condition of fish assemblages for reference strata was determined by empirical modeling in which we related fish assemblage metrics to a multimetric stressor gradient. We inferred least disturbed condition from the y-intercept, the predicted condition when stress was least. Thresholds for dividing the resource into management-relevant condition classes for biotic indicators were derived using predicted least disturbed condition to set the upper bound on the least disturbed condition class. Also discussed are the outputs of EMAP-GRE, including the assessment document, multimetric indices of condition, and unbiased data supporting state and tribal Clean Water Act reporting, adaptive management, and river restoration. PMID:18483771

  10. Petrogenesis of basalts and gabbros from an ancient continent ocean transition (External Liguride ophiolites, Northern Italy)

    NASA Astrophysics Data System (ADS)

    Montanini, Alessandra; Tribuzio, Riccardo; Vernia, Luigi

    2008-03-01

    Remnants of a fossil continent-ocean transition similar to that of the modern non-volcanic continental margins are preserved in the Jurassic External Liguride units. They consist of fertile lherzolites of subcontinental origin, MOR-type basalts and rare gabbroic intrusives, together with continental crust bodies exhumed during the rifting phases preceding the oceanization. The gabbroic rocks include troctolites, (olivine) gabbros, Fe-Ti oxide-bearing gabbros and diorites. Trace element and Nd isotope compositions indicate that these rocks were derived from N-MORB melts variably evolved through fractional crystallisation. In the gabbroic rocks, high-temperature (˜ 900 °C) shearing along ductile shear zones is locally overprinted by amphibolite-facies recrystallization ( T ˜ 650 °C), which was most likely assisted by seawater-derived fluids. Basalts crop out as lava flows and as dykes crosscutting mantle lherzolites and gabbroic rocks. They display nearly flat REE patterns and high Y/Nb values (5-14), similar to modern N-MORB. Basalts are also characterised by weak Zr enrichment relative to neighbouring REE (Zr/Zr * = 1.1-1.7) and high (Sm/Yb) DM ratios (1.5-1.8). Their Nd isotope compositions are close to typical depleted mantle (initial ɛ Nd = +7.6 to + 9.4). The geochemical features of parental melts of basaltic and gabbroic rocks may be attributed to melting of a MORB-type asthenospheric source. Trace element modelling shows that low-degree (≤ 6%) fractional melting of a depleted spinel peridotite cannot account for the elevated Sm/Yb ratios of basalts. Low-degree melting of a mixed source of spinel peridotite with small amounts of garnet pyroxenite has been proposed to explain the trace element signature of basalts.

  11. Sustaining Rocky Mountain landscapes: Science, policy and management for the Crown of the Continent ecosystem

    USGS Publications Warehouse

    Prato, Tony; Fagre, Daniel B.

    2007-01-01

    Prato and Fagre offer the first systematic, multi-disciplinary assessment of the challenges involved in managing the Crown of the Continent Ecosystem ( CCE), an area of the Rocky Mountains that includes northwestern Montana, southwestern Alberta, and southeastern British Columbia. The spectacular landscapes, extensive recreational options, and broad employment opportunities of the CCE have made it one of the fastest growing regions in the United States and Canada, and have lead to a shift in its economic base from extractive resource industries to service-oriented recreation and tourism industries. In the process, however, the amenities and attributes that draw people to this “New West” are under threat. Pastoral scenes are disappearing as agricultural lands and other open spaces are converted to residential uses, biodiversity is endangered by the fragmentation of fish and wildlife habitats, and many areas are experiencing a decline in air and water quality. Sustaining Rocky Mountain Landscapes provides a scientific basis for communities to develop policies for managing the growth and economic transformation of the CCE without sacrificing the quality of life and environment for which the land is renowned. This forthcoming edited volume focuses on five aspects of sustaining mountain landscapes in the CCE and similar regions in the Rocky Mountains. The five aspects are: 1) how social, economic, demo graphic and environmental forces are transforming ecosystem structure and function, 2) trends in use and conditions for human and environmental resources, 3) activating science, policy and education to enhance sustainable landscape management, 4) challenges to sustainable management of public and private lands, and 5) future prospects for achieving sustainable landscapes.

  12. Precipitation over urban areas in the western Maritime Continent using a convection-permitting model

    NASA Astrophysics Data System (ADS)

    Argüeso, Daniel; Di Luca, Alejandro; Evans, Jason P.

    2016-08-01

    This study investigates the effects of urban areas on precipitation in the western Maritime Continent using a convection-permitting regional atmospheric model. The Weather Research and Forecasting model was used to simulate the atmosphere at a range of spatial resolutions using a multiple nesting approach. Two experiments (with and without urban areas) were completed over a 5-year period (2008-2012) each to estimate the contribution of cities to changes in local circulation. At first, the model is evaluated against two satellite-derived precipitation products and the benefit of using a very high-resolution model (2-km grid spacing) over a region where rainfall is dominated by convective processes is demonstrated, particularly in terms of its diurnal cycle phase and amplitude. The influence of cities on precipitation characteristics is quantified for two major urban nuclei in the region (Jakarta and Kuala Lumpur) and results indicate that their presence locally enhances precipitation by over 30 %. This increase is mainly due to an intensification of the diurnal cycle. We analyse the impact on temperature, humidity and wind to put forward physical mechanisms that explain such changes. Cities increase near surface temperature, generating instability. They also make land-sea temperature contrasts stronger, which enhances sea breeze circulations. Together, they increase near-surface moisture flux convergence and favour convective processes leading to an overall increase of precipitation over urban areas. The diurnal cycle of these effects is reflected in the atmospheric footprint of cities on variables such as humidity and cloud mixing ratio and accompanies changes in precipitation.

  13. TRAC-MIP: Tropical Rain bands with an Annual cycle and Continent - Model Intercomparison Project.

    NASA Astrophysics Data System (ADS)

    Biasutti, Michela; Voigt, Aiko; Scheff, Jack; Zeppetello, Lucas Randall

    2016-04-01

    Understanding and modeling tropical rainfall has proven to be one of the most stubborn challenges in climate science. Tropical rainfall biases such as a double inter-tropical convergence zone (ITCZ) in the East Pacific have now persisted more than two decades despite the general improvements of climate models, and projections for the ITCZ and the monsoon systems remain uncertain in magnitude and sign. Progress in these areas can be fostered by a set of idealized experiments that target the dynamics of tropical rain band, as long as these simple experiments are properly integrated within a full hierarchy of model simulations. To this aim, we have designed the "Tropical Rain belts with an Annual cycle and Continent - Model Intercomparison Project." TRAC-MIP involves five experiments using idealized aquaplanet and land setups to explore the dynamics of tropical rainfall. By using interactive sea-surface temperatures and seasonally-varying insolation TRAC-MIP fills the gap between idealized aquaplanet simulations with prescribed SSTs and the fully-coupled realistic model simulations of CMIP5. TRAC-MIP includes the participation of 13 state-of-the art comprehensive climate models, and it also includes a simplified model that neglects cloud and water-vapor radiative feedbacks, thus allowing a more direct connection between the results from the TRAC-MIP comprehensive models and the theoretical studies of tropical rain belt dynamics. We will present preliminary results from the ensemble, aiming to examine the mechanisms controlling tropical precipitation in the context of forced variability. First and foremost, we are interested in the largest forced variation: the annual cycle. Second, we are interested in the response to key forcings of the future (greenhouse gases) and of the Holocene (insolation). We will draw out the similarities and the distinctions between oceanic and continental rain bands, study the ways in which the two interact with each other, and investigate

  14. Rayleigh Wave Tomography of Mid-Continent Rift (MCR) using Earthquake and Ambient Noise Data

    NASA Astrophysics Data System (ADS)

    Aleqabi, G. I.; Wiens, D.; Wysession, M. E.; Shen, W.; van der Lee, S.; Revenaugh, J.; Frederiksen, A. W.; Darbyshire, F. A.; Stein, S. A.; Jurdy, D. M.; Wolin, E.; Bollmann, T. A.

    2015-12-01

    The structure of the North American Mid-Continent Rift Zone (MCRZ) is examined using Rayleigh waves from teleseismic earthquakes and ambient seismic noise recorded by the Superior Province Rifting EarthScope Experiment (SPREE). Eighty-four broadband seismometers were deployed during 2011-2013 in Minnesota and Wisconsin, USA, and Ontario, CA, along three lines; two across the rift axis and the third along the rift axis. These stations, together with the EarthScope Transportable Array, provided excellent coverage of the MCRZ. The 1.1 Ga Mesoproterozoic failed rift consists of two arms, buried under post-rifting sedimentary formations that meet at Lake Superior. We compare two array-based tomography methods using teleseismic fundamental mode Rayleigh waves phase and amplitude measurements: the two-plane wave method (TPWM, Forsyth, 1998) and the automated surface wave phase velocity measuring system (ASWMS, Jin and Gaherty, 2015). Both array methods and the ambient noise method give relatively similar results showing low velocity zones extending along the MCRZ arms. The teleseismic Rayleigh wave results from 18 - 180 s period are combined with short period phase velocity results (period 8-30 s) obtained from ambient noise by cross correlation. Phase velocities from the methods are very similar at periods of 18-30 where results overlap; in this period range we use the average of the noise and teleseismic results. Finally the combined phase velocity curve is inverted using a Monte-Carlo inversion method at each geographic point in the model. The results show low velocities at shallow depths (5-10 km) that are the result of very deep sedimentary fill within the MCRZ. Deeper-seated low velocity regions may correspond to mafic underplating of the rift zone.

  15. Emerging rabbit haemorrhagic disease virus 2 (RHDV2) at the gates of the African continent.

    PubMed

    Martin-Alonso, Aarón; Martin-Carrillo, Natalia; Garcia-Livia, Katherine; Valladares, Basilio; Foronda, Pilar

    2016-10-01

    Until the beginning of this decade, the genetic characterization of rabbit haemorrhagic disease virus (RHDV) from Iberian Peninsula had revealed the existence of two genogroups, G1 and sporadically G6. In 2010, the new emerging rabbit haemorrhagic disease variant, RHDV2 or RHDVb, was described in France, from where it has rapidly spread throughout Europe, including Iberian Peninsula countries. Nevertheless, although cases of rabbit haemorrhagic disease (RHD) have been reported in the Canary Islands, a Spanish archipelago located 100km off the coast of Morocco, no genetic characterization of RHDV had been carried out. Consequently, in order to identify the circulating RHDV strains in this archipelago, liver samples of six farm rabbits and fifteen wild rabbits were collected from several areas of the largest island, Tenerife, and analyzed for the presence of RHDV by antigen capture double antibody sandwich ELISA. In case of positive ELISA result, we amplified and sequenced two fragments of the vp60 gene, which were concatenated for phylogenetic purposes. The sequences analysis revealed the presence of RHDV2 in both farm and wild rabbits from several areas of Tenerife. This result constitutes the first finding of RHDV2 in the Canary Islands. These RHDV2 strains found in Tenerife shared two exclusive SNPs that have not been observed in the rest of RHDV2 strains. The identification of RHDV2 and the absence of classic RHDV strains in this study suggest that RHDV2 may be replacing classic strains in Tenerife, as has been also proposed in Iberian Peninsula, France and Azores. Given the proximity of the Canary Islands to the African continent, this result should raise awareness about a possible dispersal of RHDV2 from the Canary Islands to the North of Africa. PMID:27321441

  16. Preparation of northern mid-continent petroleum. Quarterly report, July 1--September 20, 1996

    SciTech Connect

    Gerhard, L.C.; Carr, T.R.; Watney, W.L.

    1997-04-01

    Project will develop a prototype for a digital and hard-copy atlas of petroleum fields and reservoirs in the northern Mid-continent region. A limited number of reservoirs in Kansas are to be included in the prototype project,but the goal is to expand beyond the prototype atlas to include significant reservoirs representing the major plays in Kansas, Nebraska, south dakota, North Dakota, the Williston basin portion of Montana, the Denver-Julesburg basin of eastern Colorado and southeastern Colorado. Primary products of the prototype atlas will be on-line accessible digital data bases covering two selected petroleum plays in Kansas. ``Pages`` and data schema for the atlas overview and field studies have been developed and are accessible through the world-wide-web. The atlas structure includes access to geologic, geophysical and production information at levels from the national, to the regional, to the field to the individual well. Several approaches have been developed that provide efficient and flexible screening and search procedures. The prototype of the digital atlas is accessible through the Kansas Geological Survey Petroleum Research Section (PRS) HomePage (the Universal Resource Locator [URL] is http://www.kgs.ukans.edu/PRS/PRS.html). The Digital Petroleum Atlas (DPA) HomePage is available directly at http://www.kgs. ukans.edu/DPA/dpaHome.html. Technology transfer is underway through presentations at national and regional meetings and through the use of monthly electronic updates and the on-line availability of the DPA products. Project information and Quarterly Progress Reports are linked to the Digital Petroleum Atlas HomePage.

  17. Mesoscale modeling of smoke transport over the South Asian maritime continent: vertical distributions and topographic effect

    NASA Astrophysics Data System (ADS)

    Ge, C.; Wang, J.; Yang, Z.; Hyer, E. J.; Reid, J. S.; Chew, B.; Mahamod, M.

    2011-12-01

    The online-coupled Weather Research and Forecasting model with Chemistry (WRF-Chem) is used in conjunction with the FLAMBE MODIS-based biomass burning emissions to simulate the transport of smoke particles over the southeast Asian Maritime Continent (MC, 10°S - 10°N, 90°E-150°E) during September - October 2006 when the moderate El Nino event caused the largest region biomass burning outbreak since 1998. The modeled smoke transport pathway is found to be consistent with the MODIS true color images. Quantitatively, the modeled smoke particle mass can explain ~50% of temporal variability in 24-hour average observed PM10 at most ground stations, with linear correlation coefficients often larger than 0.7. Analysis of CALIOP data shows that smoke aerosols are primarily located within 3.5 km above the surface, and we found that smoke injection height in the model should be at ~800 m above surface to best match CALIOP observations downwind, instead of 2 km as used in the past literature. Comparison of CALIOP data in October 2006 with that in other years (2007-2010) reveals that the peak of aerosol extinction always occurs at ~1 km above surface, but smoke events in 2006 doubled the aerosol extinction from the surface to 3.5 km. Numerical experiments further show that the Tama Abu topography in Malaysia Peninsula has a significant impact on smoke transport and the surface in the vicinity. A conceptual model, based upon our analysis of two-month WRFchem simulation and satellite data, is proposed to explain the meteorological causes for smoke layers above the clouds as seen in the CALIOP data.

  18. Present-day groundwater recharge estimation in parts of the Indian Sub-Continent

    NASA Astrophysics Data System (ADS)

    Bhanja, S. N.; Mukherjee, A.; Wada, Y.; Scanlon, B. R.; Taylor, R. G.; Rodell, M.; Malakar, P.

    2015-12-01

    Large part of global population has been dependent on groundwater as a source of fresh water. The demand would further increase with increasing population and stress associated with climate change. We tried to provide regional-scale groundwater recharge estimates in a large part of Indian Sub-Continent. A combination of ground-based, satellite-based and numerical model simulated recharge estimates were presented in the densely populated region. Three different methods: an intense network of observational wells (n>13,000 wells), a satellite (TRMM) and global land-surface model (CLM) outputs, and a global-scale hydrological model (PCR GLOBWB) were employed to calculate recharge estimates. Groundwater recharge values exhibit large spatial variations over the entire region on the basis of aquifer hydrogeology, precipitation and groundwater withdrawal patterns. Groundwater recharge estimates from all three estimation techniques were found to be higher (>300 mm/year) in fertile planes of Indus-Ganges-Brahmaputra (IGB) river basins. A combination of favorable hydrogeologic conditions (porosity, permeability etc.), comparatively higher rates of precipitation, and return flow from rapidly withdrawn irrigation water might influence occurrence of high recharge rates. However, central and southern study area experiences lower recharge rates (<200 mm/year), might be associated with unfavorable hydrogeologic conditions associated with cratonic provinces. Statistical analysis of inter-comparison between the three different recharge estimates show good matches in some of the areas. Recharge estimates indicate dynamic nature of groundwater recharge as a function of precipitation, land use pattern, and hydrogeologic parameters. On a first hand basis, the estimates will help policy makers to understand groundwater recharge process over the densely populated region and finally would facilitate to implement sustainable policy for securing water security.

  19. SELECTION AND TREATMENT OF STRIPPER GAS WELLS FOR PRODUCTION ENHANCEMENT IN THE MID-CONTINENT

    SciTech Connect

    Scott Reeves

    2003-03-01

    Stripper gas wells are an important source of domestic energy supply and under constant threat of permanent loss (shut-in) due to marginal economics. In 1998, 192 thousand stripper gas wells produced over a Tcf of gas, at an average rate of less than 16 Mcfd. This represents about 57% of all producing gas wells in the onshore lower-48 states, yet only 8% of production. Reserves of stripper gas wells are estimated to be only 1.6 Tcf, or slightly over 1% of the onshore lower-48 total (end of year 1996 data). Obviously, stripper gas wells are at the very margin of economic sustenance. As the demand for natural gas in the U.S. grows to the forecasted estimate of over 30 Tcf annually by the year 2010, supply from current conventional sources is expected to decline. Therefore, an important need exists to fully exploit known domestic resources of natural gas, including those represented by stripper gas wells. The overall objectives of this project are to develop an efficient and low-cost methodology to broadly categorize the well performance characteristics for a stripper gas field, identify the high-potential candidate wells for remediation, and diagnose the specific causes for well underperformance. With this capability, stripper gas well operators can more efficiently and economically produce these resources and maximize these gas reserves. A further objective is to identify/develop, evaluate and test ''new and novel,'' economically viable remediation options. Finally, it is the objective of this project that all the methods and technologies developed in this project, while being tested in the Mid-Continent, be widely applicable to stripper gas wells of all types across the country. The project activities during the reporting period were: (1) The contract was signed on August 20, 2000. Little work has been performed other than preliminary planning to get the project underway.

  20. SELECTION AND TREATMENT OF STRIPPER GAS WELLS FOR PRODUCTION ENHANCEMENT IN THE MID-CONTINENT

    SciTech Connect

    Scott Reeves

    2003-04-01

    Stripper gas wells are an important source of domestic energy supply and under constant threat of permanent loss (shut-in) due to marginal economics. In 1998, 192 thousand stripper gas wells produced over a Tcf of gas, at an average rate of less than 16 Mcfd. This represents about 57% of all producing gas wells in the onshore lower-48 states, yet only 8% of production. Reserves of stripper gas wells are estimated to be only 1.6 Tcf, or slightly over 1% of the onshore lower-48 total (end of year 1996 data). Obviously, stripper gas wells are at the very margin of economic sustenance. As the demand for natural gas in the U.S. grows to the forecasted estimate of over 30 Tcf annually by the year 2010, supply from current conventional sources is expected to decline. Therefore, an important need exists to fully exploit known domestic resources of natural gas, including those represented by stripper gas wells. The overall objectives of this project are to develop an efficient and low-cost methodology to broadly categorize the well performance characteristics for a stripper gas field, identify the high-potential candidate wells for remediation, and diagnose the specific causes for well underperformance. With this capability, stripper gas well operators can more efficiently and economically produce these resources and maximize these gas reserves. A further objective is to identify/develop, evaluate and test ''new and novel,'' economically viable remediation options. Finally, it is the objective of this project that all the methods and technologies developed in this project, while being tested in the Mid-Continent, be widely applicable to stripper gas wells of all types across the country. The project activities during the reporting period were: Continued coordinating the final selection of candidates and field implementation with Oneok. Oneok plans on performing the operations early in 2003.

  1. SELECTION AND TREATMENT OF STRIPPER GAS WELLS FOR PRODUCTION ENHANCEMENT IN THE MID-CONTINENT

    SciTech Connect

    Scott Reeves

    2003-03-01

    Stripper gas wells are an important source of domestic energy supply and under constant threat of permanent loss (shut-in) due to marginal economics. In 1998, 192 thousand stripper gas wells produced over a Tcf of gas, at an average rate of less than 16 Mcfd. This represents about 57% of all producing gas wells in the onshore lower-48 states, yet only 8% of production. Reserves of stripper gas wells are estimated to be only 1.6 Tcf, or slightly over 1% of the onshore lower-48 total (end of year 1996 data). Obviously, stripper gas wells are at the very margin of economic sustenance. As the demand for natural gas in the U.S. grows to the forecasted estimate of over 30 Tcf annually by the year 2010, supply from current conventional sources is expected to decline. Therefore, an important need exists to fully exploit known domestic resources of natural gas, including those represented by stripper gas wells. The overall objectives of this project are to develop an efficient and low-cost methodology to broadly categorize the well performance characteristics for a stripper gas field, identify the high-potential candidate wells for remediation, and diagnose the specific causes for well underperformance. With this capability, stripper gas well operators can more efficiently and economically produce these resources and maximize these gas reserves. A further objective is to identify/develop, evaluate and test ''new and novel,'' economically viable remediation options. Finally, it is the objective of this project that all the methods and technologies developed in this project, while being tested in the Mid-Continent, be widely applicable to stripper gas wells of all types across the country. The project activities during the reporting period were: (1) Continued coordinating the final selection of candidates and field implementation with Oneok. Oneok plans on performing the operations early in 2003.

  2. SELECTION AND TREATMENT OF STRIPPER GAS WELLS FOR PRODUCTION ENHANCEMENT IN THE MID-CONTINENT

    SciTech Connect

    Scott Reeves

    2003-03-01

    Stripper gas wells are an important source of domestic energy supply and under constant threat of permanent loss (shut-in) due to marginal economics. In 1998, 192 thousand stripper gas wells produced over a Tcf of gas, at an average rate of less than 16 Mcfd. This represents about 57% of all producing gas wells in the onshore lower-48 states, yet only 8% of production. Reserves of stripper gas wells are estimated to be only 1.6 Tcf, or slightly over 1% of the onshore lower-48 total (end of year 1996 data). Obviously, stripper gas wells are at the very margin of economic sustenance. As the demand for natural gas in the U.S. grows to the forecasted estimate of over 30 Tcf annually by the year 2010, supply from current conventional sources is expected to decline. Therefore, an important need exists to fully exploit known domestic resources of natural gas, including those represented by stripper gas wells. The overall objectives of this project are to develop an efficient and low-cost methodology to broadly categorize the well performance characteristics for a stripper gas field, identify the high-potential candidate wells for remediation, and diagnose the specific causes for well underperformance. With this capability, stripper gas well operators can more efficiently and economically produce these resources and maximize these gas reserves. A further objective is to identify/develop, evaluate and test ''new and novel,'' economically viable remediation options. Finally, it is the objective of this project that all the methods and technologies developed in this project, while being tested in the Mid-Continent, be widely applicable to stripper gas wells of all types across the country. The project activities during the reporting period were: (1) Began preparing final project report, less the field implementation component. (2) Coordinated the final selection of candidates and field implementation with Oneok.

  3. Simulated versus observed patterns of warming over the extratropical Northern Hemisphere continents during the cold season.

    PubMed

    Wallace, John M; Fu, Qiang; Smoliak, Brian V; Lin, Pu; Johanson, Celeste M

    2012-09-01

    A suite of the historical simulations run with the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4) models forced by greenhouse gases, aerosols, stratospheric ozone depletion, and volcanic eruptions and a second suite of simulations forced by increasing CO(2) concentrations alone are compared with observations for the reference interval 1965-2000. Surface air temperature trends are disaggregated by boreal cold (November-April) versus warm (May-October) seasons and by high latitude northern (N: 40°-90 °N) versus southern (S: 60 °S-40 °N) domains. A dynamical adjustment is applied to remove the component of the cold-season surface air temperature trends (over land areas poleward of 40 °N) that are attributable to changing atmospheric circulation patterns. The model simulations do not simulate the full extent of the wintertime warming over the high-latitude Northern Hemisphere continents during the later 20th century, much of which was dynamically induced. Expressed as fractions of the concurrent trend in global-mean sea surface temperature, the relative magnitude of the dynamically induced wintertime warming over domain N in the observations, the simulations with multiple forcings, and the runs forced by the buildup of greenhouse gases only is 721, and roughly comparable to the relative magnitude of the concurrent sea-level pressure trends. These results support the notion that the enhanced wintertime warming over high northern latitudes from 1965 to 2000 was mainly a reflection of unforced variability of the coupled climate system. Some of the simulations exhibit an enhancement of the warming along the Arctic coast, suggestive of exaggerated feedbacks. PMID:22847408

  4. Interannual variations in snowpack in the Crown of the Continent Ecosystem

    NASA Astrophysics Data System (ADS)

    Selkowitz, David J.; Fagre, Daniel B.; Reardon, Blase A.

    2002-12-01

    Ecosystem changes such as glacier recession and alpine treeline advance have been documented over the previous 150 years in the Rocky Mountains of northern Montana and southern British Columbia and Alberta, a region known as the Crown of the Continent Ecosystem (CCE). Such changes are controlled, at least partially, by variations in snowpack. The CCE consists primarily of public lands, the majority of which is undeveloped or wilderness. Consequently, this region is well suited for an examination of long-term snowpack variation and associated ecosystem change. Data from nine SNOTEL sites provide an indication of the daily accumulation and ablation of snowpack over the period 1977-2001, as well as the relationship between precipitation, temperature and snowpack. 1 April data from 21 snow courses indicated the extent of regional snowpack variation and trends over the period 1950-2001, and 1 May data from three snow courses in Glacier National Park allow this record to be extended back to 1922. SNOTEL data suggest CCE snowpacks are larger and more persistent than in most regions of the western USA, and that water year precipitation is the primary control on 1 April snow water equivalent (SWE). Snow course data indicate that variations in both 1 April and 1 May mean SWE are closely tied to the Pacific decadal oscillation, an El Niño-southern oscillation-like interdecadal pattern of Pacific Ocean climate variability. Despite relatively stable snowpacks and summer temperatures since 1922, the glaciers in Glacier National Park have receded steadily during this period, implying a significant climatic shift between their Little Ice Age glacial maxima (ca 1860) and 1922. Published in 2002 by John Wiley & Sons Ltd.

  5. Simulated versus observed patterns of warming over the extratropical Northern Hemisphere continents during the cold season

    PubMed Central

    Wallace, John M.; Fu, Qiang; Smoliak, Brian V.; Lin, Pu; Johanson, Celeste M.

    2012-01-01

    A suite of the historical simulations run with the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4) models forced by greenhouse gases, aerosols, stratospheric ozone depletion, and volcanic eruptions and a second suite of simulations forced by increasing CO2 concentrations alone are compared with observations for the reference interval 1965–2000. Surface air temperature trends are disaggregated by boreal cold (November-April) versus warm (May-October) seasons and by high latitude northern (N: 40°–90 °N) versus southern (S: 60 °S–40 °N) domains. A dynamical adjustment is applied to remove the component of the cold-season surface air temperature trends (over land areas poleward of 40 °N) that are attributable to changing atmospheric circulation patterns. The model simulations do not simulate the full extent of the wintertime warming over the high-latitude Northern Hemisphere continents during the later 20th century, much of which was dynamically induced. Expressed as fractions of the concurrent trend in global-mean sea surface temperature, the relative magnitude of the dynamically induced wintertime warming over domain N in the observations, the simulations with multiple forcings, and the runs forced by the buildup of greenhouse gases only is 7∶2∶1, and roughly comparable to the relative magnitude of the concurrent sea-level pressure trends. These results support the notion that the enhanced wintertime warming over high northern latitudes from 1965 to 2000 was mainly a reflection of unforced variability of the coupled climate system. Some of the simulations exhibit an enhancement of the warming along the Arctic coast, suggestive of exaggerated feedbacks. PMID:22847408

  6. Relating Precipitation Phenomena with MODIS Detected Hot Spots in the Maritime Continent

    NASA Astrophysics Data System (ADS)

    Ramirez, E. M.; Reid, J. S.; Xian, P.; Hyer, E.; Turk, J.; Flatau, M.; Zhang, C.

    2009-12-01

    Recent studies of land use practices in SE Asia’s Maritime Continent (MC) have raised questions over potential meteorological implications including smoke-cloud interaction and changes in the regional radiation budget. Land management practices on Java, Sumatra, Sulawesi, Borneo, and the Malay Peninsula include biomass burning to clear primary forest as well as to maintain oil palm plantations. Burning is also employed for clearing unwanted remains from previous crops, rice stubble for example. However, burning activity is often dictated by weather, in particular precipitation. We studied 5 years of MODIS active fire hot spot and satellite precipitation data to investigate how observed burning activity correlated with precipitation features at four major scales: 1) Intraseasonal El Nino-Southern Oscillation (ENSO) and Indian Ocean Dipole (IOP); 2) Seasonal migration of the Intertropical Convergence Zone (ITCZ); 3) the 30-90 day Madden Julian Oscillation (MJO); and 4) regional convection from localized weather phenomenon (e.g., orographic, isolated thermal convection, sea breeze, etc…). It was found that observed burn patterns from each of the islands of the MC had differing responses to these four forcings. Observed burning activity on the islands of Borneo and Sulawesi correlated strongly with the ENSO and ITCZ indicies, whereas Sumatra was more influenced by the phase and strength of the MJO. Java, showing a mix of influence, exhibited strong fire activity in the morning rather than afternoon which is unusual for most burning regions. We hypothesize that these observed relationships reflect both physical land use differences and contextual bias/observability issues associated with the region’s heavy cloud cover. For further studies on smoke-meteorology interaction, our findings point to the need for a clear understanding of the meteorological context of satellite observations.

  7. Big Data and Ecological Forecasting: Integrating NEON Observational and Sensor Data from Reach to Continent

    NASA Astrophysics Data System (ADS)

    Vance, J. M.; Goodman, K. J.; Lunch, C. K.; Fitzgerald, M.

    2015-12-01

    The ability to forecast the response of varied ecosystems to changes in climate and land use will be crucial for the management of resources and ecosystem services. Ecological forecasting presents many significant challenges within each of the aspects of data capture, assimilation, and modeling. High space-time resolution sampling is required to address the challenges of scaling from the site level to the continent. Determining the uncertainty of data used for model input and parameterization is critical for constraining the model for accurate representation. The National Ecological Observatory Network (NEON) is poised to greatly expand the scale and availability of biogeochemical and aquatic ecological data. NEON is a continental-scale facility designed to collect and disseminate data that addresses the impacts of climate change, land-use, and invasive species on ecosystem structure and function. Using a combination of standardized observational sampling and sensor measurements, NEON will provide a rich source of biogeochemical and biophysical data from 34 aquatic and 47 terrestrial sites spatially distributed across the US, including Alaska, Hawaii and Puerto Rico for 30 years. Sites were selected to be representative of major ecosystems and maximize scalability. In addition to standardizing measurements, NEON is determining the quantitative uncertainty of each data product making them well suited to constrain models. NEON aquatic data will not only serve to baseline aquatic ecology in major ecosystems but also presents opportunities to bolster Hydrologic Models as well as incorporate aquatic biogeochemical cycling into Land Surface Models. Here we present examples of published and provisional data currently available from deployed aquatic sites, as well as an overview of the full scope and release schedule of the open source ecological data to be published on the NEON web portal. Several use cases, such as whole stream metabolism, groundwater exchange, high

  8. Northern Papua New Guinea: Structure and sedimentation in a modern arc-continent collision

    SciTech Connect

    Abbott, L.; Silver, E. )

    1990-05-01

    Northern Papua New Guinea and the Solomon Sea are the site of a modern oblique, arc-continent collision, which is progressing from northwest to southeast. By combining offshore seismic data from the Solomon Sea with geologic mapping in the Markham Valley area of northern Papua New Guinea the authors are predicting the outcome of this collision. The Huon Gulf is the present site of initial collision. Seismic profiles show this area is dominated by thin thrust sheets. Onshore, the bulk of the uplifted accretionary wedge is a melange with exotic blocks of a variety of lithologies. Structurally below the melange lies the Leron Formation composed of thick channelized sandstone and conglomerate. It dips north at approximately 40{degree} and is cut by several thrust fault with associated folds. Limestone blocks within the melange are reported to be 2 Ma, and Beryllium 10 anomalies from Bismarck arc volcanoes suggest that initial collision of the Finisterre block (375 km northwest of the present collision point) began no earlier than 3 Ma. This implies the collision is propagating laterally at about 125 km/m.y.. Large outcrops of basalt and gabbro within the melange suggest that segments of oceanic crust were incorporated into the accretionary wedge. Modern sedimentation within the collision zone grades from fluvial sediments in the Markham Valley to deep-water turbidites ponded behind a structural ridge near the point of incipient collision. The Markham submarine canyon occupies the collision front here, and efficiently erodes the accretionary wedge. This setting may serve as a modem analog for deposition of much of the Leron Formation which exhibits tremendous sediment reworking.

  9. Age relationships for magmatic units of Mid-Continent rift system

    SciTech Connect

    Van Schmus, W.R.

    1989-03-01

    K-Ar ages ranging from about 600 to 1000 Ma have recently been reported for gabbro and basalt recovered from the Texaco 1 Poersch well in Kansas. This has prompted suggestions that rift magmatism there may be distinctly younger than that in the Lake Superior region, and that development of the rift may have lasted several hundred million years. Review of ages from Keweenawan volcanic and plutonic rocks in the Lake Superior region shows that the best results are obtained from U-Pb analyses of zircon and baddeleyite; recent published results range from 1087 to 1108 Ma, with uncertainties on individual ages of /plus minus/ 4 m.y. This finding is consistent with earlier reported U-Pb zircon results. Virtually all other techniques are susceptible to geologic error and generally yield ages of significant less than 1100 Ma. The reliability decreases approximately in the sequence Rb-Sr (whole rock), K-Ar (biotite), Ar/sup 39/-Ar/sup 40/ (whole rock), K-Ar (whole rock), with fresh, coarse-grained plutonic rocks yielding older ages than altered, fine-grained volcanic rocks. K-Ar data on altered, fine-grained mafic rocks, therefore, are very poor indicators of original crystallization ages. Since the rocks from the Texaco 1 Poersch well are fine grained and slightly to moderately altered, their true ages are probably substantially older than 800-900 Ma. Interpretations based on the K-Ar ages from this well are ill advised; tectonic interpretation of the Mid-Continent rift system must wait for more accurate results. Several possibilities exist for obtaining more reliable ages from samples of the Poersch well and other, older wells in the region. These studies are in progress, and any available results will be presented.

  10. Neodymium isotopes as a new tool for quantifying exchange fluxes at the continent-ocean interface

    NASA Astrophysics Data System (ADS)

    Lacan, Francois; Jeandel, Catherine

    2005-04-01

    Continental margins are, via river sediment discharges, the major source of a number of elements to the ocean. They are also, for several reactive elements, sites of preferential removal from the water column, due to enhanced scavenging [1] [M.P. Bacon, Tracers of chemical scavenging in the ocean: Boundary effects and large-scale chemical fractionation, Philos. Trans. R. Soc. Lond., A 325 (1988) 147-160.]. They can therefore be understood as sources of elements for the ocean, sinks or both. Although exchanges of matter are suspected to occur at the continent/ocean interface [2] [P.H. Santschi, L. Guo, I.D. Walsh, M.S. Quigley, M. Baskaran, Boundary exchange and scavenging of radionuclides in continental margin waters of the Middle Atlantic Bight: implications for organic carbon fluxes, Cont. Shelf Res. 19 (1999) 609-636.] and despite their probable importance for the ocean chemistry, closed budgets have still yet to be determined. Here, based on neodymium isotopic composition data obtained during the past 6 yr, we document and quantify significant neodymium exchange at ocean boundaries, in areas covering a large spectra of hydrographical, biological and geochemical characteristics : Eastern Indian Ocean, Western Equatorial Pacific, Western Tropical Pacific and Northwestern Atlantic, with neodymium removal fluxes accounting for 74±23%, 100±38%, 62±54% and 84±45% of the neodymium input fluxes, respectively. Recognition of boundary exchange and its potential globalization have important implications for (1) our understanding of margin/ocean interactions and their influence on the oceanic isotopic chemistry, and (2) geochemical cycling of reactive elements (including pollutants) at ocean margins.

  11. Bacteria Community in the Terrestrial Deep Subsurface Microbiology Research of the Chinese Continent Scientific Drilling

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Xia, Y.; Dong, H.; Dong, X.; Yang, K.; Dong, Z.; Huang, L.

    2005-12-01

    Microbial communities in the deep drill cores from the Chinese Continent Scientific Drilling were analyzed with culture-independent and dependent techniques. Genomic DNA was extracted from two metamorphic rocks: S1 from 430 and S13 from 1033 meters below the ground surface. The 16S rRNA gene was amplified by polymerase chain reaction (PCR) followed by cloning and sequencing. The total cell number was counted using the 4',6-diamidino-2-phenylindole (DAPI) staining and biomass of two specific bacteria were quantified using real-time PCR. Enrichment was set up for a rock from 3911 meters below the surface in medium for authotrophic methanogens (i.e., CO2 + H2). The total cell number in S13 was 1.0 × 104 cells per gram of rock. 16S rRNA gene analysis indicated that low G + C Gram positive sequences were dominant (50 percent of all 54 clone sequenced) followed by the alpha-, beta, and gamma-Proteobacteria. Within the low G + C Gram positive bacteria, most clone sequences were similar to species of Bacillus from various natural environments (deserts, rivers etc.). Within the Proteobacteria, our clone sequences were similar to species of Acinetobacter, Acidovorax, and Aeromonas. The RT-RCP results showed that biomass of two particular clone sequences (CCSD1305, similar to Aeromonas caviae and CCSD1307, similar to Acidovorax facilis) was 95 and 1258 cells/g, respectively. A bacterial isolate was obtained from the 3911-m rock in methanogenic medium. It was Gram negative with no flagella, immobile, and facultative anaerobic, and grows optimally at 65oC. Phylogenetic analysis indicated that it was closely related to the genus of Bacillus. Physiological tests further revealed that it was a strain of Bacillus caldotenax.

  12. Accretionary complex structure and kinematics during Paleozoic arc continent collision in the southern Urals

    NASA Astrophysics Data System (ADS)

    Alvarez-Marron, J.; Brown, D.; Perez-Estaun, A.; Puchkov, V.; Gorozhanina, Y.

    2000-10-01

    The southern Urals contain a well-preserved accretionary complex that has overthrust the continental margin during arc-continent collision between the East European Craton (EEC) and the Magnitogorsk island arc in the Late Devonian. Within the accretionary complex, we study three tectonic units that differ in deformation style, and each provides a unique geodynamic implication. The Zilair Nappe, the largest and best exposed unit, consists of 5-6 km of syncollisional, arc-derived Upper Devonian to Lower Carboniferous polymictic and graywacke turbidites that were deposited across the continental margin and incorporated by frontal accretion into the accretionary complex. The Zilair Nappe is a bivergent thrust imbricate where the west-vergent thrusts dominate and have associated kilometer-scale ramp anticlines with well developed east-dipping axial planar cleavage. Along its eastern contact, however, the cleavage fans until it dips moderately westward and the folds are east-vergent. Following its emplacement, west-vergent, basement-involved thrusting that breached the whole accretionary complex imbricated the Zilair Nappe. The Timirovo Duplex is structurally beneath the Zilair Nappe, and outcrops for several tens of kilometers along its northwestern margin. The duplex forms a west-vergent thrust stack composed of a highly deformed and sheared Lower and Middle Devonian reef carbonates of the former EEC margin platform. These rocks were shallowly underplated at the base of the accretionary complex during emplacement over the margin. The Suvanyak Complex outcrops along the eastern contact of the Zilair Nappe, and consists of polydeformed greenschist facies metasediments of the former EEC slope that were offscraped, underplated and incorporated at the rear of the accretionary complex.

  13. Reconstructed and simulated temperature asymmetry between continents in both hemispheres over the last centuries

    NASA Astrophysics Data System (ADS)

    Goosse, Hugues

    2016-05-01

    Available proxy-based temperature reconstructions covering the past millennium display contrasted evolutions between the continents. The difference is particularly large between the two hemispheres. When driven by realistic natural and anthropogenic forcings, climate models tend to simulate a more spatially homogenous temperature response. This is associated with a relatively good agreement between model results and reconstructions in the Northern Hemisphere but a low consistency in the Southern Hemisphere. Here, simulations with data assimilations are performed to analyse the causes of this apparent disagreement. It shows that, when the uncertainties are taken into account, states of the climate system compatible with the forcing estimates, the reconstructions and the model physics can be obtained over the past millennium, except for the twentieth century in Antarctica where the simulated warming is always much larger than in the reconstructions. Such states consistent with all sources of information can be achieved even if the uncertainties of the reconstructions are underestimated. Although, well within the range of the proxy-based reconstructions, the temperatures obtained after data assimilation display more similar developments between the hemispheres than in those reconstructions. Ensuring the compatibility does not require to systematically reduce the model response to the forcing or to strongly enhance the model internal variability. From those results, there is thus no reason to suspect that the model is strongly biased in one aspect or another. The constraint imposed by the data assimilation is too low to unambiguously identify the origin of each feature displayed in the reconstructions but, as expected, changes in atmospheric circulation likely played a role in many of them. Furthermore, ocean heat uptake and release as well as oceanic heat transport are key elements to understand the delayed response of the Southern Hemisphere compared to the northern

  14. Continent-arc collision in the Banda Arc imaged by ambient noise tomography

    NASA Astrophysics Data System (ADS)

    Porritt, Robert W.; Miller, Meghan S.; O'Driscoll, Leland J.; Harris, Cooper W.; Roosmawati, Nova; Teofilo da Costa, Luis

    2016-09-01

    The tectonic configuration of the Banda region in southeast Asia captures the spatial transition from subduction of Indian Ocean lithosphere to subduction and collision of the Australian continental lithosphere beneath the Banda Arc. An ongoing broadband seismic deployment funded by NSF is aimed at better understanding the mantle and lithospheric structure in the region and the relationship of the arc-continent collision to orogenesis. Here, we present results from ambient noise tomography in the region utilizing this temporary deployment of 30 broadband instruments and 39 permanent stations in Indonesia, Timor Leste, and Australia. We measure dispersion curves for over 21,000 inter-station paths resulting in good recovery of the velocity structure of the crust and upper mantle beneath the Savu Sea, Timor Leste, and the Nusa Tenggara Timur (NTT) region of Indonesia. The resulting three dimensional model indicates up to ∼25% variation in shear velocity throughout the plate boundary region; first-order velocity anomalies are associated with the subducting oceanic lithosphere, subducted Australian continental lithosphere, obducted oceanic sediments forming the core of the island of Timor, and high velocity anomalies in the Savu Sea and Sumba. The structure in Sumba and the Savu Sea is consistent with an uplifting forearc sliver. Beneath the island of Timor, we confirm earlier inferences of pervasive crustal duplexing from surface mapping, and establish a link to underlying structural features in the lowermost crust and uppermost mantle that drive upper crustal shortening. Finally, our images of the volcanic arc under Flores, Wetar, and Alor show high velocity structures of the Banda Terrane, but also a clear low velocity anomaly at the transition between subduction of oceanic and continental lithosphere. Given that the footprint of the Banda Terrane has previously been poorly defined, this model provides important constraints on tectonic reconstructions that

  15. Interannual variations in snowpack in the Crown of the Continent Ecosystem

    USGS Publications Warehouse

    Selkowitz, D.J.; Fagre, D.B.; Reardon, B.A.

    2002-01-01

    Ecosystem changes such as glacier recession and alpine treeline advance have been documented over the previous 150 years in the Rocky Mountains of northern Montana and southern British Columbia and Alberta, a region known as the Crown of the Continent Ecosystem (CCE). Such changes are controlled, at least partially, by variations in snowpack. The CCE consists primarily of public lands, the majority of which is undeveloped or wilderness. Consequently, this region is well suited for an examination of long-term snowpack variation and associated ecosystem change. Data from nine SNOTEL sites provide an indication of the daily accumulation and ablation of snowpack over the period 1977-2001, as well as the relationship between precipitation, temperature and snowpack. 1 April data from 21 snow courses indicated the extent of regional snowpack variation and trends over the period 1950-2001, and 1 May data from three snow courses in Glacier National Park allow this record to be extended back to 1922. SNOTEL data suggest CCE snowpacks are larger and more persistent than in most regions of the western USA, and that water year precipitation is the primary control on 1 April snow water equivalent (SWE). Snow course data indicate that variations in both 1 April and 1 May mean SWE are closely tied to the Pacific decadal oscillation, an El Nino-southern oscillation-like interdecadal pattern of Pacific Ocean climate variability. Despite relatively stable snowpacks and summer temperatures since 1922, the glaciers in Glacier National Park have receded steadily during this period, implying a significant climatic shift between their Little Ice Age glacial maxima (ca 1860) and 1922. Published in 2002 by John Wiley and Sons, Ltd.

  16. Electromagnetic Subsurface Soundings at HF frequencies and Antenna Impedance Measurements on the Antarctic Continent

    NASA Astrophysics Data System (ADS)

    Valerie, C.; Jean-Jacques, B.; Richard, N.; Michel, H.; Sebastien, B.; Francois, D.; Alain, R.

    2004-05-01

    In the frame of the NETLANDER project, a ground penetrating radar (GPR) dedicated to the exploration of the Martian subsurface has been developed. This GPR is designed for deep sounding down to a depth which is sufficient to allow possible detection of liquid water and thus operates mainly at a frequency of 2 MHz. Contrary to the normal mode of operation of subsurface radars which can be moved over the soil to be explored, the GPR of NETLANDER aims at performing 3D imaging of the underground reflecting structures even if it operates in a fixed position. This is achieved by retrieving not only the distance of the reflectors but also the direction of the backscattered waves by measuring the 2 horizontal electric components and the 3 magnetic components of the reflected waves. Two perpendicular dipoles each consisting in two 35-meters electric monopoles are used for both transmission and reception, while the receiving magnetic antenna can be successively directed along 3 mutually orthogonal directions. In addition, the perfect stability of the environment allows a very large number of coherent integrations to be performed, which provide a satisfactory sensitivity Ground tests were recently carried out on the Antarctic continent in 2004. Soundings at frequencies in the range 2-5 MHz have been performed with the NETLANDER monostatic GPR prototype and with the updated version of this instrument, which operates in a real bistatic mode. As expected the echoes due to interaction with the bedrock are detected and the magnetic component measurements provide information linked to the orientation of the reflecting structures. The first experimental results will be reported. We will present results on the electric antenna impedance measurements, which give information on the permittivity of the upper subsurface layer. We will also focus on the analysis of the backscattered signals using both electric and magnetic components of the received field. Comparisons with numerical

  17. Risk factors of postoperative complications after radical cystectomy with continent or conduit urinary diversion in Armenia.

    PubMed

    Tsaturyan, Arman; Petrosyan, Varduhi; Crape, Byron; Sahakyan, Yeva; Abrahamyan, Lusine

    2016-01-01

    To estimate the surgical volume and the incidence of in-hospital complications of RC in Armenia from 2005 to 2012, and to investigate potential risk factors of complications. The study utilized a retrospective chart review in a cohort of patients who had RC followed by either continent or conduit urinary diversion in all hospitals of Armenia from 2005 to 2012. A detailed chart review was conducted abstracting information on baseline demographic and clinical characteristics, surgical procedural details, postoperative management and in-hospital complications. Multivariable logistic regression analysis was applied to estimate the independent risk factors for developing 'any postoperative complication'. The total study sample included 273 patients (mean age = 58.5 years, 93.4 % men). Overall, 28.9 % (n = 79) of patients had at least one in-hospital complication. The hospital mortality rate was 4.8 % (n = 13). The most frequent types of complications were wound-related (10.3 %), gastrointestinal (9.2 %) and infectious (7.0 %). The ischemic heart disease (OR = 3.3, 95 % CI 1.5-7.4), perioperative transfusion (OR = 2.0, 1.1-3.6), glucose level [OR = 0.71 (0.63-0.95)], and hospital type (OR = 2.3, 95 % CI 1.1-4.7) were independent predictors of postoperative complications. The rate of RC complications in Armenia was similar to those observed in other countries. Future prospective studies should evaluate the effect of RC complications on long-term outcomes and costs in Armenia. Policy recommendations should address the issues regarding surgeon training and hospital volume to decrease the risk of RC complications. PMID:26933633

  18. Study protocol: ICONS: Identifying continence options after stroke: A randomised trial

    PubMed Central

    2011-01-01

    Background Urinary incontinence following acute stroke is common, affecting between 40%-60% of people in hospital after a stroke. Despite the availability of clinical guidelines for urinary incontinence and urinary incontinence after stroke, national audit data suggest incontinence is often poorly managed. Conservative interventions (e.g. bladder training, pelvic floor muscle training and prompted voiding) have been shown to have some effect with participants in Cochrane systematic reviews, but have not had their effectiveness demonstrated with stroke patients. Methods/Design A cluster randomised controlled pilot trial designed to assess the feasibility of a full-scale cluster randomised trial and to provide preliminary evidence of the effectiveness and cost-effectiveness of a systematic voiding programme for the management of continence after stroke. Stroke services will be randomised to receive the systematic voiding programme, the systematic voiding programme plus supported implementation, or usual care. The trial aims to recruit at least 780 participants in 12 stroke services (4 per arm). The primary outcome is presence/absence of incontinence at six weeks post-stroke. Secondary outcomes include frequency and severity of incontinence, quality of life and cost-utility. Outcomes will be measured at six weeks, three months and (for participants recruited in the first three months) twelve months after stroke. Process data will include rates of recruitment and retention and fidelity of intervention delivery. An integrated qualitative evaluation will be conducted in order to describe implementation and assist in explaining the potential mediators and modifiers of the process. Trial Registration ISRCTN: ISRCTN08609907 PMID:21599945

  19. Crustal structure of the Caribbean-northeastern South America arc-continent collision zone

    NASA Astrophysics Data System (ADS)

    Christeson, Gail L.; Mann, Paul; Escalona, Alejandro; Aitken, Trevor J.

    2008-08-01

    We present the results of a 568-km-long regional wide-angle seismic profile conducted in the southeastern Caribbean that crosses an active island arc, a remnant arc, two basins possibly floored by oceanic crust, an allochthonous terrane of forearc affinity, and the passive margin of northern South America. The velocity structures of the Late Cretaceous Aves Ridge remnant arc and Miocene and younger Lesser Antilles arc are remarkably similar, which implies that magmatic processes have remained moderately steady over time. Crustal thickness is ˜26 km at the Aves Ridge and ˜24 km at the Lesser Antilles arc. In comparison to the Izu-Bonin and Aleutian arcs, the Lesser Antilles arc is thinner and has no evidence for a lower crustal cumulate layer, which is consistent with the estimated low magma production rates of the Lesser Antilles arc. Crustal thickness beneath the Grenada and Tobago basins is 4-10 km, and the velocity structure suggests that these basins could be floored by oceanic crust. A decrease of ˜1 km/s in average seismic velocity of the upper crust is observed from NW to SE across the North Coast fault zone; we argue that this marks the suture between the far-traveled Caribbean arc and the passive margin of the South American continent. Current strike-slip motion between the Caribbean and South American plates is located ˜30 km to the south, and thus material originally deposited on the South American passive margin has now been transferred to the Caribbean plate.

  20. Arc-parallel extrusion of the Timor sector of the Banda arc-continent collision

    NASA Astrophysics Data System (ADS)

    Duffy, Brendan; Quigley, Mark; Harris, Ron; Ring, Uwe

    2013-06-01

    studies of synorogenic basins in Timor using field and remote sensing techniques provide new structural and geomorphic evidence for syn-collisional extension in the converging plate boundary zone between the Australian Plate and Banda Arc. Fault mapping and kinematic analysis at scales ranging from outcrop (<1 m2) to the dimensions of the active orogen in East Timor (~100 km2) identify a predominance of NW-SE oriented dextral-normal faults and NE-SW oriented sinistral-normal faults that collectively bound large (5-20 km2) bedrock massifs throughout the island. These fault systems intersect at non-Andersonian conjugate angles of approximately 120° and accommodate an estimated 20 km of NE-directed extension across the Timor orogen based on reconstructions of fault-dismembered massifs. Major orogen-parallel ENE-oriented faults on the northern and southern sides of Timor exhibit normal-sinistral and normal-dextral kinematics, respectively. The overall pattern of deformation is one of lateral crustal extrusion sub-parallel to the Banda Arc. Stratigraphic relationships suggest that extrusion began prior to 5.5 Ma, before pronounced rapid uplift of the orogen. We link this to progressive coupling of the fore-arc to an underthrust plateau on the Australian Plate and subduction of its ocean crust. Our results enable us to track the structural evolution of the upper crust during dramatic plate-boundary reorganizations accompanying the transition from subduction to collision. The deformation structures that we document suggest that both upper and lower plate deformation during incipient island arc-continent collision was largely controlled by the geometry and topography of the lower plate.

  1. A local index of Maritime Continent intraseasonal variability based on rain rates over the land and sea

    NASA Astrophysics Data System (ADS)

    Vincent, C. L.; Lane, T. P.; Wheeler, M. C.

    2016-09-01

    A local index for describing intraseasonal variability over the Maritime Continent is developed. The index is based on the ratio of area-averaged rain rate over the land to that over the sea. It takes advantage of the fact that the main convective envelope of intraseasonal variability events tends to modulate the diurnal precipitation cycle over the land over the entire Maritime Continent. Lagged analysis is used to create composite intraseasonal variability events, where "day 0" is chosen according to when the normalized rain rate over the sea becomes greater than that over the land. The index identifies intraseasonal variability events associated with the Madden Julian Oscillation as well as equatorial Kelvin waves and westward propagating equatorial Rossby waves. The results suggest a similar local impact of all such events in suppressing the rain rate over land relative to that over the sea when the main convective envelope approaches.

  2. INDUCED SEISMICITY. High-rate injection is associated with the increase in U.S. mid-continent seismicity.

    PubMed

    Weingarten, M; Ge, S; Godt, J W; Bekins, B A; Rubinstein, J L

    2015-06-19

    An unprecedented increase in earthquakes in the U.S. mid-continent began in 2009. Many of these earthquakes have been documented as induced by wastewater injection. We examine the relationship between wastewater injection and U.S. mid-continent seismicity using a newly assembled injection well database for the central and eastern United States. We find that the entire increase in earthquake rate is associated with fluid injection wells. High-rate injection wells (>300,000 barrels per month) are much more likely to be associated with earthquakes than lower-rate wells. At the scale of our study, a well's cumulative injected volume, monthly wellhead pressure, depth, and proximity to crystalline basement do not strongly correlate with earthquake association. Managing injection rates may be a useful tool to minimize the likelihood of induced earthquakes.

  3. The effect on Earth's surface temperature from variations in rotation rate, continent formation, solar luminosity, and carbon dioxide.

    PubMed

    Kuhn, W R; Walker, J C; Marshall, H G

    1989-08-20

    Proposed evolutionary histories of solar luminosity, atmospheric carbon dioxide amounts, Earth rotation rate, and continent formation have been used to generate a time evolution of Earth's surface temperature. While speculative because of uncertainties in the input parameters, such a study does help to prioritize the areas of most concern to paleoclimatic research while illustrating the relationships and mutual dependencies. The mean temperature averages about 5 K higher than today over most of geologic time; the overall variation is less than 15 K. The evolution of Earth's rotation rate makes a significant contribution to the surface temperature distribution as late as 0.5 b.y. ago. While there is little change in equatorial temperatures, polar temperatures decrease, being some 15 K lower 3.5 b.y. ago than with present day rotation. The effect of continent growth on albedo is of secondary importance.

  4. INDUCED SEISMICITY. High-rate injection is associated with the increase in U.S. mid-continent seismicity.

    PubMed

    Weingarten, M; Ge, S; Godt, J W; Bekins, B A; Rubinstein, J L

    2015-06-19

    An unprecedented increase in earthquakes in the U.S. mid-continent began in 2009. Many of these earthquakes have been documented as induced by wastewater injection. We examine the relationship between wastewater injection and U.S. mid-continent seismicity using a newly assembled injection well database for the central and eastern United States. We find that the entire increase in earthquake rate is associated with fluid injection wells. High-rate injection wells (>300,000 barrels per month) are much more likely to be associated with earthquakes than lower-rate wells. At the scale of our study, a well's cumulative injected volume, monthly wellhead pressure, depth, and proximity to crystalline basement do not strongly correlate with earthquake association. Managing injection rates may be a useful tool to minimize the likelihood of induced earthquakes. PMID:26089509

  5. High-rate injection is associated with the increase in U.S. mid-continent seismicity

    USGS Publications Warehouse

    Weingarten, Matthew; Ge, Shemin; Godt, Jonathan W.; Bekins, Barbara A.; Rubinstein, Justin L.

    2015-01-01

    An unprecedented increase in earthquakes in the U.S. mid-continent began in 2009. Many of these earthquakes have been documented as induced by wastewater injection. We examine the relationship between wastewater injection and U.S. mid-continent seismicity using a newly assembled injection well database for the central and eastern United States. We find that the entire increase in earthquake rate is associated with fluid injection wells. High-rate injection wells (>300,000 barrels per month) are much more likely to be associated with earthquakes than lower-rate wells. At the scale of our study, a well’s cumulative injected volume, monthly wellhead pressure, depth, and proximity to crystalline basement do not strongly correlate with earthquake association. Managing injection rates may be a useful tool to minimize the likelihood of induced earthquakes.

  6. A knowledge-based reactive-transport approach for the modeling of biogeochemical cycles at the continent-ocean interface

    NASA Astrophysics Data System (ADS)

    Regnier, P.; Aguilera, D.; Jourabchi, P.; Meile, C.; van Cappellen, P.; Vanderborght, J.-P.

    2003-04-01

    Reactive-transport models (RTMs) are traditionally developed and used to investigate the fate and transport of a selected set of chemical constituents within a given compartment of the earth, mainly at the local or subregional scale. As a result, existing RTMs tend to be environment and application specific. For instance, at the continent-ocean interface, RTMs have been used to simulate, among others, biogeochemical dynamics in rivers, estuaries, coastal areas, aquifers, and sediments. The development of upscaling protocols, where RTMs of interconnected environments are progressively aggregated into larger system units is critical for merging marine and continental approaches to biogeochemical cycles. However, one of the major challenges to achieve this goal is in the realistic and consistent representation of highly complex reaction networks that characterize the chemical dynamics of the natural environments present along the continent-ocean continuum (rivers, estuaries, coastal areas, sediments). The expanding knowledge about (bio)geochemical transformation processes achieved via field- and laboratory-based experiments needs also to be made available and integrated consistently (i.e. with comparable level of complexities) across traditional disciplinary barriers, by utilizing the unifying conceptual and mathematical principles underlying all RTMs. Our modeling approach, based on a modular concept, offers the necessary flexibility for the implementation of new theoretical and experimental information on the rates and pathways of biogeochemical reactions. A key component of our reaction network simulator is the "Knowledge Base", which acts as a single evolving repository of up-to-date information on biogeochemical processes. The development of self-consistent, "Knowledge-Based" biogeochemical reaction network modules, which can be merged with existing transport models of the various compartments of the hydrosphere along the continent-ocean continuum, creates a

  7. Pattern and process in Northern Rocky Mountain headwaters: Ecological linkages in the headwaters of the Crown of the Continent

    SciTech Connect

    Hauer, F.R.; Stanford, J.A.; Lorang, M.S.

    2007-02-15

    The Crown of the Continent is one of the premiere ecosystems in North America containing Waterton-Glacier International Peace Park, the Bob Marshall-Great Bear-Scapegoat Wilderness Complex in Montana, various Provincial Parks in British Columbia and Alberta, several national and state forest lands in the USA, and Crown Lands in Canada. The region is also the headwater source for three of the continent's great rivers: Columbia, Missouri and Saskatchewan that flow to the Pacific, Atlantic and Arctic Oceans, respectively. While the region has many remarkably pristine headwater streams and receiving rivers, there are many pending threats to water quality and quantity. One of the most urgent threats comes from the coal and gas fields in the northern part of the Crown of the Continent, where coal deposits are proposed for mountain-top removal and open-pit mining operations. This will have significant effects on the waters of the region, its native plants and animals and quality of life of the people.

  8. The history of the North African mitochondrial DNA haplogroup U6 gene flow into the African, Eurasian and American continents

    PubMed Central

    2014-01-01

    Background Complete mitochondrial DNA (mtDNA) genome analyses have greatly improved the phylogeny and phylogeography of human mtDNA. Human mitochondrial DNA haplogroup U6 has been considered as a molecular signal of a Paleolithic return to North Africa of modern humans from southwestern Asia. Results Using 230 complete sequences we have refined the U6 phylogeny, and improved the phylogeographic information by the analysis of 761 partial sequences. This approach provides chronological limits for its arrival to Africa, followed by its spreads there according to climatic fluctuations, and its secondary prehistoric and historic migrations out of Africa colonizing Europe, the Canary Islands and the American Continent. Conclusions The U6 expansions and contractions inside Africa faithfully reflect the climatic fluctuations that occurred in this Continent affecting also the Canary Islands. Mediterranean contacts drove these lineages to Europe, at least since the Neolithic. In turn, the European colonization brought different U6 lineages throughout the American Continent leaving the specific sign of the colonizers origin. PMID:24885141

  9. NorthAm Fest : fostering a North American continent approach to countering terrorism.

    SciTech Connect

    Gerdes, Dick; Moore, Judy Hennessey; Whitley, John B.; Turnley, Jessica Glicken; Oborotova, Marina

    2004-12-01

    On September 14-16, 2004, the Advanced Concepts Group of Sandia National Laboratories in conjunction with the University of Texas at El Paso and the North American Institute hosted a workshop (fest) designed to explore the concept of a North American continental approach to countering terrorism. The fest began with the basic premise that the successful defense of North America against the threat of terrorism will require close collaboration among the North American allies--Canada, Mexico and the U.S.--as well as a powerful set of information collection and analysis tools and deterrence strategies. The NorthAm Fest recast the notion of ''homeland defense'' as a tri-national effort to protect the North American continent against an evolving threat that respects no borders. This is a report of the event summarizing the ideas explored. The fest examined the uniqueness of dealing with terrorism from a tri-national North American viewpoint, the role and possible features of joint security systems, concepts for ideal continental security systems for North America, and the challenges and opportunities for such systems to become reality. The following issues were identified as most important for the advancement of this concept. (1) The three countries share a set of core values--democracy, prosperity and security--which form the basis for joint interactions and allow for the development of a culture of cooperation without affecting the sovereignty of the members. (2) The creation of a continental defensive strategy will require a set of strategic guidelines and that smart secure borders play a pivotal role. (3) Joint security systems will need to operate from a set of complementary but not identical policies and procedures. (4) There is a value in joint task forces for response and shared information systems for the prevention of attacks. (5) The private sector must play a critical role in cross-border interactions. Finally, participants envisioned a ''Tri-National Security

  10. Crustal Properties Across the Mid-Continent Rift via Transfer Function Analysis

    NASA Astrophysics Data System (ADS)

    Frederiksen, A. W.; Tyomkin, Y.; Campbell, R.; van der Lee, S.; Zhang, H.

    2015-12-01

    The Mid-Continent Rift (MCR), a failed Proterozoic rift structure in central North America, is a dominant feature of North American gravity maps. The rift underwent a combination of extension, magmatism, and later compression, and it is difficult to predict how these events affected the overall crustal thickness and bulk composition in the vicinity of the rift axis, though the associated gravity high indicates that large-volume mafic magmatism took place. The Superior Province Rifting Earthscope Experiment (SPREE) project instrumented the MCR with Flexible Array broadband seismographs from 2011 through 2013 in Minnesota and Wisconsin, along two lines crossing the rift axis as well as a line following the axis. We examine teleseismic P-coda data from SPREE and nearby Transportable Array instruments using a new technique: transfer-function analysis. In this approach, possible models of crustal structure are used to generate a predicted transfer function relating the radial and vertical components of the P coda at a particular site. The transfer function then allows generation of a misfit (between the true radial component and a synthetic radial component predicted from the vertical trace) without the need to perform receiver-function deconvolution, thus avoiding the deconvolution problems encountered with receiver functions in sedimentary basins. We use the transfer-function approach to perform a grid search over three crustal properties: crustal thickness, crustal P/S velocity ratio, and the thickness of an overlying sedimentary basin. Results for our SPREE/TA data set indicate that the crust is significantly thickened along the rift axis, with maximum thicknesses approaching 50 km; the crust is thinner (ca. 40 km) outside of the rift zone. The crustal thickness structure is particularly complex beneath southeastern Minnesota, where very strong Moho topography is present, as well as up to 2 km of sediment; further north, the Moho is smoother and the basin is not

  11. Volcanic Versus Non-Volcanic Passive Margins: Two Different Ways to Break-up Continents

    NASA Astrophysics Data System (ADS)

    Geoffroy, L.; Burov, E. B.; Werner, P.; Unternehr, P.

    2014-12-01

    Volcanic passive margins (VPMs) are distinctive features of Larges Igneous Provinces. They characterize continental breakup associated with the extrusion and intrusion of large volumes of magma, predominantly mafic. In Large Igneous Provinces, regional fissural volcanism predates localized syn-magmatic break-up of the lithosphere, suggesting that mantle melting is a cause of continental break-up, not a consequence. Early melt covers as volcanic traps large cratonic or/and cratonic-edge continental areas. Crustal dilatation through dyking in the upper crust and magma underplating at Moho level is thought to occur massively during this early stage. Lithosphere extension leading to break-up and VPMs development is coeval with a 3D focusing of mantle melting, giving rise to VPMs. From a combination of deep seismic reflection profiles and onshore observations, we show that the mechanism of continental breakup at volcanic passive margins is very different from the one generally proposed for non-magmatic systems. Crustal extension and coeval extrusion of thick wedges of seaward-dipping basalts are accommodated by continentward-dipping detachment-faults at both conjugate margins. Those faults root on a deformed ductile crust whose composition seems partly magmatic. Our numerical modeling show that hardening of deep continental crust during the early magmatic stages provokes a divergent flow of the ductile lithosphere (mantle and lower crust) away from a central continental block which thins through advection with time. Magma-assisted crustal-scale faults dipping continentward root over this flowing material, isolating micro-continents which may be lost in the future oceanic domain. The structure and tectonic evolution of volcanic passive margins cannot therefore be compared to non-volcanic ones, where major detachment faults dip oceanward during the necking-stage and where mantle is finally exhumed during the mechanical breakup. Confusions may exist where ancient hyper

  12. Physical climatology of Indonesian maritime continent: An outline to comprehend observational studies

    NASA Astrophysics Data System (ADS)

    Yamanaka, Manabu D.

    2016-09-01

    The Indonesian maritime continent (IMC) is a miniature of our land-sea coexisting planet Earth. Firstly, without interior activity, the Earth becomes an even-surfaced "aqua-planet" with both atmosphere and ocean flowing almost zonally, and solar differential heating generates (global thermal tides and) Hadley's meridional circulations with the inter-tropical convergence zone (ITCZ) along the equator as observed actually over the open (Indian and Pacific) oceans on the both sides of the IMC. The ITCZ involves intraseasonal variations or super cloud clusters moving eastward with hierarchical substructures moving also westward. Secondly, the lands and seas over the actual Earth have been keeping the area ratio of 3:7 (similar to that of islands and inland/surrounding seas in the IMC), but their displacements have produced the IMC near the equator, which turns equatorial Pacific easterly ocean current northward (Kuroshio) and reflects equatorial oceanic waves that affect coupled ocean-atmosphere interannual variations such as ENSO and IOD, or displacements of Walker's zonal circulations. Thirdly, because the IMC consists of many large/small islands with very long coastlines, many narrow straits control the global (Pacific to Indian) ocean circulation, and the land-sea heat capacity contrasts along the coastlines generate the world's largest rainfall with diurnal cycles (sea-land breeze circulations). The diurnal cycles are dominant even in the rainy season (austral summer in Jawa and Bali), because rainfall-induced sprinkler-like land cooling reverses the trans-coastal temperature gradient before sunrise, and subsequent clear sky on land until around noon provides solar heating dependent on season. These processes lead to rapid land/hydrosphere-atmosphere water exchange, local air pollutant washout, and transequatorial boreal winter monsoon (cold surge). In El Niño years, for example, the cooler sea-surface temperature suppresses the morning coastal-sea rainfall, and

  13. Revisiting Seafloor-Spreading in the Red Sea: Basement Nature, Transforms and Ocean-Continent Boundary

    NASA Astrophysics Data System (ADS)

    Tapponnier, P.; Dyment, J.; Zinger, M. A.; Franken, D.; Afifi, A. M.; Wyllie, A.; Ali, H. G.; Hanbal, I.

    2013-12-01

    A new marine geophysical survey on the Saudi Arabian side of the Red Sea confirms early inferences that ~ 2/3 of the eastern Red Sea is floored by oceanic crust. Most seismic profiles south of 24°N show a strongly reflective, landward-deepening volcanic basement up to ~ 100 km east of the axial ridge, beneath thick evaporitic deposits. This position of the Ocean-Continent Boundary (OCB) is consistent with gravity measurements. The low amplitudes and long wavelengths of magnetic anomalies older than Chrons 1-3 can be accounted for by low-pass filtering due to thick sediments. Seafloor-spreading throughout the Red Sea started around 15 Ma, as in the western Gulf of Aden. Its onset was coeval with the activation of the Aqaba/Levant transform and short-cutting of the Gulf of Suez. The main difference between the southern and northern Red Sea lies not in the nature of the crust but in the direction and modulus of the plate motion rate. The ~ 30° counterclockwise strike change and halving of the spreading rate (~ 16 to ~ 8 mm/yr) between the Hermil (17°N) and Suez triple junctions results in a shift from slow (≈ North Atlantic) to highly oblique, ultra-slow (≈ Southwest Indian) ridge type. The obliquity of spreading in the central and northern basins is taken up by transform discontinuities that stop ~ 40 km short of the coastline, at the OCB. Three large transform fault systems (Jeddah, Zabargad, El Akhawein) nucleated as continental transfer faults reactivating NNE-trending Proterozoic shear zones. The former two systems divide the Red Sea into three main basins. Between ~15 and ~5 Ma, for about 10 million years, thick evaporites were deposited directly on top of oceanic crust in deep water, as the depositional environment, modulated by climate, became restricted by the Suez and Afar/Bab-el-Mandeb volcano-tectonic 'flood-gates.' The presence of these thick deposits (up to ~ 8 km) suffices to account for the difference between the Red Sea and the Gulf of Aden

  14. SELECTION AND TREATMENT OF STRIPPER GAS WELLS FOR PRODUCTION ENHANCEMENT IN THE MID-CONTINENT

    SciTech Connect

    Scott Reeves

    2003-03-01

    Stripper gas wells are an important source of domestic energy supply and under constant threat of permanent loss (shut-in) due to marginal economics. In 1998, 192 thousand stripper gas wells produced over a Tcf of gas, at an average rate of less than 16 Mcfd. This represents about 57% of all producing gas wells in the onshore lower-48 states, yet only 8% of production. Reserves of stripper gas wells are estimated to be only 1.6 Tcf, or slightly over 1% of the onshore lower-48 total (end of year 1996 data). Obviously, stripper gas wells are at the very margin of economic sustenance. As the demand for natural gas in the U.S. grows to the forecasted estimate of over 30 Tcf annually by the year 2010, supply from current conventional sources is expected to decline. Therefore, an important need exists to fully exploit known domestic resources of natural gas, including those represented by stripper gas wells. The overall objectives of this project are to develop an efficient and low-cost methodology to broadly categorize the well performance characteristics for a stripper gas field, identify the high-potential candidate wells for remediation, and diagnose the specific causes for well underperformance. With this capability, stripper gas well operators can more efficiently and economically produce these resources and maximize these gas reserves. A further objective is to identify/develop, evaluate and test ''new and novel,'' economically viable remediation options. Finally, it is the objective of this project that all the methods and technologies developed in this project, while being tested in the Mid-Continent, be widely applicable to stripper gas wells of all types across the country. The project activities during the reporting period were: (1) The search for another field site was abandoned after discussion with DOE. There is a clear absence of willing industry partners to participate in this project. The greatest obstacle is having the necessary data to perform the

  15. SELECTION AND TREATMENT OF STRIPPER GAS WELLS FOR PRODUCTION ENHANCEMENT IN THE MID-CONTINENT

    SciTech Connect

    Scott Reeves

    2003-08-01

    Stripper gas wells are an important source of domestic energy supply and under constant threat of permanent loss (shut-in) due to marginal economics. In 1998, 192 thousand stripper gas wells produced over a Tcf of gas, at an average rate of less than 16 Mcfd. This represents about 57% of all producing gas wells in the onshore lower-48 states, yet only 8% of production. Reserves of stripper gas wells are estimated to be only 1.6 Tcf, or slightly over 1% of the onshore lower-48 total (end of year 1996 data). Obviously, stripper gas wells are at the very margin of economic sustenance. As the demand for natural gas in the U.S. grows to the forecasted estimate of over 30 Tcf annually by the year 2010, supply from current conventional sources is expected to decline. Therefore, an important need exists to fully exploit known domestic resources of natural gas, including those represented by stripper gas wells. The overall objectives of this project are to develop an efficient and low-cost methodology to broadly categorize the well performance characteristics for a stripper gas field, identify the high-potential candidate wells for remediation, and diagnose the specific causes for well underperformance. With this capability, stripper gas well operators can more efficiently and economically produce these resources and maximize these gas reserves. A further objective is to identify/develop, evaluate and test ''new and novel,'' economically viable remediation options. Finally, it is the objective of this project that all the methods and technologies developed in this project, while being tested in the Mid-Continent, be widely applicable to stripper gas wells of all types across the country. The project activities during the reporting period were: (1) Compiled information and results of field activities that Oneok has conducted in relation to the project. Field activities have included performing six pressure transient tests, and implementing six workovers, four of which were

  16. SELECTION AND TREATMENT OF STRIPPER GAS WELLS FOR PRODUCTION ENHANCEMENT IN THE MID-CONTINENT

    SciTech Connect

    Scott Reeves

    2003-03-01

    Stripper gas wells are an important source of domestic energy supply and under constant threat of permanent loss (shut-in) due to marginal economics. In 1998, 192 thousand stripper gas wells produced over a Tcf of gas, at an average rate of less than 16 Mcfd. This represents about 57% of all producing gas wells in the onshore lower-48 states, yet only 8% of production. Reserves of stripper gas wells are estimated to be only 1.6 Tcf, or slightly over 1% of the onshore lower-48 total (end of year 1996 data). Obviously, stripper gas wells are at the very margin of economic sustenance. As the demand for natural gas in the U.S. grows to the forecasted estimate of over 30 Tcf annually by the year 2010, supply from current conventional sources is expected to decline. Therefore, an important need exists to fully exploit known domestic resources of natural gas, including those represented by stripper gas wells. The overall objectives of this project are to develop an efficient and low-cost methodology to broadly categorize the well performance characteristics for a stripper gas field, identify the high-potential candidate wells for remediation, and diagnose the specific causes for well underperformance. With this capability, stripper gas well operators can more efficiently and economically produce these resources and maximize these gas reserves. A further objective is to identify/develop, evaluate and test ''new and novel,'' economically viable remediation options. Finally, it is the objective of this project that all the methods and technologies developed in this project, while being tested in the Mid-Continent, be widely applicable to stripper gas wells of all types across the country. The project activities during the reporting period were: (1) Finished preparing the final project report, less the field implementation component. Sent to DOE for review. (2) Continued coordinating the final selection of candidates and field implementation with Oneok. Oneok postponed field

  17. SELECTION AND TREATMENT OF STRIPPER GAS WELLS FOR PRODUCTION ENHANCEMENT IN THE MID-CONTINENT

    SciTech Connect

    Scott Reeves

    2003-03-01

    Stripper gas wells are an important source of domestic energy supply and under constant threat of permanent loss (shut-in) due to marginal economics. In 1998, 192 thousand stripper gas wells produced over a Tcf of gas, at an average rate of less than 16 Mcfd. This represents about 57% of all producing gas wells in the onshore lower-48 states, yet only 8% of production. Reserves of stripper gas wells are estimated to be only 1.6 Tcf, or slightly over 1% of the onshore lower-48 total (end of year 1996 data). Obviously, stripper gas wells are at the very margin of economic sustenance. As the demand for natural gas in the U.S. grows to the forecasted estimate of over 30 Tcf annually by the year 2010, supply from current conventional sources is expected to decline. Therefore, an important need exists to fully exploit known domestic resources of natural gas, including those represented by stripper gas wells. The overall objectives of this project are to develop an efficient and low-cost methodology to broadly categorize the well performance characteristics for a stripper gas field, identify the high-potential candidate wells for remediation, and diagnose the specific causes for well underperformance. With this capability, stripper gas well operators can more efficiently and economically produce these resources and maximize these gas reserves. A further objective is to identify/develop, evaluate and test ''new and novel,'' economically viable remediation options. Finally, it is the objective of this project that all the methods and technologies developed in this project, while being tested in the Mid-Continent, be widely applicable to stripper gas wells of all types across the country. The project activities during the reporting period were: (1) Type curve matching continued during the reporting period. (2) A second data collection trip to Tulsa was performed to gather information on the additional reservoirs to be included in the analysis. Created updated database

  18. SELECTION AND TREATMENT OF STRIPPER GAS WELLS FOR PRODUCTION ENHANCEMENT IN THE MID-CONTINENT

    SciTech Connect

    Scott Reeves

    2003-03-01

    Stripper gas wells are an important source of domestic energy supply and under constant threat of permanent loss (shut-in) due to marginal economics. In 1998, 192 thousand stripper gas wells produced over a Tcf of gas, at an average rate of less than 16 Mcfd. This represents about 57% of all producing gas wells in the onshore lower-48 states, yet only 8% of production. Reserves of stripper gas wells are estimated to be only 1.6 Tcf, or slightly over 1% of the onshore lower-48 total (end of year 1996 data). Obviously, stripper gas wells are at the very margin of economic sustenance. As the demand for natural gas in the U.S. grows to the forecasted estimate of over 30 Tcf annually by the year 2010, supply from current conventional sources is expected to decline. Therefore, an important need exists to fully exploit known domestic resources of natural gas, including those represented by stripper gas wells. The overall objectives of this project are to develop an efficient and low-cost methodology to broadly categorize the well performance characteristics for a stripper gas field, identify the high-potential candidate wells for remediation, and diagnose the specific causes for well underperformance. With this capability, stripper gas well operators can more efficiently and economically produce these resources and maximize these gas reserves. A further objective is to identify/develop, evaluate and test ''new and novel,'' economically viable remediation options. Finally, it is the objective of this project that all the methods and technologies developed in this project, while being tested in the Mid-Continent, be widely applicable to stripper gas wells of all types across the country. The project activities during the reporting period were: (1) Continued to solicit industry research partners to provide test sites, including Patina Oil and Gas and EOG Resources, each of whom have previously worked with ARI on a similar projects funded by the Gas Technology Institute. Both

  19. SELECTION AND TREATMENT OF STRIPPER GAS WELLS FOR PRODUCTION ENHANCEMENT IN THE MID-CONTINENT

    SciTech Connect

    Scott Reeves

    2003-03-01

    Stripper gas wells are an important source of domestic energy supply and under constant threat of permanent loss (shut-in) due to marginal economics. In 1998, 192 thousand stripper gas wells produced over a Tcf of gas, at an average rate of less than 16 Mcfd. This represents about 57% of all producing gas wells in the onshore lower-48 states, yet only 8% of production. Reserves of stripper gas wells are estimated to be only 1.6 Tcf, or slightly over 1% of the onshore lower-48 total (end of year 1996 data). Obviously, stripper gas wells are at the very margin of economic sustenance. As the demand for natural gas in the U.S. grows to the forecasted estimate of over 30 Tcf annually by the year 2010, supply from current conventional sources is expected to decline. Therefore, an important need exists to fully exploit known domestic resources of natural gas, including those represented by stripper gas wells. The overall objectives of this project are to develop an efficient and low-cost methodology to broadly categorize the well performance characteristics for a stripper gas field, identify the high-potential candidate wells for remediation, and diagnose the specific causes for well underperformance. With this capability, stripper gas well operators can more efficiently and economically produce these resources and maximize these gas reserves. A further objective is to identify/develop, evaluate and test ''new and novel,'' economically viable remediation options. Finally, it is the objective of this project that all the methods and technologies developed in this project, while being tested in the Mid-Continent, be widely applicable to stripper gas wells of all types across the country. The project activities during the reporting period were: (1) Completed both type curve and artificial neural network analysis of the field. Developed list of production enhancement candidates. (2) Made final presentation of results to Oneok in Tulsa (February 26). (3) Made presentations on

  20. Deep crustal structure and continent-ocean boundary along the Galicia continental margin (NW Iberia)

    NASA Astrophysics Data System (ADS)

    Druet, María; Muñoz-Martín, Alfonso; Carbó, Andrés; Acosta, Juan; Granja Bruña, José Luis; Llanes, Pilar; Vázquez, Juan-Tomás; Ercilla, Gemma

    2016-04-01

    The Galicia continental margin is a magma-poor rifted margin with an extremely complex structure. Its formation involves several rifting episodes during the Mesozoic in the vicinity of a ridge triple junction, which produces a change in the orientation of the main structures. In addition, there is an overimposed Cenozoic partial tectonic inversion along its northern border. Although this continental margin has been widely studied since the 70's, most studies have focused on its western part in the transition to the Iberia Abyssal Plain, and there is a significant lack of information on the north and northwestern flanks of this margin. This fact, along with its great structural complexity, has resulted in the absence of a previous comprehensive regional geodynamic model integrating all the processes observed. In the present study we integrate a large volume of new geophysical data (gravity, swath bathymetry and 2D multichannel reflection seismic). Data come from the systematic mapping of the Spanish EEZ project which provides a dense grid of gravity data and full seafloor coverage with swath bathymetry, and from the ERGAP project which provides serially-arranged 2D seismic reflection profiles across the NW Iberia margin. The combined interpretation and modelling of this new information has arisen significant constraints on the origin, the deep crustal structure and the physiographic complexity of the margin, as well as on the characterization of the along- and across-strike variation of the ocean-continent transition along NW Iberia margin. The analysis of this information leads us to propose a conceptual model for the initiation of the tectonic inversion of a magma-poor rifted margin. Finally, a framework for the geodynamic evolution of the Galicia margin has been constructed, involving three main stages: A) an early stage from the end of rifting and oceanic drift in the Bay of Biscay (Santonian); B) an intermediate stage with the beginning of tectonic inversion in

  1. Thermal models of dyke intrusion during development of continent-ocean transition

    NASA Astrophysics Data System (ADS)

    Daniels, K. A.; Bastow, I. D.; Keir, D.; Sparks, R. S. J.; Menand, T.

    2014-01-01

    thickness and Moho depth in the Danakil region of northernmost Afar are markedly reduced and seismicity is shallower than in the MER. Thermally driven variations in crustal rheology over time in response to dyke intrusion thus play an important role in the development of continent-ocean transition.

  2. Physical Climatology of Indonesian Maritime Continent: An Overview of Observational Studies

    NASA Astrophysics Data System (ADS)

    Yamanaka, M. D.

    2014-12-01

    The Indonesian maritime continent (IMC) is a miniature of our land-sea coexisting planet Earth. Firstly, without interior activity, the Earth becomes an even-surfaced "aqua-planet" with both atmosphere and ocean flowing almost zonally, and solar differential heating generates (global thermal tides and) Hadley's meridional circulations with ITCZ along the equator as observed actually over open (Indian and Pacific) oceans in the both sides of IMC. ITCZ involves intraseasonal variations or super cloud clusters moving eastward. Secondly, the lands and seas over the actual Earth have been keeping the area ratio of 3:7 (similar to that of islands and inland/surrounding seas in IMC), but their displacements have produced IMC near the equator, which turns equatorial Pacific easterly current northward (Kuroshio) and reflects equatorial oceanic waves inducing coupled ocean-atmosphere interannual variations such as ENSO and IOD, or displacements of Walker's zonal circulations. Thirdly, because IMC consists of many large/small islands with very long coastlines, many narrow straits become a dam for the global (Pacific to Indian) ocean circulation, and the land-sea heat capacity contrasts along the coastlines generate the world's largest rainfall with diurnal cycles (sea-land breeze circulations). The diurnal cycles are dominant in the rainy season (austral summer in Jawa and Bali), because rainfall-induced sprinkler-like land cooling reverses the trans-coastal temperature gradient before sunrise, and subsequent clear sky on land until around noon provides solar heating dependent on season. These processes lead to rapid land/hydrosphere-atmosphere water exchange, local air pollutant washout, and transequatorial boreal winter monsoon (cold surge). In El Niño years the cooler sea-surface temperature suppresses the morning coastal-sea rainfall, and induces often serious smog over IMC. Lastly, high-resolution observations/models covering both over islands and seas are necessary. A

  3. Genetic Structure of Natural Populations of Escherichia coli in Wild Hosts on Different Continents

    PubMed Central

    Souza, Valeria; Rocha, Martha; Valera, Aldo; Eguiarte, Luis E.

    1999-01-01

    Current knowledge of genotypic and phenotypic diversity in the species Escherichia coli is based almost entirely on strains recovered from humans or zoo animals. In this study, we analyzed a collection of 202 strains obtained from 81 mammalian species representing 39 families and 14 orders in Australia and the Americas, as well as several reference strains; we also included a strain from a reptile and 10 from different families of birds collected in Mexico. The strains were characterized genotypically by multilocus enzyme electrophoresis (MLEE) and phenotypically by patterns of sugar utilization, antibiotic resistance, and plasmid profile. MLEE analysis yielded an estimated genetic diversity (H) of 0.682 for 11 loci. The observed genetic diversity in this sample is the greatest yet reported for E. coli. However, this genetic diversity is not randomly distributed; geographic effects and host taxonomic group accounted for most of the genetic differentiation. The genetic relationship among the strains showed that they are more associated by origin and host order than is expected by chance. In a dendrogram, the ancestral cluster includes primarily strains from Australia and ECOR strains from groups B and C. The most differentiated E. coli in our analysis are strains from Mexican carnivores and strains from humans, including those in the ECOR group A. The kinds and numbers of sugars utilized by the strains varied by host taxonomic group and country of origin. Strains isolated from bats were found to exploit the greatest range of sugars, while those from primates utilized the fewest. Toxins are more frequent in strains from rodents from both continents than in any other taxonomic group. Strains from Mexican wild mammals were, on average, as resistant to antibiotics as strains from humans in cities. On average, the Australian strains presented a lower antibiotic resistance than the Mexican strains. However, strains recovered from hosts in cities carried significantly more

  4. Failure was not an option- the Mid-Continent Rift system succeeded

    NASA Astrophysics Data System (ADS)

    Merino, M.; Stein, C. A.; Stein, S. A.; Keller, G. R.; Flesch, L. M.; Jurdy, D. M.

    2013-12-01

    The 1.1 Ga Mid-Continent Rift (MCR) in North America is often viewed as a failed rift formed by isolated midplate volcanism and extension within the ~1.3-~0.98 Ga Grenville orogeny. An alternative view is suggested by analogy with younger and morphologically similar rift systems, whose plate tectonic settings are more easily understood because their surroundings - including seafloor with magnetic anomalies - have not been deformed or destroyed by subsequent collisions and rifting events. In this view, the MCR was part of a larger plate boundary rifting event that resulted in a successful episode of seafloor spreading. This view is motivated by various pieces of evidence. The MCR rifting looks much like rigid plate block motion, such as associated with the West Central African Rift systems formed during the Mesozoic breakup of Africa and South America and the ongoing rifting in the East African Rift region with seafloor spreading in the Gulf of Aden and the Red Sea. This view explains the affinities of the Grenville-age rocks in the central and southern Appalachians to Amazonia rather than Canadian Grenville-age Appalachian rocks. The MCR extends farther to the south than traditionally assumed along the East Continental Gravity High (a buried feature from Ohio to Alabama). This failed portion of the rift system connected to the rift successfully separating Laurentia and Amazonia. The seafloor spreading separating Amazonia from Laurentia may explain the former's relative motion toward Greenland and Baltica. This model is consistent with some of the ~1.1 Ga geological events in Amazonia. A change in the apparent polar wander path for Laurentia during the period of volcanism of the MCR could be attributed to this plate reconfiguration. The extensional phase on the MCR may have ended because motion was taken up by seafloor spreading between Laurentia and Amazonia rather ending due to another continental collision. Later reverse faulting on the MCR normal faults due to

  5. Anomalous Subsidence at the Ocean Continent Transition of the Gulf of Aden Rifted Continental Margin

    NASA Astrophysics Data System (ADS)

    Cowie, Leanne; Kusznir, Nick; Leroy, Sylvie

    2013-04-01

    It has been proposed that some rifted continental margins have anomalous subsidence and that at break-up they were elevated at shallower bathymetries than the isostatic response predicted by classical rift models (McKenzie, 1978). The existence of anomalous syn- or early-post break-up subsidence of this form would have important implications for our understanding of the geodynamics of continental break-up and sea-floor spreading initiation. We have investigated subsidence of the young rifted continental margin of the eastern Gulf of Aden, focussing on the western Oman margin (break-up age 17.6 Ma). Lucazeau et al. (2008) have found that the observed bathymetry here is approximately 1 km shallower than the predicted bathymetry. In order to examine the proposition of an anomalous early post break-up subsidence history of the Omani Gulf of Aden rifted continental margin, we have determined the subsidence of the oldest oceanic crust adjacent to the continent-ocean boundary (COB) using residual depth anomaly (RDA) analysis corrected for sediment loading and oceanic crustal thickness variation. RDAs corrected for sediment loading using flexural backstripping and decompaction have been calculated by comparing observed and age predicted oceanic bathymetries in order to identify anomalous subsidence of the Gulf of Aden rifted continental margin. Age predicted bathymetric anomalies have been calculated using the thermal plate model predictions of Crosby and McKenzie (2009). Non-zero RDAs at the Omani Gulf of Aden rifted continental margin can be the result of non standard oceanic crustal thickness or the effect of mantle dynamic topography or a non-classical rift and break-up model. Oceanic crustal basement thicknesses from gravity inversion together with Airy isostasy have been used to predict a "synthetic" gravity RDA, in order to determine the RDA contribution from non-standard oceanic crustal thickness. Gravity inversion, used to determine crustal basement thickness

  6. A review of droughts in the African continent: a geospatial and long-term perspective

    NASA Astrophysics Data System (ADS)

    Masih, I.; Maskey, S.; Mussá, F. E. F.; Trambauer, P.

    2014-03-01

    This paper presents a comprehensive review and analysis of the available literature and information on droughts to build a continental, regional and country level perspective on geospatial and temporal variation of droughts in Africa. The study is based on the review and analysis of droughts occurred during 1900-2013 as well as evidence available from past centuries based on studies on the lake sediment analysis, tree-ring chronologies and written and oral histories and future predictions from the global climate change models. Most of the studies based on instrumental records indicate that droughts have become more frequent, intense and widespread during the last 50 yr. The extreme droughts of 1972-1973, 1983-1984 and 1991-1992 were continental in nature and stand unique in the available records. Additionally, many severe and prolonged droughts were recorded in the recent past such as the 1999-2002 drought in Northwest Africa, 1970s and 1980s droughts in West Africa (Sahel), 2010-2011 drought in East Africa (Horn of Africa) and 2001-2003 drought in Southern and Southeast Africa, to name a few. The available (though limited) evidence before the 20th century confirms the occurrence of several extreme and multi-year droughts during each century, with the most prolonged and intense droughts that occurred in Sahel and Equatorial East Africa regions. Complex and highly variant nature of many physical mechanisms such as El Niño-Southern Oscillation (ENSO), Sea Surface Temperature (SST) and land-atmosphere feedback adds to the daunting challenge of drought monitoring and forecasting. The future predictions of droughts based on global climate models indicate increased droughts and aridity at the continental scale but large differences exist due to model limitations and complexity of the processes especially for Sahel and North Africa regions. However, the available evidence from the past clearly shows that the African continent is likely to face extreme and widespread

  7. A review of droughts on the African continent: a geospatial and long-term perspective

    NASA Astrophysics Data System (ADS)

    Masih, I.; Maskey, S.; Mussá, F. E. F.; Trambauer, P.

    2014-09-01

    This paper presents a comprehensive review and analysis of the available literature and information on droughts to build a continental, regional and country level perspective on geospatial and temporal variation of droughts in Africa. The study is based on the review and analysis of droughts occurred during 1900-2013, as well as evidence available from past centuries based on studies on the lake sediment analysis, tree-ring chronologies and written and oral histories and future predictions from the global climate change models. Most of the studies based on instrumental records indicate that droughts have become more frequent, intense and widespread during the last 50 years. The extreme droughts of 1972-1973, 1983-1984 and 1991-1992 were continental in nature and stand unique in the available records. Additionally, many severe and prolonged droughts were recorded in the recent past such as the 1999-2002 drought in northwest Africa, 1970s and 1980s droughts in western Africa (Sahel), 2010-2011 drought in eastern Africa (Horn of Africa) and 2001-2003 drought in southern and southeastern Africa, to name a few. The available (though limited) evidence before the 20th century confirms the occurrence of several extreme and multi-year droughts during each century, with the most prolonged and intense droughts that occurred in Sahel and equatorial eastern Africa. The complex and highly variant nature of many physical mechanisms such as El Niño-Southern Oscillation (ENSO), sea surface temperature (SST) and land-atmosphere feedback adds to the daunting challenge of drought monitoring and forecasting. The future predictions of droughts based on global climate models indicate increased droughts and aridity at the continental scale but large differences exist due to model limitations and complexity of the processes especially for Sahel and northern Africa. However, the available evidence from the past clearly shows that the African continent is likely to face extreme and

  8. The development of extension and magmatism during continent-ocean transition: evidence from Ethiopia

    NASA Astrophysics Data System (ADS)

    Bastow, Ian; Keir, Derek; Booth, Adam; Corti, Giacomo; Magee, Craig; Jackson, Christopher; Wilkinson, Jason

    2016-04-01

    The geological record at rifts and margins worldwide often reveals along-strike variations in volumes of extruded and intruded igneous rocks. These variations may be the result of asthenospheric heterogeneity, variations in rate and timing of extension. Preexisting plate architecture and/or the evolving kinematics of extension during breakup may also influence magmatism strongly. The Ethiopian and Afar Rift systems provide an excellent opportunity to address these issues since they expose, along strike, several sectors of ongoing, asynchronous rift development from embryonic continental rifting in the south to incipient oceanic spreading in the north. A consensus has now emerged from a variety of disciplines in Ethiopia that a considerable proportion of extension in Ethiopia is accommodated by focused dyke intrusion in narrow axial zones, without marked crustal (and plate?) thinning. These "magmatic segments" may mark the final breakup boundary and location of an incipient oceanic spreading centre. However, observations of markedly thinned crust and a pulse in Quaternary-Recent basaltic volcanism within the Danakil Depression have recently been cited as evidence that an abrupt, late stage of localised plate stretching may instead mark the final stages of continent-ocean transition (Bastow & Keir, 2011). We explore this hypothesis using recently-acquired seismic reflection data and accompanying borehole geological constraints from Danakil. Thick sequences of evaporites have been deposited in an asymmetric basin, whose subsidence has been controlled primarily by a major, east dipping normal fault. Surprisingly, no significant magmatism is observed in the upper ~1000m. Age constraints on a potash-bearing sequence presently being mined in the basin point towards rapid basin infill in the last several tens-to-hundreds of thousands of years. Basin formation cannot be easily attributed to the effects of magmata intrusion. Instead, an abrupt, localised, late-stage, plate

  9. Tectonic Evolution of the Banda Arc-Continent Collision in the Timor Region

    NASA Astrophysics Data System (ADS)

    Harris, R. A.

    2011-12-01

    Recent detailed studies of the active Banda arc-continent collision reveal many new features about its tectonic evolution, such as (1) when collision initiated, (2) conditions and age of metamorphism, (3) timing of island emergence and exhumation, (4) how the arc is affected by collision, (5) differences between rock and surface uplift rates, (6) the temporal distribution of strain and (7) natural hazards. (1) The youngest Australian continental margin material incorporated into the Banda orogen is 7-8 Ma in East Timor and 6 Ma in West Timor. (2) Collision-related metamorphic rocks in East Timor yield max. temperatures of 850 °C and pressures of 12 kb. The age of the metamorphism is constrained by zircon U/Pb ages of 6.7 Ma. (3) Island emergence and erosional exhumation is constrained by foraminifera depth vs. age estimates of the transition from deep marine chalk to distal turbidite deposition at 4.2 Ma in East Timor and younger to the east and west. Exhumation of metamorphic rocks is constrained by amphibole with Ar/Ar cooling ages of ~6 Ma (~525°C), zircons with U/He ages of 4.5 Ma (215°C), and apatite with U/He ages of 3.5 Ma (90°C). Younger exhumation ages are found to the south. (4) Contamination of the volcanic arc by subducted continental material is first detected in eroded arc islands near East Timor at 5 Ma. The age of contamination youngs both east and west in less eroded, active arc islands. The main arc edifice north of East Timor is abandoned at 1-3 Ma and is shifted 30 km to the north by the Wetar backarc thrust. A new volcanic center emerges further north. (5) Coral terraces encrust the rising islands and yield highly variable uplift rates, with some as high as 1.5 mm/a. The highest rates correspond with active thrust faults and diapirs. Rock uplift rates associated with exhumation of the schist belt are as high as 8 mm/a. (6) GPS velocities in the most advanced part of the collision (central Timor) show that 70% of the 70 mm/a convergence

  10. Approaches to aspects of optimisation of protection in diagnostic radiology in six continents.

    PubMed

    Martin, C J; Le Heron, J; Borrás, C; Sookpeng, S; Ramirez, G

    2013-12-01

    There has been an expansion in the use of x-ray imaging during the last 20 years. Effective arrangements for justification of exposures as well as for optimisation of protection are crucial. The amount of effort put into the latter, the way in which it is organised and the groups carrying this out vary across the globe. A simple survey of organisational arrangements relating to performance testing of x-ray equipment, management of patient dose and other aspects of implementing optimisation has been undertaken. A total of 137 completed survey forms were received from medical physicists in 48 countries. Results for individual countries from which more responses were received, or for groups of neighbouring ones, are compared to portray variations. Some performance testing of x-ray equipment was mandated in most countries (more than 90%), with the tests being performed primarily by hospital or private medical physicists, although other groups are involved. Testing of equipment prior to clinical use was generally high for most regions, but the frequency was lower in Latin America. There was considerable variation in the frequency and regularity of subsequent testing. The prevalence of patient dose surveys was high in Europe, but lower in other continents. Organisational arrangements for testing performance of x-ray equipment, patient dose surveys and implementing optimisation of protection in medical exposures across the globe can be divided into five main groups. Hospital medical physicists take the lead in western Europe and Australia with the involvement of radiographers. Private medical physicists test equipment in Brazil, the USA and New Zealand, and have some responsibility for optimisation in Brazil. University personnel have significant involvement, together with medical physicists in eastern Europe, but the extent of the coverage is uncertain. Government personnel and service engineers carry out equipment testing in many countries of Africa and Asia, while

  11. Modeling the subsolidus evolution of melt-depleted peridotite residues beneath the continents

    NASA Astrophysics Data System (ADS)

    Brown, E. L.; Lesher, C. E.; Baker, M. B.; Schutt, D.

    2012-12-01

    The origin and stabilization of subcontinental lithospheric mantle is a consequence of 1) partial melting of peridotitic mantle in mid-ocean ridge, intraplate and/or subduction zone settings, 2) underplating of the melt-depleted residue beneath the continents as a consequence of either plume-head melting or tectonic mechanisms, 3) subsolidus evolution of the residual solid, and 4) metasomatic transformations. The evolution of phase compositions and modes within the lithospheric mantle as a consequence of these processes, and the resulting density structure, are essential to understanding the preservation or convective removal of lithosphere. Whereas melting experiments provide constraints on the range of compositions possible for either fertile or depleted peridotite, the effects of pressure and temperature changes below the solidus on peridotite mineralogy and density remain challenging to quantify. These difficulties have important implications, particularly with regard to the density structure of the lithosphere and the mechanisms enabling long-term stabilization of subcontinental lithospheric mantle. To calculate the effects of changes in P, T, and bulk composition on the subsolidus mineralogy and density of peridotite lithologies, we have coupled the algorithm of [1], which calculates modes and phase compositions of subsolidus peridotite by mass balance constrained by experimentally-determined mineral-mineral exchange and distribution coefficients with the algorithm of [2], which calculates densities at P and T conditions suitable to the upper mantle using mineral physics data. We benchmark our approach against the thermodynamic models pMELTS and PERPLE_X using recently published peridotite melting experimental data, and show that our estimates of mineral modes and compositions typically provide improvements to the fits of experimental results. We also show that our density calculations are similar to those predicted by these thermodynamic models when using

  12. Break-up of the Greater Indo-Australian Continent and accretion of blocks framing South and East Asia

    NASA Astrophysics Data System (ADS)

    Acharyya, S. K.

    1998-09-01

    The Tibetan and 'Sibumasu' continental blocks rifted apart from the northern margin of Gondwanan Indo-Australia during the Permo-Carboniferous whereas, the IndoBurma-Andamans (IBA), Sikuleh, Lolotoi micro-continents did so during the Late Jurassic. This continental margin experienced glacial or cool conditions during the Permo-Carboniferous. The Tibetan and Sibumasu blocks drifted northward during mid-late Permian initiating opening of the Neo-Tethys. The arm of the Palaeo-Tethys located to the north of these blocks closed as these blocks were accreted to the South China and Indochina blocks which had separated from the same Gondwanan margin during early Palaeozoic. All these blocks were amalgamated to form the Cathaysialand. The Sibumasu block was accreted to the Indochina block, and the Tibetan Changtang block to Eurasia during the late Permian-mid Triassic. Contemporaneously Mesozoic Neo-Tethys expanded between the Indian, Lhasa and Changtang blocks. The Indian and Australian continents separated during the Cretaceous leading to the opening up of the Indian Ocean and closing of the Tethyan ocean. The Palaeo- and Neo-Tethyan sutures in Tibet, Yunnan, Myanmar, Laos-Thailand and Vietnam reveal the complex opening and closing history of the Tethys. IBA rotated clockwise from its earlier E-W orientation, because of dextral transcurrent fault movements which ensured faster northward movement of the Indian plate relative to Australia during late Cretaceous-early Eocene. Contemporaneous to India-Tibet terminal collision during early-mid Eocene there was thloeiitic-alkalic foreland volcanism (Abor and equivalents) at the leading edge of the Indian continent. Sustained post-collisional movement of the Indian plate, caused southward propagation of the Himalayan crystalline and frontal foreland thrust sheets. It also produced E-W trending folds and thrusts even in distal Central Indian Ocean areas as well as a clockwise rotation of the amalgamated SE Asian Cathaysian

  13. Improving time to continence after robot-assisted laparoscopic prostatectomy: augmentation of the total anatomic reconstruction technique by adding dynamic detrusor cuff trigonoplasty and suprapubic tube placement.

    PubMed

    Tewari, Ashutosh K; Ali, Adnan; Ghareeb, George; Ludwig, Wesley; Metgud, Sheela; Theckumparampil, Nithin; Takenaka, Atsushi; Chugtai, Bilal; Shrivastava, Abhishek; Kaplan, Steve A; Leung, Robert; Paryani, Rahul; Grushow, Siobhan; Durand, Matthieu; Peyser, Alexandra; Chopra, Sameer; Harneja, Niyati; Lee, Richard K; Herman, Michael; Robinson, Brian; Shevchuck, Maria M

    2012-12-01

    After robot-assisted laparoscopic prostatectomy, total anatomic reconstruction (TR) with the additions of a circumapical urethral dissection, a dynamic detrusor cuff trigonoplasty, and placement of a suprapubic catheter was performed in 49 patients from June to July 2012. Continence at 6 weeks after catheter removal was assessed for an initial group of 23 patients, and also at 2 weeks in an additional 26 patients who most recently had undergone surgery. Follow-up appointments and telephone interviews were used to assess pad use and continence. Of the initial 23 patients receiving the modified TR, 60.9% had 0 pad use at 6 weeks. By 2 weeks, 65.4% of the most recent 26 patients operated on achieved continence with 0-1 pad use. Preservation and reconstruction of the pelvic floor and supporting bladder structures leads to an earlier return of continence. These key steps need to be validated and confirmed in larger and randomized trials. PMID:23230868

  14. Analysis of Aeromagnetic data of the NE region of the Indian sub-continent.

    NASA Astrophysics Data System (ADS)

    Rajaram, M.; S. P, A.

    2007-12-01

    The NE region of the Indian subcontinent is a very interesting place for geodynamic and tectonic studies due to the collision of the Indian plate with the Himalayas in the North and with Myanmar in the East. Some of these areas are difficult to access due to the high topography and air borne surveys help map the region efficiently. Further, the NE region including areas of Assam and Bangladesh are drained by the Ganges and Brahmaputra rivers that bring thick sediments with them giving rise to the Bengal Fan that has sediments of up to 20 km in some regions and these mask the underlying crust and pose severe restrictions in constructing the geodynamical history of the region. Geopotential data offer the unique opportunity of addressing some of these issues. We utilize available / published aeromagnetic maps over Bangladesh, Meghalaya, Chachar, parts of North Assam, Brahmaputra valley, Manipur and Nagaland in the North Eastern region of India for understanding the complexities of the tectonics of the Indian sub-continent. All available data are reduced to a common altitude to prepare a composite magnetic anomaly map of the region. We also look at the Grace and Bouguer / isostatic gravity maps of the region; the highest isostatic gravity anomaly of the Indian region lies over Meghalaya with a trough in Sylhet (Bangladesh) to its south. The Eocene hinge zone is a 25-km wide northeast-southwest zone that separates the Precambrian platform in the northwest from the geosynclinal basin to the southeast of Bangladesh. We find that the Hinge Zone in Bangladesh and part of the Dauki fault form a strong divide such that the gravity anomalies and aeromagnetic anomalies show high frequency anomalies to the north of this divide and also most of the magnetic sources as seen from the analytic signal are concentrated to the north and the Euler solutions give shallow solutions to the north and deep solutions to the south of this divide. The tilt derivative of the aeromagnetic data

  15. High amplitude continous infrasonic signals recorded on the Romanian Black Sea coast

    NASA Astrophysics Data System (ADS)

    Moldovan, Iren-Adelina; Emilian Toader, Victorin; Septimiu Moldovan, Adrian

    2014-05-01

    locations in order to obtain data to be compared with the data recorded at Mangalia site. The system was firstly placed in the Dobrogea Seismological Observatory, from Eforie, situated at 500m from the sea front. Similar signals appeared on the recordings around 2Hz, but without higher frequency harmonics. The second location of the portable recording unit was at Izvoarele, Galati County, at 128km from the Black Sea coast line, and 15km away from the Danube River. The recordings presented no high amplitude continous signals above 2Hz, similar to other recordings obtained with the Romanian Chaparal and MB-AZEL2007 Infrasound Network. In the last days of 2013, the system was moved in a new place, at Vrancioaia site, on the top of a hill, with steep slopes both in front and back of the measuring point. A new interesting signal was revealed. The corroboration of the infrasound recordings and spectrograms with local meteorological data, wind speed, magnitude of sea waves or atmospheric electric field amplitude, could yield important scientific conclusions, beneficial both for authorities and academic media.

  16. A novel method of bladder neck imbrication to improve early urinary continence following robotic-assisted radical prostatectomy.

    PubMed

    Beattie, K; Symons, J; Chopra, S; Yuen, C; Savdie, R; Thanigasalam, R; Haynes, A M; Matthews, J; Brenner, P C; Rasiah, K; Sutherland, R L; Stricker, P D

    2013-06-01

    Early return of continence forms an important component of quality of life for patients after robotic-assisted radical prostatectomy (RALP). Here we describe the steps of bladder neck imbrication and vesico-urethral anastomosis improving early continence after RALP. Between April 2008 and July 2009, 202 consecutive patients underwent RALP for clinically localised prostate cancer in a tertiary referral centre by a single surgeon. One hundred and thirty-two (65 %) of these patients agreed to participate in the study. Prior to November 2008, 51 patients underwent standard RALP as described by Patel et al. From November 2008, 81 patients underwent a novel method of bladder neck imbrication. The robotic urethro-vesical anastomosis commences on the posterior wall of the urethra and proceeds anteriorly. In our technique the anastomosis is halted with the suture arms fixed to the anterior abdominal wall. A new suture is used to perform a two-layer repair, anchoring proximally then continuing anteriorly to the level of the urethral stump, where it returns upon itself. The aim is to narrow the urethra to 16 Fr and tighten the second layer to create an imbrication effect. Posterior reconstruction was performed in all patients. Outcome measures were recorded prospectively using the Expanded Prostate Cancer Index Composite tool. Our technique shows significant improvement at all stages of follow-up in urinary summary and incontinence scores. Absolute continence rates increased from 8.2 to 20.5 %, 26.7 to 44.3 %, and 47.7 to 62.3 % at 1.5, 3 and 6 months, respectively. These results support the use of our technique in patients undergoing RALP. PMID:27000912

  17. The association between urinary continence and quality of life in paediatric patients with spina bifida and tethered cord

    PubMed Central

    Olesen, Jamie D; Kiddoo, Darcie A; Metcalfe, Peter D

    2013-01-01

    OBJECTIVE: To determine the association between urinary continence and quality of life (QoL) in a paediatric spina bifida population. METHODS: After appropriate ethics approval, a prospective study was initiated using multiple validated QoL instruments that were distributed to patients as they presented for their annual appointment at the Northern Alberta Spina Bifida Clinic (Edmonton, Alberta). General demographic information was collected and validated questionnaires were used. The survey package included two instruments to assess overall QoL: Global Pediatric QoL (PedsQL 4.0) and Health Specific QoL-Spina Bifida (HRQoL-SB). Two instruments were also included to quantify urinary symptoms and assess urinary specific QoL: the Urinary Incontinence Severity Index – Pediatric (ISI-P) and Urinary Specific QoL (PinQ). RESULTS: A total of 71 patients were enrolled in the study. The general QoL (PedsQL 4.0) and health-specific QoL (HRQoL-SB) scores for the population indicated an overall QoL of 66% (n=69) and 83% (n=67), respectively. Approximately 46% (33 of 71) reported >1 episode of urinary incontinence per week. Urinary continence was associated with a significantly higher urinary-specific QoL (PinQ; P<0.001), general QoL (PedsQL 4.0; P<0.05) and health-specific QoL (HRQoL-SB; P<0.05). Furthermore, urinary incontinence and its effect on QoL was not influenced by the presence of a shunt, level of the lesion or manner of dysraphism. CONCLUSION: These data suggest that QoL in patients with spina bifida is related to urinary continence. This effect appears to be independent of the type and level of the spinal dysraphism and the presence or absence of a shunt. PMID:24421717

  18. The longevity of Archean mantle residues in the convecting upper mantle and their role in young continent formation

    NASA Astrophysics Data System (ADS)

    Liu, Jingao; Scott, James M.; Martin, Candace E.; Pearson, D. Graham

    2015-08-01

    The role played by ancient melt-depleted lithospheric mantle in preserving continental crust through time is critical in understanding how continents are built, disrupted and recycled. While it has become clear that much of the extant Archean crust is underpinned by Archean mantle roots, reports of Proterozoic melt depletion ages for peridotites erupted through Phanerozoic terranes raise the possibility that ancient buoyant lithospheric mantle acts as a "life-raft" for much of the Earth's continental crust. Here we report the largest crust-lithospheric mantle age decoupling (∼2.4 Ga) so far observed on Earth and examine the potential cause for such extreme age decoupling. The Phanerozoic (<300 Ma) continental crust of West Otago, New Zealand, is intruded by Cenozoic diatremes that have erupted cratonic mantle-like highly depleted harzburgites and dunites. These peridotites have rhenium depletion Os model ages that vary from 0.5 to 2.7 Ga, firmly establishing the record of an Archean depletion event. However, the vast range in depletion ages does not correlate with melt depletion or metasomatic tracer indices, providing little support for the presence of a significant volume of ancient mantle root beneath this region. Instead, the chemical and isotopic data are best explained by mixing of relict components of Archean depleted peridotitic mantle residues that have cycled through the asthenosphere over Ga timescales along with more fertile convecting mantle. Extensive melt depletion associated with the "docking" of these melt residues beneath the young continental crust of the Zealandia continent explains the decoupled age relationship that we observe today. Hence, the newly formed lithospheric root incorporates a mixture of ancient and modern mantle derived from the convecting mantle, cooled and accreted in recent times. We argue that in this case, the ancient components played no earlier role in continent stabilization, but their highly depleted nature along with

  19. Geographic distribution of the mid-continent population of sandhill cranes and related management applications

    USGS Publications Warehouse

    Krapu, Gary L.; Brandt, David A.; Jones, Kenneth L.; Johnson, Douglas H.

    2011-01-01

    The Mid-continent Population (MCP) of sandhill cranes (Grus canadensis) is widely hunted in North America and is separated into the Gulf Coast Subpopulation and Western Subpopulation for management purposes. Effective harvest management of the MCP requires detailed knowledge of breeding distribution of subspecies and subpopulations, chronology of their use of fall staging areas and wintering grounds, and exposure to and harvest from hunting. To address these information needs, we tagged 153 sandhill cranes with Platform Transmitting Terminals (PTTs) during 22 February–12 April 1998–2003 in the Central and North Platte River valleys of south-central Nebraska. We monitored PTT-tagged sandhill cranes, hereafter tagged cranes, from their arrival to departure from breeding grounds, during their fall migration, and throughout winter using the Argos satellite tracking system. The tracking effort yielded 74,041 useable locations over 49,350 tag days; median duration of tracking of individual cranes was 352 days and 73 cranes were tracked >12 months. Genetic sequencing of mitochondrial DNA (mtDNA) from blood samples taken from each of our random sample of tagged cranes indicated 64% were G. c. canadensis and 34% were Grus canadensis tabida. Tagged cranes during the breeding season settled in northern temperate, subarctic, and arctic North America (U.S. [23%, n = 35], Canada [57%, n = 87]) and arctic regions of northeast Asia (Russia [20%, n = 31]). Distribution of tagged cranes by breeding affiliation was as follows: Western Alaska–Siberia (WA–S, 42 ± 4% [SE]), northern Canada–Nunavut (NC–N, 21 ± 4%), west-central Canada–Alaska (WC–A, 23 ± 4%) and East-central Canada–Minnesota (EC–M, 14 ± 3%). All tagged cranes returned to the same breeding affiliation used during the previous year with a median distance of 1.60 km (range: 0.08–7.7 km, n = 53) separating sites used in year 1 and year 2. Fall staging

  20. Staphylococcus aureus in Animals and Food: Methicillin Resistance, Prevalence and Population Structure. A Review in the African Continent.

    PubMed

    Lozano, Carmen; Gharsa, Haythem; Ben Slama, Karim; Zarazaga, Myriam; Torres, Carmen

    2016-01-01

    The interest about Staphylococcus aureus (S. aureus) and methicillin resistant S. aureus (MRSA) in livestock, and domestic and wild animals has significantly increased. The spread of different clonal complexes related to livestock animals, mainly CC398, and the recent description of the new mecC gene, make it necessary to know more about the epidemiology and population structure of this microorganism all over the world. Nowadays, there are several descriptions about the presence of S. aureus and/or MRSA in different animal species (dogs, sheep, donkeys, bats, pigs, and monkeys), and in food of animal origin in African countries. In this continent, there is a high diversity of ethnicities, cultures or religions, as well as a high number of wild animal species and close contact between humans and animals, which can have a relevant impact in the epidemiology of this microorganism. This review shows that some clonal lineages associated with humans (CC1, CC15, CC72, CC80, CC101, and CC152) and animals (CC398, CC130 and CC133) are present in this continent in animal isolates, although the mecC gene has not been detected yet. However, available studies are limited to a few countries, very often with incomplete information, and many more studies are necessary to cover a larger number of African countries. PMID:27681906

  1. Urinary Continence Outcomes after Puboprostatic Ligament Preserving Open Retropubic Radical Prostatectomy at a Sub-Saharan Hospital

    PubMed Central

    Kaggwa, S.; Galukande, M.

    2014-01-01

    Background. Open retropubic radical prostatectomy is a commonly performed procedure for clinically localized prostate cancer. The demand for high level functional outcomes after therapy is increasing especially for young age patients; in this regard refinements in the surgical technique have been made. There is limited data to show the success of some of these refinements in resource limited settings. Methods. A retrospective clinical study was performed over a 2-year period at Mengo Hospital, Urology Unit. Men with clinically localized prostate cancer and who consented to the procedure were eligible and were recruited. Consequently excluded were those that turned out to have advanced disease and those with severe comorbidities. Patients were followed up for 3 months after surgery. Data was entered using SPSS version 17 and analyzed. Results. A total of 24 men with clinically localized prostate cancer underwent open retropubic puboprostatic ligament preserving radical prostatectomy technique. Mean age was 66, range 54–75 years. Outcome. Two patients had stress incontinence and three were incontinent at 3 months. The urinary continence recovery rate was 19/24 (79%) at 3 months. Conclusion. Preservation of the puboprostatic ligament in open retropubic radical prostatectomy was associated with rapid and a high rate of return to urinary continence among men with clinically localized disease. PMID:27382635

  2. Stomatal controls on vegetation productivity and water cycling across the African continent in a warmer and CO2 enriched climate

    NASA Astrophysics Data System (ADS)

    Sato, H.; Kumagai, T.; Takahashi, A.; Katul, G. G.

    2014-12-01

    General Circulation Models (GCMs) forecast higher vapor pressure deficit (VPD) but unchanged relative humidity (RH) in future climates. A recent literature survey revealed some 50% of Earth System (ESMs) and Land Surface (LSMs) Models embedded within GCMs employ RH as an atmospheric aridity index when describing stomatal conductance (gs) while the remaining 50% employ VPD. Propagating the consequences of using RH or VPD in gs models on water cycling and vegetation productivity in future climates in one of the most vulnerable continents, the African continent, remains to be explored. Using process-based global dynamic vegetation model runs, changes in the hydrological cycle and concomitant vegetation productivity for a 21st century projected climate are conducted by altering only gs responses to VPD or RH while maintaining all other formulations unaltered. In the simulations under warming trend of the 21st century, both stomata functions of VPD and RH result in nearly identical changes in the geographic pattern of Gross Primary Production (GPP). However, continental total of GPP becomes bit larger for the VPD function than for the RH function. Transpiration rates becomes lower resulting in water-use-efficiency becoming higher by some 13% for the VPD function when compared to its RH counterpart.

  3. Training through gametherapy promotes coactivation of the pelvic floor and abdominal muscles in young women, nulliparous and continents

    PubMed Central

    Silva, Valeria Regina; Riccetto, Cássio; Martinho, Natalia Miguel; Marques, Joseane; Carvalho, Leonardo Cesar; Botelho, Simone

    2016-01-01

    ABSTRACT Introduction and objectives: Several studies have been investigated co-activation can enhance the effectveness of PFM training protocols allowing preventive and therapeutic goals in pelvic floor dysfunctions. The objective of the present study was to investigate if an abdominal-pelvic protocol of training (APT) using gametherapy would allow co-activation of PFM and transversus abdominis/oblique internal (TrA/OI) muscles. Patients and methods: Twenty-five nulliparous, continent, young females, with median age 24.76 (±3.76) years were evaluated using digital palpation (DP) of PFM and surface electromyography of PFM and TrA/OI simultaneously, during maximal voluntary contraction (MVC), alternating PFM and TrA/OI contraction requests. All women participated on a supervised program of APT using gametherapy, that included exercises of pelvic mobilization associated to contraction of TrA/OI muscles oriented by virtual games, for 30 minutes, three times a week, in a total of 10 sessions. Electromyographic data were processed and analyzed by ANOVA - analysis of variance. Results: When MVC of TrA/OI was solicited, it was observed simultaneous increase of electromyographic activity of PFM (p=0.001) following ATP. However, EMG activity did not change significantly during MVC of PFM. Conclusion: Training using gametherapy allowed better co-activation of pelvic floor muscles in response to contraction of TrA, in young nulliparous and continent women. PMID:27564290

  4. Rarity of a top predator triggers continent-wide collapse of mammal prey: dingoes and marsupials in Australia.

    PubMed

    Johnson, Christopher N; Isaac, Joanne L; Fisher, Diana O

    2007-02-01

    Top predators in terrestrial ecosystems may limit populations of smaller predators that could otherwise become over abundant and cause declines and extinctions of some prey. It is therefore possible that top predators indirectly protect many species of prey from excessive predation. This effect has been demonstrated in some small-scale studies, but it is not known how general or important it is in maintaining prey biodiversity. During the last 150 years, Australia has suffered the world's highest rate of mammal decline and extinction, and most evidence points to introduced mid-sized predators (the red fox and the feral cat) as the cause. Here, we test the idea that the decline of Australia's largest native predator, the dingo, played a role in these extinctions. Dingoes were persecuted from the beginning of European settlement in Australia and have been eliminated or made rare over large parts of the continent. We show a strong positive relationship between the survival of marsupials and the geographical overlap with high-density dingo populations. Our results suggest that the rarity of dingoes was a critical factor which allowed smaller predators to overwhelm marsupial prey, triggering extinction over much of the continent. This is evidence of a crucial role of top predators in maintaining prey biodiversity at large scales in terrestrial ecosystems and suggests that many remaining Australian mammals would benefit from the positive management of dingoes. PMID:17164197

  5. Staphylococcus aureus in Animals and Food: Methicillin Resistance, Prevalence and Population Structure. A Review in the African Continent.

    PubMed

    Lozano, Carmen; Gharsa, Haythem; Ben Slama, Karim; Zarazaga, Myriam; Torres, Carmen

    2016-01-01

    The interest about Staphylococcus aureus (S. aureus) and methicillin resistant S. aureus (MRSA) in livestock, and domestic and wild animals has significantly increased. The spread of different clonal complexes related to livestock animals, mainly CC398, and the recent description of the new mecC gene, make it necessary to know more about the epidemiology and population structure of this microorganism all over the world. Nowadays, there are several descriptions about the presence of S. aureus and/or MRSA in different animal species (dogs, sheep, donkeys, bats, pigs, and monkeys), and in food of animal origin in African countries. In this continent, there is a high diversity of ethnicities, cultures or religions, as well as a high number of wild animal species and close contact between humans and animals, which can have a relevant impact in the epidemiology of this microorganism. This review shows that some clonal lineages associated with humans (CC1, CC15, CC72, CC80, CC101, and CC152) and animals (CC398, CC130 and CC133) are present in this continent in animal isolates, although the mecC gene has not been detected yet. However, available studies are limited to a few countries, very often with incomplete information, and many more studies are necessary to cover a larger number of African countries.

  6. Magnetic Signatures and Curie Surface Trend Across an Arc-Continent Collision Zone: An Example from Central Philippines

    NASA Astrophysics Data System (ADS)

    Manalo, Pearlyn C.; Dimalanta, Carla B.; Ramos, Noelynna T.; Faustino-Eslava, Decibel V.; Queaño, Karlo L.; Yumul, Graciano P.

    2016-05-01

    Ground and aeromagnetic data are combined to characterize the onshore and offshore magnetic properties of the central Philippines, whose tectonic setting is complicated by opposing subduction zones, large-scale strike-slip faulting and arc-continent collision. The striking difference between the magnetic signatures of the islands with established continental affinity and those of the islands belonging to the island arc terrane is observed. Negative magnetic anomalies are registered over the continental terrane, while positive magnetic anomalies are observed over the Philippine Mobile Belt. Several linear features in the magnetic anomaly map coincide with the trace of the Philippine Fault and its splays. Power spectral analysis of the magnetic data reveals that the Curie depth across the central Philippines varies. The deepest point of the magnetic crust is beneath Mindoro Island at 32 km. The Curie surface shallows toward the east: the Curie surface is 21 km deep between the islands of Sibuyan and Masbate, and 18 km deep at the junction of Buruanga Peninsula and Panay Island. The shallowest Curie surface (18 km) coincides with the boundary of the arc-continent collision, signifying the obduction of mantle rocks over the continental basement. Comparison of the calculated Curie depth with recent crustal thickness models reveals the same eastwards thinning trend and range of depths. The coincidence of the magnetic boundary and the density boundary may support the existence of a compositional boundary that reflects the crust-mantle interface.

  7. Staphylococcus aureus in Animals and Food: Methicillin Resistance, Prevalence and Population Structure. A Review in the African Continent

    PubMed Central

    Lozano, Carmen; Gharsa, Haythem; Ben Slama, Karim; Zarazaga, Myriam; Torres, Carmen

    2016-01-01

    The interest about Staphylococcus aureus (S. aureus) and methicillin resistant S. aureus (MRSA) in livestock, and domestic and wild animals has significantly increased. The spread of different clonal complexes related to livestock animals, mainly CC398, and the recent description of the new mecC gene, make it necessary to know more about the epidemiology and population structure of this microorganism all over the world. Nowadays, there are several descriptions about the presence of S. aureus and/or MRSA in different animal species (dogs, sheep, donkeys, bats, pigs, and monkeys), and in food of animal origin in African countries. In this continent, there is a high diversity of ethnicities, cultures or religions, as well as a high number of wild animal species and close contact between humans and animals, which can have a relevant impact in the epidemiology of this microorganism. This review shows that some clonal lineages associated with humans (CC1, CC15, CC72, CC80, CC101, and CC152) and animals (CC398, CC130 and CC133) are present in this continent in animal isolates, although the mecC gene has not been detected yet. However, available studies are limited to a few countries, very often with incomplete information, and many more studies are necessary to cover a larger number of African countries. PMID:27681906

  8. Staphylococcus aureus in Animals and Food: Methicillin Resistance, Prevalence and Population Structure. A Review in the African Continent

    PubMed Central

    Lozano, Carmen; Gharsa, Haythem; Ben Slama, Karim; Zarazaga, Myriam; Torres, Carmen

    2016-01-01

    The interest about Staphylococcus aureus (S. aureus) and methicillin resistant S. aureus (MRSA) in livestock, and domestic and wild animals has significantly increased. The spread of different clonal complexes related to livestock animals, mainly CC398, and the recent description of the new mecC gene, make it necessary to know more about the epidemiology and population structure of this microorganism all over the world. Nowadays, there are several descriptions about the presence of S. aureus and/or MRSA in different animal species (dogs, sheep, donkeys, bats, pigs, and monkeys), and in food of animal origin in African countries. In this continent, there is a high diversity of ethnicities, cultures or religions, as well as a high number of wild animal species and close contact between humans and animals, which can have a relevant impact in the epidemiology of this microorganism. This review shows that some clonal lineages associated with humans (CC1, CC15, CC72, CC80, CC101, and CC152) and animals (CC398, CC130 and CC133) are present in this continent in animal isolates, although the mecC gene has not been detected yet. However, available studies are limited to a few countries, very often with incomplete information, and many more studies are necessary to cover a larger number of African countries.

  9. Study on the location and fit of continents in western central Pangea with a focus on the Mediterranean and North Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Kwon, Ohyeok; Cheong, Hyeong-Bin

    2015-04-01

    Since Alfred Wegener proposed the theory of continental drift more than a century ago, continuous effort to reconstruct the super continent Pangea has been carried out paleo-geographically during past several decades. Although a remarkable success has been achieved, there remains still a great uncertainty on the precise location and fits of the continents that constitute the Pangea. While the fits are recognized as quite complete for Gondwana, the northern part of Pangea, the fits for Laurasia which contains North Ameraica and Eurasia, are left with a lot of improvement. What the two giant continents look like when they were fitted to form the Pangea is also a unsolved question. Several hypothesis for the fits of Laurasia and Gondwana have been raised, and the scenarios of Pangea A1, Pangea A2, Pangea B, and Pangea C were proposed hitherto. Recently, an updated version very close to Pangea A2 was suggested by authors including Van der Voo, Trond H. Torsvik, which have improved several deficiencies of the Pangea A2. However, it was found that the new scenario cannot be fully supported by the paleomagnetism data. Furthermore, it is not in complete agreement with previous paleogeological surveys on major geological features such as Variscan and Caledonian orogenic belt, indicating that a more sophisticated scenario is needed still for the Pangea. The purpose of this study is to reconstruct the continents in western central Pangea with a focus on the Mediterranean and North Atlantic Ocean. A new fit of continents to form the Pangea is proposed, where the continents are fitted with enhanced accuracy compared to other models of Pangea particularly for the Mediterranean Sea, central America, Iran Plateau etc.. The results suggest that the continents were not distorted significantly on the process of drifting and merging during the past 200 million years.

  10. Use of GRACE data to monitor climate change-induced variations in water storage availability in the African continent

    NASA Astrophysics Data System (ADS)

    Ahmed, M. E.; Sultan, M.; Wahr, J. M.; Yan, E.; Milewski, A.; Mohsen, F.; Chouinard, K.

    2011-12-01

    The Gravity Recovery and Climate Experiment (GRACE) data provides direct measurements of temporal mass variations; the latter is largely controlled by variations in water volumes in various reservoirs such as surface water (e.g., lakes and streams), groundwater (e.g., shallow and deep aquifers) and in the soil profile. Climatic changes impact the amounts of precipitation and its partitioning into each of these reservoirs. We explored the use of GRACE data for monitoring climate change-induced variations in water availability in the African continent over a period of nine years and used the identified trends to predict water storage availability across the continent over the next decade. Monthly GRACE gravity field solutions (Center of Space Research [CSR] RL04) in form of Spherical Harmonic Coefficients (SHC's) that span the period from April 2002 through November 2010 were processed (temporal mean was removed, de-striped, smoothed [250 km; Gaussian], and converted to 0.5 x 0.5 deg. equivalent water thicknesses). Several relevant GRACE bi-products (e.g., standard deviation, annual trend) were generated over time periods of six, seven, eight, and nine years and compared (in a GIS environment) with relevant co-registered data sets and derived products (e.g., precipitation, topography, geology, VNIR Landsat, NDVI, stream network distribution, water bodies distribution, watershed boundaries, and Community Climate System Model [CCSM-3] products). Spatial correlations of the co-registered data sets revealed the following: (1) persistent and increasingly pronounced linear annual trends (+ve: increasing mass; -ve: decreasing mass) over periods of six to nine years with the most pronounced trends detected over domains of high signal to noise ratios; (2) +ve trends over the source areas for the Blue Nile basin (4.2 mm/yr) and over the source areas of the Congo basin (7 mm/yr) and over the Zambezi basin (24 mm/yr), whereas -ve trends were detected over Central Africa (-7 mm

  11. On the Generation of Supercontinent Cycles from Mantle Convection with Self-Consistent Plate Tectonics and Mobile Continents

    NASA Astrophysics Data System (ADS)

    Rolf, T.; Tackley, P. J.; Coltice, N.

    2012-12-01

    Kenorland, Columbia, Rodinia, Pangaea : there is some evidence in the geologic record that continental blocks have been assembled into a large landmass during some periods of Earth's history. These periods were interrupted by continental break-up events and subsequent dispersal of the fragments. The alternation between assembled and dispersed continent configurations is often called the supercontinent cycle. Plate reconstruction techniques allow for looking back into Earth's tectonic history, but only for the last 200 Ma is the necessary data well accessible, such that only the existence of the last supercontinent, Pangaea, is well documented. Especially for the first supercontinents only poor evidence exist: one of them is the correlation of peaks in the production rate of continental crust that can be detected by analyzing the osmium decay system [1] and the suggested assembly times of some of the older supercontinents. These are derived from the argument that almost all cratons that stabilized at a certain time were located next to each other in Pangaea, which is very unlikely if they have not formed in a single continental block [2]. Supercontinents are thought to generate a large-scale thermal anomaly by insulation beneath them, which enhances melting processes and with that the growth of continental crust. However, although some progress has been made, the details of the dynamic origin of the supercontinent cycle are still not well understood. What causes continental fragments to assemble into a single unit? What causes the breakup of the supercontinent? On which timescales do these processes occur? Here we use fully dynamic models of mantle convection that feature self-consistently generated plate-like behavior and buoyant, rheologically distinct continents that drift over the surface, eventually colliding or splitting. In contrast to our previous models [3] the continents in this study consist of a rheologically strong interior surrounded by a weaker

  12. An empirical investigation on different methods of economic growth rate forecast and its behavior from fifteen countries across five continents

    NASA Astrophysics Data System (ADS)

    Yin, Yip Chee; Hock-Eam, Lim

    2012-09-01

    Our empirical results show that we can predict GDP growth rate more accurately in continent with fewer large economies, compared to smaller economies like Malaysia. This difficulty is very likely positively correlated with subsidy or social security policies. The stage of economic development and level of competiveness also appears to have interactive effects on this forecast stability. These results are generally independent of the forecasting procedures. Countries with high stability in their economic growth, forecasting by model selection is better than model averaging. Overall forecast weight averaging (FWA) is a better forecasting procedure in most countries. FWA also outperforms simple model averaging (SMA) and has the same forecasting ability as Bayesian model averaging (BMA) in almost all countries.

  13. How the growth and freeboard of continents may relate to geometric and kinematic parameters of mid-ocean spreading ridges

    USGS Publications Warehouse

    Howell, D.G.

    1989-01-01

    If the volume of continents has been growing since 4 Ga then the area of the ocean basins must have been shrinking. Therefore, by inferring a constant continental freeboard, in addition to constant continental crustal thicknesses and seawater volume, it is possible to calculate the necessary combinations of increased ridge lengths and spreading rates required to displace the seawater in the larger oceans of the past in order to maintain the constant freeboard. A reasonable choice from the various possibilities is that at 4 Ga ago, the ridge length and spreading rates were ca. 2.5 times greater than the averages of these parameters during the past 200 Ma. By 2.5 Ga ago the ridge length and spreading rate decreased to about 1.8 times the recent average and by 1 Ga ago these features became reduced to approximately 1.4 times recent averages. ?? 1989.

  14. Cancer Incidence in Five Continents: Inclusion criteria, highlights from Volume X and the global status of cancer registration.

    PubMed

    Bray, F; Ferlay, J; Laversanne, M; Brewster, D H; Gombe Mbalawa, C; Kohler, B; Piñeros, M; Steliarova-Foucher, E; Swaminathan, R; Antoni, S; Soerjomataram, I; Forman, D

    2015-11-01

    Cancer Incidence in Five Continents (CI5), a longstanding collaboration between the International Agency for Research on Cancer and the International Association of Cancer Registries, serves as a unique source of cancer incidence data from high-quality population-based cancer registries around the world. The recent publication of Volume X comprises cancer incidence data from 290 registries covering 424 populations in 68 countries for the registration period 2003-2007. In this article, we assess the status of population-based cancer registries worldwide, describe the techniques used in CI5 to evaluate their quality and highlight the notable variation in the incidence rates of selected cancers contained within Volume X of CI5. We also discuss the Global Initiative for Cancer Registry Development as an international partnership that aims to reduce the disparities in availability of cancer incidence data for cancer control action, particularly in economically transitioning countries, already experiencing a rapid rise in the number of cancer patients annually.

  15. The role of interventional radiology in the management of intra-and extra-Peritoneal leakage in patients who have undergone continent urinary diversion

    SciTech Connect

    Bodner, Leonard; Nosher, John L.; Siegel, Randall; Russer, Tadeus; Cummings, Kenneth; Kraus, Stephen

    1997-07-15

    Purpose. To assess how radiologic intervention altered the hospital course of patients undergoing continent urinary diversion. Methods. Thirty-seven consecutive patients with bladder cancer invading the muscular layer were treated with total cystectomy and construction of a continent urinary reservoir. Eleven of 37 patients suffered early and late anastomotic leakage; six had prolonged extraperitoneal leakage at the urethroenteric anastomosis, three had prolonged intraperitoneal pouch leaks, and two had delayed ureteroenteric leaks. Seven of these patients required radiologic intervention.Results. Intervention in the form of drainage catheter manipulation (n=4), percutaneous nephrostomy (n=4), or ureteral stent placement (n=2) resulted in cessation of leakage without surgical intervention in all seven patients. Intraperitoneal pouch leaks were more difficult to control than extraperitoneal leakage and required longer drainage intervals.Conclusion. Interventional radiologic procedures played a key role in the management of continent urinary diversion complications obviating the need for repeat surgical intervention in all instances.

  16. Analysis of pan-African Centres of excellence in health innovation highlights opportunities and challenges for local innovation and financing in the continent

    PubMed Central

    2012-01-01

    A pool of 38 pan-African Centres of Excellence (CoEs) in health innovation has been selected and recognized by the African Network for Drugs and Diagnostics Innovation (ANDI), through a competitive criteria based process. The process identified a number of opportunities and challenges for health R&D and innovation in the continent: i) it provides a direct evidence for the existence of innovation capability that can be leveraged to fill specific gaps in the continent; ii) it revealed a research and financing pattern that is largely fragmented and uncoordinated, and iii) it highlights the most frequent funders of health research in the continent. The CoEs are envisioned as an innovative network of public and private institutions with a critical mass of expertise and resources to support projects and a variety of activities for capacity building and scientific exchange, including hosting fellows, trainees, scientists on sabbaticals and exchange with other African and non-African institutions. PMID:22838941

  17. Large-scale Distribution of CH4 in the Western North Pacific: Sources and Transport from the Asian Continent

    NASA Technical Reports Server (NTRS)

    Bartlett, Karen B.; Sachse, Glen W.; Slate, Thomas; Harward, Charles; Blake, Donald R.

    2003-01-01

    Methane (CH4) mixing ratios in the northern Pacific Basin were sampled from two aircraft during the TRACE-P mission (Transport and Chemical Evolution over the Pacific) from late February through early April 2001 using a tunable diode laser system. Described in more detail by Jacob et al., the mission was designed to characterize Asian outflow to the Pacific, determine its chemical evolution, and assess changes to the atmosphere resulting from the rapid industrialization and increased energy usage on the Asian continent. The high-resolution, high-precision data set of roughly 13,800 CH4 measurements ranged between 1602 ppbv in stratospherically influenced air and 2149 ppbv in highly polluted air. Overall, CH4 mixing ratios were highly correlated with a variety of other trace gases characteristic of a mix of anthropogenic industrial and combustion sources and were strikingly correlated with ethane (C2H6) in particular. Averages with latitude in the near-surface (0-2 km) show that CH4 was elevated well above background levels north of 15 deg N close to the Asian continent. In the central and eastern Pacific, levels of CH4 were lower as continental inputs were mixed horizontally and vertically during transport. Overall, the correlation between CH4 and other hydrocarbons such as ethane (C2H6), ethyne (C2H2), and propane (C3H8) as well as the urban/industrial tracer perchloroethene (C2Cl4), suggests that for CH4 colocated sources such as landfills, wastewater treatment, and fossil fuel use associated with urban areas dominate regional inputs at this time. Comparisons between measurements made during TRACE-P and those of PEM-West B, flown during roughly the same time of year and under a similar meteorological setting 7 years earlier, suggest that although the TRACE-P CH4 observations are higher, the changes are not significantly greater than the increases seen in background air over this time interval.

  18. Origin and development of plains-type folds in the mid-continent (United States) during the late Paleozoic

    USGS Publications Warehouse

    Merriam, D.F.

    2005-01-01

    Plains-type folds are local, subtle anticlines formed in the thin sedimentary package overlying a shallow, crystalline basement on the craton. They are small in areal extent (usually less than 1-3 km 2 [0.4-1.2 mi2]), and their amplitude increases with depth (usually tens of meters), which is mainly the result of differential compaction of sediments (usually clastic units) over tilted, rigid, basement fault blocks. The development of these structural features by continuous but intermittent movement of the basement fault blocks in the late Paleozoic in the United States mid-continent is substantiated by a record of stratigraphic and sedimentological evidence. The recurrent structural movement, which reflects adjustment to external stresses, is expressed by the change in thickness of stratigraphic units over the crest of the fold compared to the flanks. By plotting the change in thickness for different stratigraphic units of anticlines on different fault blocks, it is possible to determine the timing of movement of the blocks that reflect structural adjustment. These readjustments are confirmed by sedimentological evidence, such as convolute, soft-sediment deformation features and small intraformational faults. The stratigraphic interval change in thickness for numerous structures in the Cherokee, Forest City, and Salina basins and on the Nemaha anticline of the mid-continent United States was determined and compared for location and timing of the adjustments. Most of the adjustment occurred during and after time of deposition of the Permian-Pennsylvanian clastic units, which, in turn, reflect tectonic disturbance in adjacent areas, and the largest amount of movement on the plains-type structures occurred on those nearest and semiparallel to major positive features, such as the Nemaha anticline. Depending on the time of origin and development of plains-type folds, they may control the entrapment and occurrence of oil and gas. Copyright ??2005. The American

  19. An assessment of stressor extent and biological condition in the North American mid-continent great rivers (USA)

    USGS Publications Warehouse

    Angradi, Ted R.; Bolgriend, David W.; Jicha, Terri M.; Pearson, Mark S.; Taylor, Debra L.; Moffett, Mary F.; Blocksom, Karen A.; Walters, David M.; Elonen, Colleen M.; Anderson, Leroy E.; Lazorchak, James M.; Reavie, Euan D.; Kireta, Amy R.; Hill, Brian H.

    2011-01-01

    We assessed the North American mid-continent great rivers (Upper Mississippi, Missouri, and Ohio). We estimated the extent of each river in most- (MDC) or least-disturbed condition (LDC) based on multiple biological response indicators: fish and macroinvertebrate, trophic state based on chlorophyll a, macrophyte cover, and exposure of fish-eating wildlife to toxic contaminants in fish tissue (Hg, total chlordane, total DDT, PCBs). We estimated the extent of stressors on each river including nutrients, suspended solids, sediment toxicity, invasive species, and land use (agriculture and impervious surface). All three rivers had a greater percent of their river length in MDC than in LDC based on fish assemblages. The Upper Mississippi River had the greatest percent of river length with eutrophic status. The Ohio River had the greatest percent of river length with fish with tissue contaminant levels toxic to wildlife. Overall, condition indices based on fish assemblages were more sensitive to stress than macroinvertebrate indices. Compared to the streams in its basin, more of the Upper Mississippi and Missouri Rivers were in MDC for nutrients than the Ohio River. Invasive species (Asian carp and Dreissenid mussels) were less widespread and less abundant on the Missouri River than on the other great rivers. The Ohio River had the most urbanized floodplains (greatest percent impervious surface). The Missouri River had the most floodplain agriculture. The effect of large urban areas on river condition was apparent for several indicators. Ecosystem condition based in fish assemblages, trophic state, and fish tissue contamination was related to land use on the floodplain and at the subcatchment scale. This is the first unbiased bioassessment of the mid-continent great rivers in the United States. The indicators, condition thresholds, results, and recommendations from this program are a starting point for improved future great river assessments.

  20. Increasing Potential Risk of a Global Aquatic Invader in Europe in Contrast to Other Continents under Future Climate Change

    PubMed Central

    Liu, Xuan; Guo, Zhongwei; Ke, Zunwei; Wang, Supen; Li, Yiming

    2011-01-01

    Background Anthropogenically-induced climate change can alter the current climatic habitat of non-native species and can have complex effects on potentially invasive species. Predictions of the potential distributions of invasive species under climate change will provide critical information for future conservation and management strategies. Aquatic ecosystems are particularly vulnerable to invasive species and climate change, but the effect of climate change on invasive species distributions has been rather neglected, especially for notorious global invaders. Methodology/Principal Findings We used ecological niche models (ENMs) to assess the risks and opportunities that climate change presents for the red swamp crayfish (Procambarus clarkii), which is a worldwide aquatic invasive species. Linking the factors of climate, topography, habitat and human influence, we developed predictive models incorporating both native and non-native distribution data of the crayfish to identify present areas of potential distribution and project the effects of future climate change based on a consensus-forecast approach combining the CCCMA and HADCM3 climate models under two emission scenarios (A2a and B2a) by 2050. The minimum temperature from the coldest month, the human footprint and precipitation of the driest quarter contributed most to the species distribution models. Under both the A2a and B2a scenarios, P. clarkii shifted to higher latitudes in continents of both the northern and southern hemispheres. However, the effect of climate change varied considerately among continents with an expanding potential in Europe and contracting changes in others. Conclusions/Significance Our findings are the first to predict the impact of climate change on the future distribution of a globally invasive aquatic species. We confirmed the complexities of the likely effects of climate change on the potential distribution of globally invasive species, and it is extremely important to develop

  1. Genetically Depauperate in the Continent but Rich in Oceanic Islands: Cistus monspeliensis (Cistaceae) in the Canary Islands

    PubMed Central

    Fernández-Mazuecos, Mario; Vargas, Pablo

    2011-01-01

    Background Population genetic theory holds that oceanic island populations are expected to have lower levels of genetic variation than their mainland counterparts, due to founder effect after island colonization from the continent. Cistus monspeliensis (Cistaceae) is distributed in both the Canary Islands and the Mediterranean region. Numerous phylogenetic results obtained in the last years allow performing further phylogeographic analyses in Cistus. Methodology/Principal Findings We analyzed sequences from multiple plastid DNA regions in 47 populations of Cistus monspeliensis from the Canary Islands (21 populations) and the Mediterranean basin (26 populations). The time-calibrated phylogeny and phylogeographic analyses yielded the following results: (1) a single, ancestral haplotype is distributed across the Mediterranean, whereas 10 haplotypes in the Canary Islands; (2) four haplotype lineages are present in the Canarian Islands; (3) multiple colonization events across the archipelago are inferred; (4) the earliest split of intraspecific lineages occurred in the Early to Middle Pleistocene (<930,000 years BP). Conclusions/Significance The contrasting pattern of cpDNA variation is best explained by genetic bottlenecks in the Mediterranean during Quaternary glaciations, while the Canarian archipelago acted as a refugium of high levels of genetic diversity. Active colonization across the Canarian islands is supported not only by the distribution of C. monspeliensis in five of the seven islands, but also by our phylogeographic reconstruction in which unrelated haplotypes are present on the same island. Widespread distribution of thermophilous habitats on every island, as those found throughout the Mediterranean, has likely been responsible for the successful colonization of C. monspeliensis, despite the absence of a long-distance dispersal mechanism. This is the first example of a plant species with higher genetic variation among oceanic island populations than among

  2. Flightless rails endemic to islands have lower energy expenditures and clutch sizes than flighted rails on islands and continents.

    PubMed

    McNab, Brian K; Ellis, Hugh I

    2006-11-01

    Data are presented on the standard energetics of six flighted and five flightless species of rails (Aves: Rallidae). The factors influencing these data and those from three additional species available from the literature, one of which was flightless, are examined. Basal rate of metabolism correlates with body mass, residency on islands or continents, volant condition, pectoral muscle mass, and food habits, but not with climate. The greatest capacity (96.2%) to account for the variation in basal rate of metabolism in 15 populations that belong to the 14 species occurs when body mass, volant condition, and food habits are combined. Then flighted species have basal rates that average 1.38 times those of flightless species and herbivorous rails have basal rates that are 1.37 times those of omnivorous species, which means that, independent of body mass, flighted gallinules have basal rates that are 1.9 times those of flightless, omnivorous rails. Distribution, pectoral muscle mass, and flight ability cannot be combined in the same analysis because they code for similar information. The evolution of a flightless condition in rails requires the absence of eutherian predators, but has occurred in the presence of marsupial predators. Each of the six studied flightless rails independently evolved a flightless condition and a low basal rate, whereas the evolution of herbivory and an associated high basal rate evolved at least twice in these species. Flightless rails on islands have clutch sizes that are only about one-half those of flighted rails living on continents, the reduction in clutch size correlating with a reduction in basal rate of metabolism. Thermal conductance in rails is correlated with body mass and food habits: herbivorous rails had conductances that were 1.43 times those of omnivores, i.e., conductances are highest in species with the highest basal rates.

  3. Assessing Climatic Impacts due to Land Use Change over Southeast Asian Maritime Continent base on Mesoscale Model Simulations

    NASA Astrophysics Data System (ADS)

    Feng, N.; Christopher, S. A.; Nair, U. S.

    2014-12-01

    Due to increasing urbanization, deforestation, and agriculture, land use change over Southeast Asia has dramatically risen during the last decades. Large areas of peat swamp forests over the Southeast Asian Maritime Continent region (10°S~20°N and 90°E~135°E) have been cleared for agricultural purposes. The Center for Remote Imaging, Sensing and Processing (CRISP) Moderate Resolution Imaging Spectroradiometer (MODIS) derived land cover classification data show that changes in land use are dominated by conversion of peat swamp forests to oil palm plantation, open lowland or lowland mosaic categories. Nested grid simulations based on Weather Research Forecasting Version 3.6 modelling system (WRFV3.6) over the central region of the Sarawak coast are used to investigate the climatic impacts of land use change over Maritime Continent. Numerical simulations were conducted for August of 2009 for satellite derived land cover scenarios for years 2000 and 2010. The variations in cloud formation, precipitation, and regional radiative and non-radiative parameters on climate results from land use change have been assessed based on numerical simulation results. Modelling studies demonstrate that land use change such as extensive deforestation processes can produce a negative radiative forcing due to the surface albedo increase and evapotranspiration decrease, while also largely caused reduced rainfall and cloud formation, and enhanced shortwave radiative forcing and temperature over the study area. Land use and land cover changes, similar to the domain in this study, has also occurred over other regions in Southeast Asia including Indonesia and could also impact cloud and precipitation formation in these regions.

  4. Early Eocene (c. 50 Ma) collision of the Indian and Asian continents: Constraints from the North Himalayan metamorphic rocks, southeastern Tibet

    NASA Astrophysics Data System (ADS)

    Ding, Huixia; Zhang, Zeming; Dong, Xin; Tian, Zuolin; Xiang, Hua; Mu, Hongchen; Gou, Zhengbin; Shui, Xinfang; Li, Wangchao; Mao, Lingjuan

    2016-02-01

    Despite several decades of investigations, the nature and timing of the India-Asia collision remain debated. In the western Himalaya, the leading edge of the Indian continent was deeply subducted to mantle depths and experienced ultrahigh-pressure metamorphism in the Eocene at c. 50 Ma. In this paper, however, we demonstrate that the North Himalayan metamorphic rocks in the eastern Himalaya underwent Early Eocene (48-45 Ma) medium-pressure (MP) metamorphism due to shallow subduction of the Indian continent beneath southeastern Tibet. The studied garnet-kyanite-staurolite schists occur in the core of the Yardoi gneiss dome, the easternmost North Himalayan Gneiss Dome, and represent the upper structural level of the Higher Himalayan Crystallines (HHC). Petrology and phase equilibria modeling show that these rocks have mineral assemblages of Grt + Pl + Bt + Qz ± Ky ± St ± Ms that were formed under conditions of 7-8 kbar and 630-660 °C. Zircon U-Pb chronology shows that these rocks have peak-metamorphic ages of 48-45 Ma and protracted zircon growth, indicating that the collision between Indian and Asian continents must have occurred at c. 50 Ma in southeastern Tibet. Combining with available data, we suggest that the HHC represents a crustal section of the subducted and subsequently exhumed Indian continent. Due to shallow subduction of the continent during the Eocene, the middle to lower crust of the continent was subducted into depths of 40-60 km and underwent high-pressure (HP) and high-temperature (HT) granulite-facies metamorphism and intense anatexis, whereas the upper crust was buried to shallower depths of 20-30 km and witnessed MP metamorphism and intrusion of leucogranites derived from the lower structural level of the HHC.

  5. A Report to the U.S. Department of Education on Educational Challenges and Technical Assistance Needs for the Mid-Continent Region

    ERIC Educational Resources Information Center

    CNA Corporation, 2005

    2005-01-01

    The Mid-Continent Regional Advisory Committee (RAC) provides an assessment of the technical assistance needs of educators in our region in response to a directive from the Secretary of the U.S. Department of Education. This RAC is one of ten such committees appointed by the Secretary to conduct the assessment over the period of December 2004…

  6. A harbinger of plate tectonics: a commentary on Bullard, Everett and Smith (1965) 'The fit of the continents around the Atlantic'.

    PubMed

    Dewey, John F

    2015-04-13

    In the 1960s, geology was transformed by the paradigm of plate tectonics. The 1965 paper of Bullard, Everett and Smith was a linking transition between the theories of continental drift and plate tectonics. They showed, conclusively, that the continents around the Atlantic were once contiguous and that the Atlantic Ocean had grown at rates of a few centimetres per year since the Early Jurassic, about 160 Ma. They achieved fits of the continental margins at the 500 fathom line (approx. 900 m), not the shorelines, by minimizing misfits between conjugate margins and finding axes, poles and angles of rotation, using Euler's theorem, that defined the unique single finite difference rotation that carried congruent continents from contiguity to their present positions, recognizing that the real motion may have been more complex around a number of finite motion poles. Critically, they were concerned only with kinematic reality and were not restricted by considerations of the mechanism by which continents split and oceans grow. Many of the defining features of plate tectonics were explicit or implicit in their reconstructions, such as the torsional rigidity of continents, Euler's theorem, closure of the Tethyan ocean(s), major continental margin shear zones, the rapid rotation of small continental blocks (Iberia) around nearby poles, the consequent opening of small wedge-shaped oceans (Bay of Biscay), and misfit overlaps (deltas and volcanic piles) and underlaps (stretched continental edges). This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society.

  7. Annotated Bibliography of Children's Literature Resources on War, Terrorism, and Disaster since 1945: By Continents/Countries for Grades K-8

    ERIC Educational Resources Information Center

    Gangi, Jane M.

    2009-01-01

    This article presents an annotated bibliography of children's literature resources on war, terrorism, and disaster since 1945. This annotated bibliography focuses on grades K-8 from different continents/countries, including (1) Africa; (2) Asia; (3) The Caribbean; (4) Central and South America; (5) Europe; and (6) The Middle East.

  8. Reduction of Risk in Exploration and Prospect Generation through a Multidisciplinary Basin-Analysis Program in the South-Central Mid-Continent Region

    SciTech Connect

    Banerjee, S.; Barker, C.; Fite, J.; George, S.; Guo, Genliang; Johnson, W.; Jordan, J., Szpakiewicz, M.; Person, M.; Reeves, T.K.; Safley, E.; Swenson, J.B.; Volk, L.; and Erickson, R.

    1999-04-02

    This report will discuss a series of regional studies that were undertaken within the South-Central Mid-Continent region of the U.S. Coverage is also provided about a series of innovative techniques that were used for this assessment.

  9. Sublatitudinal Isotope Heterogeneity of The Atlantic and Adjacent Continents: A Relation To The Litospheric Plates and Superplums

    NASA Astrophysics Data System (ADS)

    Mironov, Yu. V.; Ryakhovsky, V. M.; Pustovoy, A. A.; Lapidus, I. V.

    Four Sr-Nd-Pb isotope sublatitudinal provinces are chosen in the Atlantic and on ad- jacent continents. They include mid-ocean ridges, oceanic rises and islands, as well as Late Mesozoic - Cenozoic continental rifts and traps. A modified Zindler-Hart "man- tle tetrahedron" (1986) have been used for rock systematics. Its major classification element alongside with known end-members (DM, HIMU, EM1, EM2) is any in- tratetrahedron component F ("focal") (Mironov et al., 2000; Rundquist et al., 2000; Ryakhovsky, 2000). It represents average characteristic of all known intratetrahedron components (FOZO, C, PREMA etc.), updated by methods of multidimensional statis- tics. Northern province includes Mid-Atlantic Ridge from a southern part of Reykjanes ridge up to 24S, numerous islands and rises, located at the same latitudes, Cameroon Line, African and European rifts, Aden and Red sea spreading centres, and also Co- mores in Indian ocean. The main composition dispersion of volcanics from withinplate oceanic and continental structures is determined by mixture of F and HIMU (rarely with admixture EM2). MORB within this area are characterized by stable admixture HIMU. Similar composition have the rocks in Bouvet-Antarctic province, within the limits of which the rises Spiss and Shona, the most southern part of Mid-Atlantic ridge, island Bouvet, an adjacent part of Southwest-Indian Ridge, and also traps and rifts on northern coast of Antarctic Continent are located. The Southern province lies in outlines of known Southern hemisphere DUPAL-anomaly (Hart, 1984). The with- inplate oceanic rocks (Gough, Tristan-da-Kunha, Walvis ridge, Rio Grande Plateau, Discovery) correspond to a mixture F + EM1 (sometimes F + EM1 + EM2) and are similar with traps of Southern America and Africa. Further to east this province is traced on islands and mid-ocean ridges in Indian ocean. MORB of Southern Atlantic and Indian ocean are enriched EM1. The Arctic province includes spreading ridges of

  10. Igneous to metamorphic evolution of mafic rocks from a fossile ocean-continent transition (External Liguride ophiolites, Italy)

    NASA Astrophysics Data System (ADS)

    Montanini, A.; Tribuzio, R.

    2003-04-01

    Remnants of the ocean-continent transition between the Jurassic Ligurian Tethys and the Adria margin are preserved in the External Liguride units (EL) of the Northern Apennine. The EL ophiolites crop out as gravity slide blocks within Late Cretaceous sedimentary mèlanges and sometimes preserve evidence of primary relations with continental crust rocks. These ophiolites mainly consist of subcontinental mantle ultramafics and basaltic rocks. The latter crop out as (i) massive and pillow lavas, locally erupted over slices of Variscan granitoids and covered by radiolarian cherts, (ii) dykes crosscutting mantle peridotites. The basaltic rocks display nearly flat REE pattern and initial eNd of +7.7 to +10.2. These geochemical features can be related to low degree of melting of a depleted asthenospheric mantle in the spinel stability field. The ophiolitic gabbros are rare and occur as small bodies intruding mantle lherzolites or as decametric to hectometric slide-blocks. The latter are crosscut by discordant microgabbro bodies and doleritic dykes. The gabbroic sequence mostly consists of troctolites, olivine-bearing gabbros and Fe-Ti oxide-bearing diorites. Trace element and Nd isotope compositions are consistent with crystallization from N-MORB liquids. Metamorphic evolution started with syn-kinematic crystallization of neoblastic clinopyroxene + plagioclase ± titanian pargasite ± ilmenite ± spinel along granulite-facies ductile shear zones (˜850^oC), followed by widespread development of subgreenschist metamorphic assemblages under static conditions. One of the gabbroic bodies is covered by radiolarian cherts, thus testifying exhumation to ocean-floor, and show an intermediate metamorphic stage under amphibolite-facies conditions (T ˜650^oC). This stage is mainly testified by syn-kinematic growth of plagioclase and Mg-hornblende (± ilmenite) in ductile shear zones, and was accompanied by infiltration of aqueous fluids, probably seawater-derived. The onset of

  11. Continent-wide decoupling of Y-chromosomal genetic variation from language and geography in native South Americans.

    PubMed

    Roewer, Lutz; Nothnagel, Michael; Gusmão, Leonor; Gomes, Veronica; González, Miguel; Corach, Daniel; Sala, Andrea; Alechine, Evguenia; Palha, Teresinha; Santos, Ney; Ribeiro-Dos-Santos, Andrea; Geppert, Maria; Willuweit, Sascha; Nagy, Marion; Zweynert, Sarah; Baeta, Miriam; Núñez, Carolina; Martínez-Jarreta, Begoña; González-Andrade, Fabricio; Fagundes de Carvalho, Elizeu; da Silva, Dayse Aparecida; Builes, Juan José; Turbón, Daniel; Lopez Parra, Ana Maria; Arroyo-Pardo, Eduardo; Toscanini, Ulises; Borjas, Lisbeth; Barletta, Claudia; Ewart, Elizabeth; Santos, Sidney; Krawczak, Michael

    2013-04-01

    Numerous studies of human populations in Europe and Asia have revealed a concordance between their extant genetic structure and the prevailing regional pattern of geography and language. For native South Americans, however, such evidence has been lacking so far. Therefore, we examined the relationship between Y-chromosomal genotype on the one hand, and male geographic origin and linguistic affiliation on the other, in the largest study of South American natives to date in terms of sampled individuals and populations. A total of 1,011 individuals, representing 50 tribal populations from 81 settlements, were genotyped for up to 17 short tandem repeat (STR) markers and 16 single nucleotide polymorphisms (Y-SNPs), the latter resolving phylogenetic lineages Q and C. Virtually no structure became apparent for the extant Y-chromosomal genetic variation of South American males that could sensibly be related to their inter-tribal geographic and linguistic relationships. This continent-wide decoupling is consistent with a rapid peopling of the continent followed by long periods of isolation in small groups. Furthermore, for the first time, we identified a distinct geographical cluster of Y-SNP lineages C-M217 (C3*) in South America. Such haplotypes are virtually absent from North and Central America, but occur at high frequency in Asia. Together with the locally confined Y-STR autocorrelation observed in our study as a whole, the available data therefore suggest a late introduction of C3* into South America no more than 6,000 years ago, perhaps via coastal or trans-Pacific routes. Extensive simulations revealed that the observed lack of haplogroup C3* among extant North and Central American natives is only compatible with low levels of migration between the ancestor populations of C3* carriers and non-carriers. In summary, our data highlight the fact that a pronounced correlation between genetic and geographic/cultural structure can only be expected under very specific

  12. Continent-Wide Decoupling of Y-Chromosomal Genetic Variation from Language and Geography in Native South Americans

    PubMed Central

    Gusmão, Leonor; Gomes, Veronica; González, Miguel; Corach, Daniel; Sala, Andrea; Alechine, Evguenia; Palha, Teresinha; Santos, Ney; Ribeiro-dos-Santos, Andrea; Geppert, Maria; Willuweit, Sascha; Nagy, Marion; Zweynert, Sarah; Baeta, Miriam; Núñez, Carolina; Martínez-Jarreta, Begoña; González-Andrade, Fabricio; Fagundes de Carvalho, Elizeu; da Silva, Dayse Aparecida; Builes, Juan José; Turbón, Daniel; Lopez Parra, Ana Maria; Arroyo-Pardo, Eduardo; Toscanini, Ulises; Borjas, Lisbeth; Barletta, Claudia; Ewart, Elizabeth; Santos, Sidney; Krawczak, Michael

    2013-01-01

    Numerous studies of human populations in Europe and Asia have revealed a concordance between their extant genetic structure and the prevailing regional pattern of geography and language. For native South Americans, however, such evidence has been lacking so far. Therefore, we examined the relationship between Y-chromosomal genotype on the one hand, and male geographic origin and linguistic affiliation on the other, in the largest study of South American natives to date in terms of sampled individuals and populations. A total of 1,011 individuals, representing 50 tribal populations from 81 settlements, were genotyped for up to 17 short tandem repeat (STR) markers and 16 single nucleotide polymorphisms (Y-SNPs), the latter resolving phylogenetic lineages Q and C. Virtually no structure became apparent for the extant Y-chromosomal genetic variation of South American males that could sensibly be related to their inter-tribal geographic and linguistic relationships. This continent-wide decoupling is consistent with a rapid peopling of the continent followed by long periods of isolation in small groups. Furthermore, for the first time, we identified a distinct geographical cluster of Y-SNP lineages C-M217 (C3*) in South America. Such haplotypes are virtually absent from North and Central America, but occur at high frequency in Asia. Together with the locally confined Y-STR autocorrelation observed in our study as a whole, the available data therefore suggest a late introduction of C3* into South America no more than 6,000 years ago, perhaps via coastal or trans-Pacific routes. Extensive simulations revealed that the observed lack of haplogroup C3* among extant North and Central American natives is only compatible with low levels of migration between the ancestor populations of C3* carriers and non-carriers. In summary, our data highlight the fact that a pronounced correlation between genetic and geographic/cultural structure can only be expected under very specific

  13. Mineralogical and geochemical tracers of terrigenous supply in the Gulf of Mexico: new insights on ocean-atmosphere-continent interactions

    NASA Astrophysics Data System (ADS)

    Bout-Roumazeilles, V.; Montero Serrano, J.; Sionneau, T.; Meunier, G.; Bory, A. J.; Tribovillard, N.

    2011-12-01

    The mineralogical and geochemical signatures of sediments deposited in the Gulf of Mexico (GOM) are valuable proxies to retrace the provenance of terrigenous particles transported by the Mississippi River during the last climatic cycle (Sionneau et al., 2008). The Mississippi River flow is mainly controlled by precipitations intensity and distribution during interglacial periods whereas meltwater discharges are the most prominent processes during the deglaciation. Using this approach on a series of sediment cores from the northern GOM, our research group recently gave some new insights on the connection between high-latitude climate and the subtropical hydrology and on atmosphere-ocean-continent transfers: - The clay mineral composition of sediments deposited in the GOM allows constraining the spatial evolution of the Laurentide ice sheet (LIS) southern margin during the major meltwater discharges of the last deglaciation, pinpointing the continental domains successively submitted to erosion during the ice-sheet retreat (Sionneau et al., 2010; Montero et al., 2009); - A high-resolution analysis of the most prominent meltwater discharge provides a detailed chronology of the multi-phased discharge with an initial flooding preceding the main erosional pulse and the final decantation phase (Montero et al., 2009); - The impact of a main freshwater supply on the GOM hydrology was investigated using the peculiar mineralogical signature of the main meltwater event (14.6-14 ka cal BP). The spatial propagation of the detrital flow associated with this event was constrained in the northern GOM. This result, together with the deposit sedimentological characteristics, allows estimating the terrigenous flux and checking its consistency with previously published hypotheses (Bout-Roumazeilles et al., submitted); - Recurrent modifications of the clay mineral fraction during the late Holocene allow assessing some major changes in precipitation regimes over North America resulting

  14. Application of a new method in the study of pelvic floor muscle passive properties in continent women.

    PubMed

    Morin, Mélanie; Gravel, Denis; Bourbonnais, Daniel; Dumoulin, Chantale; Ouellet, Stéphane; Pilon, Jean-François

    2010-10-01

    The aim of this study was to present a new methodology for evaluating the pelvic floor muscle (PFM) passive properties. The properties were assessed in 13 continent women using an intra-vaginal dynamometric speculum and EMG (to ensure the subjects were relaxed) in four different conditions: (1) forces recorded at minimal aperture (initial passive resistance); (2) passive resistance at maximal aperture; (3) forces and passive elastic stiffness (PES) evaluated during five lengthening and shortening cycles; and (4) percentage loss of resistance after 1min of sustained stretch. The PFMs and surrounding tissues were stretched, at constant speed, by increasing the vaginal antero-posterior diameter; different apertures were considered. Hysteresis was also calculated. The procedure was deemed acceptable by all participants. The median passive forces recorded ranged from 0.54N (interquartile range 1.52) for minimal aperture to 8.45N (interquartile range 7.10) for maximal aperture while the corresponding median PES values were 0.17N/mm (interquartile range 0.28) and 0.67N/mm (interquartile range 0.60). Median hysteresis was 17.24N *mm (interquartile range 35.60) and the median percentage of force losses was 11.17% (interquartile range 13.33). This original approach to evaluating the PFM passive properties is very promising for providing better insight into the patho-physiology of stress urinary incontinence and pinpointing conservative treatment mechanisms.

  15. Geologic Evolution of North America: Geologic features suggest that the continent has grown and differentiated through geologic time.

    PubMed

    Engel, A E

    1963-04-12

    The oldest decipherable rock complexes within continents (more than 2.5 billion years old) are largely basaltic volcanics and graywacke. Recent and modern analogs are the island arcs formed along and adjacent to the unstable interface of continental and oceanic crusts. The major interfacial reactions (orogenies) incorporate pre-existing sial, oceanic crust, and mantle into crust of a more continental type. Incipient stages of continental evolution, more than 3 billion years ago, remain obscure. They may involve either a cataclysmic granite-forming event or a succession of volcanic-sedimentary and granite-forming cycles. Intermediate and recent stages of continental evolution, as indicated by data for North America, involve accretion of numerous crustal interfaces with fragments of adjacent continental crust and their partial melting, reinjection, elevation, unroofing, and stabilization. Areas of relict provinces defined by ages of granites suggest that continental growth is approximately linear. But the advanced differentiation found in many provinces and the known overlaps permit wide deviation from linearity in the direction of a more explosive early or intermediate growth.

  16. A study on crustal shear wave splitting in the western part of the Banda arc-continent collision

    NASA Astrophysics Data System (ADS)

    Syuhada, Hananto, Nugroho D.; Puspito, Nanang T.; Anggono, Titi; Yudistira, Tedi

    2016-03-01

    We analyzed shear wave splitting parameters from local shallow (< 30 km) earthquakes recorded at six seismic stations in the western part of the Banda arc-continent collision. We determined fast polarization and delay time for 195 event-stations pairs calculated from good signal-to-noise ratio waveforms. We observed that there is evidence for shear wave splitting at all stations with dominant fast polarization directions oriented about NE-SW, which are parallel to the collision direction of the Australian plate. However, minor fast polarization directions are oriented around NW-SE being perpendicular to the strike of Timor through. Furthermore, the changes in fast azimuths with the earthquake-station back azimuth suggest that the crustal anisotropy in the study area is not uniform. Splitting delay times are within the range of 0.05 s to 0.8 s, with a mean value of 0.29±0.18 s. Major seismic stations exhibit a weak tendency increasing of delay times with increasing hypocentral distance suggesting the main anisotropy contribution of the shallow crust. In addition, these variations in fast azimuths and delay times indicate that the crustal anisotropy in this region might not only be caused by extensive dilatancy anisotropy (EDA), but also by heterogeneity shallow structure such as the presence of foliations in the rock fabric and the fracture zones associated with active faults.

  17. Death by sex in an Australian icon: a continent-wide survey reveals extensive hybridization between dingoes and domestic dogs.

    PubMed

    Stephens, Danielle; Wilton, Alan N; Fleming, Peter J S; Berry, Oliver

    2015-11-01

    Hybridization between domesticated animals and their wild counterparts can disrupt adaptive gene combinations, reduce genetic diversity, extinguish wild populations and change ecosystem function. The dingo is a free-ranging dog that is an iconic apex predator and distributed throughout most of mainland Australia. Dingoes readily hybridize with domestic dogs, and in many Australian jurisdictions, distinct management strategies are dictated by hybrid status. Yet, the magnitude and spatial extent of domestic dog-dingo hybridization is poorly characterized. To address this, we performed a continent-wide analysis of hybridization throughout Australia based on 24 locus microsatellite DNA genotypes from 3637 free-ranging dogs. Although 46% of all free-ranging dogs were classified as pure dingoes, all regions exhibited some hybridization, and the magnitude varied substantially. The southeast of Australia was highly admixed, with 99% of animals being hybrids or feral domestic dogs, whereas only 13% of the animals from remote central Australia were hybrids. Almost all free-ranging dogs had some dingo ancestry, indicating that domestic dogs could have poor survivorship in nonurban Australian environments. Overall, wild pure dingoes remain the dominant predator over most of Australia, but the speed and extent to which hybridization has occurred in the approximately 220 years since the first introduction of domestic dogs indicate that the process may soon threaten the persistence of pure dingoes.

  18. Heat flow patterns of the North American continent: A discussion of the DNAG Geothermal Map of North America

    SciTech Connect

    Blackwell, David D.; Steele, John L.; Carter, Larry C.

    1990-01-01

    The large and small-scale geothermal features of the North American continent and surrounding ocean areas illustrated on the new 1:5,000,000 DNAG Geothermal Map of North America are summarized. Sources for the data included on the map are given. The types of data included are heat flow sites coded by value, contours of heat flow with a color fill, areas of major groundwater effects on regional heat flow, the top-of-geopressure in the Gulf Coast region, temperature on the Dakota aquifer in the midcontinent, location of major hot springs and geothermal systems, and major center of Quaternary and Holocene volcanism. The large scale heat flow pattern that is well known for the conterminous United States and Canada of normal heat flow east of the Cordillera and generally high heat flow west of the front of the Cordillera dominates the continental portion of the map. However, details of the heat flow variations are also seen and are discussed briefly in this and the accompanying papers.

  19. Evaluation of regional-scale hydrological models using multiple criteria for 12 large river basins on all continents

    NASA Astrophysics Data System (ADS)

    Huang, Shaochun; Krysanova, Valentina; Hattermann, Fred; Vetter, Tobias; Flörke, Martina; Samaniego, Luis; Arheimer, Berit; Yang, Tao; van Griensven, Ann; Su, Buda; Gelfan, Alexander; Breuer, Lutz; Haberlandt, Uwe

    2016-04-01

    A good performance of hydrological impact models under historical climate and land use conditions is a prerequisite for reliable projections under climate change. The evaluation of nine regional-scale hydrological models considering monthly river discharge, long-term average seasonal dynamics and extremes was performed in the framework of the ISI-MIP project for 12 large river basins on all continents. The modelling tools include: ECOMAG, HBV, HYMOD, HYPE, mHM, SWAT, SWIM, VIC and WaterGAP3. These models were evaluated for the following basins: the Rhine and Tagus in Europe, the Niger and Blue Nile in Africa, the Ganges, Lena, Upper Yellow and Upper Yangtze in Asia, the Upper Mississippi, MacKenzie and Upper Amazon in America, and Darling in Australia. The model calibration and validation was done using WATCH climate data for all cases. The model outputs were evaluated using twelve statistical criteria to assess the fidelity of model simulations for monthly discharge, seasonal dynamics, flow duration curves, extreme floods and low flow. The reproduction of monthly discharge and seasonal dynamics was successful in all basins except the Darling, and the high flows and flood characteristics were also captured satisfactory in most cases. However, the criteria for low flow were below the thresholds in many cases. An overview of this collaborative experiment and main results on model evaluation will be presented.

  20. Potential for producing oil and gas from Woodford Shale (Devonian-Mississippian) in the southern Mid-Continent, USA

    SciTech Connect

    Comer, J.B. )

    1991-03-01

    Woodford Shale is a prolific oil source rock throughout the southern Mid-Continent of the US. Extrapolation of thickness and organic geochemical data based on the analysis of 614 samples from the region indicate that on the order of 100 {times} 10{sup 9} bbl of oil (300 {times} 10{sup 12} ft {sup 3} of natural gas equivalent). Tapping this resource is most feasible in areas where the Woodford subcrop contains competent lithofacies (e.g., chert, sandstone, siltstone, dolostone) and is high fractured. Horizontal drilling may provide the optimum exploitation technique. Areas with the greatest potential and the most prospective lithologies include (1) the Nemaha uplift (chert, sandstone, dolostone), (2) Marietta-Ardmore basin (chert), (3) southern flank of the Anadarko basin along the Wichita Mountain uplift (chert), (4) frontal zone of the Ouachita tectonic belt in Oklahoma (chert), and (5) the Central Basin platform in west Texas and New Mexico (chert and siltstone). In virtually all of these areas the Woodford is in the oil or gas window. Thus, fracture porosity would be continuously fed by hydrocarbons generated in the enclosing source rocks. Reservoir systems such as these have typically produced at low to moderate flow rates for many decades.

  1. Potential for producing oil and gas from the Woodford Shale (Devonian-Mississippian) in the southern mid-continent, USA

    SciTech Connect

    Comer, J.B. )

    1992-04-01

    The Woodford Shale is a prolific oil source rock throughout the southern mid-continent of the United States. Extrapolation of thickness and organic geochemical data based on the analysis of 614 samples from the region indicate that on the order of 100 {times} 10{sup 9} bbl of oil (300 {times} 10{sup 12} ft{sup 3} of natural gas equivalent) reside in the Woodford in Oklahoma and northwestern Arkansas. The Woodford in west Texas and southeastern New Mexico contains on the order of 80 {times} 10{sup 9} bbl of oil (240 {times} 10{sup 12} ft{sup 3} of natural gas equivalent). Tapping this resource is most feasible in areas where the Woodford subcrop contains competent lithofacies (e.g., chert, sandstone, siltstone, dolostone) and is highly fractured. Horizontal drilling may provide the optimum exploitation technique. Areas with the greatest potential and the most prospective lithologies include (1) the Nemaha uplift (chert, sandstone, dolostone), (2) Marietta-Ardmore basin (chert), (3) southern flank of the Anadarko basin along the Wichita Mountain uplift (chert), (4) frontal zone of the Ouachita tectonic belt in Oklahoma (chert), and (5) the Central Basin platform in west Texas and New Mexico (chert and siltstone). In virtually all of these areas, the Woodford is in the oil or gas window. Thus, fracture porosity would be continuously fed by hydrocarbons generated in the enclosing source rocks. Reservoir systems such as these typically have produced at low to moderate flow rates for many decades.

  2. Long aftershock sequences in North China and Central US: implications for hazard assessment in mid-continents

    NASA Astrophysics Data System (ADS)

    Liu, Mian; Luo, Gang; Wang, Hui; Stein, Seth

    2014-02-01

    Because seismic activity within mid-continents is usually much lower than that along plate boundary zones, even small earthquakes can cause widespread concerns, especially when these events occur in the source regions of previous large earthquakes. However, these small earthquakes may be just aftershocks that continue for decades or even longer. The recent seismicity in the Tangshan region in North China is likely aftershocks of the 1976 Great Tangshan earthquake. The current earthquake sequence in the New Madrid seismic zone in central United States, which includes a cluster of M ~ 7.0 events in 1811-1812 and a number of similar events in the past millennium, is believed to result from recent fault reactivation that releases pre-stored strain energy in the crust. If so, this earthquake sequence is similar to aftershocks in that the rates of energy release should decay with time and the sequence of earthquakes will eventually end. We use simple physical analysis and numerical simulations to show that the current sequence of large earthquakes in the New Madrid fault zone is likely ending or has ended. Recognizing that mid-continental earthquakes have long aftershock sequences and complex spatiotemporal occurrences are critical to improve hazard assessments.

  3. Single cell analysis of innate cytokine responses to pattern recognition receptor stimulation in children across four continents

    PubMed Central

    Smolen, Kinga K; Cai, Bing; Fortuno, Edgardo S; Gelinas, Laura; Larsen, Martin; Speert, David P; Chamekh, Mustapha; Kollmann, Tobias R

    2014-01-01

    Innate immunity instructs adaptive immunity, and suppression of innate immunity is associated with increased risk for infection. We had previously shown that whole blood cellular components from a cohort of South African children secreted significantly lower levels of most cytokines following stimulation of pattern recognition receptors (PRR) as compared to whole blood from cohorts of Ecuadorian, Belgian, or Canadian children. To begin dissecting the responsible molecular mechanisms, we now set out to identify the relevant cellular source of these differences. Across the four cohorts represented in our study, we identified significant variation in the cellular composition of whole blood; however, significant reduction of the intracellular cytokine production on the single cell level was only detected in South African childrens’ monocytes, cDC, and pDC. We also uncovered a marked reduction in polyfunctionality for each of these cellular compartments in South African children as compared to children from other continents. Together our data identify differences in cell composition as well as profoundly lower functional responses of innate cells in our cohort of South African children. A possible link between altered innate immunity and increased risk for infection or lower response to vaccines in South African infants needs to be explored. PMID:25135829

  4. From slab rollback to orogenic plateau formation - a numerical modeling study of ocean-continent subduction systems

    NASA Astrophysics Data System (ADS)

    Wolf, Sebastian; Huismans, Ritske S.; Rondenay, Stéphane

    2016-04-01

    The crustal structures of overriding plates in subduction settings around the world can vary between a wide range of deformation styles, ranging from extensional structures and back arc opening induced by slab roll back as in the Hellenic subduction zone to large, plateau-like orogens such as the central Andes. Both end member types have been intensively studied over the last decades and a range of hypotheses have been proposed to explain their characteristics. Here we model ocean-continent collision using lithospheric scale plane-strain thermo-mechanical models, which also account for phase changes of rocks which enter the eclogite stability field. We consider the oceanic plate velocity, back-arc crustal strength, back-arc lithospheric strength, subduction interface strength, strain weakening thresholds in the crust and mantle flow patterns as the main variables in upper plate deformation and conducted a sensibility study with those parameters. The influence of eclogitized lower continental crust is also accounted for and shows to have a modulating effect. To verify and discuss our modeling results, we also present a comparison of the models with natural subduction systems.

  5. Cost-utility analysis of an advanced pressure ulcer management protocol followed by trained wound, ostomy, and continence nurses.

    PubMed

    Kaitani, Toshiko; Nakagami, Gojiro; Iizaka, Shinji; Fukuda, Takashi; Oe, Makoto; Igarashi, Ataru; Mori, Taketoshi; Takemura, Yukie; Mizokami, Yuko; Sugama, Junko; Sanada, Hiromi

    2015-01-01

    The high prevalence of severe pressure ulcers (PUs) is an important issue that requires to be highlighted in Japan. In a previous study, we devised an advanced PU management protocol to enable early detection of and intervention for deep tissue injury and critical colonization. This protocol was effective for preventing more severe PUs. The present study aimed to compare the cost-effectiveness of the care provided using an advanced PU management protocol, from a medical provider's perspective, implemented by trained wound, ostomy, and continence nurses (WOCNs), with that of conventional care provided by a control group of WOCNs. A Markov model was constructed for a 1-year time horizon to determine the incremental cost-effectiveness ratio of advanced PU management compared with conventional care. The number of quality-adjusted life-years gained, and the cost in Japanese yen (¥) ($US1 = ¥120; 2015) was used as the outcome. Model inputs for clinical probabilities and related costs were based on our previous clinical trial results. Univariate sensitivity analyses were performed. Furthermore, a Bayesian multivariate probability sensitivity analysis was performed using Monte Carlo simulations with advanced PU management. Two different models were created for initial cohort distribution. For both models, the expected effectiveness for the intervention group using advanced PU management techniques was high, with a low expected cost value. The sensitivity analyses suggested that the results were robust. Intervention by WOCNs using advanced PU management techniques was more effective and cost-effective than conventional care.

  6. Urodynamic and haemodynamic effects of a single oral administration of ephedrine or phenylpropanolamine in continent female dogs.

    PubMed

    Noël, Stéphanie; Massart, Laurent; Hamaide, Annick

    2012-04-01

    This study investigated the effects of a single oral administration of ephedrine (2 mg/kg) or phenylpropanolamine (PPA) (1.5 mg/kg) on the vesico-urethral and cardiovascular functions in continent female dogs. Urethral pressure profilometry (UPP), arterial blood pressures and heart rate were measured in five control dogs and after single-dose treatment with ephedrine or PPA at T(0), T(2h), T(4h), T(6h), T(12h), T(18h) and T(24h). UPPs were performed under propofol anaesthesia and other measurements were performed on awake dogs. A telemetric urodynamic investigation was performed on three additional dogs for 24 h after the administration of each drug. Urethral pressures increased over 4-6 h and urethral functional lengths increased 2-6h after administration of both drugs. During micturition, a decrease in detrusor pressure coupled with an increase in bladder volume was observed after ephedrine administration and there was also an increase in bladder volume after PPA had been given. With both drugs increased arterial blood pressures at 4-6 h were compensated by a decreased heart rate over 12 h. Urethral function was improved after both ephedrine and PPA, and bladder function also improved during micturition following ephedrine.

  7. Death by sex in an Australian icon: a continent-wide survey reveals extensive hybridization between dingoes and domestic dogs.

    PubMed

    Stephens, Danielle; Wilton, Alan N; Fleming, Peter J S; Berry, Oliver

    2015-11-01

    Hybridization between domesticated animals and their wild counterparts can disrupt adaptive gene combinations, reduce genetic diversity, extinguish wild populations and change ecosystem function. The dingo is a free-ranging dog that is an iconic apex predator and distributed throughout most of mainland Australia. Dingoes readily hybridize with domestic dogs, and in many Australian jurisdictions, distinct management strategies are dictated by hybrid status. Yet, the magnitude and spatial extent of domestic dog-dingo hybridization is poorly characterized. To address this, we performed a continent-wide analysis of hybridization throughout Australia based on 24 locus microsatellite DNA genotypes from 3637 free-ranging dogs. Although 46% of all free-ranging dogs were classified as pure dingoes, all regions exhibited some hybridization, and the magnitude varied substantially. The southeast of Australia was highly admixed, with 99% of animals being hybrids or feral domestic dogs, whereas only 13% of the animals from remote central Australia were hybrids. Almost all free-ranging dogs had some dingo ancestry, indicating that domestic dogs could have poor survivorship in nonurban Australian environments. Overall, wild pure dingoes remain the dominant predator over most of Australia, but the speed and extent to which hybridization has occurred in the approximately 220 years since the first introduction of domestic dogs indicate that the process may soon threaten the persistence of pure dingoes. PMID:26514639

  8. Geologic Evolution of North America: Geologic features suggest that the continent has grown and differentiated through geologic time.

    PubMed

    Engel, A E

    1963-04-12

    The oldest decipherable rock complexes within continents (more than 2.5 billion years old) are largely basaltic volcanics and graywacke. Recent and modern analogs are the island arcs formed along and adjacent to the unstable interface of continental and oceanic crusts. The major interfacial reactions (orogenies) incorporate pre-existing sial, oceanic crust, and mantle into crust of a more continental type. Incipient stages of continental evolution, more than 3 billion years ago, remain obscure. They may involve either a cataclysmic granite-forming event or a succession of volcanic-sedimentary and granite-forming cycles. Intermediate and recent stages of continental evolution, as indicated by data for North America, involve accretion of numerous crustal interfaces with fragments of adjacent continental crust and their partial melting, reinjection, elevation, unroofing, and stabilization. Areas of relict provinces defined by ages of granites suggest that continental growth is approximately linear. But the advanced differentiation found in many provinces and the known overlaps permit wide deviation from linearity in the direction of a more explosive early or intermediate growth. PMID:17819825

  9. Effect of combined application insulin and insulin detemir on continous glucose monitor in children with type 1 diabetes mellitus

    PubMed Central

    Chen, Xiao-Yun; Dong, Qing; Li, Gui-Mei

    2015-01-01

    Insulin detemir is a soluble long-acting human insulin analogue at neutral pH with a unique mechanism of action, which could strengthen the effects of insulin. This study aims to explore the effects of insulin combined with insulin detemir on the continous glucose in children with type 1 diabetes mellitus. In this study, 150 patients with type 1 diabetes enrolled were included and randomly divided into 3 groups: insulin group (group A), insulin detemir group (group B) and insulin combined with insulin detemir group (group C). Each subject underwent 72 h of continuous glucose monitoring (CGM). MAGE, HbA1c and Noctumal Hypoglycemia levels were examined by using the ELISA kits. The body weight changes were also detected in this study. The results indicated that the information including age, body weight, disease duration and glucose level and HbA1c percentage on the start time point among three groups indicated no statistical differences. Insulin combined with insulin detemir decrease MAGE and HbA1c level in Group C compared to Group A and Group A (P < 0.05). Insulin combined with insulin detemir decreas noctumal hypoglycemia levels and body weight changes (P < 0.05). In conclusion, this study confirmed efficacy of insulin detemir by demonstrating non-inferiority of insulin detemir compared with insulin with respect to HbA1c, with an improved safety profile including significantly fewer hypoglycaemic episodes and less undesirable weight gain in children. PMID:26064343

  10. TRMM Based Studies of MJO Convection over the Central Indian Ocean, Maritime Continent, and Western Pacific Warm Pool

    NASA Astrophysics Data System (ADS)

    Rutledge, S. A.; Xu, W.

    2014-12-01

    The structure and organization of precipitating cloud populations related to the initiation and evolution of several MJO events have been fully investigated using data collected from the 2011-2012 DYNAMO field campaign over the Central Indian Ocean (CIO). Since DYNMO monitored the MJO behavior for only a few months, it is important to know how the DYNAMO-recorded characteristics compare to the long-term climatology, such as viewed by TRMM satellite measurements. TRMM observations are also capable of providing the regional variability of the convection as the MJO envelope propagates eastward. The objective of this study is to quantify MJO convective characteristics using 15 years of TRMM satellite measurements over three specific regions affected by the MJO including the CIO, Maritime Continent (MC), and Western Pacific (WP). TRMM data are used to quantify not only the precipitating cloud population categorized by radar echo tops and feature size (as have been previously documented), but also their convective intensity, lightning activity, precipitation structures, bulk microphysical properties, and rainfall contributions. Specifically, the radar, ice scattering (microwave), and lightning observations from TRMM are analyzed for the convective spectrum as a function of MJO stage and geographical location. Furthermore, radar characteristics of MJO events based on TRMM PR are quantitatively compared to that of the shipborne radars deployed during TOGA COARE over the WP and DYNAMO over the CIO.

  11. Sensitivity of the water cycle over the Indian Ocean and Maritime Continent to parameterized physics in a regional model

    NASA Astrophysics Data System (ADS)

    Ulate, Marcela; Dudhia, Jimy; Zhang, Chidong

    2014-12-01

    A regional model was used to simulate the water cycle over the Indian Ocean (IO) and Maritime Continent (MC). Sixteen 92 day simulations were performed using different combinations of eight cumulus parameterization schemes and three planetary boundary-layer (PBL) parameterization schemes. The strength of the water cycle in the IO and MC, measured by its domain mean precipitation and precipitable water, differs substantially among the simulations. The large spread of water cycle strength is mainly toward dry biases in comparison to global data assimilation products. The simulated water cycle, its spread, and biases differ between the IO and MC. Influences of PBL schemes can penetrate into the upper troposphere and those by cumulus schemes into the boundary layer. Dry biases in the simulations are produced mainly because of feedbacks among erroneously low diabatic heating peaks, shallow moisture convergence layers, dry lower troposphere, and weak surface evaporation. There is no single type of parameterization scheme that can be identified to be the main sources of the dry biases. It is the combination of errors from three types of parameterization schemes, namely, cumulus, PBL, and microphysics, that makes the simulated water cycle unrealistic. The lesson learned is that the tropical water cycle can be better simulated only by improving parameterization schemes of different processes all together as a package.

  12. Single-cell analysis of innate cytokine responses to pattern recognition receptor stimulation in children across four continents.

    PubMed

    Smolen, Kinga K; Cai, Bing; Gelinas, Laura; Fortuno, Edgardo S; Larsen, Martin; Speert, David P; Chamekh, Mustapha; Cooper, Philip J; Esser, Monika; Marchant, Arnaud; Kollmann, Tobias R

    2014-09-15

    Innate immunity instructs adaptive immunity, and suppression of innate immunity is associated with an increased risk for infection. We showed previously that whole-blood cellular components from a cohort of South African children secreted significantly lower levels of most cytokines following stimulation of pattern recognition receptors compared with whole blood from cohorts of Ecuadorian, Belgian, or Canadian children. To begin dissecting the responsible molecular mechanisms, we set out to identify the relevant cellular source of these differences. Across the four cohorts represented in our study, we identified significant variation in the cellular composition of whole blood; however, a significant reduction in the intracellular cytokine production on the single-cell level was only detected in South African children's monocytes, conventional dendritic cells, and plasmacytoid dendritic cells. We also uncovered a marked reduction in polyfunctionality for each of these cellular compartments in South African children compared with children from the other continents. Together, our data identify differences in cell composition, as well as profoundly lower functional responses of innate cells, in our cohort of South African children. A possible link between altered innate immunity and increased risk for infection or lower response to vaccines in South African infants needs to be explored.

  13. Wing trait-inversion associations in Drosophila subobscura can be generalized within continents, but may change through time.

    PubMed

    Simões, P; Fragata, I; Lopes-Cunha, M; Lima, M; Kellen, B; Bárbaro, M; Santos, M; Matos, M

    2015-12-01

    Clinal variation is one of the most emblematic examples of the action of natural selection at a wide geographical range. In Drosophila subobscura, parallel clines in body size and inversions, but not in wing shape, were found in Europe and South and North America. Previous work has shown that a bottleneck effect might be largely responsible for differences in wing trait-inversion association between one European and one South American population. One question still unaddressed is whether the associations found before are present across other populations of the European and South American clines. Another open question is whether evolutionary dynamics in a new environment can lead to relevant changes in wing traits-inversion association. To analyse geographical variation in these associations, we characterized three recently laboratory founded D. subobscura populations from both the European and South American latitudinal clines. To address temporal variation, we also characterized the association at a later generation in the European populations. We found that wing size and shape associations can be generalized across populations of the same continent, but may change through time for wing size. The observed temporal changes are probably due to changes in the genetic content of inversions, derived from adaptation to the new, laboratory environment. Finally, we show that it is not possible to predict clinal variation from intrapopulation associations. All in all this suggests that, at least in the present, wing traits-inversion associations are not responsible for the maintenance of the latitudinal clines in wing shape and size.

  14. OxyContin

    MedlinePlus

    ... Contact Get Information Drug Guide A Focus on Heroin & Opioids Breaking Points: Teens & Stress Parent Toolkit The ... medication, causing a rush of euphoria similar to heroin. What are its short-term effects? The most ...

  15. A upper mantle electrical conductivity profile beneath the Australian continent and a comparison with a laboratory-based model

    NASA Astrophysics Data System (ADS)

    Ichiki, M.; Fujita, K.; Wang, L.; Hitchman, A. P.

    2010-12-01

    To investigate the standard electrical conductivity profile beneath a continental craton, we conducted magnetotelluric observations with long dipole span near Alice Springs, central Australia. Central Australia is located in mid-geomagnetic latitudes, which makes it suitable to conduct magnetotelluric studies and its location in the center of a continent means we can expect the oceanic effect to be minimized. Moreover, seismic tomographic studies detect no lower mantle upwelling beneath Australia. We utilized geomagnetic data acquired at the Alice Springs geomagnetic observatory maintained by Geoscience Australia. The power spectrum densities of 3 components of the geomagnetic data are not distinctive at four principal tidal constituents (M2, S2, O1, and K1) frequencies except S2, which suggest the observed electromagnetic field variations are not affected by motional induction. Using the BIRRP processing code (Chave and Thomson, 2004), we estimated the MT and GDS transfer functions from 100 to 106 sec in period. The MT-compatible response functions converted from GDS response functions are resistive compared to the Canadian Shield (Chave et al., 1993) around 105 sec in period. The calculated MT responses have also resistive apparent resistivity values in overall period range. We inverted the average MT responses into a one-dimensional conductivity structure with the Occam inversion (Constable et al., 1987). We compared the resultant one-dimensional structure with the electrical conductivity profiles predicted from the compositional models of the earth's upper mantle by calculating phase diagrams in the CFMAS (CaO-FeO-MgO-Al2O3-SiO2) system. The on-craton and off-craton chemical composition models (Rudnick et al., 1998) were adopted for tectosphere. The Perple_X (e.g. Connolly, 2005) programs were utilized for obtaining mineral proportions and compositions with depth by minimizing the total Gibbs free energy. The used thermodynamic data base was SFO05 (Stixrude and

  16. Axonal necrosis of enteric autonomic nerves in continent ileal pouches. Possible implications for pathogenesis of Crohn's disease.

    PubMed Central

    Dvorak, A M; Onderdonk, A B; McLeod, R S; Monahan-Earley, R A; Cullen, J; Antonioli, D A; Blair, J E; Morgan, E S; Cisneros, R L; Estrella, P

    1993-01-01

    OBJECTIVE: Axonal necrosis was first described in samples of small intestine from patients with Crohn's disease (A.M. Dvorak et al. Hum Pathol 1980; 11:620-634). Clinically evident inflammation of continent ileal reservoirs (pouches) has clinical features that resemble Crohn's disease. Possible similarities in the pathogenesis of Crohn's disease and pouchitis were sought using ultrastructural and microbiologic tools to identify damaged enteric nerves and tissue bacteria. METHODS: An encoded ultrastructural and microbiologic study of replicate biopsies from 114 samples of human intestine was done. Biopsies from ileum, colon, conventional ileostomy or continent pouch were obtained from patients with ulcerative colitis, Crohn's disease, or familial polyposis and grouped into three clinical study groups (control, normal pouch, pouchitis), based on clinical and endoscopic criteria. Biopsies were prepared for electron microscopy with standard methods; replicate biopsy samples were washed extensively before preparing cultures designed to identify aerobic as well as facultative and obligate anaerobic bacteria (Onderdonk et al. J Clin Microbiol 1992; 30:312-317). The ultrastructural diagnosis of damaged enteric nerves was based on previously published criteria for axonal necrosis (A.M. Dvorak and W. Silen. Ann Surg 1985; 201:53-63). Intergroup comparisons were tested for significance using Chi-square analysis. RESULTS: The highest incidence of axonal necrosis was present in Crohn's disease control biopsies (53%), regardless of whether bacteria were present (or not) in cultures of replicate biopsies. Axonal necrosis also occurred in more ulcerative colitis and familial polyposis biopsies (regardless of biopsy site) that had positive bacterial cultures than in those that did not (p < 0.001). In addition, axonal necrosis was documented in 42% of the pouch biopsies from ulcerative colitis and familial polyposis patients, particularly in those pouches that were found to be

  17. Correlation and implications of results from recent wildcat wells in Mid-Continent rift in northeastern Kansas

    SciTech Connect

    Newll, K.D.; Berendsen, P.; Doveton, J.H.; Watney, W.L. )

    1989-08-01

    Three recent wildcat wells, the Texaco 1 Poersch (Sec. 31, T5S, R5E), the Producers Engineering et al 1 Finn (Sec. 4, T4S, R7E), and 1 Freiderich (Sec. 8, T7S, R5E), respectively, penetrated 8,455, 1,848, and 1,781 ft of Precambrian rocks in the Mid-Continent rift system (MRS) in Kansas. The Producers Engineering et al 1 Finn, which is 18 mi northeast of the Texaco 1 Poersch, encountered mostly arkosic sandstones and shales. The Producers Engineering et al 1 Freiderich, 7 mi south of the Texaco 1 Poersch, penetrated mafic igneous and volcanic clastic rocks. In contrast, the Poersch well drilled approximately 90% mafic igneous rocks and 10% arkosic sandstones in the upper 4,584 ft of the Precambrian section. In the lower 3,871 ft of the well, the proportions of these rock-types were reversed. No Precambrian petroleum source rocks were found in the Poersch and Freiderich wells, but 300 ft of gray siltstone (approximately 0.5% TOC) were encountered directly below the Precambrian unconformity in the Finn well. The Finn well also has significantly more red siltstones than the Poersch well, thereby possibly indicating more distal lacustrine or low-energy marine environments of deposition. Alluvial fans and playas are probably responsible for most of the sedimentary deposition in the Poersch well. Geophysical and well data indicate the MRS in northeastern Kansas is divided into small subbasins that probably are only a few tens of square miles in areal extent. Abrupt facies changes and complicated structure make lithostratigraphic correlations difficult.

  18. Multi-model climate impact assessment and intercomparison for three large-scale river basins on three continents

    NASA Astrophysics Data System (ADS)

    Vetter, T.; Huang, S.; Aich, V.; Yang, T.; Wang, X.; Krysanova, V.; Hattermann, F.

    2015-01-01

    Climate change impacts on hydrological processes should be simulated for river basins using validated models and multiple climate scenarios in order to provide reliable results for stakeholders. In the last 10-15 years, climate impact assessment has been performed for many river basins worldwide using different climate scenarios and models. However, their results are hardly comparable, and do not allow one to create a full picture of impacts and uncertainties. Therefore, a systematic intercomparison of impacts is suggested, which should be done for representative regions using state-of-the-art models. Only a few such studies have been available until now with the global-scale hydrological models, and our study is intended as a step in this direction by applying the regional-scale models. The impact assessment presented here was performed for three river basins on three continents: the Rhine in Europe, the Upper Niger in Africa and the Upper Yellow in Asia. For that, climate scenarios from five general circulation models (GCMs) and three hydrological models, HBV, SWIM and VIC, were used. Four representative concentration pathways (RCPs) covering a range of emissions and land-use change projections were included. The objectives were to analyze and compare climate impacts on future river discharge and to evaluate uncertainties from different sources. The results allow one to draw some robust conclusions, but uncertainties are large and shared differently between sources in the studied basins. Robust results in terms of trend direction and slope and changes in seasonal dynamics could be found for the Rhine basin regardless of which hydrological model or forcing GCM is used. For the Niger River, scenarios from climate models are the largest uncertainty source, providing large discrepancies in precipitation, and therefore clear projections are difficult to do. For the Upper Yellow basin, both the hydrological models and climate models contribute to uncertainty in the

  19. Evidence for deposition of 10 million tonnes of impact spherules across four continents 12,800 y ago

    NASA Astrophysics Data System (ADS)

    Wittke, James H.; Weaver, James C.; Bunch, Ted E.; Kennett, James P.; Kennett, Douglas J.; Moore, Andrew M. T.; Hillman, Gordon C.; Tankersley, Kenneth B.; Goodyear, Albert C.; Moore, Christopher R.; Daniel, I. Randolph, Jr.; Ray, Jack H.; Lopinot, Neal H.; Ferraro, David; Israde-Alcántara, Isabel; Bischoff, James L.; DeCarli, Paul S.; Hermes, Robert E.; Kloosterman, Johan B.; Revay, Zsolt; Howard, George A.; Kimbel, David R.; Kletetschka, Gunther; Nabelek, Ladislav; Lipo, Carl P.; Sakai, Sachiko; West, Allen; Firestone, Richard B.

    2013-06-01

    Airbursts/impacts by a fragmented comet or asteroid have been proposed at the Younger Dryas onset (12.80 ± 0.15 ka) based on identification of an assemblage of impact-related proxies, including microspherules, nanodiamonds, and iridium. Distributed across four continents at the Younger Dryas boundary (YDB), spherule peaks have been independently confirmed in eight studies, but unconfirmed in two others, resulting in continued dispute about their occurrence, distribution, and origin. To further address this dispute and better identify YDB spherules, we present results from one of the largest spherule investigations ever undertaken regarding spherule geochemistry, morphologies, origins, and processes of formation. We investigated 18 sites across North America, Europe, and the Middle East, performing nearly 700 analyses on spherules using energy dispersive X-ray spectroscopy for geochemical analyses and scanning electron microscopy for surface microstructural characterization. Twelve locations rank among the world's premier end-Pleistocene archaeological sites, where the YDB marks a hiatus in human occupation or major changes in site use. Our results are consistent with melting of sediments to temperatures >2,200 °C by the thermal radiation and air shocks produced by passage of an extraterrestrial object through the atmosphere; they are inconsistent with volcanic, cosmic, anthropogenic, lightning, or authigenic sources. We also produced spherules from wood in the laboratory at >1,730 °C, indicating that impact-related incineration of biomass may have contributed to spherule production. At 12.8 ka, an estimated 10 million tonnes of spherules were distributed across ∼50 million square kilometers, similar to well-known impact strewnfields and consistent with a major cosmic impact event.

  20. Large-scale precipitation tracking and the MJO over the Maritime Continent and Indo-Pacific warm pool

    NASA Astrophysics Data System (ADS)

    Kerns, Brandon W.; Chen, Shuyi S.

    2016-08-01

    A large-scale precipitation tracking (LPT) method is developed to track convection and precipitation associated with the Madden-Julian oscillation (MJO) using the Tropical Rainfall Measurement Mission 3B42 rainfall data from October to March 1998-2015. LPT uses spatially smoothed 3 day rainfall accumulation to identify and track precipitation features in time with a minimum size of 300,000 km2 and time continuity at least 10 days. While not all LPT systems (LPTs) are attributable to the MJO, among the 199 LPTs, there were 42 with a mean eastward propagation of at least 2 m s-1, which are considered to be MJO convective initiation events. These LPTs capture the diversity of the MJO convection, which is not well depicted by the Real-time Multivariate MJO (RMM) index or the outgoing longwave radiation MJO index. During the 17 years, there were 17 instances out of 45 with a MJO signature in the RMM without eastward propagating LPTs. Among the 42 eastward propagating LPTs, 24 propagated across the Maritime Continent (MC), which confirms the MC barrier effect. Among the cases that crossed the MC from the Indian Ocean to the western Pacific (MC crossing), 18 (75%) had a significant MJO signature in the RMM index. In contrast, only six (33%) of the non-MC-crossing cases occurred with a RMM MJO signal. There is a significant seasonal and interannual variability with MC-crossing LPTs occurring in December more commonly than other months. More MC-crossing events were observed during La Niña than El Niño, which is consistent with the observations of stronger and more frequent MJO events identified by RMM during La Niña years.

  1. Continent-wide increase of water-use efficiency in vegetation during severe droughts of the recent decade

    NASA Astrophysics Data System (ADS)

    Peters, Wouter; van der Velde, Ivar; Miller, John. B.; Tans, Pieter P.; Vaughn, Bruce; White, James W. C.

    2015-04-01

    Recent severe droughts in Europe, Russia, China, and North America have caused widespread decline of agricultural yield and reduction of forest carbon uptake during the past decade. During droughts plants limit their water-loss at the expense of carbon uptake by partially closing their stomata, which increases the intrinsic water-use efficiency defined as the ratio of gross primary production to stomatal conductance. Here we present new evidence on this drought response of terrestrial vegetation derived from year-to-year changes in the 13C:12C stable isotope ratio in atmospheric CO2 (δ13C). Observations from more than 50,000 flask samples from a global monitoring network show a strong increase in water-use efficiency over continent-wide scales during severe droughts in Europe (2003, 2006), Russia (2010), and the United States (2002). This large-scale area-integrated vegetation drought response can not be measured from laboratory experiments or local-scale field studies and the atmospheric δ13C record thus offers a unique perspective on large-scale vegetation drought dynamics. Independent evidence from multiple eddy-covariance sites supports our inverse model interpretation of the observed global atmospheric δ13C record. With the parameterized stomatal conductance and soil moisture response used in our study, as well as many current climate models, our vegetation model underestimates this increase in water-use efficiency during severe droughts. We therefore suggest minor modifications to better reproduce the observations. We conclude that the global δ13C record provides a new opportunity to test and improve interannual drought dynamics in coupled biosphere-atmosphere models for CO2.

  2. Effects of the Maritime Continent on Large-Scale Convection Associated with the Madden-Julian Oscillation

    NASA Astrophysics Data System (ADS)

    Savarin, A.; Chen, S. S.

    2014-12-01

    The Madden-Julian Oscillation (MJO) is a dominant mode of intraseasonal variability in the tropics. It has wide-ranging impacts on global patterns of precipitation and surface temperature, and it has been suggested that it has an effect on ENSO. Large-scale convection fueling the MJO is initiated over the tropical Indian Ocean and propagates eastward across the Maritime Continent (MC) and into the western Pacific as a pattern of alternating phases of active and suppressed convection. As an eastward-propagating MJO convective event encounters the MC, its nature is altered due to the complex interactions with the landmass and topography as well as the warm coastal ocean. Previous studies have shown strong diurnal cycles over land and ocean, with distinct diurnal maxima of convection during the day and night, respectively. This complex air-sea-land interaction over the MC region and its impact on the large-scale convection and the MJO are still not well understood. This study aims to improve our understanding of the effects of the MC on the MJO as it propagates eastward from the Indian Ocean to the Pacific. We use the University of Miami Coupled Model (UMCM), a fully coupled atmosphere-wave-ocean model, to investigate the air-sea-land interaction processes and their impact on the large-scale convection associated with MJO. A control simulation of an MJO is carried out first using the DYNAMO observations from 2011 as model verification. To understand the effects of the MC on the MJO convection, coupled model experiments will be conducted by varying the island topography and/or altering the landmass with water surface. Analysis of the coupled model simulations will be compared with satellite observations such as the TRMM precipitation and cloud cluster tracking using hourly IR data. The outcome of this study is expected to provide some insights into important mechanisms that underlie the complex phenomenon.

  3. Evidence for deposition of 10 million tonnes of impact spherules across four continents 12,800 y ago

    PubMed Central

    Wittke, James H.; Weaver, James C.; Bunch, Ted E.; Kennett, James P.; Kennett, Douglas J.; Moore, Andrew M. T.; Hillman, Gordon C.; Tankersley, Kenneth B.; Goodyear, Albert C.; Moore, Christopher R.; Daniel, I. Randolph; Ray, Jack H.; Lopinot, Neal H.; Ferraro, David; Israde-Alcántara, Isabel; Bischoff, James L.; DeCarli, Paul S.; Hermes, Robert E.; Kloosterman, Johan B.; Revay, Zsolt; Howard, George A.; Kimbel, David R.; Kletetschka, Gunther; Nabelek, Ladislav; Lipo, Carl P.; Sakai, Sachiko; West, Allen; Firestone, Richard B.

    2013-01-01

    Airbursts/impacts by a fragmented comet or asteroid have been proposed at the Younger Dryas onset (12.80 ± 0.15 ka) based on identification of an assemblage of impact-related proxies, including microspherules, nanodiamonds, and iridium. Distributed across four continents at the Younger Dryas boundary (YDB), spherule peaks have been independently confirmed in eight studies, but unconfirmed in two others, resulting in continued dispute about their occurrence, distribution, and origin. To further address this dispute and better identify YDB spherules, we present results from one of the largest spherule investigations ever undertaken regarding spherule geochemistry, morphologies, origins, and processes of formation. We investigated 18 sites across North America, Europe, and the Middle East, performing nearly 700 analyses on spherules using energy dispersive X-ray spectroscopy for geochemical analyses and scanning electron microscopy for surface microstructural characterization. Twelve locations rank among the world’s premier end-Pleistocene archaeological sites, where the YDB marks a hiatus in human occupation or major changes in site use. Our results are consistent with melting of sediments to temperatures >2,200 °C by the thermal radiation and air shocks produced by passage of an extraterrestrial object through the atmosphere; they are inconsistent with volcanic, cosmic, anthropogenic, lightning, or authigenic sources. We also produced spherules from wood in the laboratory at >1,730 °C, indicating that impact-related incineration of biomass may have contributed to spherule production. At 12.8 ka, an estimated 10 million tonnes of spherules were distributed across ∼50 million square kilometers, similar to well-known impact strewnfields and consistent with a major cosmic impact event. PMID:23690611

  4. Evidence for deposition of 10 million tonnes of impact spherules across four continents 12,800 y ago.

    PubMed

    Wittke, James H; Weaver, James C; Bunch, Ted E; Kennett, James P; Kennett, Douglas J; Moore, Andrew M T; Hillman, Gordon C; Tankersley, Kenneth B; Goodyear, Albert C; Moore, Christopher R; Daniel, I Randolph; Ray, Jack H; Lopinot, Neal H; Ferraro, David; Israde-Alcántara, Isabel; Bischoff, James L; DeCarli, Paul S; Hermes, Robert E; Kloosterman, Johan B; Revay, Zsolt; Howard, George A; Kimbel, David R; Kletetschka, Gunther; Nabelek, Ladislav; Lipo, Carl P; Sakai, Sachiko; West, Allen; Firestone, Richard B

    2013-06-01

    Airbursts/impacts by a fragmented comet or asteroid have been proposed at the Younger Dryas onset (12.80 ± 0.15 ka) based on identification of an assemblage of impact-related proxies, including microspherules, nanodiamonds, and iridium. Distributed across four continents at the Younger Dryas boundary (YDB), spherule peaks have been independently confirmed in eight studies, but unconfirmed in two others, resulting in continued dispute about their occurrence, distribution, and origin. To further address this dispute and better identify YDB spherules, we present results from one of the largest spherule investigations ever undertaken regarding spherule geochemistry, morphologies, origins, and processes of formation. We investigated 18 sites across North America, Europe, and the Middle East, performing nearly 700 analyses on spherules using energy dispersive X-ray spectroscopy for geochemical analyses and scanning electron microscopy for surface microstructural characterization. Twelve locations rank among the world's premier end-Pleistocene archaeological sites, where the YDB marks a hiatus in human occupation or major changes in site use. Our results are consistent with melting of sediments to temperatures >2,200 °C by the thermal radiation and air shocks produced by passage of an extraterrestrial object through the atmosphere; they are inconsistent with volcanic, cosmic, anthropogenic, lightning, or authigenic sources. We also produced spherules from wood in the laboratory at >1,730 °C, indicating that impact-related incineration of biomass may have contributed to spherule production. At 12.8 ka, an estimated 10 million tonnes of spherules were distributed across ∼50 million square kilometers, similar to well-known impact strewnfields and consistent with a major cosmic impact event.

  5. Habitat productivity constrains the distribution of social spiders across continents – case study of the genus Stegodyphus

    PubMed Central

    2013-01-01

    Introduction Sociality has evolved independently multiple times across the spider phylogeny, and despite wide taxonomic and geographical breadth the social species are characterized by a common geographical constrain to tropical and subtropical areas. Here we investigate the environmental factors that drive macro-ecological patterns in social and solitary species in a genus that shows a Mediterranean–Afro-Oriental distribution (Stegodyphus). Both selected drivers (productivity and seasonality) may affect the abundance of potential prey insects, but seasonality may further directly affect survival due to mortality caused by extreme climatic events. Based on a comprehensive dataset including information about the distribution of three independently derived social species and 13 solitary congeners we tested the hypotheses that the distribution of social Stegodyphus species relative to solitary congeners is: (1) restricted to habitats of high vegetation productivity and (2) constrained to areas with a stable climate (low precipitation seasonality). Results Using spatial logistic regression modelling and information-theoretic model selection, we show that social species occur at higher vegetation productivity than solitary, while precipitation seasonality received limited support as a predictor of social spider occurrence. An analysis of insect biomass data across the Stegodyphus distribution range confirmed that vegetation productivity is positively correlated to potential insect prey biomass. Conclusions Habitat productivity constrains the distribution of social spiders across continents compared to their solitary congeners, with group-living in spiders being restricted to areas with relatively high vegetation productivity and insect prey biomass. As known for other taxa, permanent sociality likely evolves in response to high predation pressure and imposes within-group competition for resources. Our results suggest that group living is contingent upon productive

  6. Evidence for deposition of 10 million tonnes of impact spherules across four continents 12,800 y ago

    USGS Publications Warehouse

    Wittke, James H.; Weaver, James C.; Bunch, Ted E.; Kennett, James P.; Kennett, Douglas J.; Moore, Andrew M.T.; Hillman, Gordon C.; Tankersly, Kenneth B.; Goodyear, Albert C.; Moore, Christopher R.; Daniel, I. Randolph; Ray, Jack H.; Lopinot, Neal H.; Ferraro, David; Israde-Alcántara, Isabel; Bischoff, James L.; DeCarli, Paul S.; Hermes, Robert E.; Kloosterman, Johan B.; Revay, Zsolt; Howard, George A.; Kimbel, David R.; Kletetschka, Gunther; Nabelek, Ladislav; Lipo, Carl P.; Sakai, Sachiko; West, Allen; Firestone, Richard B.

    2013-01-01

    Airbursts/impacts by a fragmented comet or asteroid have been proposed at the Younger Dryas onset (12.80 ± 0.15 ka) based on identification of an assemblage of impact-related proxies, including microspherules, nanodiamonds, and iridium. Distributed across four continents at the Younger Dryas boundary (YDB), spherule peaks have been independently confirmed in eight studies, but unconfirmed in two others, resulting in continued dispute about their occurrence, distribution, and origin. To further address this dispute and better identify YDB spherules, we present results from one of the largest spherule investigations ever undertaken regarding spherule geochemistry, morphologies, origins, and processes of formation. We investigated 18 sites across North America, Europe, and the Middle East, performing nearly 700 analyses on spherules using energy dispersive X-ray spectroscopy for geochemical analyses and scanning electron microscopy for surface microstructural characterization. Twelve locations rank among the world’s premier end-Pleistocene archaeological sites, where the YDB marks a hiatus in human occupation or major changes in site use. Our results are consistent with melting of sediments to temperatures >2,200 °C by the thermal radiation and air shocks produced by passage of an extraterrestrial object through the atmosphere; they are inconsistent with volcanic, cosmic, anthropogenic, lightning, or authigenic sources. We also produced spherules from wood in the laboratory at >1,730 °C, indicating that impact-related incineration of biomass may have contributed to spherule production. At 12.8 ka, an estimated 10 million tonnes of spherules were distributed across ∼50 million square kilometers, similar to well-known impact strewnfields and consistent with a major cosmic impact event.

  7. Nature of basement highs in ultra-distal ocean-continent transitions: on- and off-shore examples

    NASA Astrophysics Data System (ADS)

    Epin, Marie-Eva; Manatschal, Gianreto

    2016-04-01

    Despite the fact that many studies investigated magma-poor rifted margins, there are still questions that are related to the nature and the origin of basement highs in ultra-distal Ocean-Continent Transitions (OCT). Indeed it has been observed that the morphology of the OCT of magma-poor rifted margins is structured and complex. The aim of this study is to determine the nature of these basement highs, their 3D morphology, the processes associated to their creation, and the timing related to their formation. To do this, we focused on distal seismic lines with well data from the Iberia and Newfoundland margins and on field observations of the Platta nappe, which exposes an about 300 km² large, little overprinted remnant of a fossil OCT belonging to the Alpine Tethys, exposed in the area of Bivio in SE Switzerland. The first results are the establishment of criteria allowing the identification of the different types of basement highs or groups of basement highs using offshore and onshore data. The main criteria are: the top-basement morphology, seismic reflectivity patterns, rooting depth of basement highs, the size, the related sedimentary architecture, the relative location in the margin, and if possible to determine, the magmatic budget. These criteria allow us to define 4 different types of highs that are: 1) footwall crustal wedges, 2) hanging wall extensional allochthon blocks, 3) peridotite ridges, and 4) outer highs. The overall observations provide important information on the temporal and spatial organization of the structural and magmatic systems. These systems are at the origin of the creation of ultra-distal OCTs which are important for the understanding of the processes controlling the final rifting stage. The goal of this study is to use an observation driven approach and to create identification criteria that can be used to describe the nature of basement highs at not yet drilled distal magma-poor rifted margins.

  8. Phylogeography across a continent: the evolutionary and demographic history of the North American racer (Serpentes: Colubridae: Coluber constrictor).

    PubMed

    Burbrink, Frank T; Fontanella, Frank; Alexander Pyron, R; Guiher, Timothy J; Jimenez, Cynthia

    2008-04-01

    Most phylogeographic studies examine organisms that do not have transcontinental distributions and therefore the genetic and temporal effects of barriers across an entire continent cannot be assessed with respect to a single species. We examined the phylogeographic structure, lineage age, and historical demography using sequences from the mtDNA cytochrome b gene of the widespread North American racer (Coluber constrictor), one of the few abundant transcontinental snakes that occurs throughout many diverse biomes. Our results indicate that this complex is comprised of six lineages differing greatly in geographic extent, with the largest (a central US clade) being approximately 26 times greater than the smallest (a lineage restricted to the Florida Panhandle and nearby portions of adjacent States). Most of the six lineages appear to be separated at previously identified genetic barriers for several vertebrates with similar ranges. Lineage diversification in this species began in the late Miocene, separating populations in the Florida Peninsula from the remainder of the US. Diversification of lineages continued throughout the Pliocene and early Pleistocene. Four of the six lineages occur east of the Mississippi River, with only two distinctly young ( approximately 1.5 mya) lineages found west of the Mississippi River (one occurs west of Continental Divide). All methods of demographic inference, including the mismatch distribution, Fu and Li's D and Tajima's D , and Bayesian skyline plots revealed population expansion occurring in the mid-to-late Pleistocene for every lineage, regardless of size or proximity to formerly glaciated areas. Population expansion for lineages found east of the Mississippi River occurred earlier and was much greater than those found west of the River. PMID:18093846

  9. On the emergence of continents during the early evolution of the Earth's mantle: insights from analogue modeling

    NASA Astrophysics Data System (ADS)

    Davaille, Anne; Arndt, Nicholas

    2014-05-01

    The mantle convective pattern during the first half of Earth history is still debated, and major questions such as whether plate tectonics was already operating and the timing of continental growth remains unresolved. The difficulty stems from the complex rheology of mantle rocks (from viscous to brittle as temperature decreases), the presence of partial melt, and the physics of thermal convection, all of which are poorly understood in such materials. We recently discovered a material, -aqueous dispersions of colloidal nanoparticles-, that has rheological properties analogue to those of the mantle. We therefore undertook a systematic laboratory study of convection in such fluids, using an apparatus in which the fluid was continuously cooled and evaporated from above, with or without heating from below. Our experiments always show an evolution through different regimes, as a plastic skin ("lithosphere") forms and thickens at the surface while its rheological behaviour changes through time. An initially very soft lithosphere produces a stagnant lid regime of convection, which then evolves in episodic, and finally continuous, recycling of the surface layer. This sequence corresponds to the transiton from episodic to continuous subduction that characterizes the initiation of plate tectonics. We observe that pre-existing continents (i.e. buoyant rafts), as well as hot plumes are very influential in triggering subduction, usually on their edges. In the absence of hot plumes, continuous plate tectonics was never observed. On Earth, the association between plumes and subduction may be instrumental in the nucleation and growth of cratons. Moreover, strong plume episodes are seen to enhance the formation of the first supercontinents. We use this new fluid dynamics framework to interpret the geochemical, geological and petrological data and propose a scenario of evolution of the Earth in the first two billion years of its evolution.

  10. Heat-flow and hydrothermal circulation at the ocean-continent transition of the eastern gulf of Aden

    NASA Astrophysics Data System (ADS)

    Lucazeau, Francis; Leroy, Sylvie; Rolandone, Frédérique; d'Acremont, Elia; Watremez, Louise; Bonneville, Alain; Goutorbe, Bruno; Düsünur, Doga

    2010-07-01

    In order to investigate the importance of fluid circulation associated with the formation of ocean-continent transitions (OCT), we examine 162 new heat-flow (HF) measurements in the eastern Gulf of Aden, obtained at close locations along eight seismic profiles and with multi-beam bathymetry. The average HF values in the OCT and in the oceanic domain (~ 18 m.y.) are very close to the predictions of cooling models, showing that the overall importance of fluids remains small at the present time compared to oceanic ridge flanks of the same age. However, local HF anomalies are observed, although not systematically, in the vicinity of the unsedimented basement and are interpreted by the thermal effect of meteoric fluids flowing laterally. We propose a possible interpretation of hydrothermal paths based on the shape of HF anomalies and on the surface morphology: fluids can circulate either along-dip or along-strike, but are apparently focussed in narrow "pipes". In several locations in the OCT, there is no detectable HF anomaly while the seismic velocity structure suggests serpentinization and therefore past circulation. We relate the existence of the present day fluid circulation in the eastern Gulf of Aden to the presence of unsedimented basement and to the local extensional stress in the vicinity of the Socotra-Hadbeen fault zone. At the scale of rifted-margins, fluid circulation is probably not as important as in the oceanic domain because it can be inhibited rapidly with high sedimentation rates, serpentinization and stress release after the break-up.

  11. Evidence for deposition of 10 million tonnes of impact spherules across four continents 12,800 y ago.

    PubMed

    Wittke, James H; Weaver, James C; Bunch, Ted E; Kennett, James P; Kennett, Douglas J; Moore, Andrew M T; Hillman, Gordon C; Tankersley, Kenneth B; Goodyear, Albert C; Moore, Christopher R; Daniel, I Randolph; Ray, Jack H; Lopinot, Neal H; Ferraro, David; Israde-Alcántara, Isabel; Bischoff, James L; DeCarli, Paul S; Hermes, Robert E; Kloosterman, Johan B; Revay, Zsolt; Howard, George A; Kimbel, David R; Kletetschka, Gunther; Nabelek, Ladislav; Lipo, Carl P; Sakai, Sachiko; West, Allen; Firestone, Richard B

    2013-06-01

    Airbursts/impacts by a fragmented comet or asteroid have been proposed at the Younger Dryas onset (12.80 ± 0.15 ka) based on identification of an assemblage of impact-related proxies, including microspherules, nanodiamonds, and iridium. Distributed across four continents at the Younger Dryas boundary (YDB), spherule peaks have been independently confirmed in eight studies, but unconfirmed in two others, resulting in continued dispute about their occurrence, distribution, and origin. To further address this dispute and better identify YDB spherules, we present results from one of the largest spherule investigations ever undertaken regarding spherule geochemistry, morphologies, origins, and processes of formation. We investigated 18 sites across North America, Europe, and the Middle East, performing nearly 700 analyses on spherules using energy dispersive X-ray spectroscopy for geochemical analyses and scanning electron microscopy for surface microstructural characterization. Twelve locations rank among the world's premier end-Pleistocene archaeological sites, where the YDB marks a hiatus in human occupation or major changes in site use. Our results are consistent with melting of sediments to temperatures >2,200 °C by the thermal radiation and air shocks produced by passage of an extraterrestrial object through the atmosphere; they are inconsistent with volcanic, cosmic, anthropogenic, lightning, or authigenic sources. We also produced spherules from wood in the laboratory at >1,730 °C, indicating that impact-related incineration of biomass may have contributed to spherule production. At 12.8 ka, an estimated 10 million tonnes of spherules were distributed across ∼50 million square kilometers, similar to well-known impact strewnfields and consistent with a major cosmic impact event. PMID:23690611

  12. The Vulcan Project: Recent advances and emissions estimation for the NACP mid-continent intensive campaign region

    NASA Astrophysics Data System (ADS)

    Gurney, K. R.; Zhou, Y.; Geethakumar, S.; Godbole, A.; Mendoza, D. L.; Vaidhyanathan, M.; Sahni, N.

    2009-12-01

    The Vulcan Project has quantified 2002 fossil fuel CO2 for the US at the sub-county/hourly scale and is a key component of attributing CO2 fluxes within the North American Carbon Program. Vulcan approached quantification of CO2 emissions by leveraging information already contained within regulatory and monitoring agencies including the US EPA’s Acid Rain Program, the EPA’s National Emissions Inventory for the assessment of nationally regulated air pollution, the Department of Energy, the U.S. Census and the Department of Transportation. By utilizing the inventory emissions of carbon monoxide combined with fuel/device-specific emission factors, we have calculated CO2 emissions for industrial point sources, power plants, mobile sources, residential and commercial sectors with information on fuel used and source classification information. In this presentation, I provide critical recent advances in the Vulcan Project with particular emphasis on our contribution to the NACP mid-continent intensive campaign. Version 1.2 of the Vulcan fossil fuel CO2 emissions inventory includes the 2008 US Census road atlas, overcoming many of the missing roads and links that were prevalent in previous road atlas releases. This offers better spatial allocation of the onroad emissions. Figure 1 shows the improved road layer density for the MCI study region. Furthermore the temporal dimension of onroad emissions have been improved through the use of hourly traffic monitoring data at roughly 6000 monitoring locations across the US. The residential and commercial sector emissions now have hourly time structure via a spatially explicit heating degree day calculation utilizing the North American Regional Reanalysis temperature output. Finally, we have generated a multiyear (1997-2008) data product for the MCI region through use of Energy Information Administration state-level fuel sales data. Figure 1. improved road density via utilization of the new 2008 US census road layer. Left

  13. Dalbavancin Activity When Tested against Streptococcus pneumoniae Isolated in Medical Centers on Six Continents (2011 to 2014).

    PubMed

    Jones, Ronald N; Schuchert, Jason E; Mendes, Rodrigo E

    2016-06-01

    Dalbavancin, a novel lipoglycopeptide, was approved for use in 2014 by regulatory agencies in the United States and Europe for the treatment of skin and skin structure infections. The activity of dalbavancin was also widely assessed by determination of its activity against Streptococcus pneumoniae clinical isolates collected from patients on six continents monitored during two time intervals (2011 to 2013 and 2014). A total of 18,186 pneumococcal isolates were obtained from 49 nations and submitted to a monitoring laboratory as part of the SENTRY Antimicrobial Surveillance Program for reference susceptibility testing. The potency of dalbavancin against S. pneumoniae was consistent across the years that it was monitored, with the MIC50 and MIC90 being 0.015 and 0.03 μg/ml, respectively, and all isolates were inhibited by ≤0.12 μg/ml. The activity of dalbavancin was not adversely influenced by nonsusceptibility to β-lactams (ceftriaxone or penicillin), macrolides, clindamycin, fluoroquinolones, or tetracyclines or multidrug resistance (MDR). Regional variations in dalbavancin activity were not detected, but S. pneumoniae strains isolated in the Asia-Pacific region were more likely to be nonsusceptible to penicillin and ceftriaxone as well as to be MDR than strains isolated in North or South America and Europe. Direct comparisons of potency illustrated that dalbavancin (MIC50 and MIC90, 0.015 and 0.03 μg/ml, respectively) was 16-fold or more active than vancomycin (MIC50, 0.25 μg/ml), linezolid (MIC50, 1 μg/ml), levofloxacin (MIC50, 1 μg/ml), ceftriaxone (MIC90, 1 μg/ml), and penicillin (MIC90, 2 μg/ml). In conclusion, dalbavancin had potent and consistent activity against this contemporary (2011 to 2014) collection of S. pneumoniae isolates.

  14. The contribution of trees outside forests to national tree biomass and carbon stocks--a comparative study across three continents.

    PubMed

    Schnell, Sebastian; Altrell, Dan; Ståhl, Göran; Kleinn, Christoph

    2015-01-01

    In contrast to forest trees, trees outside forests (TOF) often are not included in the national monitoring of tree resources. Consequently, data about this particular resource is rare, and available information is typically fragmented across the different institutions and stakeholders that deal with one or more of the various TOF types. Thus, even if information is available, it is difficult to aggregate data into overall national statistics. However, the National Forest Monitoring and Assessment (NFMA) programme of FAO offers a unique possibility to study TOF resources because TOF are integrated by default into the NFMA inventory design. We have analysed NFMA data from 11 countries across three continents. For six countries, we found that more than 10% of the national above-ground tree biomass was actually accumulated outside forests. The highest value (73%) was observed for Bangladesh (total forest cover 8.1%, average biomass per hectare in forest 33.4 t ha(-1)) and the lowest (3%) was observed for Zambia (total forest cover 63.9%, average biomass per hectare in forest 32 t ha(-1)). Average TOF biomass stocks were estimated to be smaller than 10 t ha(-1). However, given the large extent of non-forest areas, these stocks sum up to considerable quantities in many countries. There are good reasons to overcome sectoral boundaries and to extend national forest monitoring programmes on a more systematic basis that includes TOF. Such an approach, for example, would generate a more complete picture of the national tree biomass. In the context of climate change mitigation and adaptation, international climate mitigation programmes (e.g. Clean Development Mechanism and Reduced Emission from Deforestation and Degradation) focus on forest trees without considering the impact of TOF, a consideration this study finds crucial if accurate measurements of national tree biomass and carbon pools are required.

  15. Carbon isotope variation in mid-continent Ordovician-type oils: relationship to a major middle Ordovician carbon isotope shift

    SciTech Connect

    Hatch, J.R.; Jacobson, S.R.; Witzke, B.J.; Anders, D.E.; Watney, W.L.; Newell, K.D.

    1985-05-01

    Detailed organic geochemical comparisons of Mid-Continent Ordovician oils with extracts of potential source rocks show that in the Forest City basin of northeastern Kansas and southeastern Nebraska, oil source rocks are Middle Ordovician shales of the Simpson Group. For the Keota Dome field, Washington County, Iowa, the oil source rock is the Middle Ordovician Glenwood Shale Member of the Platteville Formation. Analyses of saturated and aromatic hydrocarbon fractions of Ordovician-type oils from the Forest City basin, Keota Dome field, and the Michigan basin show that sigma TC of the two fractions are similar and that sigma T varies over a considerable range, from -32.5 per mil to -25.5 per mil (PDB). This large range in sigma TC reflects a major shift in the carbon isotope composition of organic matter during the Middle Ordovician. This shift is shown in a 62.5-ft (19 m) interval of core from the Decorah and Platteville Formations in the E.M. Greene 1 well in Washington County, Iowa, where organic carbon sigma TC changes regularly upward from -32.2 per mil to -22.7 per mil (PDB). The change in organic carbon sigma TC in this core is not related to variations in amount (0.13-41.4% TOC) or type (hydrogen index = 69 to 1000 mg HC/g TOC) of the marginally mature (T/sub max/ = 440 +/- 5C) organic matter. Ordovician-type oils in both the Forest City and Michigan basins show variable sigma TC, suggesting that the sigma TC shift displayed in the Middle Ordovician rocks of southeastern Iowa is a regional and possibly a global effect, related to changes in the sigma TC of the ocean-atmosphere carbon reservoir. Isotopic analyses of coexisting carbonate minerals support this interpretation.

  16. What is responsible for development of the Asian-Pacific transition zone: The geodynamics of oceanic plates or the Asian continent?

    NASA Astrophysics Data System (ADS)

    Utkin, V. P.

    2016-03-01

    The main unusual feature of tectogenesis of the Asian-Pacific transition zone in the Mesozoic-Cenozoic consists in the formation of left-lateral strike-slip faults, which form the East Asian global shear zone with paragenesis of its constituent variously oriented fault systems. Paragenetic analysis has revealed that continental blocks of the Asian-Pacific transition zone were displaced along systems of transit left-lateral strike-slip faults of the East Asian global shear zone by hundreds of kilometers in the southerly to southwesterly direction due to tectonic activity of the Asian continent, which drifted southwestward. This process was accompanied by the formation of compression and extension structures. Otherwise, it is difficult to explain the structuring of the overhanging margin of the continent by subduction of oceanic lithospheric plates in the northerly to northwesterly direction opposite relative to the displacement of the continental crust as is usually thought.

  17. A harbinger of plate tectonics: a commentary on Bullard, Everett and Smith (1965) 'The fit of the continents around the Atlantic'.

    PubMed

    Dewey, John F

    2015-04-13

    In the 1960s, geology was transformed by the paradigm of plate tectonics. The 1965 paper of Bullard, Everett and Smith was a linking transition between the theories of continental drift and plate tectonics. They showed, conclusively, that the continents around the Atlantic were once contiguous and that the Atlantic Ocean had grown at rates of a few centimetres per year since the Early Jurassic, about 160 Ma. They achieved fits of the continental margins at the 500 fathom line (approx. 900 m), not the shorelines, by minimizing misfits between conjugate margins and finding axes, poles and angles of rotation, using Euler's theorem, that defined the unique single finite difference rotation that carried congruent continents from contiguity to their present positions, recognizing that the real motion may have been more complex around a number of finite motion poles. Critically, they were concerned only with kinematic reality and were not restricted by considerations of the mechanism by which continents split and oceans grow. Many of the defining features of plate tectonics were explicit or implicit in their reconstructions, such as the torsional rigidity of continents, Euler's theorem, closure of the Tethyan ocean(s), major continental margin shear zones, the rapid rotation of small continental blocks (Iberia) around nearby poles, the consequent opening of small wedge-shaped oceans (Bay of Biscay), and misfit overlaps (deltas and volcanic piles) and underlaps (stretched continental edges). This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society. PMID:25750142

  18. A harbinger of plate tectonics: a commentary on Bullard, Everett and Smith (1965) ‘The fit of the continents around the Atlantic’

    PubMed Central

    Dewey, John F.

    2015-01-01

    In the 1960s, geology was transformed by the paradigm of plate tectonics. The 1965 paper of Bullard, Everett and Smith was a linking transition between the theories of continental drift and plate tectonics. They showed, conclusively, that the continents around the Atlantic were once contiguous and that the Atlantic Ocean had grown at rates of a few centimetres per year since the Early Jurassic, about 160 Ma. They achieved fits of the continental margins at the 500 fathom line (approx. 900 m), not the shorelines, by minimizing misfits between conjugate margins and finding axes, poles and angles of rotation, using Euler's theorem, that defined the unique single finite difference rotation that carried congruent continents from contiguity to their present positions, recognizing that the real motion may have been more complex around a number of finite motion poles. Critically, they were concerned only with kinematic reality and were not restricted by considerations of the mechanism by which continents split and oceans grow. Many of the defining features of plate tectonics were explicit or implicit in their reconstructions, such as the torsional rigidity of continents, Euler's theorem, closure of the Tethyan ocean(s), major continental margin shear zones, the rapid rotation of small continental blocks (Iberia) around nearby poles, the consequent opening of small wedge-shaped oceans (Bay of Biscay), and misfit overlaps (deltas and volcanic piles) and underlaps (stretched continental edges). This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society. PMID:25750142

  19. Long-term follow-up after ileocaecal continent cutaneous urinary diversion (Mainz I pouch): A retrospective study of a monocentric experience

    PubMed Central

    Khalil, Fahd; Fellahi, Saad; Ouslim, Hicham; Mhanna, Tarik; El Houmaidi, Amine; Aynaou, Mohammed; Boteng, Paapa Dua; Barki, Ali; Nouini, Yassine

    2015-01-01

    Objective To assess the long-term follow-up after ileocaecal continent cutaneous reservoir (ICCR) and to review the late complications. Patients and methods In all, 756 patients underwent an ICCR in our department, with long-term follow-up data available in 50 patients. The inclusion criterion was ICCR regardless of the indication and the exclusion criteria were orthotopic neobladder or other continent urinary diversions not performed with the ileocaecum. Patients were followed to record primary outcomes and late complications. Complications were stratified according to the Clavien–Dindo classification. Results The mean patient age was 44 years and pelvic malignancies were the first indication for urinary diversion. The mean (range) follow-up was 19 (9–36) years. A stoma stenosis was the most frequent outlet-related complication requiring re-intervention, followed by ischaemic outlet degeneration, and stoma incontinence. Six renal units (RUs) developed obstruction at the anastomotic site and were managed by open surgery. Three RUs had to be removed due to deterioration. A dederivation was necessary in three patients (6%). Conclusion The ICCR is a safe and established technique when an orthotopic pouch is impossible. The long-term follow-up shows acceptable complication rates and satisfactory continence conditions. However, large population studies are necessary to confirm this observation. PMID:26609442

  20. Phosphodiesterase type 5 inhibitor administered immediately after radical prostatectomy temporarily increases the need for incontinence pads, but improves final continence status

    PubMed Central

    Yamashita, Shinichi; Ito, Akihiro; Kawasaki, Yoshihide; Izumi, Hideaki; Kawamorita, Naoki; Adachi, Hisanobu; Mitsuzuka, Koji; Arai, Yoichi

    2016-01-01

    Purpose To evaluate the effects of phosphodiesterase type 5 inhibitor (PDE5i) on urinary continence recovery after bilateral nerve-sparing radical prostatectomy (BNSRP). Materials and Methods Between 2002 and 2012, 137 of 154 consecutive patients who underwent BNSRP in our institution retrospectively divided into 3 groups that included patients taking PDE5i immediately after surgery (immediate PDE5i group, n=41), patients starting PDE5i at an outpatient clinic after discharge (PDE5i group, n=56), and patients taking no medication (non-PDE5i group, n=40). Using self-administered questionnaires, the proportion of patients who did not require incontinence pads (pad-free patients) was calculated preoperatively and at 1, 3, 6, 12, 18, and 24 months after BNSRP. Severity of incontinence was determined based on the pad numbers and then compared among the 3 groups. Results Proportions of pad-free patients and severity of incontinence initially deteriorated in all of the groups to the lowest values soon after undergoing BNSRP, with gradual improvement noted thereafter. The deterioration was most prominent in the immediate PDE5i group. As compared to the non-PDE5i group, both the PDE5i and immediate PDE5i groups exhibited a better final continence status. Conclusions PDE5i improves final continence status. However, administration of PDE5i immediately after surgery causes a distinct temporary deterioration in urinary incontinence.

  1. Phosphodiesterase type 5 inhibitor administered immediately after radical prostatectomy temporarily increases the need for incontinence pads, but improves final continence status

    PubMed Central

    Yamashita, Shinichi; Ito, Akihiro; Kawasaki, Yoshihide; Izumi, Hideaki; Kawamorita, Naoki; Adachi, Hisanobu; Mitsuzuka, Koji; Arai, Yoichi

    2016-01-01

    Purpose To evaluate the effects of phosphodiesterase type 5 inhibitor (PDE5i) on urinary continence recovery after bilateral nerve-sparing radical prostatectomy (BNSRP). Materials and Methods Between 2002 and 2012, 137 of 154 consecutive patients who underwent BNSRP in our institution retrospectively divided into 3 groups that included patients taking PDE5i immediately after surgery (immediate PDE5i group, n=41), patients starting PDE5i at an outpatient clinic after discharge (PDE5i group, n=56), and patients taking no medication (non-PDE5i group, n=40). Using self-administered questionnaires, the proportion of patients who did not require incontinence pads (pad-free patients) was calculated preoperatively and at 1, 3, 6, 12, 18, and 24 months after BNSRP. Severity of incontinence was determined based on the pad numbers and then compared among the 3 groups. Results Proportions of pad-free patients and severity of incontinence initially deteriorated in all of the groups to the lowest values soon after undergoing BNSRP, with gradual improvement noted thereafter. The deterioration was most prominent in the immediate PDE5i group. As compared to the non-PDE5i group, both the PDE5i and immediate PDE5i groups exhibited a better final continence status. Conclusions PDE5i improves final continence status. However, administration of PDE5i immediately after surgery causes a distinct temporary deterioration in urinary incontinence. PMID:27617318

  2. A Comparison of Food Supply from 1984 to 2009 and Degree of Dietary Westernization in Taiwan with Asian Countries and World Continents

    PubMed Central

    Peng, Cheau-Jane; Lin, Cheng-Yao; Guo, How-Ran

    2015-01-01

    Objective. To compare quality, quantity, and trends of food supply from 1984 to 2009 and degree of food westernization in Taiwan with Asian countries and world continents by using food balance data. Methods. We compiled data from food balance sheets of Taiwan and Food and Agriculture Organization, including five continents and three most populated countries each in Eastern, Southern, and Southeastern Asia over the period 1984–2009. Quantity of food supply per capita was referenced to Taiwan food guides. The population-weighted means of food supply from Europe, North America, South America, and Australia and New Zealand continents in terms of energy and nutrient distributions, animal/plant sources, and sugar/alcohol contribution were used as indicators of westernization. Trends of food supply per capita of six food groups were plotted, and linear regression was applied to evaluate food changes. Findings. Taiwan's food supply provided sufficient quantity in food energy, with the lowest cereals/roots supply and rice to wheat ratio, but the highest meat and oil supplies per capita among the 10 studied Asian countries. Taiwan food supply showed the most westernization among these countries. Conclusion. Food supply of Taiwan, although currently sufficient, indicated some security problems and high tendency of diet westernization. PMID:26295045

  3. Implication of vector characteristics of Phlebotomus argentipes in the kala-azar elimination programme in the Indian sub-continent

    PubMed Central

    Chowdhury, Rajib; Kumar, Vijay; Mondal, Dinesh; Das, Murari Lal; Das, Pradeep; Dash, Aditya Prasad

    2016-01-01

    Background Visceral leishmaniasis (VL), also known as kala-azar in the Indian sub-continent (ISC), is a major public health concern in Bangladesh, India, and Nepal, where it is caused by Leishmania donovani transmitted by the sand fly Phlebotomus argentipes. Various ecological parameters including air temperature, rainfall, wind speed, relative humidity, soil moisture, pH, and organic carbon are known to influence the oviposition of female sand flies, as well as the survival and development of larvae. However, more detailed knowledge on vector behavior, such as biting times, breeding places, and preferred hosts are needed to design optimal evidence-based vector control interventions. Methods In order to facilitate rational decisions regarding VL vector control, a systematic review was conducted to identify the prevailing practice and knowledge gaps in relation to vector bionomics and behavior. Search terms included ‘sand fly bionomics’, ‘habitat’, and ‘visceral leishmaniasis/kala-azar vector control’ using the Boolean operator AND to identify the country of interest, namely: Bangladesh, India, and Nepal. Both PubMed and Google search engines were used. Additional unpublished documents in the three countries were also analyzed. Results Information on the life cycle of VL vectors, their breeding behavior, infection rate with L. donovani, feeding behavior, and seasonal variation are useful for designing vector control operations. Unfortunately, none of the studies on the life cycle of P. argentipes was conducted in field settings of the ISC, so the publications from other locations had to be used for determining the duration of life cycle and development from egg to adult. However, information about breeding places, seasonal variation of vector densities, and 47 out of the selected 51 papers are available from the ISC and can be used for intelligent design of control operations. Conclusion Vector control services should undertake routine insecticide

  4. Evidence of micro-continent entrainment in the growth of the east Gondwana margin from Bayesian ambient noise tomography

    NASA Astrophysics Data System (ADS)

    Pilia, Simone; Rawlinson, Nicholas; Cayley, Ross; Bodin, Thomas; Musgrave, Robert; Reading, Anya; Direen, Nicholas; Young, Mallory

    2015-04-01

    The Phanerozoic Tasmanides (or Tasman Fold Belt System) is located east of the locus of the Neoproterozoic Rodinia breakup and comprises an accretionary system that occupies the eastern third of the Australian continent. The Tasmanides is the result of protracted accretionary growth outboard of the Archean and Proterozoic core of central and western Australia that occurred from the Early Cambrian through to the Jurassic. Its basement structure has proven difficult to study since vast Mesozoic-Cainozoic sedimentary and volcanic cover sequences obscure older outcrops and limit the power of direct observational techniques. The Lachlan Fold Belt, which forms the southern end of the Tasmanides, is thought to be particularly complex and may include an exotic continental block, an amalgamation of multiple linear orogen parallel accretion events, a large orocline and several arc complexes. Continental growth via subduction accretion along a convergent margin is a well known process. However, simple models involving the gradual outboard accretion of material along curvilinear subduction zones are often inconsistent with field-based evidence. The evolution of accretionary orogens was recently addressed by using 3-D geodynamic models, showing that the entrainment of an exotic continental fragment within a simple subduction system can result in a complex phase of growth that may include the formation of large scale oroclines. Although kinematic models based on structural mapping and high resolution gravity and magnetic maps indicate that the pre-Carboniferous Tasmanides in southeastern Australia may have been subjected to this process, to date there has been little corroboration from crustal scale geophysical imaging. In this study, we apply Bayesian transdimensional tomography to ambient noise data recorded by the largest transportable seismic array in the southern hemisphere to constrain a detailed (20 km resolution in some areas) 3-D shear velocity model of the crust

  5. Mantle flow deduced from geochemical variations in alkaline magmas of HIMU affinity