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Sample records for extremely important discovery-the

  1. An importance sampling algorithm for estimating extremes of perpetuity sequences

    NASA Astrophysics Data System (ADS)

    Collamore, Jeffrey F.

    2012-09-01

    In a wide class of problems in insurance and financial mathematics, it is of interest to study the extremal events of a perpetuity sequence. This paper addresses the problem of numerically evaluating these rare event probabilities. Specifically, an importance sampling algorithm is described which is efficient in the sense that it exhibits bounded relative error, and which is optimal in an appropriate asymptotic sense. The main idea of the algorithm is to use a "dual" change of measure, which is employed to an associated Markov chain over a randomly-stopped time interval. The algorithm also makes use of the so-called forward sequences generated to the given stochastic recursion, together with elements of Markov chain theory.

  2. The Importance of Studying Past Extreme Floods to Prepare for Uncertain Future Extremes

    NASA Astrophysics Data System (ADS)

    Burges, S. J.

    2016-12-01

    Hoyt and Langbein, 1955 in their book `Floods' wrote: " ..meteorologic and hydrologic conditions will combine to produce superfloods of unprecedented magnitude. We have every reason to believe that in most rivers past floods may not be an accurate measure of ultimate flood potentialities. It is this superflood with which we are always most concerned". I provide several examples to offer some historical perspective on assessing extreme floods. In one example, flooding in the Miami Valley, OH in 1913 claimed 350 lives. The engineering and socio-economic challenges facing the Morgan Engineering Co in how to mitigate against future flood damage and loss of life when limited information was available provide guidance about ways to face an uncertain hydroclimate future, particularly one of a changed climate. A second example forces us to examine mixed flood populations and illustrates the huge uncertainty in assigning flood magnitude and exceedance probability to extreme floods in such cases. There is large uncertainty in flood frequency estimates; knowledge of the total flood hydrograph, not the peak flood flow rate alone, is what is needed for hazard mitigation assessment or design. Some challenges in estimating the complete flood hydrograph in an uncertain future climate, including demands on hydrologic models and their inputs, are addressed.

  3. The importance of range edges for an irruptive species during extreme weather events

    USGS Publications Warehouse

    Bateman, Brooke L.; Pidgeon, Anna M.; Radeloff, Volker C.; Allstadt, Andrew J.; Akçakaya, H. Resit; Thogmartin, Wayne E.; Vavrus, Stephen J.; Heglund, Patricia J.

    2015-01-01

    In a changing climate where more frequent extreme weather may be more common, conservation strategies for weather-sensitive species may require consideration of habitat in the edges of species’ ranges, even though non-core areas may be unoccupied in ‘normal’ years. Our results highlight the conservation importance of range edges in providing refuge from extreme events, such as drought, and climate change.

  4. The importance of rehabilitation concerning upper extremity amputees: A Systematic review

    PubMed Central

    Soyer, Kardem; Unver, Banu; Tamer, Seval; Ulger, Ozlem

    2016-01-01

    Objective: To evaluate and point out the importance of prosthetic rehabilitation of upper extremity. Methods: A systematic literature search was performed to identify studies concerning prosthetic rehabilitation in upper extremity. The PRISMA Statement 2009 was used to establish the study and the methodological quality was assessed. Results: The literature search identified 620 studies. Of these 620, 9 studies fulfilled the inclusion criteria and were included for data extraction. The studies pointed out the upper limb prosthetic rehabilitation protocols consist of general exercise programme, motor tasks, phantom exercises, Muscle Training System, edema control, functional activities, signal strengthening, prosthetic education exercises, neuromuscular reeducation, virtual image and virtual reality exercises. Conclusions: The current systematic literature review has shown that the prosthetic rehabilitation seems promising especially for upper extremity amputees. PMID:27882044

  5. Importance of location for describing typical and extreme wind speed behavior

    NASA Astrophysics Data System (ADS)

    Griffin, B. J.; Kohfeld, K. E.; Cooper, A. B.; Boenisch, G.

    2010-11-01

    Several recent studies have considered the potential impact of climate change on regional wind intensity. However, previous wind speed studies in the Pacific Northwest (PNW) present conflicting results for wind speed trends in relation to climate drivers. This study analyzes the percentiles (50th, 75th, and 95th) of the strongly positively skewed distributions for PNW maximum daily wind speeds from 92 meteorological stations, and reveals different behaviors for average and extreme wind speeds. Considerably stronger winds are found at coastal locations compared with sites further inland. Extreme wind speeds at these coastal locations appear to follow an eight to nine-year cyclic pattern, while mainland sites have a small, linear downward wind speed trend. This finding of a behavioral dependence on location helps reconcile previous, apparently contradictory results and has important global implications for wind research and infrastructure planning, such as wind energy feasibility studies and air quality management activities.

  6. An important Norwegian contribution to the study of the bursae of the upper and lower extremities

    PubMed Central

    2010-01-01

    We present a critical analysis of the monograph of A.S.D. Synnestvedt (1869) “En anatomisk beskrivelse af de paa over- og underestremiteterne forekommende Bursae mucosae”. The analysis was completed using anatomical information from the historically oldest publications dealing with the bursae of the extremities: Albinus (1734), Monro (1788), Rosenmüller (1799). We are of the opinion that Synnestvedt's publication is important, not only historically but also as a source of information for recent medical practitioners. Synnestvedt's monograph has a wealth of literary citations, unambiguous opinions of seasoned anatomists regarding the structure and function of the synovial membrane, and detailed descriptions of dissections he performed on fetal and adult cadavers. The information in this publication may enhance the diagnosis of bursopathies and enthesopathies of the extremities. PMID:20860444

  7. Minimal Clinically Important Difference of Patient Reported Outcome Measures of Lower Extremity Injuries in Orthopedics

    PubMed Central

    Çelik, Derya; Çoban, Özge; Kılıçoğlu, Önder

    2017-01-01

    Purpose: MCID scores for outcome measures are frequently used evidence-based guides to gage meaningful changes. To conduct a systematic review of the quality and content of the the minimal clinically important difference (MCID) relating to 16 patient-rated outcome measures (PROM) used in lower extremity. Methods: We conducted a systematic literature review on articles reporting MCID in lower extremity outcome measures and orthopedics from January 1, 1980, to May 10, 2016. We evaluated MCID of the 16 patient reported outcome measures (PROM) which were Harris Hip Score (HHS), Oxford Hip Score (OHS), Hip Outcome Score (HOS), Hip Disability and Osteoarthritis Outcome Score (HOOS), The International Knee Documentation Committee Subjective Knee Form (IKDC), The Lysholm Scale, The Western Ontario Meniscal Evaluation Tool (WOMET), The Anterior Cruciate Ligament Quality of Life Questionnaire (ACL-QOL), The Lower Extremity Functional Scale (LEFS), The Western Ontario and Mcmaster Universities Index (WOMAC), Knee İnjury And Osteoarthritis Outcome Score (KOOS), Oxford Knee Score (OKS), Kujala Anterior Knee Pain Scale, The Victorian Institute of Sports Assessment Patellar Tendinosis (Jumper’s Knee) (VİSA-P), Tegner Activity Rating Scale, Marx Activity Rating Scale, Foot And Ankle Outcome Score (FAOS), The Foot Function Index (FFI), Foot And Ankle Ability Measure (FAAM), The Foot And Ankle Disability Index Score and Sports Module, Achill Tendon Total Rupture Score(ATRS), The Victorian İnstitute Of Sports Assesment Achilles Questionnaire(VİSA-A), American Orthopaedic Foot and Ankle Society (AOFAS). A search of the PubMed/MEDLINE, PEDro and Cochrane Cen¬tral Register of Controlled Trials and Web of Science databases from the date of inception to May 1, 2016 was conducted. The terms “minimal clinically important difference,” “minimal clinically important change”, “minimal clinically important improvement” “were combined with one of the PROM as mentioned above

  8. Predictors for extreme summertime precipitation events over tropical South America: the importance of intraseasonal forcing

    NASA Astrophysics Data System (ADS)

    Hirata, F. E.; Hoyos, C.; Webster, P. J.

    2010-12-01

    The occurrence of extreme rainfall over tropical South America is commonly associated with warm phases of the El Niño-Southern Oscillation (ENSO). Although ENSO is important in determining favorable conditions for positive precipitation anomalies, the occurrence of single intense events is also determined by the interaction of higher frequency phenomena. In most cases, these extreme events are a consequence of South Atlantic Convergence Zone (SACZ) intensification or persistency, which is significantly influenced by intraseasonal and submonthly variability. A good example of this higher frequency interaction was the tragic event occurred in Rio de Janeiro on April 6, 2010. At that day, the city experienced a historical record of 178.5 mm of rainfall and the lost of almost 200 human lives. This 24-hour rainfall event exceeded the last maximum of 167.4 mm registered on January 16, 1962. During the pentad between April 4 and April 8, 232 mm of rainfall were recorded by the Brazilian National Institute of Meteorology (INMET). The climatology for April in Rio is below 150 mm and although the event took place during austral fall, it was similar to most summertime events associated with the SACZ. Our analyses show how the interaction of an intraseasonal MJO-related signal reaching South America in the tropics and a strong extratropical weather system propagating far into low latitudes cooperate to induce this particular extreme event. Moreover, we demonstrate that these remotely generated signals are instrumental for setting the conditions for excessive rainfall over the SACZ region. Finally, we present a set of predictors defined by their significant relationship with intraseasonal extremes of rainfall associated with SACZ events. These predictors are used in a statistical scheme for extended-range (15-30 days) forecast of rainfall over tropical South America. The results of this scheme are compared to actual events (including the one observed on April 6, 2010) and its

  9. Estimating the Effect of Climate Change on Crop Yields and Farmland Values: The Importance of Extreme Temperatures

    EPA Pesticide Factsheets

    This is a presentation titled Estimating the Effect of Climate Change on Crop Yields and Farmland Values: The Importance of Extreme Temperatures that was given for the National Center for Environmental Economics

  10. Communicating natural hazards. The case of marine extreme events and the importance of the forecast's errors.

    NASA Astrophysics Data System (ADS)

    Marone, Eduardo; Camargo, Ricardo

    2013-04-01

    possible to produce short and long term forecasts. While the statistic of extremes is useful for many stakeholders, short term forecasts could be of importance for the whole society. Whatever the case, the prediction errors have to be emphasizes even more than the forecasts. The most common forecast in terms of general public understanding is the weather prediction. Nowadays, general public knows it well enough to properly deal with the uncertainties, because after so many year of not perfect forecasts, society knows the limits. Other coastal hazards deserve to be presented more carefully, and some successful example of the use of the precautionary principle could be observed, for instance, on the Pacific Tsunami alert system. Nowadays, the preparedness of the coastal population is good enough (even in such big and diverse area) not to be bored to run up the hill, most of the times unnecessarily, because they know the uncertainty and accept it. The key issue we, scientists, have to work better at any level, is the need of properly estimate and communicate the uncertainties of our results, cause they are not obvious nor irrelevant.

  11. Stress fractures in the lower extremity. The importance of increasing awareness amongst radiologists.

    PubMed

    Berger, Ferco H; de Jonge, Milko C; Maas, Mario

    2007-04-01

    Stress fractures are fatigue injuries of bone usually caused by changes in training regimen in the population of military recruits and both professional and recreational athletes. Raised levels of sporting activity in today's population and refined imaging technologies have caused a rise in reported incidence of stress fractures in the past decades, now making up more than 10% of cases in a typical sports medicine practice. Background information (including etiology, epidemiology, clinical presentation and treatment and prevention) as well as state of the art imaging of stress fractures will be discussed to increase awareness amongst radiologists, providing the tools to play an important role in diagnosis and prognosis of stress fractures. Specific fracture sites in the lower extremity will be addressed, covering the far majority of stress fracture incidence. Proper communication between treating physician, physical therapist and radiologist is needed to obtain a high index of suspicion for this easily overlooked entity. Radiographs are not reliable for detection of stress fractures and radiologists should not falsely be comforted by them, which could result in delayed diagnosis and possibly permanent consequences for the patient. Although radiographs are mandatory to rule out differentials, they should be followed through when negative, preferably by magnetic resonance imaging (MRI), as this technique has proven to be superior to bone scintigraphy. CT can be beneficial in a limited number of patients, but should not be used routinely.

  12. Importance of Depletion Width on Charge Transport and Interfacial Recombination in Extremely Thin Absorber Solar Cells

    NASA Astrophysics Data System (ADS)

    Edley, Michael; Jones, Treavor; Baxter, Jason

    The dynamics of charge carrier transport and recombination and their dependence on physical and electrochemical length scales in extremely thin absorber (ETA) solar cells is vital to cell design. We used J-V characterization, transient photocurrent / photovoltage, and electrochemical impedance spectroscopy to study electron transport and interfacial recombination in ETA cell. ETA cells were composed of ZnO nanowires coated with an ultrathin (5 nm) CdS buffer layer and CdSe absorbers with thicknesses of 10 - 40 nm, with polysulfide electrolyte. In thinner absorbers near short circuit, the depletion region can extend radially into the nanowire, inhibiting interfacial recombination rate. However, depleting the periphery of the nanowire reduces the cross sectional area for charge transport, resulting in longer characteristic collection times. Thicker absorbers suffered more significant bias-dependent collection, and we conclude that slight radial penetration of the depletion region into the nanowires enhances charge collection. This work highlights the importance of considering the impact of depletion width on charge transport and interfacial recombination in the design of liquid junction, semiconductor-sensitized solar cells.

  13. Understanding the importance of natural neuromotor strategy in upper extremity neuroprosthetic control.

    PubMed

    Nathan, Dominic E; Prost, Robert W; Guastello, Stephen J; Jeutter, Dean C

    2014-01-01

    A key challenge in upper extremity neuroprosthetics is variable levels of skill and inconsistent functional recovery. We examine the feasibility and benefits of using natural neuromotor strategies through the design and development of a proof-of-concept model for a feed-forward upper extremity neuroprosthetic controller. Developed using Artificial Neural Networks, the model is able to extract and classify neural correlates of movement intention from multiple brain regions that correspond to functional movements. This is unique compared to contemporary controllers that record from limited physiological sources or require learning of new strategies. Functional MRI (fMRI) data from healthy subjects (N = 13) were used to develop the model, and a separate group (N = 4) of subjects were used for validation. Results indicate that the model is able to accurately (81%) predict hand movement strictly from the neural correlates of movement intention. Information from this study is applicable to the development of upper extremity technology aided interventions.

  14. Importance of the functional examination in lower extremities in patients with rheumatoid arthritis.

    PubMed

    Wareńczak, Agnieszka; Lisiński, Przemysław; Huber, Juliusz

    2014-01-01

    This paper deals with evaluation of the lower extremity efficiency and balance in rheumatoid arthritis (RA) patients. The authors' own test (LLFT-lower extremities functional test) and balance tests during normal standing and tandem positions with eyes opened or closed were used. Twelve patients with RA and fifteen controls for comparison were examined. Center feet of pressure dislocation on platform in normal standing with eyes open, normal standing with eyes closed, tandem left foot in front and tandem right foot in front positions and further dynamic balance tests on three different boards were analyzed. Visual Analogue Scale monitored the level of pain after each LLFT task. There was found a relation between the intensity of pain and overloading of joints in particular tasks, resulting in lower extremities dysfunction. A significant disbalance in medio-lateral direction during normal standing with eyes closed and tandem right foot in front positions and also in anterior-posterior direction in tandem right foot in front position during static balance tests was found. Correlations showed that patient's age, disease duration and Steinbrocker Functional Classes have an influence on parameters of balance tests. Results indicate that complex dysfunction of lower extremities causes disbalance of posture in static conditions.

  15. On the importance of cloud—cloud interaction to invigorate convective extremes

    NASA Astrophysics Data System (ADS)

    Berg, Peter; Moseley, Christopher; Hohenegger, Cathy; Haerter, Jan

    2017-04-01

    Observational studies have shown that convective extremes are invigorated with increasing temperatures beyond thermodynamic constraints through the Clausius-Clapeyron relationship (e.g. Lenderink and van Meijgaard, Nature Geosci., 2008; Berg et al., Nature Geosci., 2013). This implies that there are changes in the dynamics of the convective showers that are dependent on the environmental conditions. Observations of convective cells lack sufficient resolution to investigate the dynamics in detail. We have therefore applied a large eddy simulator (LES) at a 200 m horizontal resolution to study the dynamical interaction between convective cells in a set of idealized simulations of a full diurnal cycle with a vertical profile of a typical day with convective showers (Moseley et al., Nature Geosci., 2016). The simulations show that the convective cells are subjected to a gradual self-organization over the day, forming larger cell clusters and more intense precipitation. Further, by tracking rain cells, we find that cells that collide with other cells during their lifetime have a different response to changes in the environmental conditions, such as an increase in temperature, than cells that do not interact. Whereas the non-interacting cells remain almost unaffected by the boundary conditions, the colliding cells show a strong invigoration. Interestingly, granting more time for the self-organization to occur has a similar effect as increasing the temperature. We therefore speculate that self-organization is a key element to explain the strong response of convective extremes to increasing temperature. Our results suggest that proper modeling and predicting of convective extremes requires the description of the interaction between convective clouds.

  16. Socio-Economic Hazards and Impacts of Space Weather: The Important Range Between Mild and Extreme

    NASA Astrophysics Data System (ADS)

    Schrijver, Carolus J.

    2015-09-01

    Society needs to prepare for more severe space weather than it has experienced in the modern technological era. To enable that we must both quantify extreme-event characteristics and analyze impacts of lesser events that are frequent yet severe enough to be informative. Exploratory studies suggest that economic impacts of a century-level space hurricane and of a century of lesser space weather "gales" may turn out to be of the same order of magnitude. The economic benefits of effective mitigation of the impacts of space gales may substantially exceed the required investments, even as these investments provide valuable information to prepare for the worst possible storms.

  17. Relative importance of ring and tail currents to Dst under extremely disturbed conditions

    NASA Astrophysics Data System (ADS)

    Kalegaev, V. V.; Makarenkov, E. V.

    2008-02-01

    Relative ring current (RC) and tail current (TC) contributions to Dst were investigated on the basis of the statistical study of 70 magnetic storms of different intensities. Special attention was paid to the extremely disturbed conditions during magnetic storms in October-November 2003. Variations of the magnetic field produced by magnetospheric currents on the Earth's surface were calculated using paraboloid model of the magnetosphere A2000 [Alexeev, I.I., Belenkaya, E.S., Kalegaev, V.V., Feldstein, Y.I., Grafe, A., 1996. Journal of Geophysical Research 101,7737; Alexeev, I.I., Kalegaev, V.V., Belenkaya, E.S., Bobrovnikov, S.Yu., Feldstein, Ya.I., Gromova, L.I., 2001. Journal of Geophysical Research 106, 25683], taking into account the effect of terrestrial induced currents. For each magnetic storm we calculated Dst and contributions produced by large-scale magnetospheric current systems. The relative RC and TC contributions for each event at the storm maximum were examined in relationship to the peak pressure-corrected Dst value. Analysis of Dst sources confirms the conclusions of Kalegaev and Ganushkina [2005. In: Pulkkinen, T., Tsyganenko, N.A., Friedel, R.H.W. (Eds.), Physics and Modeling of the Inner Magnetosphere, AGU Geophysical Monograph 155. AGU, Washington, DC, p. 293] and Kalegaev and Makarenkov [2006. Geomagnetism and Aeronomy 46, 570] about saturation of the TC effect under extremely disturbed conditions. The RC becomes the dominant Dst source during severe magnetic storms, but during moderate storms its contribution to Dst is comparable with TC's contribution. The RC injection amplitude increases with the growth of magnetospheric disturbance level.

  18. The importance of interacting climate modes on Australia's contribution to global carbon cycle extremes.

    PubMed

    Cleverly, James; Eamus, Derek; Luo, Qunying; Restrepo Coupe, Natalia; Kljun, Natascha; Ma, Xuanlong; Ewenz, Cacilia; Li, Longhui; Yu, Qiang; Huete, Alfredo

    2016-03-15

    The global carbon cycle is highly sensitive to climate-driven fluctuations of precipitation, especially in the Southern Hemisphere. This was clearly manifested by a 20% increase of the global terrestrial C sink in 2011 during the strongest sustained La Niña since 1917. However, inconsistencies exist between El Niño/La Niña (ENSO) cycles and precipitation in the historical record; for example, significant ENSO-precipitation correlations were present in only 31% of the last 100 years, and often absent in wet years. To resolve these inconsistencies, we used an advanced temporal scaling method for identifying interactions amongst three key climate modes (El Niño, the Indian Ocean dipole, and the southern annular mode). When these climate modes synchronised (1999-2012), drought and extreme precipitation were observed across Australia. The interaction amongst these climate modes, more than the effect of any single mode, was associated with large fluctuations in precipitation and productivity. The long-term exposure of vegetation to this arid environment has favoured a resilient flora capable of large fluctuations in photosynthetic productivity and explains why Australia was a major contributor not only to the 2011 global C sink anomaly but also to global reductions in photosynthetic C uptake during the previous decade of drought.

  19. On the Importance of the Flare's Late Phase for the Solar Extreme Ultraviolet Irradiance

    NASA Technical Reports Server (NTRS)

    Woods, Thomas N.; Eparvier, Frank; Jones, Andrew R.; Hock, Rachel; Chamberlin, Phillip C.; Klimchuk, James A.; Didkovsky, Leonid; Judge, Darrell; Mariska, John; Bailey, Scott; hide

    2011-01-01

    The new solar extreme ultraviolet (EUV) irradiance observations from NASA Solar Dynamics Observatory (SDO) have revealed a new class of solar flares that are referred to as late phase flares. These flares are characterized by the hot 2-5 MK coronal emissions (e.g., Fe XVI 33.5 nm) showing large secondary peaks that appear many minutes to hours after an eruptive flare event. In contrast, the cool 0.7-1.5 MK coronal emissions (e.g., Fe IX 17.1 nm) usually dim immediately after the flare onset and do not recover until after the delayed second peak of the hot coronal emissions. We refer to this period of 1-5 hours after the fl amrea sin phase as the late phase, and this late phase is uniquely different than long duration flares associated with 2-ribbon flares or large filament eruptions. Our analysis of the late phase flare events indicates that the late phase involves hot coronal loops near the flaring region, not directly related to the original flaring loop system but rather with the higher post-eruption fields. Another finding is that space weather applications concerning Earth s ionosphere and thermosphere need to consider these late phase flares because they can enhance the total EUV irradiance flare variation by a factor of 2 when the late phase contribution is included.

  20. The importance of interacting climate modes on Australia’s contribution to global carbon cycle extremes

    PubMed Central

    Cleverly, James; Eamus, Derek; Luo, Qunying; Restrepo Coupe, Natalia; Kljun, Natascha; Ma, Xuanlong; Ewenz, Cacilia; Li, Longhui; Yu, Qiang; Huete, Alfredo

    2016-01-01

    The global carbon cycle is highly sensitive to climate-driven fluctuations of precipitation, especially in the Southern Hemisphere. This was clearly manifested by a 20% increase of the global terrestrial C sink in 2011 during the strongest sustained La Niña since 1917. However, inconsistencies exist between El Niño/La Niña (ENSO) cycles and precipitation in the historical record; for example, significant ENSO–precipitation correlations were present in only 31% of the last 100 years, and often absent in wet years. To resolve these inconsistencies, we used an advanced temporal scaling method for identifying interactions amongst three key climate modes (El Niño, the Indian Ocean dipole, and the southern annular mode). When these climate modes synchronised (1999–2012), drought and extreme precipitation were observed across Australia. The interaction amongst these climate modes, more than the effect of any single mode, was associated with large fluctuations in precipitation and productivity. The long-term exposure of vegetation to this arid environment has favoured a resilient flora capable of large fluctuations in photosynthetic productivity and explains why Australia was a major contributor not only to the 2011 global C sink anomaly but also to global reductions in photosynthetic C uptake during the previous decade of drought. PMID:26976754

  1. An archaeal iron-oxidizing extreme acidophile important in acid mine drainage.

    PubMed

    Edwards, K J; Bond, P L; Gihring, T M; Banfield, J F

    2000-03-10

    A new species of Archaea grows at pH approximately 0.5 and approximately 40 degrees C in slime streamers and attached to pyrite surfaces at a sulfide ore body, Iron Mountain, California. This iron-oxidizing Archaeon is capable of growth at pH 0. This species represents a dominant prokaryote in the environment studied (slimes and sediments) and constituted up to 85% of the microbial community when solution concentrations were high (conductivity of 100 to 160 millisiemens per centimeter). The presence of this and other closely related Thermoplasmales suggests that these acidophiles are important contributors to acid mine drainage and may substantially impact iron and sulfur cycles.

  2. [Johann Friedrich Meckel the Younger (1781-1833), an extremely important naturalist and scholar].

    PubMed

    Schultka, Rüdiger; Göbbel, Luminita

    2002-11-01

    Johann Friedrich Meckel the Younger (1781-1833) belongs to the famous scientists of the 19th century. His research work is enormous. Important termini e.g. diverticulum Meckelii, cartilago Meckelii, Meckel syndrome and Meckel Serres law reflect the scientific results obtained by Meckel. He worked as a professor of anatomy, pathology and zoology at the University of Halle, a town in the Central Germany. Meckel founded the scientific teratology. In the literature he is also referred to the German Cuvier. On 8 April 1802, J. F. Meckel defended his doctoral thesis "De cordis conditionibus abnormibus". On occasion of the 200th anniversary of this event, we like to honor J. F. Meckel the famous German anatomist. Therefore, during the 97th session of the Anatomische Gesellschaft at Halle, a satellite symposium "From Meck el to genom" was held.

  3. Representing ozone extremes in European megacities: the importance of resolution in a global chemistry climate model

    NASA Astrophysics Data System (ADS)

    Stock, Z. S.; Russo, M. R.; Pyle, J. A.

    2014-04-01

    The continuing growth of the world's urban population has led to an increasing number of cities with more than 10 million inhabitants. The higher emissions of pollutants, coupled to higher population density, makes predictions of air quality in these megacities of particular importance from both a science and a policy perspective. Global climate models are typically run at coarse resolution to enable both the efficient running of long time integrations, and the ability to run multiple future climate scenarios. However, when considering surface ozone concentrations at the local scale, coarse resolution can lead to inaccuracies arising from the highly nonlinear ozone chemistry and the sensitivity of ozone to the distribution of its precursors on smaller scales. In this study, we use UM-UKCA, a global atmospheric chemistry model, coupled to the UK Met Office Unified Model, to investigate the impact of model resolution on tropospheric ozone, ranging from global to local scales. We focus on the model's ability to represent the probability of high ozone concentrations in the summer and low ozone concentrations, associated with polluted megacity environments, in the winter, and how this varies with horizontal resolution. We perform time-slice integrations with two model configurations at typical climate resolution (CR, ~150 km) and at a higher resolution (HR, ~40 km). The CR configuration leads to overestimation of ozone concentrations on both regional and local scales, while it gives broadly similar results to the HR configuration on the global scale. The HR configuration is found to produce a more realistic diurnal cycle of ozone concentrations and to give a better representation of the probability density function of ozone values in urban areas such as the megacities of London and Paris. We find the observed differences in model behaviour between CR and HR configurations to be largely caused by chemical differences during the winter and meteorological differences

  4. Representing ozone extremes in European megacities: the importance of resolution in a global chemistry climate model

    NASA Astrophysics Data System (ADS)

    Stock, Z. S.; Russo, M. R.; Pyle, J. A.

    2013-10-01

    The continuing growth of the world's urban population has led to an increasing number of cities with more than 10 million inhabitants. The higher emissions of pollutants, coupled to higher population density, makes predictions of air quality in these megacities of particular importance from both a science and a policy perspective. Global climate models are typically run at coarse resolution to enable both the efficient running of long time integrations, and the ability to run multiple future climate scenarios. However, when considering surface ozone concentrations at the local scale, coarse resolution can lead to inaccuracies arising from the highly non-linear ozone chemistry and the sensitivity of ozone to the distribution of its precursors on smaller scales. In this study, we use UM-UKCA, a global atmospheric chemistry model, coupled to the UK Met Office Unified Model, to investigate the impact of model resolution on tropospheric ozone, ranging from global to local scales. We focus on the model's ability to represent the probability of high ozone concentrations in the summer and low ozone concentrations, associated with polluted megacity environments, in the winter, and how this varies with horizontal resolution. We perform time-slice integrations with two model configurations at typical climate resolution (CR, ~150 km) and at a higher resolution (HR, ~40 km). The CR configuration leads to overestimation of ozone concentrations on both regional and local scales, while it gives broadly similar results to the HR configuration on the global scale. The HR configuration is found to produce a more realistic diurnal cycle of ozone concentrations and to give a better representation of the probability density function of ozone values in urban areas such as the megacities of London and Paris. We discuss the possible causes for the observed difference in model behaviour between CR and HR configurations and estimate the relative contribution of chemical and meteorological

  5. Synthesis of Concepts in Disturbance Hydrology and the Importance for Hydrologic Response to Extreme Hydroclimatic Events in the Critical Zone

    NASA Astrophysics Data System (ADS)

    Ebel, B. A.; Mirus, B. B.

    2014-12-01

    The watersheds we rely on for water resources, ecosystem services, and protection from hydrologically driven natural hazards are increasingly impacted by landscape disturbance. Abrupt alterations of hydrologic processes resulting from wildfires, urban development, resource extraction, deforestation, hurricanes, tsunamis, and landslides change the storage or buffering capacity as well as the hydrologic functional connectivity in watersheds. We highlight some of the critical issues and major challenges to predicting disturbance impacts on water resources and natural hazards and outline some of the opportunities for improved mechanistic understanding of how disturbances propagate through landscape hydrological processes. In particular, we emphasize synthesis of conceptual commonalities and opportunities from other disciplines, primarily ecologic sciences, which are well versed in the study of disturbed landscapes. Cross scale interactions and complex adaptive systems theory are examples of useful concepts for synthesis across different disturbance effects. We also highlight the importance of improved understanding of disturbance hydrology for predicting the effects of extreme hydroclimatic events on the hydrologic response of the Critical Zone. An example from the Front Range of the Rocky Mountains, USA of a watershed with multiple disturbances subjected to a low frequency extreme rainfall event is presented to show the diversity of runoff generation mechanisms and the implications for watershed scale impacts.

  6. Revealing rate-limiting steps in complex disease biology: The crucial importance of studying rare, extreme-phenotype families.

    PubMed

    Chakravarti, Aravinda; Turner, Tychele N

    2016-06-01

    The major challenge in complex disease genetics is to understand the fundamental features of this complexity and why functional alterations at multiple independent genes conspire to lead to an abnormal phenotype. We hypothesize that the various genes involved are all functionally united through gene regulatory networks (GRN), and that mutant phenotypes arise from the consequent perturbation of one or more rate-limiting steps that affect the function of the entire GRN. Understanding a complex phenotype thus entails unraveling the details of each GRN, namely, the transcription factors that bind to cis regulatory elements affected by sequence variants altering transcription of specific genes, and their mutual feedback relationships. These GRNs can be identified through their rate-limiting steps and are best uncovered by genomic analyses of rare, extreme phenotype families, thus providing a coherent molecular basis to complex traits and disorders. © 2016 WILEY Periodicals, Inc.

  7. On the use of ocean-atmosphere-wave models during an extreme CAO event: the importance of being coupled

    NASA Astrophysics Data System (ADS)

    Carniel, Sandro; Barbariol, Francesco; Benetazzo, Alvise; Bonaldo, Davide; Falcieri, Francesco M.; Miglietta, Mario M.; Ricchi, Antonio; Sclavo, Mauro

    2015-04-01

    During winter 2012 an extreme meteorological event stroke the whole Europe and particularly its central-southern sector. A strong and persistent spit of cold air coming from Siberian region (a Cold Air Outbreak, CAO) insisted on northern Italy and the Adriatic sea basin, leading to decreases in the sea temperatures up to 6 °C in less than two weeks, ice formation on the Venice lagoon and an exceptional snow fall in the Apennine region. In the sea the CAO was associated to a significant episode of dense water formation (DWF), a crucial phenomenon that heavily impacts the whole Adriatic Sea (from the sinking of water masses and associated ventilation of the northernmost shelf, to the flow along the western coast, until the flushing of southern Adriatic open slope and submarine canyons, with associated sediment transport and bottom reshaping). The extent of the DWF event in the Northern Adriatic sub-basin was estimated by means of coastal observatories, ad hoc measurements and, until now, results from existing one-way coupled atmosphere-ocean models. These are characterized by no SST feedback from the ocean to the atmosphere, and therefore by turbulent heat fluxes that may heavily reflect a non-consistent ocean state. The study proposes an investigation of the 2012 CAO using a fully coupled, three components, ocean-atmosphere-wave system (COAWST). Results highlight that, although the energy interplays between air and sea do not seem to significantly impact the wind forecasts, when providing heat fluxes that are consistent with the ocean temperature we find modified heat fluxes and air sea temperatures figures. Moreover, the consistent description of thermal exchanges adopted in the fully coupled model can affect the basin circulation, the quantification of dense water produced mass, and the description of its migration pathways and rates of off-shelf descent.

  8. The Importance of Aerobic Fitness in Extending Thermotolerance in Extreme Environments: Connecting Molecular Biology to the Whole Body Response

    DTIC Science & Technology

    2009-10-01

    dot plots gating on CD14+ monocytes were used to delineate classic (CD14++ CD16 -) and inflammatory monocyte (CD14+ CD16 +) subsets (Figure 1...Figure 1: Flow cytometric dotplots representing sequential gating for CD14++ CD16 -/ CD14+ CD16 + and CD14Bri/CD14Dim subsets of total CD14...HSP72 in CD14Bri/CD14Dim and intracellular cytokine staining in CD14++ CD16 -/ CD14+ CD16 + (data not shown). The Importance of Aerobic Fitness in

  9. [Importance of revision- and tumor-endoprosthetics in the treatment of periprosthetic fractures of the lower extremity].

    PubMed

    Prodinger, P M; Harrasser, N; Suren, C; Pohlig, F; Mühlhofer, H; Schauwecker, J; von Eisenhart-Rothe, R

    2016-04-01

    Periprosthetic fractures of hip and knee prostheses are gaining clinical significance due to the increasing numbers of of primary arthroplasties. Additionally, these fractures are often associated with poor bone quality or present in patients after multiple revision procedures and concomitant excessive bone defects precluding those patients to be adequately treated by conventional osteosynthesis. Revision implants provide a wide range of options for the treatment of these fractures in order to achieve good clinical results. In the acetabular region cavitary defects associated with periprosthetic fractures can be treated by the use of megacups. Extensive segmental defects and pelvic discontinuity necessitate the use of cups with additional iliac support or even customized implants. Proximal femoral fractures can usually be fixed with modular stems and diaphyseal anchorage. Periprosthetic knee joint fractures can be treated with revision implants with modular sleeves or augment-combinations allowing sufficient bridging of bony defects. Functional reconstruction or refixation of the extensor mechanism is of crucial importance.

  10. How extreme are extremes?

    NASA Astrophysics Data System (ADS)

    Cucchi, Marco; Petitta, Marcello; Calmanti, Sandro

    2016-04-01

    High temperatures have an impact on the energy balance of any living organism and on the operational capabilities of critical infrastructures. Heat-wave indicators have been mainly developed with the aim of capturing the potential impacts on specific sectors (agriculture, health, wildfires, transport, power generation and distribution). However, the ability to capture the occurrence of extreme temperature events is an essential property of a multi-hazard extreme climate indicator. Aim of this study is to develop a standardized heat-wave indicator, that can be combined with other indices in order to describe multiple hazards in a single indicator. The proposed approach can be used in order to have a quantified indicator of the strenght of a certain extreme. As a matter of fact, extremes are usually distributed in exponential or exponential-exponential functions and it is difficult to quickly asses how strong was an extreme events considering only its magnitude. The proposed approach simplify the quantitative and qualitative communication of extreme magnitude

  11. The Importance of Moral Construal: Moral versus Non-Moral Construal Elicits Faster, More Extreme, Universal Evaluations of the Same Actions

    PubMed Central

    Van Bavel, Jay J.; Packer, Dominic J.; Haas, Ingrid Johnsen; Cunningham, William A.

    2012-01-01

    Over the past decade, intuitionist models of morality have challenged the view that moral reasoning is the sole or even primary means by which moral judgments are made. Rather, intuitionist models posit that certain situations automatically elicit moral intuitions, which guide moral judgments. We present three experiments showing that evaluations are also susceptible to the influence of moral versus non-moral construal. We had participants make moral evaluations (rating whether actions were morally good or bad) or non-moral evaluations (rating whether actions were pragmatically or hedonically good or bad) of a wide variety of actions. As predicted, moral evaluations were faster, more extreme, and more strongly associated with universal prescriptions—the belief that absolutely nobody or everybody should engage in an action—than non-moral (pragmatic or hedonic) evaluations of the same actions. Further, we show that people are capable of flexibly shifting from moral to non-moral evaluations on a trial-by-trial basis. Taken together, these experiments provide evidence that moral versus non-moral construal has an important influence on evaluation and suggests that effects of construal are highly flexible. We discuss the implications of these experiments for models of moral judgment and decision-making. PMID:23209557

  12. Storm pulses of particulate and dissolved organic carbon in a forested headwater stream and their environmental implications - importance of extreme rainfall events

    NASA Astrophysics Data System (ADS)

    Jung, B.-J.; Lee, J.-K.; Kim, H.; Park, J.-H.

    2014-05-01

    Despite recent debates on erosion-enhanced sinks of CO2 and contrasting findings on the biodegradation of recalcitrant organic materials in large rivers, little attention has been paid to the export and transformations of particulate organic carbon (POC) and dissolved organic C (DOC) in mountainous headwater watersheds under monsoon climates. To comparatively evaluate the significance of heavy monsoon rainfalls for the magnitude and environmental implications of storm-enhanced export of POC and DOC, the relationships between storm magnitude and C export were examined in a mountainous, forested headwater stream in the Haean Basin, South Korea, during 50 storm events over the 4 year monitoring period. We also compared biodegradation and disinfection byproduct (DBP) formation potentials of the DOC and POC exported during an extreme rainfall event. Event mean concentrations and export of POC increased nonlinearly above thresholds of precipitation and discharge, significantly exceeding the increases of DOC. The export of POC during a few storm events with a total rainfall above 200 mm per event exceeded the annual organic C export during dry years. During the large storm event (209 mm), concentrations of total trihalomethanes formed by POC-derived dissolved components changed synchronously with POC concentrations, exhibiting lower levels than those formed by DOC. During a 30 day incubation at 25 °C, both DOC and POC exported during peak flow initially exhibited rapid biodegradation of labile components, whereas POC-derived materials increased continuously not only DOC concentrations, but also fulvic- and humic-like fluorescent components. These results highlight the significance of extreme rainfall events as "hot moments" for POC export and also suggest that storm pulses of POC can provide potential sources of labile DOC components that can rapidly biodegrade and form DBPs in headwater streams, contrasting with other studies assuming mountainous rivers as a passive

  13. Extreme Heat

    MedlinePlus

    ... Hurricanes Landslides & Debris Flow Nuclear Blast Nuclear Power Plants Pandemic Power Outages Radiological Dispersion Device Severe Weather Snowstorms & Extreme Cold Space Weather Thunderstorms & Lightning Tornadoes ...

  14. Precipitation Extremes Under Climate Change.

    PubMed

    O'Gorman, Paul A

    The response of precipitation extremes to climate change is considered using results from theory, modeling, and observations, with a focus on the physical factors that control the response. Observations and simulations with climate models show that precipitation extremes intensify in response to a warming climate. However, the sensitivity of precipitation extremes to warming remains uncertain when convection is important, and it may be higher in the tropics than the extratropics. Several physical contributions govern the response of precipitation extremes. The thermodynamic contribution is robust and well understood, but theoretical understanding of the microphysical and dynamical contributions is still being developed. Orographic precipitation extremes and snowfall extremes respond differently from other precipitation extremes and require particular attention. Outstanding research challenges include the influence of mesoscale convective organization, the dependence on the duration considered, and the need to better constrain the sensitivity of tropical precipitation extremes to warming.

  15. How extreme is extreme hourly precipitation?

    NASA Astrophysics Data System (ADS)

    Papalexiou, Simon Michael; Dialynas, Yannis G.; Pappas, Christoforos

    2016-04-01

    The importance of accurate representation of precipitation at fine time scales (e.g., hourly), directly associated with flash flood events, is crucial in hydrological design and prediction. The upper part of a probability distribution, known as the distribution tail, determines the behavior of extreme events. In general, and loosely speaking, tails can be categorized in two families: the subexponential and the hyperexponential family, with the first generating more intense and more frequent extremes compared to the latter. In past studies, the focus has been mainly on daily precipitation, with the Gamma distribution being the most popular model. Here, we investigate the behaviour of tails of hourly precipitation by comparing the upper part of empirical distributions of thousands of records with three general types of tails corresponding to the Pareto, Lognormal, and Weibull distributions. Specifically, we use thousands of hourly rainfall records from all over the USA. The analysis indicates that heavier-tailed distributions describe better the observed hourly rainfall extremes in comparison to lighter tails. Traditional representations of the marginal distribution of hourly rainfall may significantly deviate from observed behaviours of extremes, with direct implications on hydroclimatic variables modelling and engineering design.

  16. Upper Extremity Amputations and Prosthetics

    PubMed Central

    Ovadia, Steven A.; Askari, Morad

    2015-01-01

    Upper extremity amputations are most frequently indicated by severe traumatic injuries. The location of the injury will determine the level of amputation. Preservation of extremity length is often a goal. The amputation site will have important implications on the functional status of the patient and options for prosthetic reconstruction. Advances in amputation techniques and prosthetic reconstructions promote improved quality of life. In this article, the authors review the principles of upper extremity amputation, including techniques, amputation sites, and prosthetic reconstructions. PMID:25685104

  17. Upper extremity amputations and prosthetics.

    PubMed

    Ovadia, Steven A; Askari, Morad

    2015-02-01

    Upper extremity amputations are most frequently indicated by severe traumatic injuries. The location of the injury will determine the level of amputation. Preservation of extremity length is often a goal. The amputation site will have important implications on the functional status of the patient and options for prosthetic reconstruction. Advances in amputation techniques and prosthetic reconstructions promote improved quality of life. In this article, the authors review the principles of upper extremity amputation, including techniques, amputation sites, and prosthetic reconstructions.

  18. The extreme disjunction between Beringia and Europe in Ranunculus glacialis s. l. (Ranunculaceae) does not coincide with the deepest genetic split - a story of the importance of temperate mountain ranges in arctic-alpine phylogeography.

    PubMed

    Ronikier, M; Schneeweiss, G M; Schönswetter, P

    2012-11-01

    The arctic-alpine Ranunculus glacialis s. l. is distributed in high-mountain ranges of temperate Europe and in the North, where it displays an extreme disjunction between the North Atlantic Arctic and Beringia. Based on comprehensive sampling and employing plastid and nuclear marker systems, we (i) test whether the European/Beringian disjunction correlates with the main evolutionary diversification, (ii) reconstruct the phylogeographic history in the Arctic and in temperate mountains and (iii) assess the susceptibility of arctic and mountain populations to climate change. Both data sets revealed several well-defined lineages, mostly with a coherent geographic distribution. The deepest evolutionary split did not coincide with the European/Beringian disjunction but occurred within the Alps. The Beringian lineage and North Atlantic Arctic populations, which reached their current distribution via rapid postglacial colonization, show connections to two divergent pools of Central European populations. Thus, immigration into the Arctic probably occurred at least twice. The presence of a rare cpDNA lineage related to Beringia in the Carpathians supports the role of these mountains as a stepping stone between temperate Europe and the non-European Arctic, and as an important area of high-mountain biodiversity. The temperate and arctic ranges presented contrasting phylogeographic histories: a largely static distribution in the former and rapid latitudinal spread in the latter. The persistence of ancient lineages with a strictly regional distribution suggests that the ability of R. glacialis to survive repeated climatic changes within southern mountain ranges is greater than what recently was predicted for alpine plants from climatic envelope modelling.

  19. Hydrological extremes and security

    NASA Astrophysics Data System (ADS)

    Kundzewicz, Z. W.; Matczak, P.

    2015-04-01

    Economic losses caused by hydrological extremes - floods and droughts - have been on the rise. Hydrological extremes jeopardize human security and impact on societal livelihood and welfare. Security can be generally understood as freedom from threat and the ability of societies to maintain their independent identity and their functional integrity against forces of change. Several dimensions of security are reviewed in the context of hydrological extremes. The traditional interpretation of security, focused on the state military capabilities, has been replaced by a wider understanding, including economic, societal and environmental aspects that get increasing attention. Floods and droughts pose a burden and serious challenges to the state that is responsible for sustaining economic development, and societal and environmental security. The latter can be regarded as the maintenance of ecosystem services, on which a society depends. An important part of it is water security, which can be defined as the availability of an adequate quantity and quality of water for health, livelihoods, ecosystems and production, coupled with an acceptable level of water-related risks to people, environments and economies. Security concerns arise because, over large areas, hydrological extremes - floods and droughts - are becoming more frequent and more severe. In terms of dealing with water-related risks, climate change can increase uncertainties, which makes the state's task to deliver security more difficult and more expensive. However, changes in population size and development, and level of protection, drive exposure to hydrological hazards.

  20. Climate Extremes and Society

    NASA Astrophysics Data System (ADS)

    Mote, Philip

    2009-10-01

    In October 2005, as the United States still was reeling from Hurricane Katrina in August and as the alphabet was too short to contain all of that year's named Atlantic tropical storms (Hurricane Wilma was forming near Jamaica), a timely workshop in Bermuda focused on climate extremes and society (see Eos, 87(3), 25, 17 January 2006). This edited volume, which corresponds roughly to the presentations given at that workshop, offers a fascinating look at the critically important intersection of acute climate stress and human vulnerabilities. A changing climate affects humans and other living things not through the variable that most robustly demonstrates the role of rising greenhouse gases—globally averaged temperature—but through local changes, especially changes in extremes. The first part of this book, “Defining and modeling the nature of weather and climate extremes,” focuses on natural science. The second part, “Impacts of weather and climate extremes,” focuses on societal impacts and responses, emphasizing an insurance industry perspective because a primary sponsor of the workshop was the Risk Prediction Initiative, whose aim is to “support scientific research on topics of interest to its sponsors” (p. 320).

  1. "A discovery! The Higgs? Why is this important? How it was done"

    SciTech Connect

    Sally Dawson; Howard Gordan

    2012-06-26

    Data collected during 2011 and 2012 at the Large Hadron Collider (LHC) at CERN in Switzerland, the world's highest-energy proton collider, has culminated in the discovery of a new particle that is about 135 times heavier than a proton. But is it really the Higgs particle predicted by the theory that explains the origin of the mass of most elementary particles in the universe? The discovery and its possible identity is discussed by two Brookhaven Lab physicists, Sally Dawson and Howard Gordon, with deep roots in the hunt for the Higgs.

  2. "A discovery! The Higgs? Why is this important? How it was done"

    ScienceCinema

    Sally Dawson; Howard Gordan

    2016-07-12

    Data collected during 2011 and 2012 at the Large Hadron Collider (LHC) at CERN in Switzerland, the world's highest-energy proton collider, has culminated in the discovery of a new particle that is about 135 times heavier than a proton. But is it really the Higgs particle predicted by the theory that explains the origin of the mass of most elementary particles in the universe? The discovery and its possible identity is discussed by two Brookhaven Lab physicists, Sally Dawson and Howard Gordon, with deep roots in the hunt for the Higgs.

  3. Effects of extreme natural events on the provision of ecosystem services in a mountain environment: The importance of trail design in delivering system resilience and ecosystem service co-benefits.

    PubMed

    Tomczyk, Aleksandra M; White, Piran C L; Ewertowski, Marek W

    2016-01-15

    A continued supply of ecosystem services (ES) from a system depends on the resilience of that system to withstand shocks and perturbations. In many parts of the world, climate change is leading to an increased frequency of extreme weather events, potentially influencing ES provision. Our study of the effects of an intense rainfall event in Gorce National Park, Poland, shows: (1) the intense rainfall event impacted heavily on the supply of ES by limiting potential recreation opportunities and reducing erosion prevention; (2) these negative impacts were not only restricted to the period of the extreme event but persisted for up to several years, depending on the pre-event trail conditions and post-event management activities; (3) to restore the pre-event supply of ES, economic investments were required in the form of active repairs to trails, which, in Gorce National Park, were an order of magnitude higher than the costs of normal trail maintenance; and (4) when recreational trails were left to natural restoration, loss of biodiversity was observed, and recovery rates of ES (recreation opportunities and soil erosion prevention) were reduced in comparison to their pre-event state. We conclude that proper trail design and construction provides a good solution to avoid some of the negative impacts of extreme events on recreation, as well as offering co-benefits in terms of protecting biodiversity and enhancing the supply of regulating services such as erosion prevention. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Extreme Heat Guidebook

    EPA Pesticide Factsheets

    The 'Climate Change and Extreme Heat: What You Can Do to Prepare' handbook explains the connection between climate change and extreme heat events, and outlines actions citizens can take to protect their health during extreme heat.

  5. [The extremely violent child].

    PubMed

    Berger, M; Bonneville, E

    2009-02-01

    More and more children have extremely violent behaviour which appears about the age of 15-16 months, when walking makes their hands free. This violence is individual, can appear suddenly at anytime, and is not accompanied by guilt. It is caused by early psychological and repeated traumas, whose importance is usually underestimated: unpredictable, violent parents, exposure to the spectacle of conjugal violence, distortion of the signals emitted by the toddler. These traumas bring about specific psychological structure. The prevention of these troubles exists but is impossible to realise in France.

  6. Spatial dependence of extreme rainfall

    NASA Astrophysics Data System (ADS)

    Radi, Noor Fadhilah Ahmad; Zakaria, Roslinazairimah; Satari, Siti Zanariah; Azman, Muhammad Az-zuhri

    2017-05-01

    This study aims to model the spatial extreme daily rainfall process using the max-stable model. The max-stable model is used to capture the dependence structure of spatial properties of extreme rainfall. Three models from max-stable are considered namely Smith, Schlather and Brown-Resnick models. The methods are applied on 12 selected rainfall stations in Kelantan, Malaysia. Most of the extreme rainfall data occur during wet season from October to December of 1971 to 2012. This period is chosen to assure the available data is enough to satisfy the assumption of stationarity. The dependence parameters including the range and smoothness, are estimated using composite likelihood approach. Then, the bootstrap approach is applied to generate synthetic extreme rainfall data for all models using the estimated dependence parameters. The goodness of fit between the observed extreme rainfall and the synthetic data is assessed using the composite likelihood information criterion (CLIC). Results show that Schlather model is the best followed by Brown-Resnick and Smith models based on the smallest CLIC's value. Thus, the max-stable model is suitable to be used to model extreme rainfall in Kelantan. The study on spatial dependence in extreme rainfall modelling is important to reduce the uncertainties of the point estimates for the tail index. If the spatial dependency is estimated individually, the uncertainties will be large. Furthermore, in the case of joint return level is of interest, taking into accounts the spatial dependence properties will improve the estimation process.

  7. Irrigation mitigates against heat extremes

    NASA Astrophysics Data System (ADS)

    Thiery, Wim; Fischer, Erich; Visser, Auke; Hirsch, Annette L.; Davin, Edouard L.; Lawrence, Dave; Hauser, Mathias; Seneviratne, Sonia I.

    2017-04-01

    Irrigation is an essential practice for sustaining global food production and many regional economies. Emerging scientific evidence indicates that irrigation substantially affects mean climate conditions in different regions of the world. Yet how this practice influences climate extremes is currently unknown. Here we use gridded observations and ensemble simulations with the Community Earth System Model to assess the impacts of irrigation on climate extremes. While the influence of irrigation on annual mean temperatures is limited, we find a large impact on temperature extremes, with a particularly strong cooling during the hottest day of the year (-0.78 K averaged over irrigated land). The strong influence on hot extremes stems from the timing of irrigation and its influence on land-atmosphere coupling strength. Together these effects result in asymmetric temperature responses, with a more pronounced cooling during hot and/or dry periods. The influence of irrigation is even more pronounced when considering subgrid-scale model output, suggesting that local effects of land management are far more important than previously thought. Finally we find that present-day irrigation is partly masking GHG-induced warming of extreme temperatures, with particularly strong effects in South Asia. Our results overall underline that irrigation substantially reduces our exposure to hot temperature extremes and highlight the need to account for irrigation in future climate projections.

  8. Extreme Environments Rig

    NASA Image and Video Library

    2013-08-13

    The Glenn Extreme Environment Chamber (GEER) simulates the extreme conditions found in space and tests many devices that will explore Venus to see if they can withstand the punishing environment and temperatures over 800 degrees F.

  9. Astrobiology: Life in Extreme Environments

    ERIC Educational Resources Information Center

    Kaur, Preeti

    2011-01-01

    Astrobiology is the study of the origin, evolution and distribution of life in the universe. It seeks to answer two important scientific questions: how did we get here and are we alone in the universe? Scientists begin by studying life on Earth and its limits. The discovery of extremophiles on Earth capable of surviving extremes encourages the…

  10. Astrobiology: Life in Extreme Environments

    ERIC Educational Resources Information Center

    Kaur, Preeti

    2011-01-01

    Astrobiology is the study of the origin, evolution and distribution of life in the universe. It seeks to answer two important scientific questions: how did we get here and are we alone in the universe? Scientists begin by studying life on Earth and its limits. The discovery of extremophiles on Earth capable of surviving extremes encourages the…

  11. Extreme Scale Visual Analytics

    SciTech Connect

    Wong, Pak C.; Shen, Han-Wei; Pascucci, Valerio

    2012-05-08

    Extreme-scale visual analytics (VA) is about applying VA to extreme-scale data. The articles in this special issue examine advances related to extreme-scale VA problems, their analytical and computational challenges, and their real-world applications.

  12. Legacies from extreme drought increase ecosystem sensitivity to future extremes

    NASA Astrophysics Data System (ADS)

    Smith, M. D.; Knapp, A.; Hoover, D. L.; Avolio, M. L.; Felton, A. J.; Wilcox, K. R.

    2016-12-01

    Climate extremes, such as drought, are increasing in frequency and intensity, and the ecological consequences of these extreme events can be substantial and widespread. Although there is still much to be learned about how ecosystems will respond to an intensification of drought, even less is known about the factors that determine post-drought recovery of ecosystem function. Such knowledge is particularly important because post-drought recovery periods can be protracted depending on the extent to which key plant populations, community structure and biogeochemical processes are affected. These drought legacies may alter ecosystem function for many years post-drought and may impact future sensitivity to climate extremes. We experimentally imposed two extreme growing season droughts in a central US grassland to assess the impacts of repeated droughts on ecosystem resistance (response) and resilience (recovery). We found that this grassland was not resistant to the first extreme drought due to reduced productivity and differential sensitivity of the co-dominant C4 grass (Andropogon gerardii) and C3 forb (Solidago canadensis) species. This differential sensitivity led to a reordering of species abundances within the plant community. Yet, despite this large shift in plant community composition, which persisted post-drought, the grassland was highly resilient post-drought, due to increased abundance of the dominant C4 grass. Because of this shift to increased C4 grass dominance, we expected that previously-droughted grassland would be more resistant to a second extreme drought. However, contrary to these expectations, previously droughted grassland was more sensitive to drought than grassland that had not experienced drought. Thus, our result suggest that legacies of drought (shift in community composition) may increase ecosystem sensitivity to future extreme events.

  13. Book review: Extreme ocean waves

    USGS Publications Warehouse

    Geist, Eric L.

    2017-01-01

    Extreme Ocean Waves”, edited by E. Pelinovsky and C. Kharif, second edition, Springer International Publishing, 2016; ISBN: 978-3-319-21574-7, ISBN (eBook): 978-3-319-21575-4The second edition of “Extreme Ocean Waves” published by Springer is an update of a collection of 12 papers edited by Efim Pelinovsky and Christian Kharif following the April 2007 meeting of the General Assembly of the European Geosciences Union. In this edition, three new papers have been added and three more have been substantially revised. Color figures are now included, which greatly aids in reading several of the papers, and is especially helpful in visualizing graphs as in the paper on symbolic computation of nonlinear wave resonance (Tobisch et al.). A note on terminology: extreme waves in this volume broadly encompass different types of waves, including deep-water and shallow-water rogue waves (which are alternatively termed freak waves), and internal waves. One new paper on tsunamis (Viroulet et al.) is now included in the second edition of this volume. Throughout the book, the reader will find a combination of laboratory, theoretical, and statistical/empirical treatment necessary for the complete examination of this subject. In the Introduction, the editors underscore the importance of studying extreme waves, documenting a dramatic instance of damaging extreme waves that recently occurred in 2014.

  14. Extreme lattices: symmetries and decorrelation

    NASA Astrophysics Data System (ADS)

    Andreanov, A.; Scardicchio, A.; Torquato, S.

    2016-11-01

    We study statistical and structural properties of extreme lattices, which are the local minima in the density landscape of lattice sphere packings in d-dimensional Euclidean space {{{R}}d} . Specifically, we ascertain statistics of the densities and kissing numbers as well as the numbers of distinct symmetries of the packings for dimensions 8 through 13 using the stochastic Voronoi algorithm. The extreme lattices in a fixed dimension of space d (d≥slant 8 ) are dominated by typical lattices that have similar packing properties, such as packing densities and kissing numbers, while the best and the worst packers are in the long tails of the distribution of the extreme lattices. We also study the validity of the recently proposed decorrelation principle, which has important implications for sphere packings in general. The degree to which extreme-lattice packings decorrelate as well as how decorrelation is related to the packing density and symmetry of the lattices as the space dimension increases is also investigated. We find that the extreme lattices decorrelate with increasing dimension, while the least symmetric lattices decorrelate faster.

  15. Moving in extreme environments: what's extreme and who decides?

    PubMed

    Cotter, James David; Tipton, Michael J

    2014-01-01

    Humans work, rest and play in immensely varied extreme environments. The term 'extreme' typically refers to insufficiency or excess of one or more stressors, such as thermal energy or gravity. Individuals' behavioural and physiological capacity to endure and enjoy such environments varies immensely. Adverse effects of acute exposure to these environments are readily identifiable (e.g. heat stroke or bone fracture), whereas adverse effects of chronic exposure (e.g. stress fractures or osteoporosis) may be as important but much less discernable. Modern societies have increasingly sought to protect people from such stressors and, in that way, minimise their adverse effects. Regulations are thus established, and advice is provided on what is 'acceptable' exposure. Examples include work/rest cycles in the heat, hydration regimes, rates of ascent to and duration of stay at altitude and diving depth. While usually valuable and well intentioned, it is important to realise the breadth and importance of limitations associated with such guidelines. Regulations and advisories leave less room for self-determination, learning and perhaps adaptation. Regulations based on stress (e.g. work/rest cycles relative to WBGT) are more practical but less direct than those based on strain (e.g. core temperature), but even the latter can be substantively limited (e.g. by lack of criterion validation and allowance for behavioural regulation in the research on which they are based). Extreme Physiology & Medicine is publishing a series of reviews aimed at critically examining the issues involved with self- versus regulation-controlled human movement acutely and chronically in extreme environments. These papers, arising from a research symposium in 2013, are about the impact of people engaging in such environments and the effect of rules and guidelines on their safety, enjoyment, autonomy and productivity. The reviews will cover occupational heat stress, sporting heat stress, hydration, diving

  16. Upper Extremity Length Equalization

    PubMed Central

    DeCoster, Thomas A.; Ritterbusch, John; Crawford, Mark

    1992-01-01

    Significant upper extremity length inequality is uncommon but can cause major functional problems. The ability to position and use the hand may be impaired by shortness of any of the long bones of the upper extremity. In many respects upper and lower extremity length problems are similar. They most commonly occur after injury to a growing bone and the treatment modalities utilized in the lower extremity may be applied to the upper extremity. These treatment options include epiphysiodesis, shortening osteotomy, angulatory correction osteotomy and lengthening. This report reviews the literature relative to upper extremity length inequality and equalization and presents an algorithm for evaluation and planning appropriate treatment for patients with this condition. This algorithm is illustrated by two clinical cases of posttraumatic shortness of the radius which were effectively treated. ImagesFigure 1Figure 2Figure 3

  17. Controlling extreme events on complex networks

    NASA Astrophysics Data System (ADS)

    Chen, Yu-Zhong; Huang, Zi-Gang; Lai, Ying-Cheng

    2014-08-01

    Extreme events, a type of collective behavior in complex networked dynamical systems, often can have catastrophic consequences. To develop effective strategies to control extreme events is of fundamental importance and practical interest. Utilizing transportation dynamics on complex networks as a prototypical setting, we find that making the network ``mobile'' can effectively suppress extreme events. A striking, resonance-like phenomenon is uncovered, where an optimal degree of mobility exists for which the probability of extreme events is minimized. We derive an analytic theory to understand the mechanism of control at a detailed and quantitative level, and validate the theory numerically. Implications of our finding to current areas such as cybersecurity are discussed.

  18. Quorum Sensing in Extreme Environments

    PubMed Central

    Montgomery, Kate; Charlesworth, James C.; LeBard, Rebecca; Visscher, Pieter T.; Burns, Brendan P.

    2013-01-01

    Microbial communication, particularly that of quorum sensing, plays an important role in regulating gene expression in a range of organisms. Although this phenomenon has been well studied in relation to, for example, virulence gene regulation, the focus of this article is to review our understanding of the role of microbial communication in extreme environments. Cell signaling regulates many important microbial processes and may play a pivotal role in driving microbial functional diversity and ultimately ecosystem function in extreme environments. Several recent studies have characterized cell signaling in modern analogs to early Earth communities (microbial mats), and characterization of cell signaling systems in these communities may provide unique insights in understanding the microbial interactions involved in function and survival in extreme environments. Cell signaling is a fundamental process that may have co-evolved with communities and environmental conditions on the early Earth. Without cell signaling, evolutionary pressures may have even resulted in the extinction rather than evolution of certain microbial groups. One of the biggest challenges in extremophile biology is understanding how and why some microbial functional groups are located where logically they would not be expected to survive, and tightly regulated communication may be key. Finally, quorum sensing has been recently identified for the first time in archaea, and thus communication at multiple levels (potentially even inter-domain) may be fundamental in extreme environments. PMID:25371335

  19. Extreme Velocity Wind Sensor

    NASA Technical Reports Server (NTRS)

    Perotti, Jose; Voska, Ned (Technical Monitor)

    2002-01-01

    This presentation provides an overview of the development of new hurricane wind sensor (Extreme Velocity Wind Sensor) for the Kennedy Space Center (KSC) which is designed to withstand winds of up to three hundred miles an hour. The proposed Extreme Velocity Wind Sensor contains no moveable components that would be exposed to extreme wind conditions. Topics covered include: need for new hurricane wind sensor, conceptual design, software applications, computational fluid dynamic simulations of design concept, preliminary performance tests, and project status.

  20. 21st Birthday Drinking: Extremely Extreme

    ERIC Educational Resources Information Center

    Rutledge, Patricia C.; Park, Aesoon; Sher, Kenneth J.

    2008-01-01

    Despite public recognition of the hazards of 21st birthday drinking, there is little empirical information concerning its prevalence, severity, and risk factors. Data from a sample of 2,518 college students suggest that 21st birthday drinking poses an extreme danger: (a) 4 of every 5 participants (83%) reported drinking to celebrate, (b) birthday…

  1. 21st Birthday Drinking: Extremely Extreme

    ERIC Educational Resources Information Center

    Rutledge, Patricia C.; Park, Aesoon; Sher, Kenneth J.

    2008-01-01

    Despite public recognition of the hazards of 21st birthday drinking, there is little empirical information concerning its prevalence, severity, and risk factors. Data from a sample of 2,518 college students suggest that 21st birthday drinking poses an extreme danger: (a) 4 of every 5 participants (83%) reported drinking to celebrate, (b) birthday…

  2. Are hourly precipitation extremes increasing faster than daily precipitation extremes?

    NASA Astrophysics Data System (ADS)

    Barbero, Renaud; Fowler, Hayley; Blenkinsop, Stephen; Lenderink, Geert

    2016-04-01

    Extreme precipitation events appear to be increasing with climate change in many regions of the world, including the United States. These extreme events have large societal impacts, as seen during the recent Texas-Oklahoma flooding in May 2015 which caused several billion in damages and left 47 deaths in its path. Better understanding of past changes in the characteristics of extreme rainfall events is thus critical for reliable projections of future changes. Although it has been documented in several studies that daily precipitation extremes are increasing across parts of the contiguous United States, very few studies have looked at hourly extremes. However, this is of primary importance as recent studies on the temperature scaling of extreme precipitation have shown that increases above the Clausius-Clapeyron (~ 7% °C-1) are possible for hourly precipitation. In this study, we used hourly precipitation data (HPD) from the National Climatic Data Center and extracted more than 1,000 stations across the US with more than 40 years of data spanning the period 1950-2010. As hourly measurements are often associated with a range of issues, the data underwent multiple quality control processes to exclude erroneous data. While no significant changes were found in annual maximum precipitation using both hourly and daily resolution datasets, significant increasing trends in terms of frequency of episodes exceeding present-day 95th percentiles of wet hourly/daily precipitation were observed across a significant portion of the US. The fraction of stations with significant increasing trends falls outside the confidence interval range during all seasons but the summer. While less than 12% of stations exhibit significant trends at the daily scale in the wintertime, more than 45% of stations, mostly clustered in central and Northern United States, show significant increasing trends at the hourly scale. This suggests that short-duration storms have increased faster than daily

  3. Shear Fractures of Extreme Dynamics

    NASA Astrophysics Data System (ADS)

    Tarasov, Boris

    2016-10-01

    Natural and laboratory observations show that shear ruptures (faults) can propagate with extreme dynamics (up to intersonic rupture velocities) through intact materials and along pre-existing faults with frictional and coherent (bonded) interfaces. The rupture propagation is accompanied by significant fault strength weakening in the rupture head. Although essential for understanding earthquakes, rock mechanics, tribology and fractures, the question of what physical processes determine how that weakening occurs is still unresolved. The general approach today to explain the fault weakening is based upon the strong velocity-weakening friction law according to which the fault strength drops rapidly with slip velocity. Different mechanisms of strength weakening caused by slip velocity have been proposed including thermal effect, high-frequency compressional waves, expansion of pore fluid, macroscopic melting and gel formation. This paper proposes that shear ruptures of extreme dynamics propagating in intact materials and in pre-existing frictional and coherent interfaces are governed by the same recently identified mechanism which is associated with an intensive microcracking process in the rupture tip observed for all types of extreme ruptures. The microcracking process creates, in certain conditions, a special fan-like microstructure shear resistance of which is extremely low (up to an order of magnitude less than the frictional strength). The fan-structure representing the rupture head provides strong interface weakening and causes high slip and rupture velocities. In contrast with the velocity-weakening dependency, this mechanism provides the opposite weakening-velocity effect. The fan-mechanism differs remarkably from all reported earlier mechanisms, and it can provide such important features observed in extreme ruptures as: extreme slip and rupture velocities, high slip velocity without heating, off-fault tensile cracking, transition from crack-like to pulse

  4. Characteristics of Extreme Auroral Charging Events

    NASA Technical Reports Server (NTRS)

    Minow, Joseph I.; Willis, Emily; Parker, Linda Neergaard

    2014-01-01

    Today’s presentation describes preliminary results from a study of extreme auroral charging in low Earth orbit. Goal of study is to document characteristics of auroral charging events of importance to spacecraft design, operations, and anomaly investigations.

  5. Bivariate extreme value distributions

    NASA Technical Reports Server (NTRS)

    Elshamy, M.

    1992-01-01

    In certain engineering applications, such as those occurring in the analyses of ascent structural loads for the Space Transportation System (STS), some of the load variables have a lower bound of zero. Thus, the need for practical models of bivariate extreme value probability distribution functions with lower limits was identified. We discuss the Gumbel models and present practical forms of bivariate extreme probability distributions of Weibull and Frechet types with two parameters. Bivariate extreme value probability distribution functions can be expressed in terms of the marginal extremel distributions and a 'dependence' function subject to certain analytical conditions. Properties of such bivariate extreme distributions, sums and differences of paired extremals, as well as the corresponding forms of conditional distributions, are discussed. Practical estimation techniques are also given.

  6. A Millennial Challenge: Extremism in Uncertain Times.

    PubMed

    Fiske, Susan T

    2013-09-01

    This comment highlights the relevance and importance of the uncertainty-extremism topic, both scientifically and societally, identifies common themes, locates this work in a wider scientific and social context, describes what we now know and what we still do not, acknowledges some limitations, foreshadowing future directions, and discusses some potential policy relevance. Common themes emerge around the importance of social justice as sound anti-extremism policy.

  7. A Millennial Challenge: Extremism in Uncertain Times

    PubMed Central

    Fiske, Susan T.

    2014-01-01

    This comment highlights the relevance and importance of the uncertainty-extremism topic, both scientifically and societally, identifies common themes, locates this work in a wider scientific and social context, describes what we now know and what we still do not, acknowledges some limitations, foreshadowing future directions, and discusses some potential policy relevance. Common themes emerge around the importance of social justice as sound anti-extremism policy. PMID:24511155

  8. Generalized extreme gust wind speeds distributions

    USGS Publications Warehouse

    Cheng, E.; Yeung, C.

    2002-01-01

    Since summer 1996, the US wind engineers are using the extreme gust (or 3-s gust) as the basic wind speed to quantify the destruction of extreme winds. In order to better understand these destructive wind forces, it is important to know the appropriate representations of these extreme gust wind speeds. Therefore, the purpose of this study is to determine the most suitable extreme value distributions for the annual extreme gust wind speeds recorded in large selected areas. To achieve this objective, we are using the generalized Pareto distribution as the diagnostic tool for determining the types of extreme gust wind speed distributions. The three-parameter generalized extreme value distribution function is, thus, reduced to either Type I Gumbel, Type II Frechet or Type III reverse Weibull distribution function for the annual extreme gust wind speeds recorded at a specific site.With the considerations of the quality and homogeneity of gust wind data collected at more than 750 weather stations throughout the United States, annual extreme gust wind speeds at selected 143 stations in the contiguous United States were used in the study. ?? 2002 Elsevier Science Ltd. All rights reserved.

  9. Importance of transient resonances in extreme-mass-ratio inspirals

    NASA Astrophysics Data System (ADS)

    Berry, Christopher P. L.; Cole, Robert H.; Cañizares, Priscilla; Gair, Jonathan R.

    2016-12-01

    The inspiral of stellar-mass compact objects, like neutron stars or stellar-mass black holes, into supermassive black holes provides a wealth of information about the strong gravitational-field regime via the emission of gravitational waves. In order to detect and analyze these signals, accurate waveform templates which include the effects of the compact object's gravitational self-force are required. For computational efficiency, adiabatic templates are often used. These accurately reproduce orbit-averaged trajectories arising from the first-order self-force, but neglect other effects, such as transient resonances, where the radial and poloidal fundamental frequencies become commensurate. During such resonances the flux of gravitational waves can be diminished or enhanced, leading to a shift in the compact object's trajectory and the phase of the waveform. We present an evolution scheme for studying the effects of transient resonances and apply this to an astrophysically motivated population. We find that a large proportion of systems encounter a low-order resonance in the later stages of inspiral; however, the resulting effect on signal-to-noise recovery is small as a consequence of the low eccentricity of the inspirals. Neglecting the effects of transient resonances leads to a loss of 4% of detectable signals.

  10. Extremal surface barriers

    NASA Astrophysics Data System (ADS)

    Engelhardt, Netta; Wall, Aron C.

    2014-03-01

    We present a generic condition for Lorentzian manifolds to have a barrier that limits the reach of boundary-anchored extremal surfaces of arbitrary dimension. We show that any surface with nonpositive extrinsic curvature is a barrier, in the sense that extremal surfaces cannot be continuously deformed past it. Furthermore, the outermost barrier surface has nonnegative extrinsic curvature. Under certain conditions, we show that the existence of trapped surfaces implies a barrier, and conversely. In the context of AdS/CFT, these barriers imply that it is impossible to reconstruct the entire bulk using extremal surfaces. We comment on the implications for the firewall controversy.

  11. Extreme environments and exobiology

    NASA Technical Reports Server (NTRS)

    Friedmann, E. I.

    1993-01-01

    Ecological research on extreme environments can be applied to exobiological problems such as the question of life on Mars. If life forms (fossil or extant) are found on Mars, their study will help to solve fundamental questions about the nature of life on Earth. Extreme environments that are beyond the range of adaptability of their inhabitants are defined as "absolute extreme". Such environments can serve as terrestrial models for the last stages of life in the history of Mars, when the surface cooled down and atmosphere and water disappeared. The cryptoendolithic microbial community in porous rocks of the Ross Desert in Antarctica and the microbial mats at the bottom of frozen Antarctic lakes are such examples. The microbial communities of Siberian permafrost show that, in frozen but stable communities, long-term survival is possible. In the context of terraforming Mars, selected microorganisms isolated from absolute extreme environments are considered for use in creation of a biological carbon cycle.

  12. Survival of extreme opinions

    NASA Astrophysics Data System (ADS)

    Hsu, Jiann-wien; Huang, Ding-wei

    2009-12-01

    We study the survival of extreme opinions in various processes of consensus formation. All the opinions are treated equally and subjected to the same rules of changing. We investigate three typical models to reach a consensus in each case: (A) personal influence, (B) influence from surroundings, and (C) influence to surroundings. Starting with uniformly distributed random opinions, our calculated results show that the extreme opinions can survive in both models (A) and (B), but not in model (C). We obtain a conclusion that both personal influence and passive adaptation to the environment are not sufficient enough to eradicate all the extreme opinions. Only the active persuasion to change the surroundings eliminates the extreme opinions completely.

  13. Extreme environments and exobiology.

    PubMed

    Friedmann, E I

    1993-01-01

    Ecological research on extreme environments can be applied to exobiological problems such as the question of life on Mars. If life forms (fossil or extant) are found on Mars, their study will help to solve fundamental questions about the nature of life on Earth. Extreme environments that are beyond the range of adaptability of their inhabitants are defined as "absolute extreme". Such environments can serve as terrestrial models for the last stages of life in the history of Mars, when the surface cooled down and atmosphere and water disappeared. The cryptoendolithic microbial community in porous rocks of the Ross Desert in Antarctica and the microbial mats at the bottom of frozen Antarctic lakes are such examples. The microbial communities of Siberian permafrost show that, in frozen but stable communities, long-term survival is possible. In the context of terraforming Mars, selected microorganisms isolated from absolute extreme environments are considered for use in creation of a biological carbon cycle.

  14. Extreme environments and exobiology

    NASA Technical Reports Server (NTRS)

    Friedmann, E. I.

    1993-01-01

    Ecological research on extreme environments can be applied to exobiological problems such as the question of life on Mars. If life forms (fossil or extant) are found on Mars, their study will help to solve fundamental questions about the nature of life on Earth. Extreme environments that are beyond the range of adaptability of their inhabitants are defined as "absolute extreme". Such environments can serve as terrestrial models for the last stages of life in the history of Mars, when the surface cooled down and atmosphere and water disappeared. The cryptoendolithic microbial community in porous rocks of the Ross Desert in Antarctica and the microbial mats at the bottom of frozen Antarctic lakes are such examples. The microbial communities of Siberian permafrost show that, in frozen but stable communities, long-term survival is possible. In the context of terraforming Mars, selected microorganisms isolated from absolute extreme environments are considered for use in creation of a biological carbon cycle.

  15. Extreme Programming: Maestro Style

    NASA Technical Reports Server (NTRS)

    Norris, Jeffrey; Fox, Jason; Rabe, Kenneth; Shu, I-Hsiang; Powell, Mark

    2009-01-01

    "Extreme Programming: Maestro Style" is the name of a computer programming methodology that has evolved as a custom version of a methodology, called extreme programming that has been practiced in the software industry since the late 1990s. The name of this version reflects its origin in the work of the Maestro team at NASA's Jet Propulsion Laboratory that develops software for Mars exploration missions. Extreme programming is oriented toward agile development of software resting on values of simplicity, communication, testing, and aggressiveness. Extreme programming involves use of methods of rapidly building and disseminating institutional knowledge among members of a computer-programming team to give all the members a shared view that matches the view of the customers for whom the software system is to be developed. Extreme programming includes frequent planning by programmers in collaboration with customers, continually examining and rewriting code in striving for the simplest workable software designs, a system metaphor (basically, an abstraction of the system that provides easy-to-remember software-naming conventions and insight into the architecture of the system), programmers working in pairs, adherence to a set of coding standards, collaboration of customers and programmers, frequent verbal communication, frequent releases of software in small increments of development, repeated testing of the developmental software by both programmers and customers, and continuous interaction between the team and the customers. The environment in which the Maestro team works requires the team to quickly adapt to changing needs of its customers. In addition, the team cannot afford to accept unnecessary development risk. Extreme programming enables the Maestro team to remain agile and provide high-quality software and service to its customers. However, several factors in the Maestro environment have made it necessary to modify some of the conventional extreme

  16. Electronics for Extreme Environments

    NASA Technical Reports Server (NTRS)

    Patel, J. U.; Cressler, J.; Li, Y.; Niu, G.

    2001-01-01

    Most of the NASA missions involve extreme environments comprising radiation and low or high temperatures. Current practice of providing friendly ambient operating environment to electronics costs considerable power and mass (for shielding). Immediate missions such as the Europa orbiter and lander and Mars landers require the electronics to perform reliably in extreme conditions during the most critical part of the mission. Some other missions planned in the future also involve substantial surface activity in terms of measurements, sample collection, penetration through ice and crust and the analysis of samples. Thus it is extremely critical to develop electronics that could reliably operate under extreme space environments. Silicon On Insulator (SOI) technology is an extremely attractive candidate for NASA's future low power and high speed electronic systems because it offers increased transconductance, decreased sub-threshold slope, reduced short channel effects, elimination of kink effect, enhanced low field mobility, and immunity from radiation induced latch-up. A common belief that semiconductor devices function better at low temperatures is generally true for bulk devices but it does not hold true for deep sub-micron SOI CMOS devices with microscopic device features of 0.25 micrometers and smaller. Various temperature sensitive device parameters and device characteristics have recently been reported in the literature. Behavior of state of the art technology devices under such conditions needs to be evaluated in order to determine possible modifications in the device design for better performance and survivability under extreme environments. Here, we present a unique approach of developing electronics for extreme environments to benefit future NASA missions as described above. This will also benefit other long transit/life time missions such as the solar sail and planetary outposts in which electronics is out open in the unshielded space at the ambient space

  17. Deep venous thrombosis of the upper extremity.

    PubMed

    Stephens, M B

    1997-02-01

    Deep venous thrombosis (DVT) of the upper extremity is a relatively uncommon but important cause of morbidity, especially in young active persons. The causes of upper extremity DVT may be categorized as catheter-related, spontaneous (effort-related) and miscellaneous (e.g., trauma, intravenous drug use). Diagnosis is based on clinical history and confirmed by either duplex ultrasonography or contrast venography. Significant controversy surrounds the optimal management of upper extremity DVT. Treatment options include conservative therapy, anticoagulation, catheter-directed thrombolysis and surgical intervention to remove intravascular clot or revise the anatomy of the costoclavicular space. Early aggressive treatment of active young patients may decrease long-term morbidity.

  18. 21st Birthday Drinking: Extremely Extreme

    PubMed Central

    Rutledge, Patricia C.; Park, Aesoon; Sher, Kenneth J.

    2009-01-01

    Despite public recognition of the hazards of 21st birthday drinking, there is little empirical information concerning its prevalence, severity, and risk factors. Data from a sample of 2,518 college students suggest that 21st birthday drinking poses an extreme danger: (a) 4 of every 5 participants (83%) reported drinking to celebrate, (b) birthday drinkers indicated high levels of consumption, (c) 12% of birthday drinkers (men and women) reported consuming 21 drinks, and (d) about half of birthday drinkers exceeded their prior maximum number of drinks. Current problematic alcohol involvement and its typical correlates strongly predicted both the occurrence and severity of 21st birthday drinking. It is imperative that investigators consider a variety of potential interventions to minimize the harm associated with this rite of passage. PMID:18540744

  19. Typologies of Extreme Longevity Myths

    PubMed Central

    Young, Robert D.; Desjardins, Bertrand; McLaughlin, Kirsten; Poulain, Michel; Perls, Thomas T.

    2010-01-01

    Purpose. Political, national, religious, and other motivations have led the media and even scientists to errantly accept extreme longevity claims prima facie. We describe various causes of false claims of extraordinary longevity. Design and Methods. American Social Security Death Index files for the period 1980–2009 were queried for individuals with birth and death dates yielding ages 110+ years of age. Frequency was compared to a list of age-validated supercentenarians maintained by the Gerontology Research Group who died during the same time period. Age claims of 110+ years and the age validation experiences of the authors facilitated a list of typologies of false age claims. Results. Invalid age claim rates increase with age from 65% at age 110-111 to 98% by age 115 to 100% for 120+ years. Eleven typologies of false claims were: Religious Authority Myth, Village Elder Myth, Fountain of Youth Myth (substance), Shangri-La Myth (geographic), Nationalist Pride, Spiritual Practice, Familial Longevity, Individual and/or Family Notoriety, Military Service, Administrative Entry Error, and Pension-Social Entitlement Fraud. Conclusions. Understanding various causes of false extreme age claims is important for placing current, past, and future extreme longevity claims in context and for providing a necessary level of skepticism. PMID:21461047

  20. Typologies of extreme longevity myths.

    PubMed

    Young, Robert D; Desjardins, Bertrand; McLaughlin, Kirsten; Poulain, Michel; Perls, Thomas T

    2010-01-01

    Purpose. Political, national, religious, and other motivations have led the media and even scientists to errantly accept extreme longevity claims prima facie. We describe various causes of false claims of extraordinary longevity. Design and Methods. American Social Security Death Index files for the period 1980-2009 were queried for individuals with birth and death dates yielding ages 110+ years of age. Frequency was compared to a list of age-validated supercentenarians maintained by the Gerontology Research Group who died during the same time period. Age claims of 110+ years and the age validation experiences of the authors facilitated a list of typologies of false age claims. Results. Invalid age claim rates increase with age from 65% at age 110-111 to 98% by age 115 to 100% for 120+ years. Eleven typologies of false claims were: Religious Authority Myth, Village Elder Myth, Fountain of Youth Myth (substance), Shangri-La Myth (geographic), Nationalist Pride, Spiritual Practice, Familial Longevity, Individual and/or Family Notoriety, Military Service, Administrative Entry Error, and Pension-Social Entitlement Fraud. Conclusions. Understanding various causes of false extreme age claims is important for placing current, past, and future extreme longevity claims in context and for providing a necessary level of skepticism.

  1. Adventure and Extreme Sports.

    PubMed

    Gomez, Andrew Thomas; Rao, Ashwin

    2016-03-01

    Adventure and extreme sports often involve unpredictable and inhospitable environments, high velocities, and stunts. These activities vary widely and include sports like BASE jumping, snowboarding, kayaking, and surfing. Increasing interest and participation in adventure and extreme sports warrants understanding by clinicians to facilitate prevention, identification, and treatment of injuries unique to each sport. This article covers alpine skiing and snowboarding, skateboarding, surfing, bungee jumping, BASE jumping, and whitewater sports with emphasis on epidemiology, demographics, general injury mechanisms, specific injuries, chronic injuries, fatality data, and prevention. Overall, most injuries are related to overuse, trauma, and environmental or microbial exposure. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Occult fractures of extremities.

    PubMed

    Ahn, Joong Mo; El-Khoury, Georges Y

    2007-05-01

    Recent advances in cross-sectional imaging, particularly in CT and MR imaging, have given these modalities a prominent role in the diagnosis of fractures of the extremities. This article describes the clinical application and imaging features of cross-sectional imaging (CT and MR imaging) in the evaluation of patients who have occult fractures of the extremities. Although CT or MR imaging is not typically required for evaluation of acute fractures, these modalities could be helpful in the evaluation of the occult osseous injuries in which radiographic findings are equivocal or inconclusive.

  3. Extreme black hole holography

    NASA Astrophysics Data System (ADS)

    Hartman, Thomas Edward

    The connection between black holes in four dimensions and conformal field theories (CFTs) in two dimensions is explored, focusing on zero temperature (extreme) black holes and their low-temperature cousins. It is shown that extreme black holes in a theory of quantum gravity are holographically dual to field theories living in two dimensions without gravity, and that the field theory reproduces a variety of black hole phenomena in detail. The extreme black hole/CFT correspondence is derived from a symmetry analysis near the horizon of a Kerr black hole with mass M and maximal angular momentum J=M 2. The asymptotic symmetry generators form one copy of the Virasoro algebra with central charge c=12J, which implies that the near-horizon quantum states are identical to those of a two-dimensional CFT. We discuss extensions of this result to near-extreme black holes and cosmological horizons. Astrophysical black holes are never exactly extremal, but the black hole GRS1915+105 observed through X-ray and radio telescopy is likely within 1% of the extremal spin, suggesting that this extraordinary and well studied object is approximately dual to a two-dimensional CFT with c˜1079. As evidence for the correspondence, microstate counting in the CFT is used to derive the Bekenstein-Hawking area law for the Kerr entropy, S=Horizon area/4. Furthermore, the correlators in the dual CFT are shown to reproduce the scattering amplitudes of a charged scalar or spin-½ field by a near-extreme Kerr-Newman black hole, and a neutral spin-1 or spin-2 field by a near-extreme Kerr black hole. Scattering amplitudes probe the vacuum of fields living on the black hole background. For scalars, bound superradiant modes lead to an instability, while for fermions, it is shown that the bound superradiant modes condense and form a Fermi sea which extends well outside the ergosphere. Assuming no further instabilities, the low energy effective theory near the black hole is described by ripples in the

  4. Book review: New concepts and discoveries: the Geological Society of Nevada 2015 Symposium Proceedings

    USGS Publications Warehouse

    Day, Warren C.

    2016-01-01

    The Nevada Geological Society has a long history of convening meetings and workshops focused on the geology and metallogeny of the western United States relevant to the mineral exploration and mining community across the Great Basin. One outgrowth of the Geological Society of Nevada’s 2015 Symposium is a two-volume set, edited by W.M. Pennell and L.J. Garside, entitled New Concepts and Discoveries. The symposium was held in Sparks, Nevada, May 14–23, 2015, with more than 1,000 attendees, 59 talks in 10 thematic sessions, 7 field trips, and 10 short courses, all focused on serving the geologic, exploration, and mining community. The attractively produced, hardbound, two-volume set includes a CD-ROM containing all the manuscripts as well as numerous abstracts from presentations arranged by the thematic session in which they were presented. The papers range from detailed case study descriptions of individual deposits to important syntheses covering the geologic evolution and resulting metallogeny of the Great Basin and beyond.

  5. Important plasma problems in astrophysics

    SciTech Connect

    Kulsrud, R.M.

    1995-01-01

    In astrophysics, plasmas occur under very extreme conditions. For example there are ultra strong magnetic fields in neutron stars) relativistic plasmas around black holes and in jets, extremely energetic particles such as cosmic rays in the interstellar medium, extremely dense plasmas in accretion disks, and extremely large magnetic Reynold`s numbers in the interstellar medium. These extreme limits for astrophysical plasmas make plasma phenomena much simpler to analyze in astrophysics than in the laboratory. An understanding of such phenomena often results in an interesting way, by simply taking the extreme limiting case of a known plasma theory. I will describe one of the more exciting examples. I will attempt to convey the excitement I felt when I was first exposed to it. However, not all plasma astrophysical phenomena are so simple. There are certain important plasma phenomena in astrophysics, which have not been so easily resolved. In fact a resolution of them is blocking significant progress in astrophysical research. They have not yet yielded to attacks by theoretical astrophysicists nor to extensive numerical simulation. I will attempt to describe one of the more important of these plasma-astrophysical problems, and discuss why its resolution is so important to astrophysics. This significant example is fast, magnetic reconnection. Another significant example is the large-magnetic-Reynold`s-number MHD dynamos.

  6. Imported malaria.

    PubMed

    Schultz, M G

    1974-01-01

    There have been 4 waves of imported malaria in the USA. They occurred during the colonization of the country and during the Second World War, the UN Police Action in Korea, and the Viet-Nam conflict. The first 3 episodes are briefly described and the data on imported malaria from Viet-Nam are discussed in detail.Endemic malaria is resurgent in many tropical countries and international travel is also on the rise. This increases the likelihood of malaria being imported from an endemic area and introduced into a receptive area. The best defence for countries threatened by imported malaria is a vigorous surveillance programme. The principles of surveillance are discussed and an example of their application is provided by a description of the methods used to conduct surveillance of malaria in the USA.

  7. Astron extreme lightweighting

    NASA Astrophysics Data System (ADS)

    Tromp, Niels; Drost, Marco; Pragt, Johan

    2004-09-01

    Producing extreme light weighted structures by combining a new design concept with the most recent production machines and production software tools. Weight reductions of up to 50% compared to the traditional techniques are feasible with the same stiffness performance. Suitable for standard materials like aluminium and steel, for single construction parts out of mono material and with a single production process. Astronomical instruments for space applications and ground-based applications require more and more extreme light and extreme stiff structures. The traditional technique like 3-axis or multisided machining of metal parts seems limited and not suitable for the next generation instruments. New materials with new production technologies are used more and more with all their specialties and restrictions. ASTRON developed a new structural design of traditional materials with heritage optimized for production with the most recent milling machines. The structural shapes are closely linked to the extremes of 5-axis simultaneous milling. The design and production process is patented and now free for publication.

  8. Injuries in extreme sports.

    PubMed

    Laver, Lior; Pengas, Ioannis P; Mei-Dan, Omer

    2017-04-18

    Extreme sports (ES) are usually pursued in remote locations with little or no access to medical care with the athlete competing against oneself or the forces of nature. They involve high speed, height, real or perceived danger, a high level of physical exertion, spectacular stunts, and heightened risk element or death.Popularity for such sports has increased exponentially over the past two decades with dedicated TV channels, Internet sites, high-rating competitions, and high-profile sponsors drawing more participants.Recent data suggest that the risk and severity of injury in some ES is unexpectedly high. Medical personnel treating the ES athlete need to be aware there are numerous differences which must be appreciated between the common traditional sports and this newly developing area. These relate to the temperament of the athletes themselves, the particular epidemiology of injury, the initial management following injury, treatment decisions, and rehabilitation.The management of the injured extreme sports athlete is a challenge to surgeons and sports physicians. Appropriate safety gear is essential for protection from severe or fatal injuries as the margins for error in these sports are small.The purpose of this review is to provide an epidemiologic overview of common injuries affecting the extreme athletes through a focus on a few of the most popular and exciting extreme sports.

  9. USACE Extreme Sea levels

    DTIC Science & Technology

    2014-03-14

    will discuss with Jason Engle and determine the best way to proceed. • Kate will provide a copy of the storm climate analysis report that Andy Garcia ...Kossin J, Luo Y, Marengo J, McInnes K, Rahimi M, Reichstein M, Sorteberg A, Vera C, Zhang X (2012) Changes in climate extremes and their impacts on the

  10. Climate extremes and the carbon cycle (Invited)

    NASA Astrophysics Data System (ADS)

    Reichstein, M.; Bahn, M.; Ciais, P.; Mahecha, M. D.; Seneviratne, S. I.; Zscheischler, J.

    2013-12-01

    The terrestrial biosphere is a key component of the global carbon cycle and its carbon balance is strongly influenced by climate. Ongoing environmental changes are thought to increase global terrestrial carbon uptake. But evidence is mounting that rare climate extremes can lead to a decrease in ecosystem carbon stocks and therefore have the potential to negate the expected increase in terrestrial carbon uptake. Here we explore the mechanisms and impacts of climate extremes on the terrestrial carbon cycle, and propose a pathway to improve our understanding of present and future impacts of climate extremes on the terrestrial carbon budget. In addition to direct impact on the carbon fluxes of photosynthesis and respiration via extreme temperature and (or) drought, effects of extreme events may also lead to lagged responses, such as wildfires triggered by heat waves and droughts, or pest and pathogen outbreaks following wind-throw caused by heavy storms, reduced plant health due to drought stress or due to less frequent cold extremes in presently cold regions. One extreme event can potentially override accumulated previous carbon sinks, as shown by the Western European 2003 heat wave.. Extreme events have the potential to affect the terrestrial ecosystem carbon balance through a single factor, or as a combination of factors. Climate extremes can cause carbon losses from accumulated stocks, as well as long-lasting impacts on (e.g. lagged effects) on plant growth and mortality, extending beyond the duration of the extreme event itself. The sensitivity of terrestrial ecosystems and their carbon balance to climate change and extreme events varies according to the type of extreme, the climatic region, the land cover, and the land management. Extreme event impacts are very relevant in forests due to the importance of lagged and memory effects on tree growth and mortality, the longevity of tree species, the large forest carbon stocks and their vulnerability, as well as the

  11. Comparison of spatial extreme value models for snow depth extremes in Austria

    NASA Astrophysics Data System (ADS)

    Schellander, Harald; Hell, Tobias

    2017-04-01

    In Alpine regions like Austria a spatial representation of extreme snow depth is of crucial importance for numerous purposes such as the designing of construction projects. Extreme value theory builds the well-established foundation of modeling extremes. Two different approaches for the spatial modeling of snow depth extremes have been extensively investigated lately: Smooth Spatial Modeling (Blanchet and Lehning, 2010) and different classes of max-stable processes (Blanchet and Davison, 2011; Nicolet et al., 2015), both outperforming classical interpolation techniques. While max-stable models are generally considered as improvement over smooth modeling, the methods have not been compared in the context of extreme snow depth. In the present study a great variety of different GEV models is fitted to seasonal snow depth maxima measured at more than 200 Austrian weather stations. Return levels of smooth spatial models and several max-stable representations (Schlather, Brown-Resnick, Geometric Gaussian, Extremal-t) and covariance models (Powered Exponential, Brown, Whittle-Matern), also allowing for anisotropic extremal dependence are compared by a modified Anderson-Darling score and a normalized RMSE. Preliminary results show, that for snow depth extremes in Austria smooth spatial modeling and a version with extremal coefficients as covariates deliver slightly better scores than (an)-isotropic max-stable models.

  12. Extreme weather events and infectious disease outbreaks

    PubMed Central

    McMichael, Anthony J

    2015-01-01

    Human-driven climatic changes will fundamentally influence patterns of human health, including infectious disease clusters and epidemics following extreme weather events. Extreme weather events are projected to increase further with the advance of human-driven climate change. Both recent and historical experiences indicate that infectious disease outbreaks very often follow extreme weather events, as microbes, vectors and reservoir animal hosts exploit the disrupted social and environmental conditions of extreme weather events. This review article examines infectious disease risks associated with extreme weather events; it draws on recent experiences including Hurricane Katrina in 2005 and the 2010 Pakistan mega-floods, and historical examples from previous centuries of epidemics and ‘pestilence’ associated with extreme weather disasters and climatic changes. A fuller understanding of climatic change, the precursors and triggers of extreme weather events and health consequences is needed in order to anticipate and respond to the infectious disease risks associated with human-driven climate change. Post-event risks to human health can be constrained, nonetheless, by reducing background rates of persistent infection, preparatory action such as coordinated disease surveillance and vaccination coverage, and strengthened disaster response. In the face of changing climate and weather conditions, it is critically important to think in ecological terms about the determinants of health, disease and death in human populations. PMID:26168924

  13. Extraction method of extreme rainfall data

    NASA Astrophysics Data System (ADS)

    Zakaria, Roslinazairimah; Radi, Noor Fadhilah Ahmad; Zanariah Satari, Siti

    2017-09-01

    This study is aimed to describe step by step procedure in extracting extreme rainfall data series. Basically, the extraction of extreme rainfall data can be achieved using two methods, block maxima (BM) and peak over threshold (POT) methods. The BM method considers extracting the extreme rainfall data recorded each year during a specific duration, meanwhile the POT method is extracting all extreme rainfall data above a predefined threshold. Using the BM method, the regional pooling of 1-, 3-, 5- and 10-day are used and the maximum rainfall data are chosen among the pooled day within each year. For POT method, two methods are presented. Method 1 of POT method determines a threshold based on 95% percentile while Method 2 determines the threshold graphically using mean residual life plot and threshold stability plot. Based on the selection of the threshold value, a simulation study is conducted to identify the range of appropriate quantile estimate for a proper selection of the threshold value. For illustration of the methodology, daily rainfall data from the rainfall station at Klinik Chalok Barat, Terengganu is chosen. Both methods used are able to identify the extreme rainfall series. This study is important as it helps in identifying the good set of extreme rainfall series for further use such as in extreme rainfall modelling.

  14. Extreme weather events and infectious disease outbreaks.

    PubMed

    McMichael, Anthony J

    2015-01-01

    Human-driven climatic changes will fundamentally influence patterns of human health, including infectious disease clusters and epidemics following extreme weather events. Extreme weather events are projected to increase further with the advance of human-driven climate change. Both recent and historical experiences indicate that infectious disease outbreaks very often follow extreme weather events, as microbes, vectors and reservoir animal hosts exploit the disrupted social and environmental conditions of extreme weather events. This review article examines infectious disease risks associated with extreme weather events; it draws on recent experiences including Hurricane Katrina in 2005 and the 2010 Pakistan mega-floods, and historical examples from previous centuries of epidemics and 'pestilence' associated with extreme weather disasters and climatic changes. A fuller understanding of climatic change, the precursors and triggers of extreme weather events and health consequences is needed in order to anticipate and respond to the infectious disease risks associated with human-driven climate change. Post-event risks to human health can be constrained, nonetheless, by reducing background rates of persistent infection, preparatory action such as coordinated disease surveillance and vaccination coverage, and strengthened disaster response. In the face of changing climate and weather conditions, it is critically important to think in ecological terms about the determinants of health, disease and death in human populations.

  15. Controlling extreme events on complex networks

    PubMed Central

    Chen, Yu-Zhong; Huang, Zi-Gang; Lai, Ying-Cheng

    2014-01-01

    Extreme events, a type of collective behavior in complex networked dynamical systems, often can have catastrophic consequences. To develop effective strategies to control extreme events is of fundamental importance and practical interest. Utilizing transportation dynamics on complex networks as a prototypical setting, we find that making the network “mobile” can effectively suppress extreme events. A striking, resonance-like phenomenon is uncovered, where an optimal degree of mobility exists for which the probability of extreme events is minimized. We derive an analytic theory to understand the mechanism of control at a detailed and quantitative level, and validate the theory numerically. Implications of our finding to current areas such as cybersecurity are discussed. PMID:25131344

  16. Materials in extreme environments.

    SciTech Connect

    Hemley, R. J.; Crabtree, G. W.; Buchanan, M. V.; Materials Science Division; Geophysical Lab.; ORNL

    2009-11-01

    Nature is rich with examples of phenomena and environments we might consider extreme, at least from our familiar experience on Earth's surface: large fluxes of radiation and particles from the Sun, explosive asteroid collisions in space, volcanic eruptions that originate deep underground, extraordinary pressures and temperatures in the interiors of planets and stars, and electromagnetic discharges that occur, say, in sunspots and pulsars. We often intentionally create similar extreme environments - for example, in high-powered lasers, high-temperature turbines, internal-combustion engines, and industrial chemical plants. The response of materials to the broad range of such environments signals the materials underlying structure and dynamics, provides insight into new phenomena, exposes failure modes that limit technological possibility, and presents novel routes for making new materials.

  17. Extremal quantum cloning machines

    NASA Astrophysics Data System (ADS)

    Chiribella, G.; D'Ariano, G. M.; Perinotti, P.; Cerf, N. J.

    2005-10-01

    We investigate the problem of cloning a set of states that is invariant under the action of an irreducible group representation. We then characterize the cloners that are extremal in the convex set of group covariant cloning machines, among which one can restrict the search for optimal cloners. For a set of states that is invariant under the discrete Weyl-Heisenberg group, we show that all extremal cloners can be unitarily realized using the so-called double-Bell states, whence providing a general proof of the popular ansatz used in the literature for finding optimal cloners in a variety of settings. Our result can also be generalized to continuous-variable optimal cloning in infinite dimensions, where the covariance group is the customary Weyl-Heisenberg group of displacements.

  18. Extremal quantum cloning machines

    SciTech Connect

    Chiribella, G.; D'Ariano, G. M.; Perinotti, P.; Cerf, N.J.

    2005-10-15

    We investigate the problem of cloning a set of states that is invariant under the action of an irreducible group representation. We then characterize the cloners that are extremal in the convex set of group covariant cloning machines, among which one can restrict the search for optimal cloners. For a set of states that is invariant under the discrete Weyl-Heisenberg group, we show that all extremal cloners can be unitarily realized using the so-called double-Bell states, whence providing a general proof of the popular ansatz used in the literature for finding optimal cloners in a variety of settings. Our result can also be generalized to continuous-variable optimal cloning in infinite dimensions, where the covariance group is the customary Weyl-Heisenberg group of displacement000.

  19. Lower extremity venous reflux

    PubMed Central

    Baliyan, Vinit; Tajmir, Shahein; Ganguli, Suvranu; Prabhakar, Anand M.

    2016-01-01

    Venous incompetence in the lower extremity is a common clinical problem. Basic understanding of venous anatomy, pathophysiologic mechanisms of venous reflux is essential for choosing the appropriate treatment strategy. The complex interplay of venous pressure, abdominal pressure, venous valvular function and gravitational force determine the venous incompetence. This review is intended to provide a succinct review of the pathophysiology of venous incompetence and the current role of imaging in its management. PMID:28123974

  20. Extreme geomagnetically induced currents

    NASA Astrophysics Data System (ADS)

    Kataoka, Ryuho; Ngwira, Chigomezyo

    2016-12-01

    We propose an emergency alert framework for geomagnetically induced currents (GICs), based on the empirically extreme values and theoretical upper limits of the solar wind parameters and of d B/d t, the time derivative of magnetic field variations at ground. We expect this framework to be useful for preparing against extreme events. Our analysis is based on a review of various papers, including those presented during Extreme Space Weather Workshops held in Japan in 2011, 2012, 2013, and 2014. Large-amplitude d B/d t values are the major cause of hazards associated with three different types of GICs: (1) slow d B/d t with ring current evolution (RC-type), (2) fast d B/d t associated with auroral electrojet activity (AE-type), and (3) transient d B/d t of sudden commencements (SC-type). We set "caution," "warning," and "emergency" alert levels during the main phase of superstorms with the peak Dst index of less than -300 nT (once per 10 years), -600 nT (once per 60 years), or -900 nT (once per 100 years), respectively. The extreme d B/d t values of the AE-type GICs are 2000, 4000, and 6000 nT/min at caution, warning, and emergency levels, respectively. For the SC-type GICs, a "transient alert" is also proposed for d B/d t values of 40 nT/s at low latitudes and 110 nT/s at high latitudes, especially when the solar energetic particle flux is unusually high.

  1. Microbial diversity of extreme habitats in human homes

    PubMed Central

    Hills, Justin; Driscoll, Katherine; Fergus, Daniel J.; Grunden, Amy M.; Dunn, Robert R.

    2016-01-01

    High-throughput sequencing techniques have opened up the world of microbial diversity to scientists, and a flurry of studies in the most remote and extreme habitats on earth have begun to elucidate the key roles of microbes in ecosystems with extreme conditions. These same environmental extremes can also be found closer to humans, even in our homes. Here, we used high-throughput sequencing techniques to assess bacterial and archaeal diversity in the extreme environments inside human homes (e.g., dishwashers, hot water heaters, washing machine bleach reservoirs, etc.). We focused on habitats in the home with extreme temperature, pH, and chemical environmental conditions. We found a lower diversity of microbes in these extreme home environments compared to less extreme habitats in the home. However, we were nonetheless able to detect sequences from a relatively diverse array of bacteria and archaea. Habitats with extreme temperatures alone appeared to be able to support a greater diversity of microbes than habitats with extreme pH or extreme chemical environments alone. Microbial diversity was lowest when habitats had both extreme temperature and one of these other extremes. In habitats with both extreme temperatures and extreme pH, taxa with known associations with extreme conditions dominated. Our findings highlight the importance of examining interactive effects of multiple environmental extremes on microbial communities. Inasmuch as taxa from extreme environments can be both beneficial and harmful to humans, our findings also suggest future work to understand both the threats and opportunities posed by the life in these habitats. PMID:27672493

  2. Microbial diversity of extreme habitats in human homes.

    PubMed

    Savage, Amy M; Hills, Justin; Driscoll, Katherine; Fergus, Daniel J; Grunden, Amy M; Dunn, Robert R

    2016-01-01

    High-throughput sequencing techniques have opened up the world of microbial diversity to scientists, and a flurry of studies in the most remote and extreme habitats on earth have begun to elucidate the key roles of microbes in ecosystems with extreme conditions. These same environmental extremes can also be found closer to humans, even in our homes. Here, we used high-throughput sequencing techniques to assess bacterial and archaeal diversity in the extreme environments inside human homes (e.g., dishwashers, hot water heaters, washing machine bleach reservoirs, etc.). We focused on habitats in the home with extreme temperature, pH, and chemical environmental conditions. We found a lower diversity of microbes in these extreme home environments compared to less extreme habitats in the home. However, we were nonetheless able to detect sequences from a relatively diverse array of bacteria and archaea. Habitats with extreme temperatures alone appeared to be able to support a greater diversity of microbes than habitats with extreme pH or extreme chemical environments alone. Microbial diversity was lowest when habitats had both extreme temperature and one of these other extremes. In habitats with both extreme temperatures and extreme pH, taxa with known associations with extreme conditions dominated. Our findings highlight the importance of examining interactive effects of multiple environmental extremes on microbial communities. Inasmuch as taxa from extreme environments can be both beneficial and harmful to humans, our findings also suggest future work to understand both the threats and opportunities posed by the life in these habitats.

  3. On extreme geomagnetic storms

    NASA Astrophysics Data System (ADS)

    Cid, Consuelo; Palacios, Judith; Saiz, Elena; Guerrero, Antonio; Cerrato, Yolanda

    2014-10-01

    Extreme geomagnetic storms are considered as one of the major natural hazards for technology-dependent society. Geomagnetic field disturbances can disrupt the operation of critical infrastructures relying on space-based assets, and can also result in terrestrial effects, such as the Quebec electrical disruption in 1989. Forecasting potential hazards is a matter of high priority, but considering large flares as the only criterion for early-warning systems has demonstrated to release a large amount of false alarms and misses. Moreover, the quantification of the severity of the geomagnetic disturbance at the terrestrial surface using indices as Dst cannot be considered as the best approach to give account of the damage in utilities. High temporal resolution local indices come out as a possible solution to this issue, as disturbances recorded at the terrestrial surface differ largely both in latitude and longitude. The recovery phase of extreme storms presents also some peculiar features which make it different from other less intense storms. This paper goes through all these issues related to extreme storms by analysing a few events, highlighting the March 1989 storm, related to the Quebec blackout, and the October 2003 event, when several transformers burnt out in South Africa.

  4. Conditional simulations for fields of extreme precipitation

    NASA Astrophysics Data System (ADS)

    Bechler, Aurélien; Vrac, Mathieu; Bel, Liliane

    2014-05-01

    Many environmental models, such as hydrological models, require input data, e.g. precipitation values, correctly simulated and distributed, even at locations where no observation is available. This is particularly true for extreme events that may be of high importance for impact studies. The last decade has seen max-stable processes emerge as a powerful tool for the statistical modeling of spatial extremes. Recently, such processes have been used in climate context to perform simulations at ungauged sites based on empirical distributions of a spatial field conditioned by observed values in some locations. In this work conditional simulations of extremal t process are investigated, taking benefits of its spectral construction. The methodology of conditional simulations proposed by Dombry et al. [2013] for Brown-Resnick and Schlather models is adapted for the extremal t process with some improvements which enlarge the possible number of conditional points. A simulation study enables to highlight the role of the different parameters of the model and to emphasize the importance of the steps of the algorithm. In this work, we focus on the French Mediterranean basin, which is a key spot of occurrences of meteorological extremes such as heavy precipitation. Indeed, major extreme precipitation are regularly observed in this region near the 'cévenol" mountains. The modeling and the understanding of these extreme precipitation - the so-called 'cévenol events" - are of major importance for hydrological studies in this complex terrain since they often trigger major floods in this region. The application of our methodology on real data in this region shows that the model and the algorithm perform well provided the stationary assumptions are fulfilled.

  5. Distant collaboration in drug discovery: The LINK3D project

    NASA Astrophysics Data System (ADS)

    Pastor, Manuel; Benedetti, Paolo; Carotti, Angelo; Carrieri, Antonio; Díaz, Carlos; Herráiz, Cristina; Höltje, Hans-Dieter; Loza, M. Isabel; Oprea, Tudor; Padín, Fernando; Pubill, Francesc; Sanz, Ferran; Stoll, Friederike; the LINK3D Consortium

    2002-11-01

    The work describes the development of novel software supporting synchronous distant collaboration between scientists involved in drug discovery and development projects. The program allows to visualize and share data as well as to interact in real time using standard intranets and Internet resources. Direct visualization of 2D and 3D molecular structures is supported and original tools for facilitating remote discussion have been integrated. The software is multiplatform (MS-Windows, SGI-IRIX, Linux), allowing for a seamless integration of heterogeneous working environments. The project aims to support collaboration both within and between academic and industrial institutions. Since confidentiality is very important in some scenarios, special attention has been paid to security aspects. The article presents the research carried out to gather the requirements of collaborative software in the field of drug discovery and development and describes the features of the first fully functional prototype obtained. Real-world testing activities carried out on this prototype in order to guarantee its adequacy in diverse environments are also described and discussed.

  6. [Imported histoplasmosis].

    PubMed

    Stete, Katarina; Kern, Winfried V; Rieg, Siegbert; Serr, Annerose; Maurer, Christian; Tintelnot, Kathrin; Wagner, Dirk

    2015-06-01

    Infections with Histoplasma capsulatum are rare in Germany, and mostly imported from endemic areas. Infections can present as localized or disseminated diseases in immunocompromised as well as immunocompetent hosts. A travel history may be a major clue for diagnosing histoplasmosis. Diagnostic tools include histology, cultural and molecular detection as well as serology. Here we present four cases of patients diagnosed and treated in Freiburg between 2004 and 2013 that demonstrate the broad range of clinical manifestations of histoplasmosis: an immunocompetent patient with chronic basal meningitis; a patient with HIV infection and fatal disseminated disease; a patient with pulmonary and cutaneous disease and mediastinal and cervical lymphadenopathy; and an immunosuppressed patient with disseminated involvement of lung, bone marrow and adrenal glands.

  7. Upper extremity golf injuries.

    PubMed

    Cohn, Michael A; Lee, Steven K; Strauss, Eric J

    2013-01-01

    Golf is a global sport enjoyed by an estimated 60 million people around the world. Despite the common misconception that the risk of injury during the play of golf is minimal, golfers are subject to a myriad of potential pathologies. While the majority of injuries in golf are attributable to overuse, acute traumatic injuries can also occur. As the body's direct link to the golf club, the upper extremities are especially prone to injury. A thorough appreciation of the risk factors and patterns of injury will afford accurate diagnosis, treatment, and prevention of further injury.

  8. Upper Extremity Regional Anesthesia

    PubMed Central

    Neal, Joseph M.; Gerancher, J.C.; Hebl, James R.; Ilfeld, Brian M.; McCartney, Colin J.L.; Franco, Carlo D.; Hogan, Quinn H.

    2009-01-01

    Brachial plexus blockade is the cornerstone of the peripheral nerve regional anesthesia practice of most anesthesiologists. As part of the American Society of Regional Anesthesia and Pain Medicine’s commitment to providing intensive evidence-based education related to regional anesthesia and analgesia, this article is a complete update of our 2002 comprehensive review of upper extremity anesthesia. The text of the review focuses on (1) pertinent anatomy, (2) approaches to the brachial plexus and techniques that optimize block quality, (4) local anesthetic and adjuvant pharmacology, (5) complications, (6) perioperative issues, and (6) challenges for future research. PMID:19282714

  9. Extremely High Velocity Outflows

    NASA Astrophysics Data System (ADS)

    Choi, Minho; Evans, Neal J., II; Jaffe, Daniel T.

    1993-11-01

    Extremely high velocity (EHV) wings, with full widths of 72 to 140 km s-1, are seen on the CO J = 3 → 2 lines toward W3 IRS 5, GL 490, NGC 2071, W28 A2 (G05.89-0.39), GL 2591, S140, and Cepheus A. Observations of 12CO and 13CO J = 3 → 2 and J = 2 → 1 lines indicate that optical depth generally decreases with increasing velocity separation from the ambient cloud velocity. Maps of the extremely high velocity (|V-V0| ≳ 20 km s-1) and the high-velocity (5 ≲ |V-V0| ≲ 20 km s-1) CO emission components show that the morphology of the two components is similar in W3 IRS 5 and W28 A2 but may be different in GL 2591, S140, and Cepheus A. The results of our survey suggest that EHV wings are common around infrared sources of moderate to high luminosity [500 to (4 × 105) Lsun] in dense regions. Line ratios imply that the EHV gas is usually optically thin and warm. Characteristic velocities range from 20 to 40 km s-1, yielding timescales of 1600-4200 yr. Since most sources in this study are producing some ionizing photons, these short timescales suggest that neutral winds coexist with ionizing photons. We examined two possible sources for the extremely high velocity CO emission: a neutral stellar wind; and swept-up or entrained molecular gas. Neither can be ruled out. If the high-velocity (HV) gas is swept up by a momentum-conserving stellar wind traced by the extremely high velocity CO emission, most of the C in the winds from luminous objects cannot be in CO. If the EHV and HV forces are equal, the fraction of C in a form other than CO increases with source luminosity and with the production rate of ionizing photons. This trend is natural in the stellar wind hypothesis, but models of winds around such luminous objects are needed. We consider other possible chemical states for the carbon in the stellar wind.

  10. Characterizing Extreme Ionospheric Storms

    NASA Astrophysics Data System (ADS)

    Sparks, L.; Komjathy, A.; Altshuler, E.

    2011-12-01

    Ionospheric storms consist of disturbances of the upper atmosphere that generate regions of enhanced electron density typically lasting several hours. Depending upon the storm magnitude, gradients in electron density can sometimes become large and highly localized. The existence of such localized, dense irregularities is a major source of positioning error for users of the Global Positioning System (GPS). Consequently, satellite-based augmentation systems have been implemented to improve the accuracy and to ensure the integrity of user position estimates derived from GPS measurements. Large-scale irregularities generally do not pose a serious threat to estimate integrity as they can be readily detected by such systems. Of greater concern, however, are highly localized irregularities that interfere with the propagation of a signal detected by a user measurement but are poorly sampled by the receivers in the system network. The most challenging conditions have been found to arise following disturbances of large magnitude that occur only rarely over the course of a solar cycle. These extremely disturbed conditions exhibit behavior distinct from moderately disturbed conditions and, hence, have been designated "extreme storms". In this paper we examine and compare the behavior of the extreme ionospheric storms of solar cycle 23 (or, more precisely, extreme storms occurring between January 1, 2000, and December 31, 2008), as represented in maps of vertical total electron content. To identify these storms, we present a robust means of quantifying the regional magnitude of an ionospheric storm. Ionospheric storms are observed frequently to occur in conjunction with magnetic storms, i.e., periods of geophysical activity as measured by magnetometers. While various geomagnetic indices, such as the disturbance storm time (Dst) and the planetary Kp index, have long been used to rank the magnitudes of distinct magnetic storms, no comparable, generally recognized index exists for

  11. Mineralogy under extreme conditions

    SciTech Connect

    Shu, Jinfu

    2012-02-07

    We have performed measurements of minerals based on the synchrotron source for single crystal and powder X-ray diffraction, inelastic scattering, spectroscopy and radiography by using diamond anvil cells. We investigated the properties of iron (Fe), iron-magnesium oxides (Fe, Mg)O, silica(SiO{sub 2}), iron-magnesium silicates (Fe, Mg)SiO{sub 3} under simulated high pressure-high temperature extreme conditions of the Earth's crust, upper mantle, low mantle, core-mantle boundary, outer core, and inner core. The results provide a new window on the investigation of the mineral properties at Earth's conditions.

  12. Temperature Extremes, Health, and Human Capital

    ERIC Educational Resources Information Center

    Zivin, Joshua Graff; Shrader, Jeffrey

    2016-01-01

    The extreme temperatures expected under climate change may be especially harmful to children. Children are more vulnerable to heat partly because of their physiological features, but, perhaps more important, because they behave and respond differently than adults do. Children are less likely to manage their own heat risk and may have fewer ways to…

  13. "Extreme Programming" in a Bioinformatics Class

    ERIC Educational Resources Information Center

    Kelley, Scott; Alger, Christianna; Deutschman, Douglas

    2009-01-01

    The importance of Bioinformatics tools and methodology in modern biological research underscores the need for robust and effective courses at the college level. This paper describes such a course designed on the principles of cooperative learning based on a computer software industry production model called "Extreme Programming" (EP).…

  14. Some characterizations of unique extremality

    NASA Astrophysics Data System (ADS)

    Yao, Guowu

    2008-07-01

    In this paper, it is shown that some necessary characteristic conditions for unique extremality obtained by Zhu and Chen are also sufficient and some sufficient ones by them actually imply that the uniquely extremal Beltrami differentials have a constant modulus. In addition, some local properties of uniquely extremal Beltrami differentials are given.

  15. Monster symmetry and extremal CFTs

    NASA Astrophysics Data System (ADS)

    Gaiotto, Davide

    2012-11-01

    We test some recent conjectures about extremal selfdual CFTs, which are the candidate holographic duals of pure gravity in AdS 3. We prove that no c = 48 extremal selfdual CFT or SCFT may possess Monster symmetry. Furthermore, we disprove a recent argument against the existence of extremal selfdual CFTs of large central charge.

  16. Solar extreme events

    NASA Astrophysics Data System (ADS)

    Hudson, Hugh S.

    2015-08-01

    Solar flares and CMEs have a broad range of magnitudes. This review discusses the possibility of “extreme events,” defined as those with magnitudes greater than have been seen in the existing historical record. For most quantitative measures, this direct information does not extend more than a century and a half into the recent past. The magnitude distributions (occurrence frequencies) of solar events (flares/CMEs) typically decrease with the parameter measured or inferred (peak flux, mass, energy etc. Flare radiation fluxes tend to follow a power law slightly flatter than S-2, where S represents a peak flux; solar particle events (SPEs) follow a still flatter power law up to a limiting magnitude, and then appear to roll over to a steeper distribution, which may take an exponential form or follow a broken power law. This inference comes from the terrestrial 14C record and from the depth dependence of various radioisotope proxies in the lunar regolith and in meteorites. Recently major new observational results have impacted our use of the relatively limited historical record in new ways: the detection of actual events in the 14C tree-ring records, and the systematic observations of flares and “superflares” by the Kepler spacecraft. I discuss how these new findings may affect our understanding of the distribution function expected for extreme solar events.

  17. Identification of victims in extreme events

    NASA Astrophysics Data System (ADS)

    Talipova, Yu.; Polukhina, O.

    2009-04-01

    Catastrophic natural disasters including tsunami events are increased the frequency in last years. One of very important problems here is the identification of personality of the victims. Due to difficult identification of the dead bodies lied into water for a long time the analysis of tooth-jaw system is proposed to apply because teeth are extremely stable to the destructive actions of environment. The method of identification of the age, sex and race of victims based on the mathematic model of pattern recognition and collected database is described. Some examples from extreme sea wave events are analyzed.

  18. Increasing Temperature Extremes during the Recent Global Warming Hiatus

    NASA Astrophysics Data System (ADS)

    Johnson, N. C.; Kosaka, Y.; Xie, S. P.

    2015-12-01

    Although the recent global warming hiatus has featured a slowdown in the annual, global mean surface air temperature trend, temperature extremes have exhibited contrasting changes, as both wintertime cold and summertime hot extremes have increased over Northern Hemisphere (NH) land from 2002-2014. To investigate the sources of NH temperature extreme variability, we use multiple linear regression analysis that includes as predictors the typical drivers of global-scale climate variability - tropical Pacific sea surface temperatures (SST), volcanic aerosols, solar variability, and the linear time trend. This analysis suggests that natural forcings, including tropical SSTs and solar variations, have contributed to the recent increase in NH winter cold extremes. The magnitude of the recent increase in summer hot extremes is only captured after including an additional SST predictor for a pattern that resembles the Atlantic Multidecadal Oscillation, which suggests the importance of Atlantic Ocean SSTs for recent increases in hot extremes. When the regression models are applied to local, grid point scales, they indicate the promise for substantial skill in seasonal predictions of extreme temperature over some NH regions. Overall, this work reveals important sources of natural variability in extreme temperature trends superimposed upon the long-term increase of hot extremes and decrease of cold extremes.

  19. Ultrasonography of the lower extremity veins: anatomy and basic approach

    PubMed Central

    Lee, Dong-Kyu; Kang, Chang Ho; Cho, Sung Bum

    2017-01-01

    Ultrasonography is an imaging modality widely used to evaluate venous diseases of the lower extremities. It is important to understand the normal venous anatomy of the lower extremities, which has deep, superficial, and perforating venous components, in order to determine the pathophysiology of venous disease. This review provides a basic description of the anatomy of the lower extremity veins and useful techniques for approaching each vein via ultrasonography. PMID:28260355

  20. Investigating NARCCAP Precipitation Extremes via Bivariate Extreme Value Theory (Invited)

    NASA Astrophysics Data System (ADS)

    Weller, G. B.; Cooley, D. S.; Sain, S. R.; Bukovsky, M. S.; Mearns, L. O.

    2013-12-01

    We introduce methodology from statistical extreme value theory to examine the ability of reanalysis-drive regional climate models to simulate past daily precipitation extremes. Going beyond a comparison of summary statistics such as 20-year return values, we study whether the most extreme precipitation events produced by climate model simulations exhibit correspondence to the most extreme events seen in observational records. The extent of this correspondence is formulated via the statistical concept of tail dependence. We examine several case studies of extreme precipitation events simulated by the six models of the North American Regional Climate Change Assessment Program (NARCCAP) driven by NCEP reanalysis. It is found that the NARCCAP models generally reproduce daily winter precipitation extremes along the Pacific coast quite well; in contrast, simulation of past daily summer precipitation extremes in a central US region is poor. Some differences in the strength of extremal correspondence are seen in the central region between models which employ spectral nudging and those which do not. We demonstrate how these techniques may be used to draw a link between extreme precipitation events and large-scale atmospheric drivers, as well as to downscale extreme precipitation simulated by a future run of a regional climate model. Specifically, we examine potential future changes in the nature of extreme precipitation along the Pacific coast produced by the pineapple express (PE) phenomenon. A link between extreme precipitation events and a "PE Index" derived from North Pacific sea-surface pressure fields is found. This link is used to study PE-influenced extreme precipitation produced by a future-scenario climate model run.

  1. (Welding under extreme conditions)

    SciTech Connect

    Davis, S.A.

    1989-09-29

    The traveler was an invited member of the United States delegation and representative of the Basic Energy Science Welding Science program at the 42nd Annual International Institute of Welding (IIW) Assembly and Conference held in Helsinki, Finland. The conference and the assembly was attended by about 600 delegates representing 40 countries. The theme of the conference was welding under extreme conditions. The conference program contained several topics related to welding in nuclear, arctic petrochemical, underwater, hyperbaric and space environments. At the annual assembly the traveler was a delegate (US) to two working groups of the IIW, namely Commission IX and welding research study group 212. Following the conference the traveler visited the Danish Welding Institute in Copenhagen and the Risoe National Laboratory in Roskilde. Prior to the conference the traveler visited Lappeenranta University of Technology and presented an invited seminar entitled Recent Advances in Welding Science and Technology.''

  2. Extreme Scale Computational Astrophysics

    NASA Astrophysics Data System (ADS)

    Shoemaker, Deirdre

    2009-11-01

    We live in extraordinary times. With increasingly sophisticated observatories opening up new vistas on the universe, astrophysics is becoming more complex and data-driven. The success in understanding astrophysical systems that are inherently multi-physical, nonlinear systems demands realism in our models of the phenomena. We cannot hope to advance the realism of these models to match the expected sophistication of future observations without extreme-scale computation. Just one example is the advent of gravitational wave astronomy. Detectors like LIGO are about to make the first ever detection of gravitational waves. The gravitational waves are produced during violent events such as the merger of two black holes. The detection of these waves or ripples in the fabric of spacetime is a formidable undertaking, requiring innovative engineering, powerful data analysis tools and careful theoretical modeling. I will discuss the computational and theoretical challenges ahead in our new understanding of physics and astronomy where gravity exhibits its strongest grip on our spacetime.

  3. Spatial distribution of precipitation extremes in Norway

    NASA Astrophysics Data System (ADS)

    Verpe Dyrrdal, Anita; Skaugen, Thomas; Lenkoski, Alex; Thorarinsdottir, Thordis; Stordal, Frode; Førland, Eirik J.

    2015-04-01

    Estimates of extreme precipitation, in terms of return levels, are crucial in planning and design of important infrastructure. Through two separate studies, we have examined the levels and spatial distribution of daily extreme precipitation over catchments in Norway, and hourly extreme precipitation in a point. The analyses were carried out through the development of two new methods for estimating extreme precipitation in Norway. For daily precipitation we fit the Generalized Extreme Value (GEV) distribution to areal time series from a gridded dataset, consisting of daily precipitation during the period 1957-today with a resolution of 1x1 km². This grid-based method is more objective and less manual and time-consuming compared to the existing method at MET Norway. In addition, estimates in ungauged catchments are easier to obtain, and the GEV approach includes a measure of uncertainty, which is a requirement in climate studies today. Further, we go into depth on the debated GEV shape parameter, which plays an important role for longer return periods. We show that it varies according to dominating precipitation types, having positive values in the southeast and negative values in the southwest. We also find indications that the degree of orographic enhancement might affect the shape parameter. For hourly precipitation, we estimate return levels on a 1x1 km² grid, by linking GEV distributions with latent Gaussian fields in a Bayesian hierarchical model (BHM). Generalized linear models on the GEV parameters, estimated from observations, are able to incorporate location-specific geographic and meteorological information and thereby accommodate these effects on extreme precipitation. Gaussian fields capture additional unexplained spatial heterogeneity and overcome the sparse grid on which observations are collected, while a Bayesian model averaging component directly assesses model uncertainty. We find that mean summer precipitation, mean summer temperature, latitude

  4. Lower extremity injuries sustained while farming.

    PubMed

    Neil, Janice A

    2002-01-01

    Today's complex farm environment can pose many threats to the lower extremities of all people especially those with chronic diseases that affect the lower extremities. The purpose of this study was to investigate the incidence of injuries to the lower extremities among farmers and to rank the importance of these incidents in order to plan prevention programs. one hundred farmers were surveyed at a large farm show in the southeastern United States. An average of 4.86 injuries per farmer were reported. Blisters from work shoes or boots, followed by injuries from animals stepping on the feet were the most common injuries. Since those with chronic illnesses are especially prone to injury and disability, regular foot assessments, evaluation, and education about the hazards of farming are mainstays of prevention.

  5. Modeling, Forecasting and Mitigating Extreme Earthquakes

    NASA Astrophysics Data System (ADS)

    Ismail-Zadeh, A.; Le Mouel, J.; Soloviev, A.

    2012-12-01

    Recent earthquake disasters highlighted the importance of multi- and trans-disciplinary studies of earthquake risk. A major component of earthquake disaster risk analysis is hazards research, which should cover not only a traditional assessment of ground shaking, but also studies of geodetic, paleoseismic, geomagnetic, hydrological, deep drilling and other geophysical and geological observations together with comprehensive modeling of earthquakes and forecasting extreme events. Extreme earthquakes (large magnitude and rare events) are manifestations of complex behavior of the lithosphere structured as a hierarchical system of blocks of different sizes. Understanding of physics and dynamics of the extreme events comes from observations, measurements and modeling. A quantitative approach to simulate earthquakes in models of fault dynamics will be presented. The models reproduce basic features of the observed seismicity (e.g., the frequency-magnitude relationship, clustering of earthquakes, occurrence of extreme seismic events). They provide a link between geodynamic processes and seismicity, allow studying extreme events, influence of fault network properties on seismic patterns and seismic cycles, and assist, in a broader sense, in earthquake forecast modeling. Some aspects of predictability of large earthquakes (how well can large earthquakes be predicted today?) will be also discussed along with possibilities in mitigation of earthquake disasters (e.g., on 'inverse' forensic investigations of earthquake disasters).

  6. Biological Extreme Events: A Research Framework

    NASA Astrophysics Data System (ADS)

    Gutschick, Vincent P.; BassiriRad, Hormoz

    2010-03-01

    Efforts designed to understand and predict adaptation responses of organisms and populations to global climate change must make a clear distinction between responses to changes in average conditions (e.g., doubling of atmospheric carbon dioxide concentration accompanied by an average increase of 1°-3°C in global air temperature by the end of this century) and responses resulting from increased incidence of extreme events [Loehle and LeBlanc, 1996; Easterling et al., 2000; Garrett et al., 2006]. Such distinction is critical because, unlike changes in average conditions, extremes (e.g., megadroughts, fire, flooding, hurricanes, heat waves, and pest outbreaks) are typically short in duration but challenge organisms and populations considerably further beyond their ability to acclimate than those expected from average trends in climate changes. There is growing evidence that climatic extremes have been rising in frequency or magnitude during the last part of the twentieth century and will continue to increase during the remainder of this century [Easterling et al., 2000; Meehl et al., 2000; Parmesan and Yohe, 2003; Barnett et al., 2006]. More important, the frequency of extremes is likely to increase even if the climatic means do not change substantially [Intergovernmental Panel on Climate Change (IPCC), 2001, chapter 10]. Therefore, it makes sense to pay special attention to extremes as major agents of biological adaption (genetic change) when considering global climate change.

  7. Present-day irrigation mitigates heat extremes

    NASA Astrophysics Data System (ADS)

    Thiery, Wim; Davin, Edouard L.; Lawrence, David M.; Hirsch, Annette L.; Hauser, Mathias; Seneviratne, Sonia I.

    2017-02-01

    Irrigation is an essential practice for sustaining global food production and many regional economies. Emerging scientific evidence indicates that irrigation substantially affects mean climate conditions in different regions of the world. Yet how this practice influences climate extremes is currently unknown. Here we use ensemble simulations with the Community Earth System Model to assess the impacts of irrigation on climate extremes. An evaluation of the model performance reveals that irrigation has a small yet overall beneficial effect on the representation of present-day near-surface climate. While the influence of irrigation on annual mean temperatures is limited, we find a large impact on temperature extremes, with a particularly strong cooling during the hottest day of the year (-0.78 K averaged over irrigated land). The strong influence on extremes stems from the timing of irrigation and its influence on land-atmosphere coupling strength. Together these effects result in asymmetric temperature responses, with a more pronounced cooling during hot and/or dry periods. The influence of irrigation is even more pronounced when considering subgrid-scale model output, suggesting that local effects of land management are far more important than previously thought. Our results underline that irrigation has substantially reduced our exposure to hot temperature extremes in the past and highlight the need to account for irrigation in future climate projections.

  8. Women in extreme poverty.

    PubMed

    1994-01-01

    Population is estimated to increase from 5.5 billion in 1990 to 10 billion by 2050; the poverty level is expected to increase from 1 billion to 2-3 billion people. Women in development has been promoted throughout the UN and development system, but women in poverty who perform work in the informal sector are still uncounted, and solutions are elusive. The issue of extreme poverty can not be approached as just another natural disaster with immediate emergency relief. Many people live in precarious economic circumstances throughout their lives. Recent research reveals a greater understanding of the underlying causes and the need for inclusion of poor women in sustainable development. Sanitation, water, housing, health facilities need to be improved. Women must have access to education, opportunities for trading, and loans on reasonable terms. UNESCO makes available a book on survival strategies for poor women in the informal sector. The profile shows common problems of illiteracy, broken marriages, and full time involvement in provision of subsistence level existence. Existence is a fragile balance. Jeanne Vickers' "Women and the World" offers simple, low cost interventions for aiding extremely poor women. The 1992 Commission on the Status of Women was held in Vienna. Excerpts from several speeches are provided. The emphasis is on some global responses and an analysis of solutions. The recommendation is for attention to the gender dimension of poverty. Women's dual role contributes to greater disadvantages. Women are affected differently by macroeconomic factors, and that there is intergenerational transfer of poverty. Social services should be viewed as investments and directed to easing the burdens on time and energy. Public programs must be equipped to deal with poverty and to bring about social and economic change. Programs must be aware of the different distribution of resources within households. Women must be recognized as principal economic providers within

  9. Extreme ultraviolet lithography machine

    DOEpatents

    Tichenor, Daniel A.; Kubiak, Glenn D.; Haney, Steven J.; Sweeney, Donald W.

    2000-01-01

    An extreme ultraviolet lithography (EUVL) machine or system for producing integrated circuit (IC) components, such as transistors, formed on a substrate. The EUVL machine utilizes a laser plasma point source directed via an optical arrangement onto a mask or reticle which is reflected by a multiple mirror system onto the substrate or target. The EUVL machine operates in the 10-14 nm wavelength soft x-ray photon. Basically the EUV machine includes an evacuated source chamber, an evacuated main or project chamber interconnected by a transport tube arrangement, wherein a laser beam is directed into a plasma generator which produces an illumination beam which is directed by optics from the source chamber through the connecting tube, into the projection chamber, and onto the reticle or mask, from which a patterned beam is reflected by optics in a projection optics (PO) box mounted in the main or projection chamber onto the substrate. In one embodiment of a EUVL machine, nine optical components are utilized, with four of the optical components located in the PO box. The main or projection chamber includes vibration isolators for the PO box and a vibration isolator mounting for the substrate, with the main or projection chamber being mounted on a support structure and being isolated.

  10. Stacked Extreme Learning Machines.

    PubMed

    Zhou, Hongming; Huang, Guang-Bin; Lin, Zhiping; Wang, Han; Soh, Yeng Chai

    2015-09-01

    Extreme learning machine (ELM) has recently attracted many researchers' interest due to its very fast learning speed, good generalization ability, and ease of implementation. It provides a unified solution that can be used directly to solve regression, binary, and multiclass classification problems. In this paper, we propose a stacked ELMs (S-ELMs) that is specially designed for solving large and complex data problems. The S-ELMs divides a single large ELM network into multiple stacked small ELMs which are serially connected. The S-ELMs can approximate a very large ELM network with small memory requirement. To further improve the testing accuracy on big data problems, the ELM autoencoder can be implemented during each iteration of the S-ELMs algorithm. The simulation results show that the S-ELMs even with random hidden nodes can achieve similar testing accuracy to support vector machine (SVM) while having low memory requirements. With the help of ELM autoencoder, the S-ELMs can achieve much better testing accuracy than SVM and slightly better accuracy than deep belief network (DBN) with much faster training speed.

  11. Detectors in Extreme Conditions

    SciTech Connect

    Blaj, G.; Carini, G.; Carron, S.; Haller, G.; Hart, P.; Hasi, J.; Herrmann, S.; Kenney, C.; Segal, J.; Tomada, A.

    2015-08-06

    Free Electron Lasers opened a new window on imaging the motion of atoms and molecules. At SLAC, FEL experiments are performed at LCLS using 120Hz pulses with 1012 - 1013 photons in 10 femtoseconds (billions of times brighter than the most powerful synchrotrons). This extreme detection environment raises unique challenges, from obvious to surprising. Radiation damage is a constant threat due to accidental exposure to insufficiently attenuated beam, focused beam and formation of ice crystals reflecting the beam onto the detector. Often high power optical lasers are also used (e.g., 25TW), increasing the risk of damage or impeding data acquisition through electromagnetic pulses (EMP). The sample can contaminate the detector surface or even produce shrapnel damage. Some experiments require ultra high vacuum (UHV) with strict design, surface contamination and cooling requirements - also for detectors. The setup is often changed between or during experiments with short turnaround times, risking mechanical and ESD damage, requiring work planning, training of operators and sometimes continuous participation of the LCLS Detector Group in the experiments. The detectors used most often at LCLS are CSPAD cameras for hard x-rays and pnCCDs for soft x-rays.

  12. Early neurodevelopmental outcomes of extremely preterm infants.

    PubMed

    Rogers, Elizabeth E; Hintz, Susan R

    2016-12-01

    Infants born at extreme preterm gestation are at risk for both death and disability. Although rates of survival have improved for this population, and some evidence suggests a trend toward decreased neuromotor impairment over the past decades, a significant improvement in overall early neurodevelopmental outcome has not yet been realized. This review will examine the rates and types of neurodevelopmental impairment seen after extremely preterm birth, including neurosensory, motor, cognitive, and behavioral outcomes. We focus on early outcomes in the first 18-36 months of life, as the majority of large neonatal studies examining neurodevelopmental outcomes stop at this age. However, this early age is clearly just a first glimpse into lifetime outcomes; the neurodevelopmental effects of extreme prematurity may last through school age, adolescence, and beyond. Importantly, prematurity appears to be an independent risk factor for adverse development, but this population demonstrates considerable variability in the types and severity of impairments. Understanding both the nature and prevalence of neurodevelopmental impairment among extremely preterm infants is important because it can lead to targeted interventions that in turn may lead to improved outcomes.

  13. Understanding water extremes with caution

    NASA Astrophysics Data System (ADS)

    Stehlík, Milan; Stehlíková, Silvia; Torres, Sebastián

    2016-06-01

    We discuss a sensitive topic, how to scientifically estimate extremes in water quality managements. Such extremes are incorporating establishment of thresholds or levels of certain chemicals in the drinking water. In particular, we address the water fluoridation and quality of drinking water in Chile. Statistical approaches demonstrating the necessary background of water manager will be given in a survey exposition to establish link between statistics of extremes and practice.

  14. Detection and attribution of extreme weather disasters

    NASA Astrophysics Data System (ADS)

    Huggel, Christian; Stone, Dáithí; Hansen, Gerrit

    2014-05-01

    Single disasters related to extreme weather events have caused loss and damage on the order of up to tens of billions US dollars over the past years. Recent disasters fueled the debate about whether and to what extent these events are related to climate change. In international climate negotiations disaster loss and damage is now high on the agenda, and related policy mechanisms have been discussed or are being implemented. In view of funding allocation and effective risk reduction strategies detection and attribution to climate change of extreme weather events and disasters is a key issue. Different avenues have so far been taken to address detection and attribution in this context. Physical climate sciences have developed approaches, among others, where variables that are reasonably sampled over climatically relevant time periods and related to the meteorological characteristics of the extreme event are examined. Trends in these variables (e.g. air or sea surface temperatures) are compared between observations and climate simulations with and without anthropogenic forcing. Generally, progress has been made in recent years in attribution of changes in the chance of some single extreme weather events to anthropogenic climate change but there remain important challenges. A different line of research is primarily concerned with losses related to the extreme weather events over time, using disaster databases. A growing consensus is that the increase in asset values and in exposure are main drivers of the strong increase of economic losses over the past several decades, and only a limited number of studies have found trends consistent with expectations from climate change. Here we propose a better integration of existing lines of research in detection and attribution of extreme weather events and disasters by applying a risk framework. Risk is thereby defined as a function of the probability of occurrence of an extreme weather event, and the associated consequences

  15. Extreme wind climate in the Czech Republic

    NASA Astrophysics Data System (ADS)

    Pop, L.; Hanslian, D.; Jiri, H.

    2011-12-01

    -convective extreme wind events is roughly at the same order. The convective events usually occur from April to August, whereas the non-convective events are typical for cold months from October to March. In mountainous regions, the non-convective events are most important, however, the impact of convective storms is high in lowlands, partially because of the seasonal foliage. The convective events are usually connected with squall lines or frontal waves. The non-convective events are mostly caused by strong southwest to northwest flow; a smaller specific group of these events, typical for some regions, is connected with south to southeast flow.

  16. Climate change, climatic variation and extreme biological responses

    PubMed Central

    Brereton, Tom; Chapman, Jason W.; Dytham, Calvin; Fox, Richard; Pearce-Higgins, James W.; Roy, David B.; Hill, Jane K.; Thomas, Chris D.

    2017-01-01

    Extreme climatic events could be major drivers of biodiversity change, but it is unclear whether extreme biological changes are (i) individualistic (species- or group-specific), (ii) commonly associated with unusual climatic events and/or (iii) important determinants of long-term population trends. Using population time series for 238 widespread species (207 Lepidoptera and 31 birds) in England since 1968, we found that population ‘crashes’ (outliers in terms of species' year-to-year population changes) were 46% more frequent than population ‘explosions’. (i) Every year, at least three species experienced extreme changes in population size, and in 41 of the 44 years considered, some species experienced population crashes while others simultaneously experienced population explosions. This suggests that, even within the same broad taxonomic groups, species are exhibiting individualistic dynamics, most probably driven by their responses to different, short-term events associated with climatic variability. (ii) Six out of 44 years showed a significant excess of species experiencing extreme population changes (5 years for Lepidoptera, 1 for birds). These ‘consensus years’ were associated with climatically extreme years, consistent with a link between extreme population responses and climatic variability, although not all climatically extreme years generated excess numbers of extreme population responses. (iii) Links between extreme population changes and long-term population trends were absent in Lepidoptera and modest (but significant) in birds. We conclude that extreme biological responses are individualistic, in the sense that the extreme population changes of most species are taking place in different years, and that long-term trends of widespread species have not, to date, been dominated by these extreme changes. This article is part of the themed issue ‘Behavioural, ecological and evolutionary responses to extreme climatic events’. PMID:28483874

  17. Grassland responses to precipitation extremes

    USDA-ARS?s Scientific Manuscript database

    Grassland ecosystems are naturally subjected to periods of prolonged drought and sequences of wet years. Climate change is expected to enhance the magnitude and frequency of extreme events at the intraannual and multiyear scales. Are grassland responses to extreme precipitation simply a response to ...

  18. Glenn Extreme Environment Rig (GEER)

    NASA Image and Video Library

    2017-01-17

    NASA Glenn research engineers prepare our extreme environments chamber (GEER) for a test. GEER, which simulates the extreme conditions found in space, tests many devices that will explore Venus to see if they can withstand the punishing environment and temperatures over 800˚F.

  19. Denitrification by extremely halophilic bacteria

    NASA Technical Reports Server (NTRS)

    Hochstein, L. I.; Tomlinson, G. A.

    1985-01-01

    Extremely halophilic bacteria were isolated from widely separated sites by anaerobic enrichment in the presence of nitrate. The anaerobic growth of several of these isolates was accompanied by the production of nitrite, nitrous oxide, and dinitrogen. These results are a direct confirmation of the existence of extremely halophilic denitrifying bacteria, and suggest that such bacteria may be common inhabitants of hypersaline environments.

  20. Gender, Education, Extremism and Security

    ERIC Educational Resources Information Center

    Davies, Lynn

    2008-01-01

    This paper examines the complex relationships between gender, education, extremism and security. After defining extremism and fundamentalism, it looks first at the relationship of gender to violence generally, before looking specifically at how this plays out in more extremist violence and terrorism. Religious fundamentalism is also shown to have…

  1. Gender, Education, Extremism and Security

    ERIC Educational Resources Information Center

    Davies, Lynn

    2008-01-01

    This paper examines the complex relationships between gender, education, extremism and security. After defining extremism and fundamentalism, it looks first at the relationship of gender to violence generally, before looking specifically at how this plays out in more extremist violence and terrorism. Religious fundamentalism is also shown to have…

  2. Denitrification by extremely halophilic bacteria

    NASA Technical Reports Server (NTRS)

    Hochstein, L. I.; Tomlinson, G. A.

    1985-01-01

    Extremely halophilic bacteria were isolated from widely separated sites by anaerobic enrichment in the presence of nitrate. The anaerobic growth of several of these isolates was accompanied by the production of nitrite, nitrous oxide, and dinitrogen. These results are a direct confirmation of the existence of extremely halophilic denitrifying bacteria, and suggest that such bacteria may be common inhabitants of hypersaline environments.

  3. The Antidote to Extremism

    ERIC Educational Resources Information Center

    Jackson, Anthony

    2016-01-01

    For centuries, education has been seen as an antidote to intolerance and conflict. In a world rocked by violence, much of it across cultural borders, developing students' cultural understanding has become more important than ever. In this article, Asia Society vice president Anthony Jackson discusses how two high schools in the Society's…

  4. The Antidote to Extremism

    ERIC Educational Resources Information Center

    Jackson, Anthony

    2016-01-01

    For centuries, education has been seen as an antidote to intolerance and conflict. In a world rocked by violence, much of it across cultural borders, developing students' cultural understanding has become more important than ever. In this article, Asia Society vice president Anthony Jackson discusses how two high schools in the Society's…

  5. Multivariate Bayesian Models of Extreme Rainfall

    NASA Astrophysics Data System (ADS)

    Rahill-Marier, B.; Devineni, N.; Lall, U.; Farnham, D.

    2013-12-01

    Accounting for spatial heterogeneity in extreme rainfall has important ramifications in hydrological design and climate models alike. Traditional methods, including areal reduction factors and kriging, are sensitive to catchment shape assumptions and return periods, and do not explicitly model spatial dependence between between data points. More recent spatially dense rainfall simulators depend on newer data sources such as radar and may struggle to reproduce extremes because of physical assumptions in the model and short historical records. Rain gauges offer the longest historical record, key when considering rainfall extremes and changes over time, and particularly relevant in today's environment of designing for climate change. In this paper we propose a probabilistic approach of accounting for spatial dependence using the lengthy but spatially disparate hourly rainfall network in the greater New York City area. We build a hierarchical Bayesian model allowing extremes at one station to co-vary with concurrent rainfall fields occurring at other stations. Subsequently we pool across the extreme rainfall fields of all stations, and demonstrate that the expected catchment-wide events are significantly lower when considering spatial fields instead of maxima-only fields. We additionally demonstrate the importance of using concurrent spatial fields, rather than annual maxima, in producing covariance matrices that describe true storm dynamics. This approach is also unique in that it considers short duration storms - from one hour to twenty-four hours - rather than the daily values typically derived from rainfall gauges. The same methodology can be extended to include the radar fields available in the past decade. The hierarchical multilevel approach lends itself easily to integration of long-record parameters and short-record parameters at a station or regional level. In addition climate covariates can be introduced to support the relationship of spatial covariance with

  6. Representing Extremes in Agricultural Models

    NASA Technical Reports Server (NTRS)

    Ruane, Alex

    2015-01-01

    AgMIP and related projects are conducting several activities to understand and improve crop model response to extreme events. This involves crop model studies as well as the generation of climate datasets and scenarios more capable of capturing extremes. Models are typically less responsive to extreme events than we observe, and miss several forms of extreme events. Models also can capture interactive effects between climate change and climate extremes. Additional work is needed to understand response of markets and economic systems to food shocks. AgMIP is planning a Coordinated Global and Regional Assessment of Climate Change Impacts on Agricultural Production and Food Security with an aim to inform the IPCC Sixth Assessment Report.

  7. Extreme Mean and Its Applications

    NASA Technical Reports Server (NTRS)

    Swaroop, R.; Brownlow, J. D.

    1979-01-01

    Extreme value statistics obtained from normally distributed data are considered. An extreme mean is defined as the mean of p-th probability truncated normal distribution. An unbiased estimate of this extreme mean and its large sample distribution are derived. The distribution of this estimate even for very large samples is found to be nonnormal. Further, as the sample size increases, the variance of the unbiased estimate converges to the Cramer-Rao lower bound. The computer program used to obtain the density and distribution functions of the standardized unbiased estimate, and the confidence intervals of the extreme mean for any data are included for ready application. An example is included to demonstrate the usefulness of extreme mean application.

  8. Lightcurves of Extreme Debris Disks

    NASA Astrophysics Data System (ADS)

    Rieke, George; Meng, Huan; Su, Kate

    2012-12-01

    We have recently discovered that some planetary debris disks with extreme fractional luminosities are variable on the timescale of a few years. This behavior opens a new possibility to understand planet building. Two of the known variable disks are around solar-like stars in the age range of 30 to 100+ Myr, which is the expected era of the final stages of terrestrial planet building. Such variability can be attributed to violent collisions (up to ones on the scale of the Moon-forming event between the proto-Earth and another proto-planet). The collisional cascades that are the aftermaths of these events can produce large clouds of tiny dust grains, possibly even condensed from silica vapor. A Spitzer pilot program has obtained the lightcurve of such a debris disk and caught two minor outbursts. Here we propose to continue the lightcurve monitoring with higher sampling rates and to expand it to more disks. The proposed time domain observations are a new dimension of debris disk studies that can bring unique insight to their evolution, providing important constraints on the collisional and dynamical models of terrestrial planet formation.

  9. Meteorological conditions for extreme crop yield seasons

    NASA Astrophysics Data System (ADS)

    van der Wiel, Karin; Selten, Frank; Bintanja, Richard

    2017-04-01

    Year-to-year variability in crop yield causes large variability in yearly total crop production. This variability in production causes uncertainty in farmers' income and destabilisation of food supply and food security world wide. We use a large model ensemble generated using the global climate model EC-Earth to characterise the meteorological conditions of highest impact on crop yields and production. We use a new approach of investigating high impact events: selecting by impact rather than by the extremeness of a chosen meteorological variable. This direct selection approach allows for compound extreme events (events caused by multiple, statistically related variables) to be included in the analysis and guarantees the events of highest societal importance are the focus of the study. We discuss the meteorological conditions that lead to the seasons of extreme crop production. We show that these are not necessarily extreme seasons in meteorological or climatic terms, since crop yield may vary due to relatively small deviations in, for example, temperature or precipitation at a significant periods in the growing season.

  10. Anders Breivik: Extreme Beliefs Mistaken for Psychosis.

    PubMed

    Rahman, Tahir; Resnick, Phillip J; Harry, Bruce

    2016-03-01

    The case of Anders Breivik, who committed mass murder in Norway in 2011, stirred controversy among forensic mental health experts. His bizarrely composed compendium and references to himself as the "Knights Templar" raised concerns that he had a psychotic mental illness. Beliefs such as Mr. Breivik's that precede odd, unusual, or extremely violent behavior present a unique challenge to the forensic evaluator, who sometimes struggles to understand those beliefs. Psychotic disorder frequently is invoked to characterize odd, unusual, or extreme beliefs, with a classification that has evolved over time. However, the important concept of overvalued idea, largely ignored in American psychiatry, may better characterize these beliefs in some cases. We discuss the definitions of delusion and overvalued ideas in the context of Anders Breivik's rigidly held extreme beliefs. We also review the British definition of overvalued idea and discuss McHugh's construct, to introduce the term "extreme overvalued belief" as an aid in sharpening the forensic evaluator's conceptualization of these and similar beliefs.

  11. Extreme Events: Dynamics, Statistics and Prediction

    NASA Astrophysics Data System (ADS)

    Ghil, M.

    2013-05-01

    In this talk, I will review some recent work on extreme events, their causes and consequences. The review covers theoretical aspects of time series analysis and of extreme value theory, as well as of the deterministic modeling of extreme events, via continuous and discrete dynamic models. The applications include climatic, seismic and socio-economic events, along with their prediction. Two important results refer to (i) the complementarity of spectral analysis of a time series in terms of the continuous and the discrete part of its power spectrum; and (ii) the need for coupled modeling of natural and socio-economic systems. Both these results have implications for the study and prediction of natural hazards and their human impacts. US GDP data used in validating the vulnerability paradox found in a Non-Equilibrium Dynamical Model (NEDyM) for studying the impact of extreme events on a dynamic economy. The paradoxical result is that natural hazards affect more strongly an economy in expansion than when it is in a recession. The connection to the macroeconomic data is given by fluctuation-dissipation theory.

  12. Extreme Rainfall In A City

    NASA Astrophysics Data System (ADS)

    Nkemdirim, Lawrence

    industrialization. The development of small cloud droplets into larger particles requires time. A single thunderstorm cell has a mean development time of about 20 minutes and a life time of around 45 minutes with a mean mind of 10m/s, an air parcel would travel 12 km from the beginning of droplet formation to the first precipitation. That means that the precipitation field is shifted downwind of settlements. It could also explain the the higher frequency of the trace to small amounts observed in Calgary since those events occur under relatively calm weather. Whereas the majority of studies have focused on summer convectional type events, little appears to have been done on the extreme rainfall events on which most structural designs are based. Is there a detectable urban bias in these events? Do urban areas intensify them? What are the implications of point distribution of extreme rainfall events on flood frequency across a city. This paper examines the spatial distribution of the mean annual maximum rainfall event in Calgary, Canada, with a view to determining the relative contribution of geographical setting and urbanisation to point patterns. The data are subsequently maximized to produce maps of probable maximum precipitation for the city. The major results are as follows: (a) position along storm path is the most important variable determining maximum rainfall hazard, (b) higher grounds receive up to seventy percent more maximum rainfall than values based on spatial trend, (c) urban structure and geometry correlate negatively with maximum rainfall intensity, however, (d) zones of maximum flood peaks are found down slope of areas of maximum precipitation increasing flood hazard in the inner city in spite of its lower precipitation. Drainage networks based on point rainfall patterns have proved grossly inadequate for flood mitigation. The new design based on this study recognizes the strong moisture gradients caused by rapid movement of water and other elements down slope. Snow

  13. Spatial extremes modeling applied to extreme precipitation data in the state of Paraná

    NASA Astrophysics Data System (ADS)

    Olinda, R. A.; Blanchet, J.; dos Santos, C. A. C.; Ozaki, V. A.; Ribeiro, P. J., Jr.

    2014-11-01

    Most of the mathematical models developed for rare events are based on probabilistic models for extremes. Although the tools for statistical modeling of univariate and multivariate extremes are well developed, the extension of these tools to model spatial extremes includes an area of very active research nowadays. A natural approach to such a modeling is the theory of extreme spatial and the max-stable process, characterized by the extension of infinite dimensions of multivariate extreme value theory, and making it possible then to incorporate the existing correlation functions in geostatistics and therefore verify the extremal dependence by means of the extreme coefficient and the Madogram. This work describes the application of such processes in modeling the spatial maximum dependence of maximum monthly rainfall from the state of Paraná, based on historical series observed in weather stations. The proposed models consider the Euclidean space and a transformation referred to as space weather, which may explain the presence of directional effects resulting from synoptic weather patterns. This method is based on the theorem proposed for de Haan and on the models of Smith and Schlather. The isotropic and anisotropic behavior of these models is also verified via Monte Carlo simulation. Estimates are made through pairwise likelihood maximum and the models are compared using the Takeuchi Information Criterion. By modeling the dependence of spatial maxima, applied to maximum monthly rainfall data from the state of Paraná, it was possible to identify directional effects resulting from meteorological phenomena, which, in turn, are important for proper management of risks and environmental disasters in countries with its economy heavily dependent on agribusiness.

  14. Propagation of precipitation extremes into discharge extremes in a changing climate

    NASA Astrophysics Data System (ADS)

    Piras, Monica; Mascaro, Giuseppe; Deidda, Roberto; Vivoni, Enrique R.

    2015-04-01

    sub-basins with loamy soils. Hence, both soil properties and topography play an important role in the basin response to extreme events.

  15. Habitability in Extreme Conditions

    NASA Astrophysics Data System (ADS)

    de Lobkowicz, Ysaline; de Crombrugghe, Guerric; Le Maire, Victor; Jago, Alban; Denies, Jonathan; van Vynckt, Delphine; Reydams, Marc; Mertens, Alexandre

    A manned space mission could be perfectly prepared in terms of sciences and technologies, but without a good habitat, a place where the needs of the crew are respected, this isolation and confinement can turn into a nightmare. There is the limitation of engineering: it is more than important to take care about architecture, when human lives are part of the experiment. The goal of the research is the analysis of the hard life of isolation and confinement in Mars' hostile environment and how architecture is a way to improve it. The objective is to place the human in the middle of the analysis. What does a person really need? Therefore Maslow's idea, the pyramid of primary needs, gives us the hierarchy to follow: first survival, food and beverage, then sleep, and only then protection, social activities and work. [1] No more luxury. If all these aspects are respected, a human is able to survive, like it did since so many years. The idea is that each of these main activities has to be related to a different type of space, to provide variability in this close environment. For example, work and relaxing areas have to be separated; a human being needs time for himself, without concentration. A workspace and a relaxing area have a different typology, different colours and lighting, dimensions, furniture. This has also to be respected in a spacecraft. For this research, different sources are used, mainly in the psychological aspect, which is the most important. [2] Therefore questionnaires, interviews, diaries of past expeditions are full of treasures. We do not have to search too far: on earth; polar expeditions, submarines, military camps, etc., give a lot of information. Some very realistic simulations, as on the Mars Desert Research Station (MDRS), will also be used as material: a good analysis of the defaults and well-organized part of the station can conduct to important conclusions. [3] A found analysis and a well-designed habitat are considerable keys for the success

  16. How important is patient education?

    PubMed

    Ramos-Remus, C; Salcedo-Rocha, A L; Prieto-Parra, R E; Galvan-Villegas, F

    2000-12-01

    The prevalence and disability rate of rheumatic diseases are increasing. It seems that non-medical causes play an important role in the morbidity, disability and mortality of these patients. Efforts to reduce their impact are extremely important. Patient education is thought to be one way to limit disability in rheumatic diseases and to achieve an improvement in quality of life. In this chapter, we review the influence of non-medical causes of morbidity on disease outcome, some basic aspects of education and the evidence of the effectiveness of patient education in diseases such as ankylosing spondylitis, systemic lupus erythematosus, rheumatoid arthritis and fibromyalgia syndrome.

  17. Hall sensors for extreme temperatures.

    PubMed

    Jankowski, Jakub; El-Ahmar, Semir; Oszwaldowski, Maciej

    2011-01-01

    We report on the preparation of the first complete extreme temperature Hall sensor. This means that the extreme-temperature magnetic sensitive semiconductor structure is built-in an extreme-temperature package especially designed for that purpose. The working temperature range of the sensor extends from -270 °C to +300 °C. The extreme-temperature Hall-sensor active element is a heavily n-doped InSb layer epitaxially grown on GaAs. The magnetic sensitivity of the sensor is ca. 100 mV/T and its temperature coefficient is less than 0.04 %/K. This sensor may find applications in the car, aircraft, spacecraft, military and oil and gas industries.

  18. Extreme hypertriglyceridemia managed with insulin.

    PubMed

    Thuzar, Moe; Shenoy, Vasant V; Malabu, Usman H; Schrale, Ryan; Sangla, Kunwarjit S

    2014-01-01

    Extreme hypertriglyceridemia can lead to acute pancreatitis and rapid lowering of serum triglycerides (TG) is necessary for preventing such life-threatening complications. However, there is no established consensus on the acute management of extreme hypertriglyceridemia. We retrospectively reviewed 10 cases of extreme hypertriglyceridemia with mean serum TG on presentation of 101.5 ± 23.4 mmol/L (8982 ± 2070 mg/dL) managed with insulin. Serum TG decreased by 87 ± 4% in 24 hours in those patients managed with intravenous insulin and fasting and 40 ± 8.4% in those managed with intravenous insulin alone (P = .0003). The clinical course was uncomplicated in all except 1 patient who subsequently developed a pancreatic pseudocyst. Thus, combination of intravenous insulin with fasting appears to be an effective, simple, and safe treatment strategy in immediate management of extreme hypertriglyceridemia.

  19. Extreme events in computational turbulence

    PubMed Central

    Yeung, P. K.; Zhai, X. M.; Sreenivasan, Katepalli R.

    2015-01-01

    We have performed direct numerical simulations of homogeneous and isotropic turbulence in a periodic box with 8,1923 grid points. These are the largest simulations performed, to date, aimed at improving our understanding of turbulence small-scale structure. We present some basic statistical results and focus on “extreme” events (whose magnitudes are several tens of thousands the mean value). The structure of these extreme events is quite different from that of moderately large events (of the order of 10 times the mean value). In particular, intense vorticity occurs primarily in the form of tubes for moderately large events whereas it is much more “chunky” for extreme events (though probably overlaid on the traditional vortex tubes). We track the temporal evolution of extreme events and find that they are generally short-lived. Extreme magnitudes of energy dissipation rate and enstrophy occur simultaneously in space and remain nearly colocated during their evolution. PMID:26424452

  20. Evaluation of dynamically downscaled extreme temperature using a spatially-aggregated generalized extreme value (GEV) model

    NASA Astrophysics Data System (ADS)

    Wang, Jiali; Han, Yuefeng; Stein, Michael L.; Kotamarthi, Veerabhadra R.; Huang, Whitney K.

    2016-11-01

    The weather research and forecast (WRF) model downscaling skill in extreme maximum daily temperature is evaluated by using the generalized extreme value (GEV) distribution. While the GEV distribution has been used extensively in climatology and meteorology for estimating probabilities of extreme events, accurately estimating GEV parameters based on data from a single pixel can be difficult, even with fairly long data records. This work proposes a simple method assuming that the shape parameter, the most difficult of the three parameters to estimate, does not vary over a relatively large region. This approach is applied to evaluate 31-year WRF-downscaled extreme maximum temperature through comparison with North American regional reanalysis (NARR) data. Uncertainty in GEV parameter estimates and the statistical significance in the differences of estimates between WRF and NARR are accounted for by conducting a novel bootstrap procedure that makes no assumption of temporal or spatial independence within a year, which is especially important for climate data. Despite certain biases over parts of the United States, overall, WRF shows good agreement with NARR in the spatial pattern and magnitudes of GEV parameter estimates. Both WRF and NARR show a significant increase in extreme maximum temperature over the southern Great Plains and southeastern United States in January and over the western United States in July. The GEV model shows clear benefits from the regionally constant shape parameter assumption, for example, leading to estimates of the location and scale parameters of the model that show coherent spatial patterns.

  1. Extremal surfaces and entanglement entropy

    NASA Astrophysics Data System (ADS)

    Pal, Shesansu Sekhar

    2014-05-01

    We have obtained the equation of the extremal hypersurface by considering the Jacobson-Myers functional and computed the entanglement entropy. In this context, we show that the higher derivative corrected extremal surfaces cannot penetrate the horizon. Also, we have studied the entanglement temperature and entanglement entropy for low excited states for such higher derivative theories when the entangling region is of the strip type.

  2. A dynamical systems approach to studying midlatitude weather extremes

    NASA Astrophysics Data System (ADS)

    Messori, Gabriele; Caballero, Rodrigo; Faranda, Davide

    2017-04-01

    Extreme weather occurrences carry enormous social and economic costs and routinely garner widespread scientific and media coverage. The ability to predict these events is therefore a topic of crucial importance. Here we propose a novel predictability pathway for extreme events, by building upon recent advances in dynamical systems theory. We show that simple dynamical systems metrics can be used to identify sets of large-scale atmospheric flow patterns with similar spatial structure and temporal evolution on time scales of several days to a week. In regions where these patterns favor extreme weather, they afford a particularly good predictability of the extremes. We specifically test this technique on the atmospheric circulation in the North Atlantic region, where it provides predictability of large-scale wintertime surface temperature extremes in Europe up to 1 week in advance.

  3. Resuscitation of extremely preterm infants - controversies and current evidence

    PubMed Central

    Patel, Pooja N; Banerjee, Jayanta; Godambe, Sunit V

    2016-01-01

    Despite significant advances in perinatal medicine, the management of extremely preterm infants in the delivery room remains a challenge. There is an increasing evidence for improved outcomes regarding the resuscitation and stabilisation of extremely preterm infants but there is a lack of evidence in the periviable (gestational age 23-25 wk) preterm subgroup. Presence of an experienced team during the delivery of extremely preterm infant to improve outcome is reviewed. Adaptation from foetal to neonatal cardiorespiratory haemodynamics is dependent on establishing an optimal functional residual capacity in the extremely preterm infants, thus enabling adequate gas exchange. There is sufficient evidence for a gentle approach to stabilisation of these fragile infants in the delivery room. Evidence for antenatal steroids especially in the periviable infants, delayed cord clamping, strategies to establish optimal functional residual capacity, importance of temperature control and oxygenation in delivery room in extremely premature infants is reviewed in this article. PMID:27170925

  4. Atomistic material behavior at extreme pressures

    DOE PAGES

    Beland, Laurent K.; Osetskiy, Yury N.; Stoller, Roger E.

    2016-08-05

    Computer simulations are routinely performed to model the response of materials to extreme environments, such as neutron (or ion) irradiation. The latter involves high-energy collisions from which a recoiling atom creates a so-called atomic displacement cascade. These cascades involve coordinated motion of atoms in the form of supersonic shockwaves. These shockwaves are characterized by local atomic pressures >15 GPa and interatomic distances <2 Å. Similar pressures and interatomic distances are observed in other extreme environment, including short-pulse laser ablation, high-impact ballistic collisions and diamond anvil cells. Displacement cascade simulations using four different force fields, with initial kinetic energies ranging frommore » 1 to 40 keV, show that there is a direct relationship between these high-pressure states and stable defect production. An important shortcoming in the modeling of interatomic interactions at these short distances, which in turn determines final defect production, is brought to light.« less

  5. Atomistic material behavior at extreme pressures

    SciTech Connect

    Beland, Laurent K.; Osetskiy, Yury N.; Stoller, Roger E.

    2016-08-05

    Computer simulations are routinely performed to model the response of materials to extreme environments, such as neutron (or ion) irradiation. The latter involves high-energy collisions from which a recoiling atom creates a so-called atomic displacement cascade. These cascades involve coordinated motion of atoms in the form of supersonic shockwaves. These shockwaves are characterized by local atomic pressures >15 GPa and interatomic distances <2 Å. Similar pressures and interatomic distances are observed in other extreme environment, including short-pulse laser ablation, high-impact ballistic collisions and diamond anvil cells. Displacement cascade simulations using four different force fields, with initial kinetic energies ranging from 1 to 40 keV, show that there is a direct relationship between these high-pressure states and stable defect production. An important shortcoming in the modeling of interatomic interactions at these short distances, which in turn determines final defect production, is brought to light.

  6. Extreme Learning Machines for spatial environmental data

    NASA Astrophysics Data System (ADS)

    Leuenberger, Michael; Kanevski, Mikhail

    2015-12-01

    The use of machine learning algorithms has increased in a wide variety of domains (from finance to biocomputing and astronomy), and nowadays has a significant impact on the geoscience community. In most real cases geoscience data modelling problems are multivariate, high dimensional, variable at several spatial scales, and are generated by non-linear processes. For such complex data, the spatial prediction of continuous (or categorical) variables is a challenging task. The aim of this paper is to investigate the potential of the recently developed Extreme Learning Machine (ELM) for environmental data analysis, modelling and spatial prediction purposes. An important contribution of this study deals with an application of a generic self-consistent methodology for environmental data driven modelling based on Extreme Learning Machine. Both real and simulated data are used to demonstrate applicability of ELM at different stages of the study to understand and justify the results.

  7. Atomistic material behavior at extreme pressures

    NASA Astrophysics Data System (ADS)

    Béland, Laurent Karim; Osetsky, Yuri N.; Stoller, Roger E.

    2016-08-01

    Computer simulations are routinely performed to model the response of materials to extreme environments, such as neutron (or ion) irradiation. The latter involves high-energy collisions from which a recoiling atom creates a so-called atomic displacement cascade. These cascades involve coordinated motion of atoms in the form of supersonic shockwaves. These shockwaves are characterized by local atomic pressures >15 GPa and interatomic distances <2 Å. Similar pressures and interatomic distances are observed in other extreme environment, including short-pulse laser ablation, high-impact ballistic collisions and diamond anvil cells. Displacement cascade simulations using four different force fields, with initial kinetic energies ranging from 1 to 40 keV, show that there is a direct relationship between these high-pressure states and stable defect production. An important shortcoming in the modeling of interatomic interactions at these short distances, which in turn determines final defect production, is brought to light.

  8. Refinements in lower extremity free flap surgery.

    PubMed

    Acland, R D

    1990-10-01

    This chapter recommends numerous factors that are significant refinements in approach and execution of lower extremity free flaps. I encourage a clear conceptual separation between the two essential phases of successful reconstruction of problem wounds: wound preparation and flap transfer. I have found that antibiotic beads maintain the sterility of temporary bony dead space. Due emphasis should be given to preparation of the surgeon, patient, and wound, allowing a nonemergency approach to lower extremity free flap coverage. The surgeon needs to be familiar with a variety of flaps beyond the usual workhorse group. Also, attention should be paid to perioperative warmth and hydration, and vessels affected by posttraumatic vessel disease must be avoided. A positive attitude toward the use of vein grafts whenever necessary is important. I also favor careful planning of the exact size and shape of the flap and length of the vessels along with use of a widely spatulated technique of end-to-side anastomoses.

  9. Extreme Energy in China

    SciTech Connect

    Khanna, Nina; Fridley, David; Cai, Lixue

    2013-06-01

    Over the last decade, China has focused its policies simultaneously on moderating the rapid energy demand growth that has been driven by three decades of rapid economic growth and industrialization and on increasing its energy supply. In spite of these concerted efforts, however, China continues to face growing energy supply challenges, particularly with accelerating demand for oil and natural gas, both of which are now heavily dependent on imports. On the supply side, the recent 11th and 12th Five-Year Plans have emphasized accelerating conventional and nonconventional oil and gas exploration and development through pricing reforms, pipeline infrastructure expansions and 2015 production targets for shale gas and coal seam methane. This study will analyze China’s new and nonconventional oil and gas resources base, possible development paths and outlook, and the potential role for these nonconventional resources in meeting oil and gas demand. The nonconventional resources currently being considered by China and included in this study include: shale gas, coal seam methane (coal mine methane and coal bed methane), tight gas, in-situ coal gasification, tight oil and oil shale, and gas hydrates.

  10. The Relationships Between the Trends of Mean and Extreme Precipitation

    NASA Technical Reports Server (NTRS)

    Zhou, Yaping; Lau, William K.-M.

    2017-01-01

    This study provides a better understanding of the relationships between the trends of mean and extreme precipitation in two observed precipitation data sets: the Climate Prediction Center Unified daily precipitation data set and the Global Precipitation Climatology Program (GPCP) pentad data set. The study employs three kinds of definitions of extreme precipitation: (1) percentile, (2) standard deviation and (3) generalize extreme value (GEV) distribution analysis for extreme events based on local statistics. Relationship between trends in the mean and extreme precipitation is identified with a novel metric, i.e. area aggregated matching ratio (AAMR) computed on regional and global scales. Generally, more (less) extreme events are likely to occur in regions with a positive (negative) mean trend. The match between the mean and extreme trends deteriorates for increasingly heavy precipitation events. The AAMR is higher in regions with negative mean trends than in regions with positive mean trends, suggesting a higher likelihood of severe dry events, compared with heavy rain events in a warming climate. AAMR is found to be higher in tropics and oceans than in the extratropics and land regions, reflecting a higher degree of randomness and more important dynamical rather than thermodynamical contributions of extreme events in the latter regions.

  11. Extreme weather caused by concurrent cyclone, front and thunderstorm occurrences

    NASA Astrophysics Data System (ADS)

    Dowdy, Andrew J.; Catto, Jennifer L.

    2017-01-01

    Phenomena such as cyclones, fronts and thunderstorms can cause extreme weather in various regions throughout the world. Although these phenomena have been examined in numerous studies, they have not all been systematically examined in combination with each other, including in relation to extreme precipitation and extreme winds throughout the world. Consequently, the combined influence of these phenomena represents a substantial gap in the current understanding of the causes of extreme weather events. Here we present a systematic analysis of cyclones, fronts and thunderstorms in combination with each other, as represented by seven different types of storm combinations. Our results highlight the storm combinations that most frequently cause extreme weather in various regions of the world. The highest risk of extreme precipitation and extreme wind speeds is found to be associated with a triple storm type characterized by concurrent cyclone, front and thunderstorm occurrences. Our findings reveal new insight on the relationships between cyclones, fronts and thunderstorms and clearly demonstrate the importance of concurrent phenomena in causing extreme weather.

  12. Extreme weather caused by concurrent cyclone, front and thunderstorm occurrences.

    PubMed

    Dowdy, Andrew J; Catto, Jennifer L

    2017-01-11

    Phenomena such as cyclones, fronts and thunderstorms can cause extreme weather in various regions throughout the world. Although these phenomena have been examined in numerous studies, they have not all been systematically examined in combination with each other, including in relation to extreme precipitation and extreme winds throughout the world. Consequently, the combined influence of these phenomena represents a substantial gap in the current understanding of the causes of extreme weather events. Here we present a systematic analysis of cyclones, fronts and thunderstorms in combination with each other, as represented by seven different types of storm combinations. Our results highlight the storm combinations that most frequently cause extreme weather in various regions of the world. The highest risk of extreme precipitation and extreme wind speeds is found to be associated with a triple storm type characterized by concurrent cyclone, front and thunderstorm occurrences. Our findings reveal new insight on the relationships between cyclones, fronts and thunderstorms and clearly demonstrate the importance of concurrent phenomena in causing extreme weather.

  13. The Relationships Between the Trends of Mean and Extreme Precipitation

    NASA Technical Reports Server (NTRS)

    Zhou, Yaping; Lau, William K.-M.

    2017-01-01

    This study provides a better understanding of the relationships between the trends of mean and extreme precipitation in two observed precipitation data sets: the Climate Prediction Center Unified daily precipitation data set and the Global Precipitation Climatology Program (GPCP) pentad data set. The study employs three kinds of definitions of extreme precipitation: (1) percentile, (2) standard deviation and (3) generalize extreme value (GEV) distribution analysis for extreme events based on local statistics. Relationship between trends in the mean and extreme precipitation is identified with a novel metric, i.e. area aggregated matching ratio (AAMR) computed on regional and global scales. Generally, more (less) extreme events are likely to occur in regions with a positive (negative) mean trend. The match between the mean and extreme trends deteriorates for increasingly heavy precipitation events. The AAMR is higher in regions with negative mean trends than in regions with positive mean trends, suggesting a higher likelihood of severe dry events, compared with heavy rain events in a warming climate. AAMR is found to be higher in tropics and oceans than in the extratropics and land regions, reflecting a higher degree of randomness and more important dynamical rather than thermodynamical contributions of extreme events in the latter regions.

  14. Extreme weather caused by concurrent cyclone, front and thunderstorm occurrences

    PubMed Central

    Dowdy, Andrew J.; Catto, Jennifer L.

    2017-01-01

    Phenomena such as cyclones, fronts and thunderstorms can cause extreme weather in various regions throughout the world. Although these phenomena have been examined in numerous studies, they have not all been systematically examined in combination with each other, including in relation to extreme precipitation and extreme winds throughout the world. Consequently, the combined influence of these phenomena represents a substantial gap in the current understanding of the causes of extreme weather events. Here we present a systematic analysis of cyclones, fronts and thunderstorms in combination with each other, as represented by seven different types of storm combinations. Our results highlight the storm combinations that most frequently cause extreme weather in various regions of the world. The highest risk of extreme precipitation and extreme wind speeds is found to be associated with a triple storm type characterized by concurrent cyclone, front and thunderstorm occurrences. Our findings reveal new insight on the relationships between cyclones, fronts and thunderstorms and clearly demonstrate the importance of concurrent phenomena in causing extreme weather. PMID:28074909

  15. Disaster Risks Reduction for Extreme Natural Hazards

    NASA Astrophysics Data System (ADS)

    Plag, H.; Jules-Plag, S.

    2013-12-01

    . Integration of these low-probability, high-impact events in DRR requires an approach focused on resilience and antifragility, as well as the ability to cope with, and recover from failure of infrastructure and social systems. Resilience does not primarily result from the robustness of infrastructure but mainly is a function of the social capital. While it is important to understand the hazards (the contribution of geosciences), it is equally important to understand the processes that let us cope with the hazards, or lead to failure (the contribution of social sciences and engineering). For the latter, we need a joint effort of social sciences and engineering and a revised science-policy relationship. Democratizing knowledge about extreme geohazards is very important in order to inform deliberations of DRR through increased resilience and reduced fragility. The current science-society dialog is not fully capable of supporting deliberative governance. Most scientific knowledge is created independent of those who could put it to use, and a transition to co-design and co-development of knowledge involving a broad stakeholder base is necessary for DRR, particularly for extreme events. This transition may have the consequence of more responsibility and even liability for science.

  16. Linking Extreme Weather Events and Extreme ENSO States

    NASA Astrophysics Data System (ADS)

    Perlwitz, J.; Hoerling, M. P.; Xu, T.; Hoell, A.; Cheng, L.; Wolter, K.

    2015-12-01

    To what extent are the risks of extreme weather events over the contiguous US, such as heavy precipitation, heat and cold waves, conditioned by the state of tropical east Pacific SSTs? Further, do extreme magnitudes of El Niño and La Niña events exert a unique and particularly strong controlling effect on weather extremes? Here, we utilize both observations and multi-model large ensemble historical simulations to characterize the behavior of 5-day maximum precipitation distributions. We focus on relations between ENSO impacts on seasonal means and weather extremes, and explore the distinction between effects based on ENSO phase and intensity. For the cold season (November to April), overall ENSO impacts on mean precipitation are shown to be consistent with observations. This signal includes enhanced seasonal mean precipitation over the southern part of the U.S. and central Great Plains during El Niño, and enhanced seasonal mean precipitation over the Midwest during La Nina. We further demonstrate how these signals change under the influence of the most extreme ENSO events, conditions that are difficult to verify from observations owing to small sample sizes, but are modeled via large ensemble methods. The statistics of 5-day maximum precipitation, with a focus on 20-year return levels that characterizes rare but potentially damaging events, are examined. We demonstrate substantial differences in changes in the risk of extreme 5-day precipitation and the seasonal mean precipitation signal, especially in such regions as California, and the western Great Plains including the Front Range of the Rockies from Montana to New Mexico. The plausibility of such behavior is discussed via physical considerations and by examining the structural uncertainty in such outcomes across three different climate models.

  17. Transverse deformations of extreme horizons

    NASA Astrophysics Data System (ADS)

    Li, Carmen; Lucietti, James

    2016-04-01

    We consider the inverse problem of determining all extreme black hole solutions to the Einstein equations with a prescribed near-horizon geometry. We investigate this problem by considering infinitesimal deformations of the near-horizon geometry along transverse null geodesics. We show that, up to a gauge transformation, the linearised Einstein equations reduce to an elliptic PDE for the extrinsic curvature of a cross-section of the horizon. We deduce that for a given near-horizon geometry there exists a finite dimensional moduli space of infinitesimal transverse deformations. We then establish a uniqueness theorem for transverse deformations of the extreme Kerr horizon. In particular, we prove that the only smooth axisymmetric transverse deformation of the near-horizon geometry of extreme Kerr, such that cross-sections of the horizon are marginally trapped surfaces, corresponds to that of the extreme Kerr black hole. Furthermore, we determine all smooth and biaxisymmetric transverse deformations of the near-horizon geometry of the five-dimensional extreme Myers-Perry black hole with equal angular momenta. We find a three parameter family of solutions such that cross-sections of the horizon are marginally trapped, which is more general than the known black hole solutions. We discuss the possibility that they correspond to new five-dimensional vacuum black holes.

  18. Rainfall variability and extremes over southern Africa: assessment of a climate model to reproduce daily extremes

    NASA Astrophysics Data System (ADS)

    Williams, C.; Kniveton, D.; Layberry, R.

    2009-04-01

    It is increasingly accepted that that any possible climate change will not only have an influence on mean climate but may also significantly alter climatic variability. A change in the distribution and magnitude of extreme rainfall events (associated with changing variability), such as droughts or flooding, may have a far greater impact on human and natural systems than a changing mean. This issue is of particular importance for environmentally vulnerable regions such as southern Africa. The subcontinent is considered especially vulnerable to and ill-equipped (in terms of adaptation) for extreme events, due to a number of factors including extensive poverty, famine, disease and political instability. Rainfall variability and the identification of rainfall extremes is a function of scale, so high spatial and temporal resolution data are preferred to identify extreme events and accurately predict future variability. The majority of previous climate model verification studies have compared model output with observational data at monthly timescales. In this research, the assessment of ability of a state of the art climate model to simulate climate at daily timescales is carried out using satellite derived rainfall data from the Microwave Infra-Red Algorithm (MIRA). This dataset covers the period from 1993-2002 and the whole of southern Africa at a spatial resolution of 0.1 degree longitude/latitude. The ability of a climate model to simulate current climate provides some indication of how much confidence can be applied to its future predictions. In this paper, simulations of current climate from the UK Meteorological Office Hadley Centre's climate model, in both regional and global mode, are firstly compared to the MIRA dataset at daily timescales. This concentrates primarily on the ability of the model to simulate the spatial and temporal patterns of rainfall variability over southern Africa. Secondly, the ability of the model to reproduce daily rainfall extremes will

  19. Achondrogenesis type II with normally developed extremities: a case report.

    PubMed

    Kocakoc, Ercan; Kiris, Adem

    2002-07-01

    We present a case of achondrogenesis type II with normally developed extremities that was confirmed with postmortem ultrasonographic and radiographic examination. The length of the long bones may vary and the diagnosis of achondrogenesis should not be ruled out with normally developed extremities. Intrauterine sonographic examination of the vertebrae is very important and the absence of vertebral body ossification may be the unique finding of achondrogenesis type II. Axial ultrasonographic images and postmortem plain radiographs are useful to clarify the pathology.

  20. On the Bimodality of ENSO Cycle Extremes

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2000-01-01

    On the basis of sea surface temperature in the El Nino 3.4 region (5 deg. N.,-5 deg. S., 120-170 deg. W.) during the interval of 1950-1997, Kevin Trenberth previously has identified some 16 El Nino and 10 La Nina, these 26 events representing the extremes of the quasi-periodic El Nino-Southern Oscillation (ENSO) cycle. Runs testing shows that the duration, recurrence period, and sequencing of these extremes vary randomly. Hence, the decade of the 1990's, especially for El Nino, is not significantly different from that of previous decadal epochs, at least, on the basis of the frequency of onsets of ENSO extremes. Additionally, the distribution of duration for both El Nino and La Nina looks strikingly bimodal, each consisting of two preferred modes, about 8- and 16-mo long for El Nino and about 9- and 18-mo long for La Nina, as does the distribution of the recurrence period for El Nino, consisting of two preferred modes about 21- and 50-mo long. Scatterplots of the recurrence period versus duration for El Nino are found to be statistically important, displaying preferential associations that link shorter (longer) duration with shorter (longer) recurrence periods. Because the last onset of El Nino occurred in April 1997 and the event was of longer than average duration, onset of the next anticipated El Nino is not expected until February 2000 or later.

  1. On The Bimodality of ENSO Cycle Extremes

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2000-01-01

    On the basis of sea surface temperature in the El Nino 3.4 region (5N.-5S., 120-170W.) during the interval of 1950-1997, Kevin Trenberth previously has identified some 16 El Nino and 10 La Nina, these 26 events representing the extremes of the quasi-periodic El Nino-Southern Oscillation (ENSO) cycle. Runs testing shows that the duration, recurrence period, and sequencing of these extremes vary randomly. Hence, the decade of the 1990's, especially for El Nino, is not significantly different from that of previous decadal epochs, at least, on the basis of the frequency of onsets of ENSO extremes. Additionally, the distribution of duration for both El Nino and La Nina looks strikingly bimodal, each consisting of two preferred modes, about 8- and 16-months long for El Nino and about 9- and 18-months long for La Nina, as does the distribution of the recurrence period for El Nino, consisting of two preferred modes about 21- and 50- mo long. Scatterplots of the recurrence period versus duration for El Nino are found to be statistically important, displaying preferential associations that link shorter (longer) duration with shorter (longer) recurrence periods. Because the last onset of El Nino occurred in April 1997 and the event was of longer than average duration, onset of the next anticipated El Nino is not expected until February 2000 or later.

  2. Extreme hydrological events and security

    NASA Astrophysics Data System (ADS)

    Kundzewicz, Z. W.; Matczak, P.

    2015-06-01

    Economic losses caused by hydrological extremes - floods and droughts - have been on the rise, worldwide. Hydrological extremes jeopardize human security and cause serious threats to human life and welfare and societal livelihood. Floods and droughts can undermine societies' security, understood as freedom from threat and the ability of societies to maintain their independent identity and their functional integrity against forces of change. Several dimensions of security are reviewed in the context of hydrological extremes. Floods and droughts pose a burden and serious challenges to the state, responsible to sustain economic development, societal and environmental security - the maintenance of ecosystem services, on which a society depends. It is shown that reduction of risk of hydrological disasters improves human security.

  3. Functional metagenomics of extreme environments.

    PubMed

    Mirete, Salvador; Morgante, Verónica; González-Pastor, José Eduardo

    2016-04-01

    The bioprospecting of enzymes that operate under extreme conditions is of particular interest for many biotechnological and industrial processes. Nevertheless, there is a considerable limitation to retrieve novel enzymes as only a small fraction of microorganisms derived from extreme environments can be cultured under standard laboratory conditions. Functional metagenomics has the advantage of not requiring the cultivation of microorganisms or previous sequence information to known genes, thus representing a valuable approach for mining enzymes with new features. In this review, we summarize studies showing how functional metagenomics was employed to retrieve genes encoding for proteins involved not only in molecular adaptation and resistance to extreme environmental conditions but also in other enzymatic activities of biotechnological interest. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Extreme solar-terrestrial events

    NASA Astrophysics Data System (ADS)

    Dal Lago, A.; Antunes Vieira, L. E.; Echer, E.; Balmaceda, L. A.; Rockenbach, M.; Gonzalez, W. D.

    2017-10-01

    Extreme solar-terrestrial events are those in which very energetic solar ejections hit the earth?s magnetosphere, causing intense energization of the earth?s ring current. Statistically, their occurrence is approximately once per Gleissberg solar cycle (70-100yrs). The solar transient occurred on July, 23rd (2012) was potentially one of such extreme events. The associated coronal mass ejection (CME), however, was not ejected towards the earth. Instead, it hit the STEREO A spacecraft, located 120 degrees away from the Sun-Earth line. Estimates of the geoeffectiveness of such a CME point to a scenario of extreme Space Weather conditions. In terms of the ring current energization, as measured by the Disturbance Storm-Time index (Dst), had this CME hit the Earth, it would have caused the strongest geomagnetic storm in space era.

  5. Approach to Lower Extremity Edema.

    PubMed

    Ratchford, Elizabeth V; Evans, Natalie S

    2017-03-01

    Lower extremity edema is extremely common among patients seen across multiple specialties. The differential diagnosis is broad and ranges from simple dependent edema to more complex conditions such as chronic venous disease and lymphedema. Several key features from the history and physical exam can assist with the diagnosis. Imaging is rarely necessary at the initial visit unless venous thromboembolism is suspected. Treatment is specific to the etiology of the edema, but compression stockings, elevation, exercise, and weight loss remain the cornerstone in most cases.

  6. Extreme Conditions Modeling Workshop Report

    SciTech Connect

    Coe, R. G.; Neary, V. S.; Lawson, M. J.; Yu, Y.; Weber, J.

    2014-07-01

    Sandia National Laboratories (SNL) and the National Renewable Energy Laboratory (NREL) hosted the Wave Energy Converter (WEC) Extreme Conditions Modeling (ECM) Workshop in Albuquerque, NM on May 13th-14th, 2014. The objective of the workshop was to review the current state of knowledge on how to model WECs in extreme conditions (e.g. hurricanes and other large storms) and to suggest how U.S. Department of Energy (DOE) and national laboratory resources could be used to improve ECM methods for the benefit of the wave energy industry.

  7. Automation Rover for Extreme Environments

    NASA Technical Reports Server (NTRS)

    Sauder, Jonathan; Hilgemann, Evan; Johnson, Michael; Parness, Aaron; Hall, Jeffrey; Kawata, Jessie; Stack, Kathryn

    2017-01-01

    Almost 2,300 years ago the ancient Greeks built the Antikythera automaton. This purely mechanical computer accurately predicted past and future astronomical events long before electronics existed1. Automata have been credibly used for hundreds of years as computers, art pieces, and clocks. However, in the past several decades automata have become less popular as the capabilities of electronics increased, leaving them an unexplored solution for robotic spacecraft. The Automaton Rover for Extreme Environments (AREE) proposes an exciting paradigm shift from electronics to a fully mechanical system, enabling longitudinal exploration of the most extreme environments within the solar system.

  8. Extreme value analysis in biometrics.

    PubMed

    Hüsler, Jürg

    2009-04-01

    We review some approaches of extreme value analysis in the context of biometrical applications. The classical extreme value analysis is based on iid random variables. Two different general methods are applied, which will be discussed together with biometrical examples. Different estimation, testing, goodness-of-fit procedures for applications are discussed. Furthermore, some non-classical situations are considered where the data are possibly dependent, where a non-stationary behavior is observed in the data or where the observations are not univariate. A few open problems are also stated.

  9. Uncommon upper extremity compression neuropathies.

    PubMed

    Knutsen, Elisa J; Calfee, Ryan P

    2013-08-01

    Hand surgeons routinely treat carpal and cubital tunnel syndromes, which are the most common upper extremity nerve compression syndromes. However, more infrequent nerve compression syndromes of the upper extremity may be encountered. Because they are unusual, the diagnosis of these nerve compression syndromes is often missed or delayed. This article reviews the causes, proposed treatments, and surgical outcomes for syndromes involving compression of the posterior interosseous nerve, the superficial branch of the radial nerve, the ulnar nerve at the wrist, and the median nerve proximal to the wrist. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Characteristics of Extreme Auroral Charging Events

    NASA Technical Reports Server (NTRS)

    Minow, Joseph I.; Willis, Emily M.; Parker, Linda Neergard

    2014-01-01

    The highest level spacecraft charging observed in low Earth orbit (LEO) occurs when spacecraft are exposed to energetic auroral electrons. Since auroral charging has been identified as a mechanism responsible for on-orbit anomalies and even possible satellite failures it is important to consider extreme auroral charging events as design and test environments for spacecraft to be used in high inclination LEO orbits. This paper will report on studies of extreme auroral charging events using data from the SSJ/4 and SSJ/5 precipitating electron and ion sensors on the Defense Meteorology Satellite Program (DMSP) satellites. Early studies of DMSP charging to negative potentials =100 V focused on statistics of the electron environment responsible for charging. Later statistical studies of auroral charging have generally focused on solar cycle dependence of charging behavior and magnitude of the maximum potential and duration of the charging events. We extend these studies to focus on more detailed investigations of extreme charging event characteristics that are required to evaluate potential threats to spacecraft systems. A collection of example auroral charging events is assembled from the DMSP data set using the criteria that "extreme auroral charging" is defined as periods with spacecraft negative potentials =400 V. Specific characteristics to be treated include (but are not limited to) maximum and mean potentials, time history of spacecraft potentials through the events, total charging duration and the time potentials exceed voltage thresholds, frame charging/discharging rates, and information on geographic and geomagnetic latitudes at which the events are observed. Finally, we will comment on the implications of these studies for potential auroral charging risks to the International Space Station.

  11. Upper Extremity Deep Vein Thrombosis: A Community-Based Perspective

    PubMed Central

    Spencer, Frederick A.; Emery, Cathy; Lessard, Darleen; Goldberg, Robert J.

    2010-01-01

    Purpose The purpose of this study was to examine the magnitude, risk factors, management strategies, and outcomes in a population-based investigation of patients with upper, as compared to lower, extremity deep vein thrombosis diagnosed in 1999. Methods The medical records of all residents from Worcester, Massachusetts (2000 census=478,000) diagnosed with ICD-9 codes consistent with possible deep vein thrombosis at all Worcester hospitals during 1999 were reviewed and validated. Results The age-adjusted attack rate (per 100,000 population) of upper extremity deep vein thrombosis was 16 (95% CI 13, 20) compared to 91 (83,100) for lower extremity deep vein thrombosis. Patients with upper extremity deep vein thrombosis were significantly more likely to have undergone recent central line placement, a cardiac procedure, or an intensive care unit admission than patients with lower extremity deep vein thrombosis. Although short and 1-year recurrence rates of venous thromboembolism and all-cause mortality were not significantly different between patients with upper, versus lower, extremity deep vein thrombosis, patients with upper extremity deep vein thrombosis were less likely to have pulmonary embolism at presentation or in follow-up. Conclusions Patients with upper extremity deep vein thrombosis represent a clinically important patient population in the community setting. Risk factors, occurrence of pulmonary embolism, and timing and location of venous thromboembolism recurrence differ between patients with upper as compared to lower extremity deep vein thrombosis. These data suggest that strategies for prophylaxis and treatment of upper extremity deep vein thrombosis need further study and refinement. PMID:17679126

  12. Representing Extreme Temperature Events and Resolving Their Implications for Yield

    NASA Astrophysics Data System (ADS)

    Huybers, P. J.; Mueller, N. D.; Butler, E. E.; Tingley, M.; McKinnon, K. A.; Rhines, A. N.

    2014-12-01

    Although it is well recognized that extreme temperatures occurring at particular growth stages are destructive to yield, there appears substantial scope for improved empirical assessment and simulation of the relationship between temperature and yield. Several anecdotes are discussed. First, a statistical analysis of historical U.S. extreme temperatures is provided. It is demonstrated that both reanalysis and model simulations significantly differ from near-surface temperature observations in the frequency and magnitude of extremes. This finding supports empirical assessment using near-surface instrumental records and underscores present difficulties in simulating past and predicting future changes. Second, an analysis of the implications of extreme temperatures on U.S. maize yield is provided where the response is resolved regionally and according to growth stage. Sensitivity to extreme temperatures during silking is found to be uniformly high across the U.S., but the response during grain filling varies spatially, with higher sensitivity in the North. This regional and growth-stage dependent sensitivity implies the importance of representing cultivar, planting times, and development rates, and is also indicative of the potential for future changes according to the combined effects of climate and technology. Finally, interaction between extreme temperatures and agriculture is indicated by analysis showing that historical extreme temperatures in the U.S. Midwest have cooled in relation to changes in regional productivity, possibly because of greater potential for cooling through evapotranspiration. This interpretation is consistent with changes in crop physiology and management, though also noteworthy is that the moderating influence of increased evapotranspiration on extreme temperatures appears to be lost during severe drought. Together, these findings indicate that a more accurate assessment of the historical relationship between extreme temperatures and yield

  13. A comparative assessment of statistical methods for extreme weather analysis

    NASA Astrophysics Data System (ADS)

    Schlögl, Matthias; Laaha, Gregor

    2017-04-01

    Extreme weather exposure assessment is of major importance for scientists and practitioners alike. We compare different extreme value approaches and fitting methods with respect to their value for assessing extreme precipitation and temperature impacts. Based on an Austrian data set from 25 meteorological stations representing diverse meteorological conditions, we assess the added value of partial duration series over the standardly used annual maxima series in order to give recommendations for performing extreme value statistics of meteorological hazards. Results show the merits of the robust L-moment estimation, which yielded better results than maximum likelihood estimation in 62 % of all cases. At the same time, results question the general assumption of the threshold excess approach (employing partial duration series, PDS) being superior to the block maxima approach (employing annual maxima series, AMS) due to information gain. For low return periods (non-extreme events) the PDS approach tends to overestimate return levels as compared to the AMS approach, whereas an opposite behavior was found for high return levels (extreme events). In extreme cases, an inappropriate threshold was shown to lead to considerable biases that may outperform the possible gain of information from including additional extreme events by far. This effect was neither visible from the square-root criterion, nor from standardly used graphical diagnosis (mean residual life plot), but from a direct comparison of AMS and PDS in synoptic quantile plots. We therefore recommend performing AMS and PDS approaches simultaneously in order to select the best suited approach. This will make the analyses more robust, in cases where threshold selection and dependency introduces biases to the PDS approach, but also in cases where the AMS contains non-extreme events that may introduce similar biases. For assessing the performance of extreme events we recommend conditional performance measures that focus

  14. Statistical downscaling of extreme events in the Mediterranean area

    NASA Astrophysics Data System (ADS)

    Hertig, Elke; Jacobeit, Jucundus

    2010-05-01

    In the context of future projections of climate change, extreme events are considered to be more important than slowly changing mean conditions. In the present study percentile-based indices of extreme temperature and precipitation are derived from station data as well as from high-resolution gridded data for terrestrial areas in the Mediterranean region. As large-scale predictors for statistical downscaling models, geopotential heights, thickness of the 1000hPa/500hPa layer, and atmospheric humidity are primarily considered. Downscaling from these predictors to Mediterranean extremes indices is done by Multiple Regression and Canonical Correlation Analyses. In order to account for non-stationarities of the models, analyses are realised for different calibration periods and corresponding verification periods. Model performance in the verification periods is assessed by means of correlation coefficients between modelled and observed extremes indices as well as by the reduction of variance being similar to the root mean squared skill score. Output from different coupled global circulation models integrated under A1B- and B1-scenario assumptions is used to assess changes of extreme temperature and precipitation due to enhanced greenhouse warming conditions. Results indicate that the downscaling assessments can vary considerably depending on the particular predictors used in the statistical models. Climatic as well as dynamic factors influence extreme conditions and should be considered in a combined manner within downscaling models. Regarding temperature extremes, results imply that changes do not follow a simple shift of the whole temperature distribution to higher values since the intra-annual extreme temperature range is indicated to decrease in most parts of the Mediterranean area during the course of the 21st century. This is due to widespread findings that extreme minimum temperatures in winter will increase stronger compared to extreme maximum temperatures in

  15. Consequences and Costs of Lower Extremity Injuries

    PubMed Central

    Dischinger, PC; Read, KM; Kufera, JA; Kerns, TJ; Burch, CA; Jawed, N; Ho, SM; Burgess, AR

    2004-01-01

    Lower extremity injuries resulting from motor vehicle crashes are common and have become relatively more important as more drivers with newer occupant restraints survive high-energy crashes. CIREN data provide a greater level of clinical detail based on coding guidelines from the Orthopedic Trauma Association. These detailed data, in conjunction with long-term follow-up data obtained from patient interviews, reveal that the most costly and disabling injuries are those involving articular (joint) surfaces, especially those of the ankle/foot. Patients with such injuries exhibit residual physical and psychosocial problems, even at one year post-trauma. PMID:15319134

  16. [Importance of biotin metabolism].

    PubMed

    Rodríguez Meléndez, R

    2000-01-01

    Biotin is a water soluble enzyme cofactor that belongs to the vitamin B complex. In humans, biotin is involved in important metabolic pathways such as gluconeogenesis, fatty acid synthesis, and amino acid catabolism by acting a as prosthetic group for pyruvate carboxylase, propionyl-CoA carboxylase, beta-methylcrotinyl-CoA carboxylase, and acetyl-CoA carboxylase. Carboxylases are synthesized as apo-carboxylases without biotin and the active form is produced by their covalent binding of biotin to the epsilon-amino group of a lysine residue of the apocarboxylases. This reaction is catalyzed by the holo-carboxylase synthetase. The last step in the degradation of carboxylases, the cleavage of the biotinyl moiety from the epsilon-amino group lysine residues, is catalyzed by biotinidase and results in the release of free biotin, which can be recycled. Biotin regulates the catabolic enzyme propionyl-CoA carboxylase at the posttranscriptional level whereas the holo-carboxylase synthetase is regulated at the transcriptional level. Aside from its role in the regulation of gene expression of carboxylases, biotin has been implicated in the induction of the receptor for the asialoglycoprotein, glycolytic enzymes and of egg yolk biotin binding proteins. Biotin deficiency in humans is extremely rare and is generally associated with prolonged parenteral nutrition, the consumption of large quantities of avidin, usually in the form of raw eggs, severe malnutrition and, inherited metabolic disorders. In humans, there are autosomal recessive disorders of biotin metabolism that result from the disruption of the activity of biotinidase or holo-carboxylase synthetase.

  17. Expansion of chemical space for collaborative lead generation and drug discovery: the European Lead Factory Perspective.

    PubMed

    Karawajczyk, Anna; Giordanetto, Fabrizio; Benningshof, Jorg; Hamza, Daniel; Kalliokoski, Tuomo; Pouwer, Kees; Morgentin, Remy; Nelson, Adam; Müller, Gerhard; Piechot, Alexander; Tzalis, Dimitrios

    2015-11-01

    High-throughput screening (HTS) represents a major cornerstone of drug discovery. The availability of an innovative, relevant and high-quality compound collection to be screened often dictates the final fate of a drug discovery campaign. Given that the chemical space to be sampled in research programs is practically infinite and sparsely populated, significant efforts and resources need to be invested in the generation and maintenance of a competitive compound collection. The European Lead Factory (ELF) project is addressing this challenge by leveraging the diverse experience and know-how of academic groups and small and medium enterprises (SMEs) engaged in synthetic and/or medicinal chemistry. Here, we describe the novelty, diversity, structural complexity, physicochemical characteristics and overall attractiveness of this first batch of ELF compounds for HTS purposes.

  18. How extreme is extreme? An assessment of daily rainfall distribution tails

    NASA Astrophysics Data System (ADS)

    Papalexiou, S. M.; Koutsoyiannis, D.; Makropoulos, C.

    2013-02-01

    The upper part of a probability distribution, usually known as the tail, governs both the magnitude and the frequency of extreme events. The tail behaviour of all probability distributions may be, loosely speaking, categorized into two families: heavy-tailed and light-tailed distributions, with the latter generating "milder" and less frequent extremes compared to the former. This emphasizes how important for hydrological design it is to assess the tail behaviour correctly. Traditionally, the wet-day daily rainfall has been described by light-tailed distributions like the Gamma distribution, although heavier-tailed distributions have also been proposed and used, e.g., the Lognormal, the Pareto, the Kappa, and other distributions. Here we investigate the distribution tails for daily rainfall by comparing the upper part of empirical distributions of thousands of records with four common theoretical tails: those of the Pareto, Lognormal, Weibull and Gamma distributions. Specifically, we use 15 029 daily rainfall records from around the world with record lengths from 50 to 172 yr. The analysis shows that heavier-tailed distributions are in better agreement with the observed rainfall extremes than the more often used lighter tailed distributions. This result has clear implications on extreme event modelling and engineering design.

  19. How extreme is extreme? An assessment of daily rainfall distribution tails

    NASA Astrophysics Data System (ADS)

    Papalexiou, S. M.; Koutsoyiannis, D.; Makropoulos, C.

    2012-05-01

    The upper part of a probability distribution, usually known as the tail, governs both the magnitude and the frequency of extreme events. The tail behaviour of all probability distributions may be, loosely speaking, categorized in two families: heavy-tailed and light-tailed distributions, with the latter generating more "mild" and infrequent extremes compared to the former. This emphasizes how important for hydrological design is to assess correctly the tail behaviour. Traditionally, the wet-day daily rainfall has been described by light-tailed distributions like the Gamma, although heavier-tailed distributions have also been proposed and used, e.g. the Lognormal, the Pareto, the Kappa, and others. Here, we investigate the issue of tails for daily rainfall by comparing the upper part of empirical distributions of thousands of records with four common theoretical tails: those of the Pareto, Lognormal, Weibull and Gamma distributions. Specifically, we use 15 029 daily rainfall records from around the world with record lengths from 50 to 163 yr. The analysis shows that heavier-tailed distributions are in better agreement with the observed rainfall extremes than the more often used lighter tailed distributios, with clear implications on extreme event modelling and engineering design.

  20. Penetrating trauma to the extremity.

    PubMed

    Manthey, David E; Nicks, Bret A

    2008-02-01

    Penetrating trauma to the extremities is a complex disease that foremost requires the evaluation for vascular injury. This monograph will address an algorithm to assess for associated vascular injury that includes current evaluation techniques. Approaches to wound management and use of antibiotics in the ED are also addressed.

  1. How Cells Endure Extreme Conditions

    SciTech Connect

    2009-01-01

    One of natures most gripping feats of survival is now better understood. For the first time, Berkeley Lab scientists observed the chemical changes in individual cells that enable them to survive in conditions that should kill them. http://newscenter.lbl.gov/feature-stories/2009/07/07/cells-endure-extremes/

  2. The extreme ultraviolet explorer archive

    NASA Astrophysics Data System (ADS)

    Polomski, E.; Drake, J. J.; Dobson, C.; Christian, C.

    1993-09-01

    The Extreme Ultrviolet Explorer (EUVE) public archive was created to handle the storage, maintenance, and distribution of EUVE data and ancillary documentation, information, and software. Access to the archive became available to the public on July 17, 1992, only 40 days after the launch of the EUVE satellite. A brief overview of the archive's contents and the various methods of access will be described.

  3. Tetrasulfide extreme pressure lubricant additives

    SciTech Connect

    Gast, L.E.; Kenney, H.E.; Schwab, A.W.

    1980-08-19

    A novel class of compounds has been prepared comprising the tetrasulfides of /sup 18/C hydrocarbons, /sup 18/C fatty acids, and /sup 18/C fatty and alkyl and triglyceride esters. These tetrasulfides are useful as extreme pressure lubricant additives and show potential as replacements for sulfurized sperm whale oil.

  4. Atmospheric Extreme Events in the North Atlantic Region

    NASA Astrophysics Data System (ADS)

    Franzke, C.

    2012-04-01

    An important part of European weather and climate are storms. European winter storms cause economic damage and insurance losses on the order of billions of Euro per year. European winter storms rank as the second highest cause of global natural catastrophe insurance loss. Many of these hazard events are not independent; for instance, severe storms can occur in trains of storms. Recent examples of such subsequently occurring storms include January 2008 (Paula and Resi) and March 2008 (Emma, Johanna and Kirsten). Each of these trains of storms caused damages on the order of ~€1bn. Extreme value statistics are based on the premise that extreme events are iid but this is rarely the case in natural systems where extreme events tend to cluster. Thus, no account is taken of memory and correlation that characterise many natural time series; this fundamentally limits our ability to forecast and to estimate return periods of extreme events. In my presentation I will discuss two possible causes of this clustering: (i) The propensity of extreme events to depend on large-scale circulation regimes and (ii) the long-range correlation properties of surface windspeeds enhances the likelihood of extreme events to cluster. These two characteristics affect the return periods of atmospheric extreme events and thus insurance pricing.

  5. Extreme events in Faraday waves

    NASA Astrophysics Data System (ADS)

    Punzmann, Horst; Shats, Michael; Xia, Hua

    2014-05-01

    Observations of extreme wave events in the ocean are rare due to their low statistical probability. In the laboratory however, the evolution of extreme wave events can be studied in great detail with high spatial and temporal resolution. The reported surface wave experiments in the short wavelength gravity-capillary range aim to contribute to the understanding of some of the underlying mechanisms for rogue wave generation. In this talk, we report on extreme wave events in parametrically excited Faraday waves. Faraday waves appear if a fluid is accelerated (normal to the fluid surface) above a critical threshold. A variety of novel tools have been deployed to characterize the 2D surface elevation. The results presented show spatio-temporal and statistical data on the surface wave conditions leading up to extreme wave events. The peak in wave amplitude during such an event is shown to exceed six times the standard deviation of the average wave field with significantly increased statistical probability compared to the background wave field [1]. The experiments also show that parametrically excited waves can be viewed as assembles of oscillons [2] (or oscillating solitons) where modulation instability seems to play a crucial role in their formation. More detailed studies on the oscillon dynamics reveal that the onset of an increased probability of extreme wave events correlates with the increase in the oscillons mobility and merger [3]. Reference: 1. Xia H., Maimbourg T., Punzmann H., and Shats M., Oscillon dynamics and rogue wave generation in Faraday surface ripples, Physical Review Letters 109, 114502 (2012) 2. Shats M., Xia H., and Punzmann H., Parametrically excited water surface ripples as ensembles of oscillons, Physical Review Letters 108, 034502 (2012) 3. Shats M., Punzmann H., Xia H., Capillary rogue waves, Physical Review Letters, 104, 104503 (2010)

  6. The Extreme Universe Space Observatory

    NASA Technical Reports Server (NTRS)

    Adams, Jim; Six, N. Frank (Technical Monitor)

    2002-01-01

    This talk will describe the Extreme Universe Space Observatory (EUSO) mission. EUSO is an ESA mission to explore the most powerful energy sources in the universe. The mission objectives of EUSO are to investigate EECRs, those with energies above 3x10(exp 19) eV, and very high-energy cosmic neutrinos. These objectives are directly related to extreme conditions in the physical world and possibly involve the early history of the big bang and the framework of GUTs. EUSO tackles the basic problem posed by the existence of these extreme-energy events. The solution could have a unique impact on fundamental physics, cosmology, and/or astrophysics. At these energies, magnetic deflection is thought to be so small that the EECR component would serve as the particle channel for astronomy. EUSO will make the first measurements of EAS from space by observing atmospheric fluorescence in the Earth's night sky. With measurements of the airshower track, EUSO will determine the energy and arrival direction of these extreme-energy events. EUSO will make high statistics observations of CRs beyond the predicted GZK cutoff energy and widen the channel for high-energy neutrino astronomy. The energy spectra, arrival directions, and shower profiles will be analyzed to distinguish the nature of these events and search for their sources. With EUSO data, we will have the possibility to discover a local EECR source, test Z-burst scenarios and other theories, and look for evidence of the breakdown of the relativity principle at extreme Lorentz factors.

  7. Extreme Value Laws for Dynamical Systems with Countable Extremal Sets

    NASA Astrophysics Data System (ADS)

    Azevedo, Davide; Freitas, Ana Cristina Moreira; Freitas, Jorge Milhazes; Rodrigues, Fagner B.

    2017-06-01

    We consider stationary stochastic processes arising from dynamical systems by evaluating a given observable along the orbits of the system. We focus on the extremal behaviour of the process, which is related to the entrance in certain regions of the phase space, which correspond to neighbourhoods of the maximal set M, i.e.,the set of points where the observable is maximised. The main novelty here is the fact that we consider that the set M may have a countable number of points, which are associated by belonging to the orbit of a certain point, and may have accumulation points. In order to prove the existence of distributional limits and study the intensity of clustering, given by the Extremal Index, we generalise the conditions previously introduced in Freitas (Adv Math 231(5): 2626-2665, 2012, Stoch Process Appl 125(4): 1653-1687, 2015).

  8. A global quantification of compound precipitation and wind extremes

    NASA Astrophysics Data System (ADS)

    Martius, Olivia; Pfahl, Stephan; Chevalier, Clément

    2017-04-01

    The concomitant occurrence of extreme precipitation and winds can have severe impacts. Here this concomitant occurrence is quantified globally using ERA-Interim reanalysis data. A logistic regression model is used to determine significant changes in the odds ratio of precipitation extremes given a wind extreme occurs on the same day, the day before or the day after. High percentages of co-occurring wind and precipitation extremes are found in coastal regions and in areas with frequent tropical cyclones, with maxima of more than 50% of concomitant events. Strong regional-scale variations in this percentage are related to the interaction of weather systems with topography resulting in Föhn winds, gap winds, and orographic drying, and the structure and tracks of extratropical and tropical cyclones. The percentage of concomitant events increases substantially if spatial shifts by one grid point are taken into account. Such spatially shifted, but co-occurring events are important in insurance applications.

  9. A global quantification of compound precipitation and wind extremes

    NASA Astrophysics Data System (ADS)

    Martius, Olivia; Pfahl, Stephan; Chevalier, Clément

    2016-07-01

    The concomitant occurrence of extreme precipitation and winds can have severe impacts. Here this concomitant occurrence is quantified globally using ERA-Interim reanalysis data. A logistic regression model is used to determine significant changes in the odds of precipitation extremes given a wind extreme that occurs on the same day, the day before, or the day after. High percentages of cooccurring wind and precipitation extremes are found in coastal regions and in areas with frequent tropical cyclones, with maxima of more than 50% of concomitant events. Strong regional-scale variations in this percentage are related to the interaction of weather systems with topography resulting in Föhn winds, gap winds, and orographic drying and the structure and tracks of extratropical and tropical cyclones. The percentage of concomitant events increases substantially if spatial shifts by one grid point are taken into account. Such spatially shifted but cooccurring events are important in insurance applications.

  10. [Prehospital care in extremity major vascular injuries].

    PubMed

    Samokhvallov, I M; Reva, V A; Pronchenko, A A; Seleznev, A B

    2011-09-01

    The problem of temporary hemorrhage control is one of the most important issues of modern war surgery and surgery of trauma. It is a review of literature devoted to prehospital care in extremity major vascular injuries, embraced up-to-date domestic materials as well as the modern foreign papers in this area. The most important historical landmarks of temporary hemorrhage control system are considered. We paid special attention to the most usable methods and means of hemorrhage control which are utilized at the modern time: pressure bandages, tourniquets, local haemostatic agents. The comprehensive analysis of the contamporary haemostatic means concerning U.S. Army has done. The experience of foreign colleagues in development of prehospital care for the injured, creation and progress of new haemostatic methods, application of temporary hemorrhage control system is analyzed.

  11. Future crop production threatened by extreme heat

    NASA Astrophysics Data System (ADS)

    Siebert, Stefan; Ewert, Frank

    2014-04-01

    Heat is considered to be a major stress limiting crop growth and yields. While important findings on the impact of heat on crop yield have been made based on experiments in controlled environments, little is known about the effects under field conditions at larger scales. The study of Deryng et al (2014 Global crop yield response to extreme heat stress under multiple climate change futures Environ. Res. Lett. 9 034011), analysing the impact of heat stress on maize, spring wheat and soya bean under climate change, represents an important contribution to this emerging research field. Uncertainties in the occurrence of heat stress under field conditions, plant responses to heat and appropriate adaptation measures still need further investigation.

  12. The 2014 Silba Precipitation Extreme

    NASA Astrophysics Data System (ADS)

    Rasol, Dubravka; Ólafsson, Haraldur

    2015-04-01

    On 30 July 2014 a 24 h precipitation record of 218 mm was set at the island of Silba in the N-Adriatic Sea. The precipitation was of convective nature and significantly less precipitation was recorded only small distances away, at the coast of mainland Croatia. The event is reproduced numerically and discussed in terms of dynamics and predictability. On a large scale, the precipitation extreme was associated with a slow-moving upper tropospheric low that formed over the N-Atlantic several days earlier. At lower levels, there were humid mediterranean airmasses. On a smaller scale, there are indications that the extreme convection may have been triggered by an orographic disturbance.

  13. On causality of extreme events

    PubMed Central

    2016-01-01

    Multiple metrics have been developed to detect causality relations between data describing the elements constituting complex systems, all of them considering their evolution through time. Here we propose a metric able to detect causality within static data sets, by analysing how extreme events in one element correspond to the appearance of extreme events in a second one. The metric is able to detect non-linear causalities; to analyse both cross-sectional and longitudinal data sets; and to discriminate between real causalities and correlations caused by confounding factors. We validate the metric through synthetic data, dynamical and chaotic systems, and data representing the human brain activity in a cognitive task. We further show how the proposed metric is able to outperform classical causality metrics, provided non-linear relationships are present and large enough data sets are available. PMID:27330866

  14. Extreme Conditions Modeling Workshop Report

    SciTech Connect

    Coe, Ryan Geoffrey; Neary, Vincent Sinclair; Lawon, Michael J.; Yu, Yi-Hsiang; Weber, Jochem

    2014-07-01

    Sandia National Laboratories (SNL) and the National Renewable Energy Laboratory (NREL) hosted the Wave Energy Converter (WEC) Extreme Conditions Modeling (ECM) Workshop in Albuquerque, New Mexico on May 13–14, 2014. The objective of the workshop was to review the current state of knowledge on how to numerically and experimentally model WECs in extreme conditions (e.g. large ocean storms) and to suggest how national laboratory resources could be used to improve ECM methods for the benefit of the wave energy industry. More than 30 U.S. and European WEC experts from industry, academia, and national research institutes attended the workshop, which consisted of presentations from W EC developers, invited keynote presentations from subject matter experts, breakout sessions, and a final plenary session .

  15. The Extremes of AGN Variability

    NASA Astrophysics Data System (ADS)

    Komossa, S.; Grupe, D.; Schartel, N.; Gallo, L.; Gomez, J. L.; Kollatschny, W.; Kriss, G.; Leighly, K.; Longinotti, A. L.; Parker, M.; Santos-Lleo, M.; Wilkins, D.; Zetzl, M.

    We present results from our ongoing monitoring programs aimed at identifying and understanding Active Galactic Nuclei (AGN) in extreme flux and spectral states. Observations of AGN in extreme states can reveal the nature of the inner accretion flow, the physics of matter under strong gravity, and they provide insight on the properties of ionized absorbers and outflows launched near supermassive black holes (SMBHs). We present new results from our long-term monitoring of IC 3599, WPVS007, and Mrk 335, multi-wavelength follow-ups of the newly identified changing-look AGN HE 1136-2304, and UV-X-ray follow-ups of the binary SMBH candidate OJ 287 after its 2015 optical maximum, now in a new optical-X-ray-high-state.

  16. Method for extreme ultraviolet lithography

    DOEpatents

    Felter, T. E.; Kubiak, G. D.

    2000-01-01

    A method of producing a patterned array of features, in particular, gate apertures, in the size range 0.4-0.05 .mu.m using projection lithography and extreme ultraviolet (EUV) radiation. A high energy laser beam is used to vaporize a target material in order to produce a plasma which in turn, produces extreme ultraviolet radiation of a characteristic wavelength of about 13 nm for lithographic applications. The radiation is transmitted by a series of reflective mirrors to a mask which bears the pattern to be printed. The demagnified focused mask pattern is, in turn, transmitted by means of appropriate optics and in a single exposure, to a substrate coated with photoresists designed to be transparent to EUV radiation and also satisfy conventional processing methods.

  17. Method for extreme ultraviolet lithography

    DOEpatents

    Felter, T. E.; Kubiak, Glenn D.

    1999-01-01

    A method of producing a patterned array of features, in particular, gate apertures, in the size range 0.4-0.05 .mu.m using projection lithography and extreme ultraviolet (EUV) radiation. A high energy laser beam is used to vaporize a target material in order to produce a plasma which in turn, produces extreme ultraviolet radiation of a characteristic wavelength of about 13 nm for lithographic applications. The radiation is transmitted by a series of reflective mirrors to a mask which bears the pattern to be printed. The demagnified focused mask pattern is, in turn, transmitted by means of appropriate optics and in a single exposure, to a substrate coated with photoresists designed to be transparent to EUV radiation and also satisfy conventional processing methods.

  18. Extreme Rainfall and Flooding in Urban Environments

    NASA Astrophysics Data System (ADS)

    Smith, J. A.

    2006-12-01

    The Baltimore Ecosystem Study (BES) has provided an exceptional laboratory for examining the coupled hydrometeorological, hydrologic and hydraulic processes that control extreme floods in urban environments. In this paper, we survey the major conclusions drawn from this "laboratory" concerning extreme floods in urban environments. An important effect of urbanization is to increase the sensitivity of urban watersheds to the distribution of short-duration (1 - 60 minutes) rainfall rates. As a consequence, the climatology of urban flooding is closely linked to the climatology of warm season thunderstorm systems. Warm season thunderstorm systems that produce flash floods in Baltimore, exhibit characteristic life cycles that include storm initiation over the Blue Ridge, propagation and upscale growth over the Piedmont region, and interaction with the urban environment and sea breeze circulation systems in the Baltimore metropolitan region. There are pronounced spatial heterogeneities in thunderstorm rainfall over the Baltimore region and these heterogeneities are linked to the effects of urbanization (including frictional effects associated with urban canopy, urban heat island effects and the effects of urban aerosols on storm microphysics and dynamics). The hydrologic response of urban watersheds reflects the interplay of urban infrastructure, rainfall variability and soil hydraulic properties of urban soils in controlling runoff processes. Urban drainage basins in Baltimore include USGS gaging stations with record or near-record frequencies of "extreme floods" for the continental US (extreme floods are defined as unit discharge flood peaks exceeding 1 cms per square km). The hydrologic response of these watersheds is characterized by highly efficient concentration of runoff through the storm drain network and relatively low runoff ratios (the ratio of storm total runoff to rainfall). Analyses suggest that elaboration of the drainage network plays a more important role

  19. Islamist Extremism in East Africa

    DTIC Science & Technology

    2016-08-01

    for the Office of the European Union Special Representative for the Horn of Africa with a specific focus on extreme violence . The views set out in...return home, presenting a new security threat. The rising violence of Islamist extremists has gener- ated a strong response from security actors in...Islamist ideology has been spread- ing throughout East African communities—bringing with it greater societal polarization and violence . Further

  20. [Genes for extreme violent behaviour?].

    PubMed

    Jordan, Bertrand

    2015-01-01

    A new genetic study focussing on the degree of violence in criminals and using both candidate gene and GWAS approaches finds statistically significant associations of extreme violent behaviour with low activity alleles of monoamine oxydase A (MAOA) and with the CD13 gene. However, the alleles implicated are common in the general population, thus they cannot be causal, and only represent potential indicators of increased risk.

  1. Destroying extremal magnetized black holes

    NASA Astrophysics Data System (ADS)

    Siahaan, Haryanto M.

    2017-07-01

    The gedanken experiment by Wald to destroy a black hole using a test particle in the equatorial plane is adapted to the case of extremal magnetized black holes. We find that the presence of external magnetic fields resulting from the "Ernst magnetization" permits a test particle to have strong enough energy to destroy the black hole. However, the corresponding effective potentials show that such particles would never reach the horizon.

  2. Countering Extremism; Beyond Interagency Cooperation

    DTIC Science & Technology

    2011-04-18

    the comparative advantages that DOD has to offer in order to help illuminate how those resources and expertise can best be brought to bear...National Security Strategy. There is no doubt that helping developing nations become peaceful, stable and economically self-sufficient is in the best ...ongoing global extremism; a backlash to Globalization, a Global Insurgency, a Civil War inside Islam, and Asymmetric Warfare. These views are each best

  3. Upper Extremity Injuries in Gymnasts.

    PubMed

    Wolf, Megan R; Avery, Daniel; Wolf, Jennifer Moriatis

    2017-02-01

    Gymnastics is a unique sport, which loads the wrist and arms as weight-bearing extremities. Because of the load demands on the wrist in particular, stress fractures, physeal injury, and overuse syndromes may be observed. This spectrum of injury has been termed "gymnast's wrist," and incorporates such disorders as wrist capsulitis, ligamentous tears, triangular fibrocartilage complex tears, chondromalacia of the carpus, stress fractures, distal radius physeal arrest, and grip lock injury.

  4. Aerospace Materials for Extreme Environments

    DTIC Science & Technology

    2013-03-07

    AFOSR/RTD Air Force Research Laboratory AEROSPACE MATERIALS FOR EXTREME ENVIRONMENTS Date: 7 March 2013 Report Documentation Page Form...ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for...to Washington Headquarters Services, Directorate for Information Operations and Reports , 1215 Jefferson Davis Highway, Suite 1204, Arlington VA

  5. Technology improves upper extremity rehabilitation.

    PubMed

    Kowalczewski, Jan; Prochazka, Arthur

    2011-01-01

    Stroke survivors with hemiparesis and spinal cord injury (SCI) survivors with tetraplegia find it difficult or impossible to perform many activities of daily life. There is growing evidence that intensive exercise therapy, especially when supplemented with functional electrical stimulation (FES), can improve upper extremity function, but delivering the treatment can be costly, particularly after recipients leave rehabilitation facilities. Recently, there has been a growing level of interest among researchers and healthcare policymakers to deliver upper extremity treatments to people in their homes using in-home teletherapy (IHT). The few studies that have been carried out so far have encountered a variety of logistical and technical problems, not least the difficulty of conducting properly controlled and blinded protocols that satisfy the requirements of high-level evidence-based research. In most cases, the equipment and communications technology were not designed for individuals with upper extremity disability. It is clear that exercise therapy combined with interventions such as FES, supervised over the Internet, will soon be adopted worldwide in one form or another. Therefore it is timely that researchers, clinicians, and healthcare planners interested in assessing IHT be aware of the pros and cons of the new technology and the factors involved in designing appropriate studies of it. It is crucial to understand the technical barriers, the role of telesupervisors, the motor improvements that participants can reasonably expect and the process of optimizing IHT-exercise therapy protocols to maximize the benefits of the emerging technology.

  6. Societal Impacts of Climate Extremes

    NASA Astrophysics Data System (ADS)

    Cutter, S. L.

    2011-12-01

    Direct economic losses from weather and climate-sensitive perils in the US are on the rise averaging more than $10billion annually during the past 50 years, a very conservative estimate. Starting in the 1990s and continuing today, crop and property losses from climate extremes are escalating, especially those related to hurricanes/ tropical storms and floods. The pattern for hazard-related mortality is less clear. However, as the US lacks a comprehensive inventory or database of natural hazard losses, these figures are rough estimates. This paper examines the temporal and spatial pattern of losses from climate-sensitive hazards for the US over the past fifty years. It illustrates that how and what you measure matters in the loss calculus (dollars or deaths, insured versus uninsured losses, impacts, or costs, or extreme versus non extreme events). The paper also examines the geographic variability in losses and the differential burdens of climate hazard losses on people and places in the U.S. The paper concludes with two questions: How can the nation reduce losses from climate-sensitive hazards when we don't know how much and where such losses occur? Furthermore, how can policy makers and practitioners assess the effectiveness of any hazard or disaster risk reduction policy when we lack the fundamental baseline of losses against which to measure progress?

  7. Geoeffectiveness of Extreme Solar Winds

    NASA Astrophysics Data System (ADS)

    Alleyne, H.; Nanan, B.; Walker, S.; Reme, H.; Lucek, E.; Andre, M.; Cornilleau-Wehrlin, N.; Fazakerley, A.; Decreau, P.; McCrea, I.; Zhang, S.; van Eyken, A.

    2006-12-01

    The geoeffectiveness of the extreme solar winds that flowed pass the Earth on 24 October 2003, 07 November 2004 and 09 November 2004 are presented using Cluster (FGM, CIS, PEACE, STAFF and EFW) and ground- based (EISCAT radars at 69.6N, 19.2E and IMAGE magnetometer network at 68-79N)observations. The Cluster observations suggest that magnetic reconnection need not be the main process for solar wind entry into the magnetosphere during extreme solar winds. The ion velocity in the magnetosheath-cusp region remains strongly anti-sunward and poleward and ion density remains high irrespective of IMF Bz is negative or positive. The ion velocity components are also found to agree with the ExB velocities. The ground-based observations indicate that the extreme solar winds directly affect the high latitude ionosphere. The solar wind plasma is found to enter the ionosphere through an afternoon cusp that descends to low latitudes during negative IMF Bz period when a westward electrojet is also found to ascend to high latitudes.

  8. Extreme DMSP Auroral Charging: Implications for Auroral Charging Benchmarks

    NASA Astrophysics Data System (ADS)

    Parker, L. N.; Minow, J. I.

    2016-12-01

    One of the more important impacts of severe space weather events on spacecraft systems is surface charging that can result in operational impacts to space missions or even lead to catastrophic failure of critical spacecraft systems. Defining the extreme charging environments within the Earth's magnetosphere is therefore an important task because it not only identifies potential threats to currently operational spacecraft, but it also informs engineering design work on future space systems to assure they will be better able to withstand the most challenging charging environments encountered during extreme space weather events. This presentation will focus on the surface charging measurements available from low Earth orbit, high inclination satellites that can be used to provide insight into auroral charging conditions during extreme space weather events. We will first provide examples of extreme surface charging events identified in records from the SSJ/4 and SSJ/5 precipitating ion and electron sensors on the Defense Meteorological Satellite Program (DMSP) spacecraft. These instruments have been used for many years to characterize the auroral charging threat to spacecraft low Earth orbit at high latitudes. Next, we will discuss which specific space plasma environment parameters are of importance to specifying surface charging and how well these parameters can be characterized using the SSJ records. Finally, we will show examples of extreme charging and the corresponding environments and discuss the implications of the DMSP records for our ability to fully define the "worst case" extreme space weather events required to meet the National Space Weather Action Plan goals of characterizing extreme space weather event benchmarks.

  9. Outcomes for extremely premature infants.

    PubMed

    Glass, Hannah C; Costarino, Andrew T; Stayer, Stephen A; Brett, Claire M; Cladis, Franklyn; Davis, Peter J

    2015-06-01

    Premature birth is a significant cause of infant and child morbidity and mortality. In the United States, the premature birth rate, which had steadily increased during the 1990s and early 2000s, has decreased annually for 7 years and is now approximately 11.39%. Human viability, defined as gestational age at which the chance of survival is 50%, is currently approximately 23 to 24 weeks in developed countries. Infant girls, on average, have better outcomes than infant boys. A relatively uncomplicated course in the intensive care nursery for an extremely premature infant results in a discharge date close to the prenatal estimated date of confinement. Despite technological advances and efforts of child health experts during the last generation, the extremely premature infant (less than 28 weeks gestation) and extremely low birth weight infant (<1000 g) remain at high risk for death and disability with 30% to 50% mortality and, in survivors, at least 20% to 50% risk of morbidity. The introduction of continuous positive airway pressure, mechanical ventilation, and exogenous surfactant increased survival and spurred the development of neonatal intensive care in the 1970s through the early 1990s. Routine administration of antenatal steroids during premature labor improved neonatal mortality and morbidity in the late 1990s. The recognition that chronic postnatal administration of steroids to infants should be avoided may have improved outcomes in the early 2000s. Evidence from recent trials attempting to define the appropriate target for oxygen saturation in preterm infants suggests arterial oxygen saturation between 91% and 95% (compared with 85%-89%) avoids excess mortality; however, final analyses of data from these trials have not been published, so definitive recommendations are still pending. The development of neonatal neurocritical intensive care units may improve neurocognitive outcomes in this high-risk group. Long-term follow-up to detect and address

  10. Advanced Instrumentation for Extreme Environments

    SciTech Connect

    Melin, Alexander M; Kisner, Roger; Fugate, David L

    2013-01-01

    The Department of Energy (DOE) Office of Nuclear Energy (NE) is pursuing embedded instrumentation and controls (I&C) technology for next generation nuclear power generation applications. Embedded systems encompass a wide range of configurations and technologies; we define embedding in this instance as the integration of the sensors and the control system design into the component design using a systems engineering process. Embedded I&C systems are often an essential part of developing new capabilities, improving reliability, enhancing performance, and reducing operational costs. The new intrinsically safe, more efficient, and cost effective reactor technologies (Next Generation Nuclear Plant and Small Modular Reactors) require the development and application of new I&C technologies. These new designs raise extreme environmental challenges such as high temperatures (over 700 C) and material compatibility (e.g., molten salts). The desired reliability and functionality requires measurements in these extreme conditions including high radiation environments which were not previously monitored in real time. The DOE/NE Nuclear Energy Enabling Technologies (NEET) program currently has several projects investigating I&C technologies necessary to make these reactor designs realizable. The project described in this paper has the specific goal of investigating embedded I&C with the following objectives: 1.Explore and quantify the potential gains from embedded I&C improved reliability, increased performance, and reduced cost 2.Identify practical control, sensing, and measurement techniques for the extreme environments found in high-temperature reactors 3.Design and fabricate a functional prototype high-temperature cooling pump for molten salts represents target demonstration of improved performance, reliability, and widespread usage There are many engineering challenges in the design of a high-temperature liquid salt cooling pump. The pump and motor are in direct contact with

  11. Simulating multimodal seasonality in extreme daily precipitation occurrence

    NASA Astrophysics Data System (ADS)

    Tye, Mari R.; Blenkinsop, Stephen; Fowler, Hayley J.; Stephenson, David B.; Kilsby, Christopher G.

    2016-06-01

    Floods pose multi-dimensional hazards to critical infrastructure and society and these hazards may increase under climate change. While flood conditions are dependent on catchment type and soil conditions, seasonal precipitation extremes also play an important role. The extreme precipitation events driving flood occurrence may arrive non-uniformly in time. In addition, their seasonal and inter-annual patterns may also cause sequences of several events and enhance likely flood responses. Spatial and temporal patterns of extreme daily precipitation occurrence are characterized across the UK. Extreme and very heavy daily precipitation is not uniformly distributed throughout the year, but exhibits spatial differences, arising from the relative proximity to the North Atlantic Ocean or North Sea. Periods of weeks or months are identified during which extreme daily precipitation occurrences are most likely to occur, with some regions of the UK displaying multimodal seasonality. A Generalized Additive Model is employed to simulate extreme daily precipitation occurrences over the UK from 1901 to 2010 and to allow robust statistical testing of temporal changes in the seasonal distribution. Simulations show that seasonality has the strongest correlation with intra-annual variations in extreme event occurrence, while Sea Surface Temperature (SST) and Mean Sea Level Pressure (MSLP) have the strongest correlation with inter-annual variations. The north and west of the UK are dominated by MSLP in the mid-North Atlantic and the south and east are dominated by local SST. All regions now have a higher likelihood of autumnal extreme daily precipitation than earlier in the twentieth century. This equates to extreme daily precipitation occurring earlier in the autumn in the north and west, and later in the autumn in the south and east. The change in timing is accompanied by increases in the probability of extreme daily precipitation occurrences during the autumn, and in the number of

  12. Moving in extreme environments: extreme loading; carriage versus distance.

    PubMed

    Lucas, Samuel J E; Helge, Jørn W; Schütz, Uwe H W; Goldman, Ralph F; Cotter, James D

    2016-01-01

    This review addresses human capacity for movement in the context of extreme loading and with it the combined effects of metabolic, biomechanical and gravitational stress on the human body. This topic encompasses extreme duration, as occurs in ultra-endurance competitions (e.g. adventure racing and transcontinental races) and expeditions (e.g. polar crossings), to the more gravitationally limited load carriage (e.g. in the military context). Juxtaposed to these circumstances is the extreme metabolic and mechanical unloading associated with space travel, prolonged bedrest and sedentary lifestyle, which may be at least as problematic, and are therefore included as a reference, e.g. when considering exposure, dangers and (mal)adaptations. As per the other reviews in this series, we describe the nature of the stress and the associated consequences; illustrate relevant regulations, including why and how they are set; present the pros and cons for self versus prescribed acute and chronic exposure; describe humans' (mal)adaptations; and finally suggest future directions for practice and research. In summary, we describe adaptation patterns that are often U or J shaped and that over time minimal or no load carriage decreases the global load carrying capacity and eventually leads to severe adverse effects and manifest disease under minimal absolute but high relative loads. We advocate that further understanding of load carrying capacity and the inherent mechanisms leading to adverse effects may advantageously be studied in this perspective. With improved access to insightful and portable technologies, there are some exciting possibilities to explore these questions in this context.

  13. Plant volatiles in extreme terrestrial and marine environments.

    PubMed

    Rinnan, Riikka; Steinke, Michael; McGenity, Terry; Loreto, Francesco

    2014-08-01

    This review summarizes the current understanding on plant and algal volatile organic compound (VOC) production and emission in extreme environments, where temperature, water availability, salinity or other environmental factors pose stress on vegetation. Here, the extreme environments include terrestrial systems, such as arctic tundra, deserts, CO₂ springs and wetlands, and marine systems such as sea ice, tidal rock pools and hypersaline environments, with mangroves and salt marshes at the land-sea interface. The emission potentials at fixed temperature and light level or actual emission rates for phototrophs in extreme environments are frequently higher than for organisms from less stressful environments. For example, plants from the arctic tundra appear to have higher emission potentials for isoprenoids than temperate species, and hypersaline marine habitats contribute to global dimethyl sulphide (DMS) emissions in significant amounts. DMS emissions are more widespread than previously considered, for example, in salt marshes and some desert plants. The reason for widespread VOC, especially isoprenoid, emissions from different extreme environments deserves further attention, as these compounds may have important roles in stress resistance and adaptation to extremes. Climate warming is likely to significantly increase VOC emissions from extreme environments both by direct effects on VOC production and volatility, and indirectly by altering the composition of the vegetation.

  14. Seasonal Variability of Precipitation Extremes in New York City

    NASA Astrophysics Data System (ADS)

    Polanco, W.

    2016-12-01

    Precipitation extremes can have very important impacts, and it is not known as to how precipitation extremes might change with global warming. New York City is located in the mid-latitude region where there are specific storms that can cause precipitation extremes, predominantly, hurricanes, extratropical cyclones, and quasi-linear convective systems. These storms preferentially occur during different seasons. Therefore, to understand how these different storms relate to precipitation extremes, this study examines NYC precipitation extremes per season. First, NOAA weather station data from January 1979 to December 2014 from the three NYC airports (JFK, LaGuardia and Newark) will be analyzed to derive the climatology, the counts of non-rain events, and the counts of extreme precipitation events. Next, a multi-station average will be used to compare the precipitation events that occur in Spring, Summer, and Fall. The precipitation strength will be compared as well as the temperature anomalies for each season. Then, using reanalysis, composites of the sea level pressure and temperature fields will be calculated for the top events from each season.

  15. Impacts of Amazon deforestation on regional weather and climate extremes

    NASA Astrophysics Data System (ADS)

    Medvigy, D.; Walko, R. L.; Avissar, R.

    2010-12-01

    Recent deforestation projections estimate that 40% of the Amazon rainforest will be deforested by 2050. Many modeling studies have indicated that deforestation will reduce average rainfall in the Amazon. However, very few studies have investigated the potential for deforestation to change the frequency and intensity of extreme climate and weather events. To fill this gap in our understanding, we use a variable-resolution GCM to investigate how precipitation and temperature extremes throughout South America respond to deforestation. The model’s grid mesh is set up to cover South America and nearby oceans at mesoscale (25 km) resolution, and then to gradually coarsen and cover the rest of the world at 200 km resolution. This approach differs from the two most common current approaches: (1) to use a GCM with too coarse of a resolution to evaluate regional climate extremes, or (2) to use a regional atmospheric model that requires lateral boundary conditions from a GCM or reanalysis. We find that deforestation induces large changes in winter (June-July-August) climate throughout much of South America. Extreme cold events become much more common along the eastern slopes of the Andes. The largest changes were in the western Amazon and, surprisingly, in Argentina, far from the actual deforested area. We also find shifts in precipitation extremes, especially in September-October-November. Such changes in temperature and precipitation extremes have important consequences for agriculture, natural ecosystems, and human society.

  16. Compound summer temperature and precipitation extremes over central Europe

    NASA Astrophysics Data System (ADS)

    Sedlmeier, Katrin; Feldmann, H.; Schädler, G.

    2017-02-01

    Reliable knowledge of the near-future climate change signal of extremes is important for adaptation and mitigation strategies. Especially compound extremes, like heat and drought occurring simultaneously, may have a greater impact on society than their univariate counterparts and have recently become an active field of study. In this paper, we use a 12-member ensemble of high-resolution (7 km) regional climate simulations with the regional climate model COSMO-CLM over central Europe to analyze the climate change signal and its uncertainty for compound heat and drought extremes in summer by two different measures: one describing absolute (i.e., number of exceedances of absolute thresholds like hot days), the other relative (i.e., number of exceedances of time series intrinsic thresholds) compound extreme events. Changes are assessed between a reference period (1971-2000) and a projection period (2021-2050). Our findings show an increase in the number of absolute compound events for the whole investigation area. The change signal of relative extremes is more region-dependent, but there is a strong signal change in the southern and eastern parts of Germany and the neighboring countries. Especially the Czech Republic shows strong change in absolute and relative extreme events.

  17. Soft-Nano-Materials: Extreme Mechanics at Extreme Length Scales

    NASA Astrophysics Data System (ADS)

    Zhao, Xuanhe

    2013-03-01

    Over decades of intensive research, various technologies have been developed to manufacture large-scale nanomaterials such as nanoparticles, quantum dots, nanowires, carbon nanotubes, biomolecules, nanofilms, and graphene. Meanwhile, extraordinary properties and functionalities of nanomaterials have been demonstrated by harnessing their deformations and instabilities coupled with their small length scales. However, a grand challenge still exists on how to control the deformations and instabilities of large-scale nanomaterials for scaling-up functions and applications that can impact the society. An emerging paradigm that addresses this challenge is by using soft materials such as polymers, gels and biomaterials to assemble large amounts of nanomaterials and regulate their deformations and instabilities in controlled manners. Successful examples range from nanostructured tissues such as bones and cartilages found in nature to polymer composites with nanowire/nanotube/graphene, flexible electronics, nano-generators and nano-batteries. This talk is focused on extreme mechanics of these soft-nano-materials and systems. We will discuss large deformation, instabilities, and fractures of one-dimensional and two dimensional nanomaterials, such as nanowires and graphene, interacting with matrices of soft materials. We will further illustrate extraordinary properties and functions achieved by understanding and exploiting the extreme mechanics of soft-nano-materials and systems.

  18. Analysis of WRF extreme daily precipitation over Alaska using self-organizing maps

    NASA Astrophysics Data System (ADS)

    Glisan, Justin M.; Gutowski, William J.; Cassano, John J.; Cassano, Elizabeth N.; Seefeldt, Mark W.

    2016-07-01

    We analyze daily precipitation extremes from simulations of a polar-optimized version of the Weather Research and Forecasting (WRF) model. Simulations cover 19 years and use the Regional Arctic System Model (RASM) domain. We focus on Alaska because of its proximity to the Pacific and Arctic oceans; both provide large moisture fetch inland. Alaska's topography also has important impacts on orographically forced precipitation. We use self-organizing maps (SOMs) to understand circulation characteristics conducive for extreme precipitation events. The SOM algorithm employs an artificial neural network that uses an unsupervised training process, which results in finding general patterns of circulation behavior. The SOM is trained with mean sea level pressure (MSLP) anomalies. Widespread extreme events, defined as at least 25 grid points experiencing 99th percentile precipitation, are examined using SOMs. Widespread extreme days are mapped onto the SOM of MSLP anomalies, indicating circulation patterns. SOMs aid in determining high-frequency nodes, and hence, circulations are conducive to extremes. Multiple circulation patterns are responsible for extreme days, which are differentiated by where extreme events occur in Alaska. Additionally, several meteorological fields are composited for nodes accessed by extreme and nonextreme events to determine specific conditions necessary for a widespread extreme event. Individual and adjacent node composites produce more physically reasonable circulations as opposed to composites of all extremes, which include multiple synoptic regimes. Temporal evolution of extreme events is also traced through SOM space. Thus, this analysis lays the groundwork for diagnosing differences in atmospheric circulations and their associated widespread, extreme precipitation events.

  19. Fiberoptic characteristics for extreme operating environments

    NASA Technical Reports Server (NTRS)

    Delcher, R. C.

    1992-01-01

    Fiberoptics could offer several major benefits for cryogenic liquid-fueled rocket engines, including lightning immunity, weight reduction, and the possibility of implementing a number of new measurements for engine condition monitoring. The technical feasibility of using fiberoptics in the severe environments posed by cryogenic liquid-fueled rocket engines was determined. The issues of importance and subsequent requirements for this use of fiberoptics were compiled. These included temperature ranges, moisture embrittlement succeptability, and the ability to withstand extreme shock and vibration levels. Different types of optical fibers were evaluated and several types of optical fibers' ability to withstand use in cryogenic liquid-fueled rocket engines was demonstrated through environmental testing of samples. This testing included: cold-bend testing, moisture embrittlement testing, temperature cycling, temperature extremes testing, vibration testing, and shock testing. Three of five fiber samples withstood the tests to a level proving feasibility, and two of these remained intact in all six of the tests. A fiberoptic bundle was also tested, and completed testing without breakage. Preliminary cabling and harnessing for fiber protection was also demonstrated. According to cable manufacturers, the successful -300 F cold bend, vibration, and shock tests are the first instance of any major fiberoptic cable testing below roughly -55 F. This program has demonstrated the basic technical feasibility of implementing optical fibers on cryogenic liquid-fueled rocket engines, and a development plan is included highlighting requirements and issues for such an implementation.

  20. Benchmark Generation and Simulation at Extreme Scale

    SciTech Connect

    Lagadapati, Mahesh; Mueller, Frank; Engelmann, Christian

    2016-01-01

    The path to extreme scale high-performance computing (HPC) poses several challenges related to power, performance, resilience, productivity, programmability, data movement, and data management. Investigating the performance of parallel applications at scale on future architectures and the performance impact of different architectural choices is an important component of HPC hardware/software co-design. Simulations using models of future HPC systems and communication traces from applications running on existing HPC systems can offer an insight into the performance of future architectures. This work targets technology developed for scalable application tracing of communication events. It focuses on extreme-scale simulation of HPC applications and their communication behavior via lightweight parallel discrete event simulation for performance estimation and evaluation. Instead of simply replaying a trace within a simulator, this work promotes the generation of a benchmark from traces. This benchmark is subsequently exposed to simulation using models to reflect the performance characteristics of future-generation HPC systems. This technique provides a number of benefits, such as eliminating the data intensive trace replay and enabling simulations at different scales. The presented work features novel software co-design aspects, combining the ScalaTrace tool to generate scalable trace files, the ScalaBenchGen tool to generate the benchmark, and the xSim tool to assess the benchmark characteristics within a simulator.

  1. Is climate change modifying precipitation extremes?

    NASA Astrophysics Data System (ADS)

    Montanari, Alberto; Papalexiou, Simon Michael

    2016-04-01

    The title of the present contribution is a relevant question that is frequently posed to scientists, technicians and managers of local authorities. Although several research efforts were recently dedicated to rainfall observation, analysis and modelling, the above question remains essentially unanswered. The question comes from the awareness that the frequency of floods and the related socio-economic impacts are increasing in many countries, and climate change is deemed to be the main trigger. Indeed, identifying the real reasons for the observed increase of flood risk is necessary in order to plan effective mitigation and adaptation strategies. While mitigation of climate change is an extremely important issue at the global level, at small spatial scales several other triggers may interact with it, therefore requiring different mitigation strategies. Similarly, the responsibilities of administrators are radically different at local and global scales. This talk aims to provide insights and information to address the question expressed by its title. High resolution and long term rainfall data will be presented, as well as an analysis of the frequency of their extremes and its progress in time. The results will provide pragmatic indications for the sake of better planning flood risk mitigation policies.

  2. Extreme Environments in Tierra del Fuego, Argentina

    NASA Astrophysics Data System (ADS)

    Schultz, C.; D'Antoni, H.; Burgess, S.; Zamora, J.; Skiles, J.

    2007-12-01

    The upper timberline of the Andes Cordillera on the island of Tierra del Fuego at the tip of South America is an environment subject to extreme conditions. In order to further understand this environment, ecosystem parameters were measured within two transects of the Andes at Glaciar Martial and Cerro Guanaco. The measurements included pH, soil temperature, soil moisture, nitrogen, sodium and potassium concentration, chlorophyll absorbance, and irradiance in the ultraviolet range (200-400 nm). These data comprise a survey that serves as a baseline for an intensive research program. Chlorophyll concentration and soil data were within the range of our observations at several other sites, from Lapataia Bay on the southwestern boundary with Chile, through the eastern end of Lake Fagnano. However, unusual levels of solar irradiance were found in the open sites of both transects while those in the forest exhibited lower UV values, suggesting strong absorption and/or reflection by the forest canopy. High levels of UV radiation damage important biomolecules and may be partially responsible for the presence of life forms such as the krummholz belt in the upper timberline. These UV values may be due to the effects of global ozone depletion and the ozone hole. The low temperatures, strong winds, snow and ice-covered soil and especially the exposure to UV radiation make this area an extreme environment for life.

  3. Changing Pattern of Indian Monsoon Extremes: Global and Local Factors

    NASA Astrophysics Data System (ADS)

    Ghosh, Subimal; Shastri, Hiteshri; Pathak, Amey; Paul, Supantha

    2017-04-01

    Indian Summer Monsoon Rainfall (ISMR) extremes have remained a major topic of discussion in the field of global change and hydro-climatology over the last decade. This attributes to multiple conclusions on changing pattern of extremes along with poor understanding of multiple processes at global and local scales associated with monsoon extremes. At a spatially aggregate scale, when number of extremes in the grids are summed over, a statistically significant increasing trend is observed for both Central India (Goswami et al., 2006) and all India (Rajeevan et al., 2008). However, such a result over Central India does not satisfy flied significance test of increase and no decrease (Krishnamurthy et al., 2009). Statistically rigorous extreme value analysis that deals with the tail of the distribution reveals a spatially non-uniform trend of extremes over India (Ghosh et al., 2012). This results into statistically significant increasing trend of spatial variability. Such an increase of spatial variability points to the importance of local factors such as deforestation and urbanization. We hypothesize that increase of spatial average of extremes is associated with the increase of events occurring over large region, while increase in spatial variability attributes to local factors. A Lagrangian approach based dynamic recycling model reveals that the major contributor of moisture to wide spread extremes is Western Indian Ocean, while land surface also contributes around 25-30% of moisture during the extremes in Central India. We further test the impacts of local urbanization on extremes and find the impacts are more visible over West central, Southern and North East India. Regional atmospheric simulations coupled with Urban Canopy Model (UCM) shows that urbanization intensifies extremes in city areas, but not uniformly all over the city. The intensification occurs over specific pockets of the urban region, resulting an increase in spatial variability even within the city

  4. Extreme weather: Subtropical floods and tropical cyclones

    NASA Astrophysics Data System (ADS)

    Shaevitz, Daniel A.

    Extreme weather events have a large effect on society. As such, it is important to understand these events and to project how they may change in a future, warmer climate. The aim of this thesis is to develop a deeper understanding of two types of extreme weather events: subtropical floods and tropical cyclones (TCs). In the subtropics, the latitude is high enough that quasi-geostrophic dynamics are at least qualitatively relevant, while low enough that moisture may be abundant and convection strong. Extratropical extreme precipitation events are usually associated with large-scale flow disturbances, strong ascent, and large latent heat release. In the first part of this thesis, I examine the possible triggering of convection by the large-scale dynamics and investigate the coupling between the two. Specifically two examples of extreme precipitation events in the subtropics are analyzed, the 2010 and 2014 floods of India and Pakistan and the 2015 flood of Texas and Oklahoma. I invert the quasi-geostrophic omega equation to decompose the large-scale vertical motion profile to components due to synoptic forcing and diabatic heating. Additionally, I present model results from within the Column Quasi-Geostrophic framework. A single column model and cloud-revolving model are forced with the large-scale forcings (other than large-scale vertical motion) computed from the quasi-geostrophic omega equation with input data from a reanalysis data set, and the large-scale vertical motion is diagnosed interactively with the simulated convection. It is found that convection was triggered primarily by mechanically forced orographic ascent over the Himalayas during the India/Pakistan flood and by upper-level Potential Vorticity disturbances during the Texas/Oklahoma flood. Furthermore, a climate attribution analysis was conducted for the Texas/Oklahoma flood and it is found that anthropogenic climate change was responsible for a small amount of rainfall during the event but the

  5. Probability distribution analysis of observational extreme events and model evaluation

    NASA Astrophysics Data System (ADS)

    Yu, Q.; Lau, A. K. H.; Fung, J. C. H.; Tsang, K. T.

    2016-12-01

    Earth's surface temperatures were the warmest in 2015 since modern record-keeping began in 1880, according to the latest study. In contrast, a cold weather occurred in many regions of China in January 2016, and brought the first snowfall to Guangzhou, the capital city of Guangdong province in 67 years. To understand the changes of extreme weather events as well as project its future scenarios, this study use statistical models to analyze on multiple climate data. We first use Granger-causality test to identify the attribution of global mean temperature rise and extreme temperature events with CO2 concentration. The four statistical moments (mean, variance, skewness, kurtosis) of daily maximum temperature distribution is investigated on global climate observational, reanalysis (1961-2010) and model data (1961-2100). Furthermore, we introduce a new tail index based on the four moments, which is a more robust index to measure extreme temperatures. Our results show that the CO2 concentration can provide information to the time series of mean and extreme temperature, but not vice versa. Based on our new tail index, we find that other than mean and variance, skewness is an important indicator should be considered to estimate extreme temperature changes and model evaluation. Among the 12 climate model data we investigate, the fourth version of Community Climate System Model (CCSM4) from National Center for Atmospheric Research performs well on the new index we introduce, which indicate the model have a substantial capability to project the future changes of extreme temperature in the 21st century. The method also shows its ability to measure extreme precipitation/ drought events. In the future we will introduce a new diagram to systematically evaluate the performance of the four statistical moments in climate model output, moreover, the human and economic impacts of extreme weather events will also be conducted.

  6. Life at extreme limits: the anaerobic halophilic alkalithermophiles.

    PubMed

    Mesbah, Noha M; Wiegel, Juergen

    2008-03-01

    The ability of anaerobic microorganisms to proliferate under extreme conditions is of widespread importance for microbial physiology, remediation, industry, and evolution. The halophilic alkalithermophiles are a novel group of polyextremophiles. Tolerance to alkaline pH, elevated NaCl concentrations, and high temperatures necessitates mechanisms for cytoplasmic pH acidification; permeability control of the cell membrane; and stability of proteins, the cell wall, and other cellular constituents to multiple extreme conditions. Although it is generally assumed that extremophiles growing at more than one extreme combine adaptive mechanisms for each individual extreme, adaptations for individual extremes often counteract each other. However, in alkaline, hypersaline niches heated via intense solar irradiation, culture-independent analyses have revealed the presence of an extensive diversity of aerobic and anaerobic microorganisms belonging to Bacteria and Archaea that survive and grow under multiple harsh conditions. Thus, polyextremophiles must have developed novel adaptive strategies enabling them to grow and proliferate under multiple extreme conditions. The recent isolation of two novel anaerobic, halophilic alkalithermophiles, Natranaerobius thermophilus and Halonatronum saccharophilum, will provide a platform for detailed biochemical, genomic, and proteomic experiments, allowing a greater understanding of the novel adaptive mechanisms undoubtedly employed by polyextremophiles. In this review, we highlight growth characteristics, ecology, and phylogeny of the anaerobic halophilic alkalithermophiles isolated. We also describe the bioenergetic and physiological problems posed by growth at the multiple extreme conditions of alkaline pH, high NaCl concentration, and elevated temperature under anoxic conditions and highlight recent findings and unresolved problems regarding adaptation to multiple extreme conditions.

  7. Communication path for extreme environments

    NASA Technical Reports Server (NTRS)

    Jorgensen, Charles C. (Inventor); Betts, Bradley J. (Inventor)

    2010-01-01

    Methods and systems for using one or more radio frequency identification devices (RFIDs), or other suitable signal transmitters and/or receivers, to provide a sensor information communication path, to provide location and/or spatial orientation information for an emergency service worker (ESW), to provide an ESW escape route, to indicate a direction from an ESW to an ES appliance, to provide updated information on a region or structure that presents an extreme environment (fire, hazardous fluid leak, underwater, nuclear, etc.) in which an ESW works, and to provide accumulated thermal load or thermal breakdown information on one or more locations in the region.

  8. Advances in upper extremity prosthetics.

    PubMed

    Zlotolow, Dan A; Kozin, Scott H

    2012-11-01

    Until recently, upper extremity prostheses had changed little since World War II. In 2006, the Defense Advanced Research Projects Agency responded to an increasing number of military amputees with the Revolutionizing Prosthetics program. The program has yielded several breakthroughs both in the engineering of new prosthetic arms and in the control of those arms. Direct brain-wave control of a limb with 22° of freedom may be within reach. In the meantime, advances such as individually powered digits have opened the door to multifunctional full and partial hand prostheses. Restoring sensation to the prosthetic limb remains a major challenge to full integration of the limb into a patient's self-image.

  9. Gravity and Extreme Magnetism SMEX

    NASA Technical Reports Server (NTRS)

    2012-01-01

    The Gravity and Extreme Magnetism SMEX mission will be the first mission to catalogue the X-ray polarisation of many astrophysical objects including black-holes and pulsars. This first of its kind mission is enabled by the novel use of a time projection chamber as an X-ray polarimeter. The detector has been developed over the last 5 years, with the current effort charged toward a demonstration of it's technical readiness to be at level 6 prior to the preliminary design review. This talk will describe the design GEMS polarimeter and the results to date from the engineering test unit.

  10. Window performance in extreme cold

    NASA Astrophysics Data System (ADS)

    Flanders, S. N.; Buska, J. S.; Barrett, S. A.

    1982-12-01

    Extreme cold causes heavy buildup of frost, ice and condensation on many windows. It also increases the incentive for improving the airtightness of windows against heat loss. Our study shows that tightening specifications for Alaskan windows to permit only 30% of the air leakage allowed by current American airtightness standards is economically attractive. We also recommend triple glazing in much of Alaska to avoid window icing in homes and barracks. We base our conclusions on a two year field study of Alaskan military bases that included recording humidity and temperature data, observing moisture accumulation on windows and measuring airtightness with a fan pressurized device.

  11. Extreme Geomagnetic Storms - 1868 - 2010

    NASA Astrophysics Data System (ADS)

    Vennerstrom, S.; Lefevre, L.; Dumbović, M.; Crosby, N.; Malandraki, O.; Patsou, I.; Clette, F.; Veronig, A.; Vršnak, B.; Leer, K.; Moretto, T.

    2016-05-01

    We present the first large statistical study of extreme geomagnetic storms based on historical data from the time period 1868 - 2010. This article is the first of two companion papers. Here we describe how the storms were selected and focus on their near-Earth characteristics. The second article presents our investigation of the corresponding solar events and their characteristics. The storms were selected based on their intensity in the aa index, which constitutes the longest existing continuous series of geomagnetic activity. They are analyzed statistically in the context of more well-known geomagnetic indices, such as the Kp and Dcx/Dst index. This reveals that neither Kp nor Dcx/Dst provide a comprehensive geomagnetic measure of the extreme storms. We rank the storms by including long series of single magnetic observatory data. The top storms on the rank list are the New York Railroad storm occurring in May 1921 and the Quebec storm from March 1989. We identify key characteristics of the storms by combining several different available data sources, lists of storm sudden commencements (SSCs) signifying occurrence of interplanetary shocks, solar wind in-situ measurements, neutron monitor data, and associated identifications of Forbush decreases as well as satellite measurements of energetic proton fluxes in the near-Earth space environment. From this we find, among other results, that the extreme storms are very strongly correlated with the occurrence of interplanetary shocks (91 - 100 %), Forbush decreases (100 %), and energetic solar proton events (70 %). A quantitative comparison of these associations relative to less intense storms is also presented. Most notably, we find that most often the extreme storms are characterized by a complexity that is associated with multiple, often interacting, solar wind disturbances and that they frequently occur when the geomagnetic activity is already elevated. We also investigate the semiannual variation in storm occurrence

  12. Materials Response under extreme conditions

    SciTech Connect

    Remington, B A; Lorenz, K T; Pollaine, S; McNaney, J M

    2005-10-06

    Solid state experiments at extreme pressures, 10-100 GPa (0.1-1 Mbar) and strain rates (10{sup 6}-10{sup 8} s{sup -1}) are being developed on high-energy laser facilities. The goal is an experimental capability to test constitutive models for high-pressure, solid-state strength for a variety of materials. Relevant constitutive models are discussed, and our progress in developing a quasi-isentropic, ramped-pressure, shockless drive is given. Designs to test the constitutive models with experiments measuring perturbation growth due to the Rayleigh-Taylor instability in solid-state samples are presented.

  13. Neuropsychological Assessment in Extreme Environments

    DTIC Science & Technology

    2007-01-01

    Archives of Clinical Neuropsychology 22S (2007) S89–S99 Neuropsychological assessment in extreme environments Michael Lowe a,∗, Wayne Harris b...c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 S90 M. Lowe et al. / Archives of Clinical Neuropsychology 22S...et al. / Archives of Clinical Neuropsychology 22S (2007) S89–S99 S91 There was a 10% reduction in this score during the final hour of toluene

  14. Extreme Events: The Indian Experience

    NASA Astrophysics Data System (ADS)

    Murty, K. S.

    2008-05-01

    The geographical situation of India is such that it experiences varied types of climate in different parts of the country and invariably the natural events, extreme and normal, would affect such areas that are prone to them. Cyclones hit the eastern coast, while floods affect mostly northern India, while earthquakes hit any part of the country, particuarly when itbecame evident after the 1967 earthquake of Koyna that the peninsular part toois prone to seismic events. The National Commission on Floods estimated that nearly 40 millionn hectares of land is prone to flooding, which could rise to60 million soon. The cropped area thus affected annually is about 10 millionhectares. On an average 1500 lives are lost during floods annually, while the damage to property could run into billions of dollars. The total loss on account of floods damage to crops is estimated at about Rs 53,000 crores(crore= 100 lakhs), during the period 1953-1998. The other extreme natural event is drought which affects large parts of the country, except the northeast. Both floods and droughts can hit different parts of the country during the same period. The 2001 earthquake that hit Gujarat is perhaps the severest and studies on that event are still in progress. The 2004 tsunami which hit large parts of southeast Asia did not spare India. Its southern coast was battered and many lives were lost. In fact some geogrphic landmarks were lost, while some of the cities have suffered a shift in their position. It was estimated that about 1.2 billion dollars were required ro meet the rehabilitation and relief measures. The seismic zone map of India thus had to be revised more often than before. Apart from these, extreme rainfall has also caused floods in urban areas as in Mumbai in 2005, but this was mostly because of lack of proper drainage system and the existing system proved ineffective. Human hand in such cases is evident. There are systems working to forecast floods, cyclones, and droughts, though

  15. Extreme ultraviolet spectroscopy of Capella

    NASA Technical Reports Server (NTRS)

    Green, James C.; Wilkinson, Erik; Ayres, Thomas R.; Cash, Webster C.

    1992-01-01

    The X-ray active binary system Capella was observed with a moderate-resolution extreme ultraviolet spectrograph from 200 to 330 A. Two low-level emission features were detected. One most likely is geocoronal He II 304 A emission, while the other probably originates from the corona of Capella. The weak stellar emission at 304 A is in direct conflict with predictions of the intrinsic stellar He II flux based on standard scaling arguments but is consistent with the only previous observation of Capella in the EUV. The most plausible explanation for the lack of stellar 304 A emission is a warm wind from the active G0 III star.

  16. Outcomes for Extremely Premature Infants

    PubMed Central

    Glass, Hannah C.; Costarino, Andrew T.; Stayer, Stephen A.; Brett, Claire; Cladis, Franklyn; Davis, Peter J.

    2015-01-01

    Premature birth is a significant cause of infant and child morbidity and mortality. In the United States, the premature birth rate, which had steadily increased during the 1990s and early 2000s, has decreased annually for four years and is now approximately 11.5%. Human viability, defined as gestational age at which the chance of survival is 50%, is currently approximately 23–24 weeks in developed countries. Infant girls, on average, have better outcomes than infant boys. A relatively uncomplicated course in the intensive care nursery for an extremely premature infant results in a discharge date close to the prenatal EDC. Despite technological advances and efforts of child health experts during the last generation, the extremely premature infant (less than 28 weeks gestation) and extremely low birth weight infant (ELBW) (< 1000 grams) remain at high risk for death and disability with 30–50% mortality and, in survivors, at least 20–50% risk of morbidity. The introduction of CPAP, mechanical ventilation, and exogenous surfactant increased survival and spurred the development of neonatal intensive care in the 1970s through the early 1990s. Routine administration of antenatal steroids during premature labor improved neonatal mortality and morbidity in the late 1990s. The recognition that chronic postnatal administration of steroids to infants should be avoided may have improved outcomes in the early 2000s. Evidence from recent trials attempting to define the appropriate target for oxygen saturation in preterm infants suggests arterial oxygen saturation between 91–95% (compared to 85–89%) avoids excess mortality. However, final analyses of data from these trials have not been published, so definitive recommendations are still pending The development of neonatal neurocognitive care visits may improve neurocognitive outcomes in this high-risk group. Long-term follow up to detect and address developmental, learning, behavioral, and social problems is critical for

  17. Rainfall variability and extremes over southern Africa: Assessment of a climate model to reproduce daily extremes

    NASA Astrophysics Data System (ADS)

    Williams, C. J. R.; Kniveton, D. R.; Layberry, R.

    2009-04-01

    It is increasingly accepted that that any possible climate change will not only have an influence on mean climate but may also significantly alter climatic variability. A change in the distribution and magnitude of extreme rainfall events (associated with changing variability), such as droughts or flooding, may have a far greater impact on human and natural systems than a changing mean. This issue is of particular importance for environmentally vulnerable regions such as southern Africa. The subcontinent is considered especially vulnerable to and ill-equipped (in terms of adaptation) for extreme events, due to a number of factors including extensive poverty, famine, disease and political instability. Rainfall variability and the identification of rainfall extremes is a function of scale, so high spatial and temporal resolution data are preferred to identify extreme events and accurately predict future variability. The majority of previous climate model verification studies have compared model output with observational data at monthly timescales. In this research, the assessment of ability of a state of the art climate model to simulate climate at daily timescales is carried out using satellite derived rainfall data from the Microwave Infra-Red Algorithm (MIRA). This dataset covers the period from 1993-2002 and the whole of southern Africa at a spatial resolution of 0.1 degree longitude/latitude. The ability of a climate model to simulate current climate provides some indication of how much confidence can be applied to its future predictions. In this paper, simulations of current climate from the UK Meteorological Office Hadley Centre's climate model, in both regional and global mode, are firstly compared to the MIRA dataset at daily timescales. This concentrates primarily on the ability of the model to simulate the spatial and temporal patterns of rainfall variability over southern Africa. Secondly, the ability of the model to reproduce daily rainfall extremes will

  18. Physical examination of upper extremity compressive neuropathies.

    PubMed

    Popinchalk, Samuel P; Schaffer, Alyssa A

    2012-10-01

    A thorough history and physical examination are vital to the assessment of upper extremity compressive neuropathies. This article summarizes relevant anatomy and physical examination findings associated with upper extremity compressive neuropathies. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Will extreme climatic events facilitate biological invasions?

    USDA-ARS?s Scientific Manuscript database

    Extreme climatic events, such as intense heat waves, hurricanes, floods and droughts, can dramatically affect ecological and evolutionary processes, and more extreme events are projected with ongoing climate change. However, the implications of these events for biological invasions, which themselves...

  20. Assessing the extreme overwash regime along an embayed urban beach

    NASA Astrophysics Data System (ADS)

    Silveira, Tanya M.; Taborda, Rui; Carapuço, Mafalda M.; Andrade, César; Freitas, Maria C.; Duarte, João F.; Psuty, Norbert P.

    2016-12-01

    Coastal overwash is one of the most important hazards affecting the coastal zone and therefore has been the focus of several studies related to the establishment of setback lines. However, studies of extreme overwash (EO) events along urban beaches backed by a seawall or structure are scarce, and reveal the difficulties associated with its assessment, measurement and validation. The Nazaré coastal urban area (located on the west coast of Portugal) is developed adjacent to an embayed reflective beach and is subject to frequent and localized inundation due to EO events capable of overtopping the protection seawall. The current work develops a methodological approach to simulate total water levels (TWL) and seawall overtopping occurrences in time and space, with the ultimate goal of identifying the factors that govern the extreme overwash regime. The method uses multi-decadal time series of site-specific wave and tide, and high-resolution topo-bathymetric data, and recreates the TWL time series for a 36-year period. The model is successfully validated against video imagery and maximum swash line data that provide information on the reach of the water levels measured during modal and extreme TWL conditions along the studied beach. This study establishes the importance of the interaction of the modal and extreme hydrodynamic processes with the beach and backshore morphology. The Nazaré embayment is in equilibrium with the alongshore-varying modal wave conditions, resulting in higher vulnerability of the most sheltered sector during extreme events.

  1. Climatic extremes improve predictions of spatial patterns of tree species

    USGS Publications Warehouse

    Zimmermann, N.E.; Yoccoz, N.G.; Edwards, T.C.; Meier, E.S.; Thuiller, W.; Guisan, A.; Schmatz, D.R.; Pearman, P.B.

    2009-01-01

    Understanding niche evolution, dynamics, and the response of species to climate change requires knowledge of the determinants of the environmental niche and species range limits. Mean values of climatic variables are often used in such analyses. In contrast, the increasing frequency of climate extremes suggests the importance of understanding their additional influence on range limits. Here, we assess how measures representing climate extremes (i.e., interannual variability in climate parameters) explain and predict spatial patterns of 11 tree species in Switzerland. We find clear, although comparably small, improvement (+20% in adjusted D2, +8% and +3% in cross-validated True Skill Statistic and area under the receiver operating characteristics curve values) in models that use measures of extremes in addition to means. The primary effect of including information on climate extremes is a correction of local overprediction and underprediction. Our results demonstrate that measures of climate extremes are important for understanding the climatic limits of tree species and assessing species niche characteristics. The inclusion of climate variability likely will improve models of species range limits under future conditions, where changes in mean climate and increased variability are expected.

  2. Application of RFID technology—upper extremity rehabilitation training

    PubMed Central

    Chen, Chih-Chen; Chen, Yu-Luen; Chen, Shih-Ching

    2016-01-01

    [Purpose] Upper extremity rehabilitation after an injury is very important. This study proposes radio frequency identification (RFID) technology to improve and enhance the effectiveness of the upper extremity rehabilitation. [Subjects and Methods] People use their upper extremities to conduct daily activities. When recovering from injuries, many patients neglect the importance of rehabilitation, which results in degraded function. This study recorded the training process using the traditional rehabilitation hand gliding cart with a RFID reader, RFID tags in the panel, and a servo host computer. [Results] Clinical evidence, time taken to achieve a full score, counts of missing the specified spots, and Brunnstrom stage of aided recovery, the proximal part of the upper extremity show that the RFID-based upper extremity training significantly and reduce negative impacts of the disability in daily life and activities. [Conclusion] This study combined a hand-gliding cart with an RFID reader, and when patients moved the cart, the movement could be observed via the activated RFID tags. The training data was collected and quantified for a better understanding of the recovery status of the patients. Each of the participating patients made progress as expected. PMID:27065539

  3. Permutation importance: a corrected feature importance measure.

    PubMed

    Altmann, André; Toloşi, Laura; Sander, Oliver; Lengauer, Thomas

    2010-05-15

    In life sciences, interpretability of machine learning models is as important as their prediction accuracy. Linear models are probably the most frequently used methods for assessing feature relevance, despite their relative inflexibility. However, in the past years effective estimators of feature relevance have been derived for highly complex or non-parametric models such as support vector machines and RandomForest (RF) models. Recently, it has been observed that RF models are biased in such a way that categorical variables with a large number of categories are preferred. In this work, we introduce a heuristic for normalizing feature importance measures that can correct the feature importance bias. The method is based on repeated permutations of the outcome vector for estimating the distribution of measured importance for each variable in a non-informative setting. The P-value of the observed importance provides a corrected measure of feature importance. We apply our method to simulated data and demonstrate that (i) non-informative predictors do not receive significant P-values, (ii) informative variables can successfully be recovered among non-informative variables and (iii) P-values computed with permutation importance (PIMP) are very helpful for deciding the significance of variables, and therefore improve model interpretability. Furthermore, PIMP was used to correct RF-based importance measures for two real-world case studies. We propose an improved RF model that uses the significant variables with respect to the PIMP measure and show that its prediction accuracy is superior to that of other existing models. R code for the method presented in this article is available at http://www.mpi-inf.mpg.de/ approximately altmann/download/PIMP.R CONTACT: altmann@mpi-inf.mpg.de, laura.tolosi@mpi-inf.mpg.de Supplementary data are available at Bioinformatics online.

  4. Dancing with Nature: Rhythm and Harmony in Extreme Sport Participation

    ERIC Educational Resources Information Center

    Brymer, Eric; Gray, Tonia

    2009-01-01

    Research on extreme sports has downplayed the importance of the athletes' connection to the natural world. This neglect stems, in part, from the assumption that these activities derive their meaning primarily from risk. The authors' long-term research reveals that the interplay between adventure athletes and the natural world is, in fact, crucial…

  5. Dancing with Nature: Rhythm and Harmony in Extreme Sport Participation

    ERIC Educational Resources Information Center

    Brymer, Eric; Gray, Tonia

    2009-01-01

    Research on extreme sports has downplayed the importance of the athletes' connection to the natural world. This neglect stems, in part, from the assumption that these activities derive their meaning primarily from risk. The authors' long-term research reveals that the interplay between adventure athletes and the natural world is, in fact, crucial…

  6. Min and Max Extreme Interval Values

    ERIC Educational Resources Information Center

    Jance, Marsha L.; Thomopoulos, Nick T.

    2011-01-01

    The paper shows how to find the min and max extreme interval values for the exponential and triangular distributions from the min and max uniform extreme interval values. Tables are provided to show the min and max extreme interval values for the uniform, exponential, and triangular distributions for different probabilities and observation sizes.

  7. Statistical analysis of extreme river flows

    NASA Astrophysics Data System (ADS)

    Mateus, Ayana; Caeiro, Frederico; Gomes, Dora Prata; Sequeira, Inês J.

    2016-12-01

    Floods are recurrent events that can have a catastrophic impact. In this work we are interested in the analysis of a data set of gauged daily flows from the Whiteadder Water river, Scotland. Using statistic techniques based on extreme value theory, we estimate several extreme value parameters, including extreme quantiles and return periods of high levels.

  8. Dome cities for extreme environments

    NASA Technical Reports Server (NTRS)

    Leonard, Raymond S.; Schwartz, Milton

    1992-01-01

    Extreme environments whether they be the frigid nights of the polar regions, the burning sands of the desert, or the harsh environment of space pose interesting challenges to the architect, the engineer, and the constructor in their efforts to create habitats for mankind. In space, the goals are to provide radiation protection while also providing an aesthetic living environment for long duration missions. Because of the need to provide both radiation protection and options for expansion of base facilities, a unique structural system which separates the radiation protection systems from the pressure envelope of the habitats was created. The system uses cable networks in a tensioned structural system, which supports the lunar regolith used for shielding above the facilities. The system is modular, easily expandable, and simple to construct. Additional innovations include the use of rock melting perpetrators for piles and anchoring deadmen, and various sized craters to provide side shielding. The reflective properties of the fabric used in the membrane are utilized to provide diffuse illumination. The use of craters along with the suspended shielding allows the dome to be utilized in fashions similar to those proposed by various designers unaware of the Moon's hostile radiation environment. Additional topics addressed deal with construction techniques for large domes, i.e., on the order of 100's to 1000's of meters, thermal control, the integration of tertiary water treatment schemes with architectural design, human factors, and its implications for the design of habitats for long term use in extreme environments.

  9. Laser Driven, Extreme Compression Science

    NASA Astrophysics Data System (ADS)

    Eggert, Jon

    2014-03-01

    Extreme-compression science is blessed by a number of new techniques and facilities that are shattering previous experimental limitations: static pressures above 600 GPa, equation of state (EOS) experiments on pulsed-power machines, picosecond-resolved x-ray diffraction on free-electron lasers, and many new experiments on high-energy lasers. Our goals, using high-energy lasers, have been to push the limits of high pressure accessible to measurement and to bridge the gap between static- and dynamic-compression experiments by exploring off-Hugoniot states. I will review laser techniques for both shock- and ramp-compression experiments, and discuss a variety of diagnostics. I will present recent results including: impedance-matching Hugoniot experiments, absolute-Hugoniot implosive-shock radiography, coupled radiometry and velocimetry, ramp-compression EOS, and in-situ x-ray diffraction and absorption spectroscopy into the TPa regime. As the National Ignition Facility (NIF) transitions to a laser user facility for basic and applied science, we are transferring many of these techniques. The unprecedented quality and variety of diagnostics available, coupled with exquisite pulse-shaping predictability and control make the NIF a premier facility for extreme-compression experiments.

  10. Laser Driven, Extreme Compression Science

    NASA Astrophysics Data System (ADS)

    Eggert, Jon

    2013-06-01

    Extreme-compression science is blessed by a number of new techniques and facilities that are shattering previous experimental limitations: static pressures above 600 GPa, equation of state (EOS) experiments on pulsed-power machines, picosecond-resolved x-ray diffraction on free-electron lasers, and many new experiments on high-energy lasers. Our goals, using high-energy lasers, have been to push the limits of high pressure accessible to measurement and to bridge the gap between static- and dynamic-compression experiments by exploring off-Hugoniot states. I will review laser techniques for both shock- and ramp-compression experiments, and discuss a variety of diagnostics. I will present recent results including: impedance-matching Hugoniot experiments, absolute-Hugoniot implosive-shock radiography, coupled radiometry and velocimetry, ramp-compression EOS, and in-situ x-ray diffraction and absorption spectroscopy into the TPa regime. As the National Ignition Facility (NIF) transitions to a laser user facility for basic and applied science, we are transferring many of these techniques. The unprecedented quality and variety of diagnostics available, coupled with exquisite pulse-shaping predictability and control make the NIF a premier facility for extreme-compression experiments.

  11. Lower extremity abnormalities in children.

    PubMed

    Sass, Pamela; Hassan, Ghinwa

    2003-08-01

    Rotational and angular problems are two types of lower extremity abnormalities common in children. Rotational problems include intoeing and out-toeing. Intoeing is caused by one of three types of deformity: metatarsus adductus, internal tibial torsion, and increased femoral anteversion. Out-toeing is less common than intoeing, and its causes are similar but opposite to those of intoeing. These include femoral retroversion and external tibial torsion. Angular problems include bowlegs and knock-knees. An accurate diagnosis can be made with careful history and physical examination, which includes torsional profile (a four-component composite of measurements of the lower extremities). Charts of normal values and values with two standard deviations for each component of the torsional profile are available. In most cases, the abnormality improves with time. A careful physical examination, explanation of the natural history, and serial measurements are usually reassuring to the parents. Treatment is usually conservative. Special shoes, cast, or braces are rarely beneficial and have no proven efficacy. Surgery is reserved for older children with deformity from three to four standard deviations from the normal.

  12. Dome cities for extreme environments

    NASA Technical Reports Server (NTRS)

    Leonard, Raymond S.; Schwartz, Milton

    1992-01-01

    Extreme environments whether they be the frigid nights of the polar regions, the burning sands of the desert, or the harsh environment of space pose interesting challenges to the architect, the engineer, and the constructor in their efforts to create habitats for mankind. In space, the goals are to provide radiation protection while also providing an aesthetic living environment for long duration missions. Because of the need to provide both radiation protection and options for expansion of base facilities, a unique structural system which separates the radiation protection systems from the pressure envelope of the habitats was created. The system uses cable networks in a tensioned structural system, which supports the lunar regolith used for shielding above the facilities. The system is modular, easily expandable, and simple to construct. Additional innovations include the use of rock melting perpetrators for piles and anchoring deadmen, and various sized craters to provide side shielding. The reflective properties of the fabric used in the membrane are utilized to provide diffuse illumination. The use of craters along with the suspended shielding allows the dome to be utilized in fashions similar to those proposed by various designers unaware of the Moon's hostile radiation environment. Additional topics addressed deal with construction techniques for large domes, i.e., on the order of 100's to 1000's of meters, thermal control, the integration of tertiary water treatment schemes with architectural design, human factors, and its implications for the design of habitats for long term use in extreme environments.

  13. The Extremes of Quasar Variability

    NASA Astrophysics Data System (ADS)

    Stern, Daniel

    2016-04-01

    Variability is one of the key observational properties of quasars, and it can be used as a probe of their fueling, physics, and evolution. A new generation of synoptic sky surveys, in combination with the novel data analytics tools, offers unprecedented data sets for the studies of quasars in the time domain. I will illustrate this with examples from the Catalina Real-Time Transient Survey (CRTS), which has an open and growing archive of 500 million light curves, including 350,000 spectroscopically confirmed quasars, with the time baselines ranging from 10 minutes to 10 years. I will discuss a new approach to discover quasars using a combination of variability and mid-IR colors from WISE, which results in a catalog of over a million quasar candidates. I will then discuss quasars with extreme, anomolous light curves, including quasars that have gone through extreme brightening events over the past decade with concordant large changes in their spectroscopic properties. I will also discuss a small subset of quasars with periodic light curves which we interpret as a signature of close (milliparsec scale) supermassive black hole (SMBH) binaries.

  14. Obstetric outcome of extreme macrosomia.

    PubMed

    Alsunnari, Sahar; Berger, Howard; Sermer, Mathew; Seaward, Gareth; Kelly, Edmond; Farine, Dan

    2005-04-01

    To determine the effect of extreme macrosomia on perinatal outcome. We conducted a retrospective review of all deliveries with birth weight > or = 5000 g in a tertiary centre from 1986 to 2000 and analyzed the method of delivery and perinatal outcome. Extreme macrosomia (birth weight > or = 5000 g) was coded in 111 deliveries. There were 62 deliveries by Caesarean section (CS) (25 in labour and 37 elective). The 49 vaginal deliveries were complicated by 10 (20%) cases of shoulder dystocia and 3 (6%) of Erb's palsy. Permanent Erb's palsy was noted in only 1 of these 3 cases. Shoulder dystocia was associated with use of oxytocin and instrumental deliveries. Implementing the 2002 guidelines from the American College of Obstetricians and Gynecologists (that is, recommending Caesarean delivery of fetuses with an estimated weight of at least 5000 g) would have a negligible effect on the CS rate while eliminating 10 cases of shoulder dystocia in 49 births. A policy eliminating the use of oxytocin and instrumental deliveries would have prevented most birth traumas in this group. Unfortunately, this high-risk group is difficult to identify in the antepartum period, complicating the implementation of these guidelines and probably leading to higher rates of CS. In addition, the effect of endorsing such a policy on overall neonatal and maternal morbidity is minimal, because most morbidity occurs in newborns weighing less than 4000 g.

  15. Medical homicide and extreme negligence.

    PubMed

    Duncanson, Emily; Richards, Virginia; Luce, Kasey M; Gill, James R

    2009-03-01

    Deaths that occur during medical care for the treatment of a disease are rarely certified as homicides. Some "medical" deaths, however, have been criminally prosecuted for manslaughter, reckless endangerment, or reckless homicide. We describe 5 deaths due to medical complications that underwent criminal prosecution. Three of the deaths were certified as homicides. Deaths certified as homicides due to the actions (or inactions) of a caregiver occur in 3 circumstances. The first is when the medical caregiver intentionally causes the death of the patient. The second is a death due to treatment by an unlicensed fraud or quack. The final circumstance is due to extreme medical negligence that involves a gross and wanton disregard for the well-being of the patient and is the most controversial in the medical community. The law defines reckless endangerment as the conscious disregard of a known substantial likelihood of injury to the patient. Criminal neglect typically is defined as the failure to provide timely, safe, adequate, and appropriate services, treatment, and/or care to a patient. In instances of extreme medical negligence, a homicide manner of death is appropriate because the fatality is due to the criminal acts (or inactions) of another. It also furthers one of the major goals of the medicolegal death investigation system, which is to safeguard the public health.

  16. Melorheostosis in the upper extremity.

    PubMed

    Yildirim, Cengiz; Ozyürek, Selahattin; Ciçek, Engin Ilker; Kuskucu, Mesih

    2009-04-01

    Melorheostosis is a rare mesodermal disease affecting the skeleton and adjacent soft tissues. Often it is incidentally detected on radiographs. In the standard radiology and orthopedics literature, melorheostosis is described as a "flowing hyperostosis, resembling dripping candle wax as an incidental radiographic finding." A 22-year-old man presented with a 2-year history of right-hand pain. Radiologic evaluation of the hand showed massive sclerotic changes in the first and second metacarpal and phalangeal bones on the right side. Further radiographic evaluation of the right upper extremity revealed the same sclerotic changes in the right scapula, humerus, radius, and scaphoid. Computed tomography (CT) scans showed a high attenuation undulating cortical hyperostosis with a "dripping candle wax appearance" involving the radial and/or dorsal aspects of humerus, radius, scaphoid, and first and second ray bones of the hand. Radionuclide triphasic bone scintigraphy showed diffuse homogenous radiotracer uptake within the entire right upper extremity involving the scapula, humerus, radius, scaphoid, and first and second metacarpals and phalangeal bones of the hand. The patient was followed conservatively, and 1-year follow-up revealed no change in the clinical, laboratory, or radiological findings. The diagnosis of melorheostosis was made on the basis of the characteristic distribution, location, and combined radiographic, CT, and radionuclide imaging features of the abnormalities. Conservative treatment was recommended for the patient. After 26 months of follow-up, despite the persistence of the radiologic findings, the patient is currently well, with no painful symptoms unless he performs forceful exercise.

  17. Digital subtraction angiography in extremity trauma

    SciTech Connect

    Goodman, P.C.; Jeffrey, R.B. Jr.; Brant-Zawadzki, M.

    1984-10-01

    Digital subtraction angiography (DSA) may have considerable impact on the work-up of patients who have suffered trauma. The angiographic evaluation of vascular injuries can be accomplished rapidly and with minimal catheter use and manipulation, which is particularly important for those critically ill patients who have significant immobility because of multiple fractures. The authors retrospectively reviewed the digital subtraction angiograms in 50 consecutive cases of extremity trauma. The quality of the images in 44 of these permitted a confident diagnosis, the accuracy of which was confirmed by surgical or clinical follow-up. DSA reduces the time required to perform the procedure, the amount of contrast material injected, patient discomfort, and film cost. Its major disadvantage is the limited field size of the image intensifier.

  18. Two Architectural Practices for Extreme Programming

    NASA Astrophysics Data System (ADS)

    Azim Sharifloo, Amir; Saffarian, Amir S.; Shams, Fereidoon

    Extreme programming (XP) is one of the important agile methods and is being used widely. Although XP itself is quite new, many of the practices utilized by it have been around for some time. The most controversial aspect of XP is the change management aspect of the process. In XP, the on-site customer requests the changes informally, often by verbally informing the development team. In spite of all benefits known about XP, it does not involve architectural techniques that are necessary to expect acceptable level of quality for the system being developed. This paper introduces two practices in order to empower XP's development process toward improving system's architecture. The main characteristic of proposed solution is that it is derived from values and practices of XP so as to be compatible with this process model and to keep its agility intact.

  19. Extreme wave runup on a vertical cliff

    NASA Astrophysics Data System (ADS)

    Carbone, Francesco; Dutykh, Denys; Dudley, John M.; Dias, FréDéRic

    2013-06-01

    Wave impact and runup onto vertical obstacles are among the most important phenomena which must be taken into account in the design of coastal structures. From linear wave theory, we know that the wave amplitude on a vertical wall is twice the incident wave amplitude with weakly nonlinear theories bringing small corrections to this result. In this present study, however, we show that certain simple wave groups may produce much higher runups than previously predicted, with particular incident wave frequencies resulting in runup heights exceeding the initial wave amplitude by a factor of 5, suggesting that the notion of the design wave used in coastal structure design may need to be revisited. The results presented in this study can be considered as a note of caution for practitioners, on one side, and as a challenging novel material for theoreticians who work in the field of extreme wave-coastal structure interaction.

  20. Extreme genomic variation in a natural population.

    PubMed

    Small, Kerrin S; Brudno, Michael; Hill, Matthew M; Sidow, Arend

    2007-03-27

    Whole-genome sequence data from samples of natural populations provide fertile grounds for analyses of intraspecific variation and tests of population genetic theory. We show that the urochordate Ciona savignyi, one of the species of ocean-dwelling broadcast spawners commonly known as sea squirts, exhibits the highest rates of single-nucleotide and structural polymorphism ever comprehensively quantified in a multicellular organism. We demonstrate that the cause for the extreme heterozygosity is a large effective population size, and, consistent with prediction by the neutral theory, we find evidence of strong purifying selection. These results constitute in-depth insight into the dynamics of highly polymorphic genomes and provide important empirical support of population genetic theory as it pertains to population size, heterozygosity, and natural selection.

  1. Outcome Trajectories in Extremely Preterm Infants

    PubMed Central

    Carlo, Waldemar A.; Tyson, Jon E.; Langer, John C.; Walsh, Michele C.; Parikh, Nehal A.; Das, Abhik; Van Meurs, Krisa P.; Shankaran, Seetha; Stoll, Barbara J.; Higgins, Rosemary D.

    2012-01-01

    OBJECTIVE: Methods are required to predict prognosis with changes in clinical course. Death or neurodevelopmental impairment in extremely premature neonates can be predicted at birth/admission to the ICU by considering gender, antenatal steroids, multiple birth, birth weight, and gestational age. Predictions may be improved by using additional information available later during the clinical course. Our objective was to develop serial predictions of outcome by using prognostic factors available over the course of NICU hospitalization. METHODS: Data on infants with birth weight ≤1.0 kg admitted to 18 large academic tertiary NICUs during 1998–2005 were used to develop multivariable regression models following stepwise variable selection. Models were developed by using all survivors at specific times during hospitalization (in delivery room [n = 8713], 7-day [n = 6996], 28-day [n = 6241], and 36-week postmenstrual age [n = 5118]) to predict death or death/neurodevelopmental impairment at 18 to 22 months. RESULTS: Prediction of death or neurodevelopmental impairment in extremely premature infants is improved by using information available later during the clinical course. The importance of birth weight declines, whereas the importance of respiratory illness severity increases with advancing postnatal age. The c-statistic in validation models ranged from 0.74 to 0.80 with misclassification rates ranging from 0.28 to 0.30. CONCLUSIONS: Dynamic models of the changing probability of individual outcome can improve outcome predictions in preterm infants. Various current and future scenarios can be modeled by input of different clinical possibilities to develop individual “outcome trajectories” and evaluate impact of possible morbidities on outcome. PMID:22689874

  2. Outcome trajectories in extremely preterm infants.

    PubMed

    Ambalavanan, Namasivayam; Carlo, Waldemar A; Tyson, Jon E; Langer, John C; Walsh, Michele C; Parikh, Nehal A; Das, Abhik; Van Meurs, Krisa P; Shankaran, Seetha; Stoll, Barbara J; Higgins, Rosemary D

    2012-07-01

    Methods are required to predict prognosis with changes in clinical course. Death or neurodevelopmental impairment in extremely premature neonates can be predicted at birth/admission to the ICU by considering gender, antenatal steroids, multiple birth, birth weight, and gestational age. Predictions may be improved by using additional information available later during the clinical course. Our objective was to develop serial predictions of outcome by using prognostic factors available over the course of NICU hospitalization. Data on infants with birth weight ≤ 1.0 kg admitted to 18 large academic tertiary NICUs during 1998-2005 were used to develop multivariable regression models following stepwise variable selection. Models were developed by using all survivors at specific times during hospitalization (in delivery room [n = 8713], 7-day [n = 6996], 28-day [n = 6241], and 36-week postmenstrual age [n = 5118]) to predict death or death/neurodevelopmental impairment at 18 to 22 months. Prediction of death or neurodevelopmental impairment in extremely premature infants is improved by using information available later during the clinical course. The importance of birth weight declines, whereas the importance of respiratory illness severity increases with advancing postnatal age. The c-statistic in validation models ranged from 0.74 to 0.80 with misclassification rates ranging from 0.28 to 0.30. Dynamic models of the changing probability of individual outcome can improve outcome predictions in preterm infants. Various current and future scenarios can be modeled by input of different clinical possibilities to develop individual "outcome trajectories" and evaluate impact of possible morbidities on outcome.

  3. Plasma physics of extreme astrophysical environments.

    PubMed

    Uzdensky, Dmitri A; Rightley, Shane

    2014-03-01

    Among the incredibly diverse variety of astrophysical objects, there are some that are characterized by very extreme physical conditions not encountered anywhere else in the Universe. Of special interest are ultra-magnetized systems that possess magnetic fields exceeding the critical quantum field of about 44 TG. There are basically only two classes of such objects: magnetars, whose magnetic activity is manifested, e.g., via their very short but intense gamma-ray flares, and central engines of supernovae (SNe) and gamma-ray bursts (GRBs)--the most powerful explosions in the modern Universe. Figuring out how these complex systems work necessarily requires understanding various plasma processes, both small-scale kinetic and large-scale magnetohydrodynamic (MHD), that govern their behavior. However, the presence of an ultra-strong magnetic field modifies the underlying basic physics to such a great extent that relying on conventional, classical plasma physics is often not justified. Instead, plasma-physical problems relevant to these extreme astrophysical environments call for constructing relativistic quantum plasma (RQP) physics based on quantum electrodynamics (QED). In this review, after briefly describing the astrophysical systems of interest and identifying some of the key plasma-physical problems important to them, we survey the recent progress in the development of such a theory. We first discuss the ways in which the presence of a super-critical field modifies the properties of vacuum and matter and then outline the basic theoretical framework for describing both non-relativistic and RQPs. We then turn to some specific astrophysical applications of relativistic QED plasma physics relevant to magnetar magnetospheres and to central engines of core-collapse SNe and long GRBs. Specifically, we discuss the propagation of light through a magnetar magnetosphere; large-scale MHD processes driving magnetar activity and responsible for jet launching and propagation in

  4. Plasma physics of extreme astrophysical environments

    NASA Astrophysics Data System (ADS)

    Uzdensky, Dmitri A.; Rightley, Shane

    2014-03-01

    Among the incredibly diverse variety of astrophysical objects, there are some that are characterized by very extreme physical conditions not encountered anywhere else in the Universe. Of special interest are ultra-magnetized systems that possess magnetic fields exceeding the critical quantum field of about 44 TG. There are basically only two classes of such objects: magnetars, whose magnetic activity is manifested, e.g., via their very short but intense gamma-ray flares, and central engines of supernovae (SNe) and gamma-ray bursts (GRBs)—the most powerful explosions in the modern Universe. Figuring out how these complex systems work necessarily requires understanding various plasma processes, both small-scale kinetic and large-scale magnetohydrodynamic (MHD), that govern their behavior. However, the presence of an ultra-strong magnetic field modifies the underlying basic physics to such a great extent that relying on conventional, classical plasma physics is often not justified. Instead, plasma-physical problems relevant to these extreme astrophysical environments call for constructing relativistic quantum plasma (RQP) physics based on quantum electrodynamics (QED). In this review, after briefly describing the astrophysical systems of interest and identifying some of the key plasma-physical problems important to them, we survey the recent progress in the development of such a theory. We first discuss the ways in which the presence of a super-critical field modifies the properties of vacuum and matter and then outline the basic theoretical framework for describing both non-relativistic and RQPs. We then turn to some specific astrophysical applications of relativistic QED plasma physics relevant to magnetar magnetospheres and to central engines of core-collapse SNe and long GRBs. Specifically, we discuss the propagation of light through a magnetar magnetosphere; large-scale MHD processes driving magnetar activity and responsible for jet launching and propagation in

  5. Gini characterization of extreme-value statistics

    NASA Astrophysics Data System (ADS)

    Eliazar, Iddo I.; Sokolov, Igor M.

    2010-11-01

    This paper presents a profound connection between Gini’s index and extreme-value statistics. Gini’s index is a quantitative gauge for the evenness of probability laws defined on the positive half-line, and is the common measure of societal egalitarianism applied in Economics and in the Social Sciences. Extreme-value statistics-namely, the Gumbel, Fréchet and Weibull probability laws-are the only possible asymptotic statistics emerging from the extremes of large ensembles of independent and identically distributed random variables. Extreme-value statistics play a major role-all across Science and Engineering-in the analysis of rare and extreme events. Introducing generalizations of Gini’s index, and exploring an elemental Poissonian structure underlying the extreme-value statistics, we establish in this paper a Gini-based characterization of extreme-value statistics.

  6. Quantitative risk assessment of the effects of drought on extreme temperature in eastern China

    NASA Astrophysics Data System (ADS)

    Hao, Zengchao; Hao, Fanghua; Singh, Vijay P.; Ouyang, Wei

    2017-09-01

    Hot extremes may lead to disastrous impacts on human health and agricultural production. Previous studies have revealed the feedback between drought and hot extremes in large regions of eastern China, while quantifying the impact of antecedent drought on hot extremes has been limited. This study aims at quantitatively assessing the risk of extreme temperature conditioned on the antecedent drought condition represented by Standardized Precipitation Index (SPI) during summer time in eastern China. A copula-based model is proposed to construct the joint probability distribution of extreme temperature and drought based on 6 month SPI (SPI6). Accordingly, the conditional probability distribution is employed to quantify impacts of antecedent dry (and wet) conditions on the exceedance probability of extreme temperature. Results show that the likelihood of extreme temperature exceeding high quantiles is higher given antecedent dry conditions than that given antecedent wet conditions in large regions from southwestern to northeastern China. Specifically, the conditional probability difference of temperature exceeding 80th percentile given SPI6 lower than or equal to -0.5 and SPI6 higher than 0.5 is around 0.2-0.3. The case study of the 2006 summer hot extremes and drought in Sichuan and Chongqing region shows that the conditional return period of extreme temperature conditioned on antecedent drought is around 5-50 years shorter than univariate return period. These results quantify the impact of antecedent drought on subsequent extreme temperature and highlight the important role of antecedent drought in intensifying hot extremes in these regions.

  7. Can reanalysis datasets describe the persistent temperature and precipitation extremes over China?

    NASA Astrophysics Data System (ADS)

    Zhu, Jian; Huang, Dan-Qing; Yan, Pei-Wen; Huang, Ying; Kuang, Xue-Yuan

    2016-08-01

    The persistent temperature and precipitation extremes may bring damage to the economy and human due to their intensity, duration and areal coverage. Understanding the quality of reanalysis datasets in descripting these extreme events is important for detection, attribution and model evaluation. In this study, the performances of two reanalysis datasets [the twentieth century reanalysis (20CR) and Interim ECMWF reanalysis (ERA-Interim)] in reproducing the persistent temperature and precipitation extremes in China are evaluated. For the persistent temperature extremes, the two datasets can better capture the intensity indices than the frequency indices. The increasing/decreasing trend of persistent warm/cold extremes has been reasonably detected by the two datasets, particularly in the northern part of China. The ERA-Interim better reproduces the climatology and tendency of persistent warm extremes, while the 20CR has better skill to depict the persistent cold extremes. For the persistent precipitation extremes, the two datasets have the ability to reproduce the maximum consecutive 5-day precipitation. The two datasets largely underestimate the maximum consecutive dry days over the northern part of China, while overestimate the maximum consecutive wet days over the southern part of China. For the response of the precipitation extremes against the temperature variations, the ERA-Interim has good ability to depict the relationship among persistent precipitation extremes, local persistent temperature extremes, and global temperature variations over specific regions.

  8. Graph Embedded Extreme Learning Machine.

    PubMed

    Iosifidis, Alexandros; Tefas, Anastasios; Pitas, Ioannis

    2016-01-01

    In this paper, we propose a novel extension of the extreme learning machine (ELM) algorithm for single-hidden layer feedforward neural network training that is able to incorporate subspace learning (SL) criteria on the optimization process followed for the calculation of the network's output weights. The proposed graph embedded ELM (GEELM) algorithm is able to naturally exploit both intrinsic and penalty SL criteria that have been (or will be) designed under the graph embedding framework. In addition, we extend the proposed GEELM algorithm in order to be able to exploit SL criteria in arbitrary (even infinite) dimensional ELM spaces. We evaluate the proposed approach on eight standard classification problems and nine publicly available datasets designed for three problems related to human behavior analysis, i.e., the recognition of human face, facial expression, and activity. Experimental results denote the effectiveness of the proposed approach, since it outperforms other ELM-based classification schemes in all the cases.

  9. Extreme driven ion acoustic waves

    NASA Astrophysics Data System (ADS)

    Friedland, L.; Shagalov, A. G.

    2017-08-01

    The excitation of large amplitude, strongly nonlinear ion acoustic waves from trivial equilibrium by a chirped frequency drive is discussed. Under certain conditions, after passage through the linear resonance in this system, the nonlinearity and the variation of parameters work in tandem to preserve the phase-locking with the driving wave via excursion of the excited ion acoustic wave in its parameter space, yielding controlled growth of the wave amplitude. We study these autoresonant waves via a fully nonlinear warm fluid model and predict the formation of sharply peaked (extreme) ion acoustic excitations with local ion density significantly exceeding the unperturbed plasma density. The driven wave amplitude is bound by the kinetic wave-breaking, as the local maximum fluid velocity of the wave approaches the phase velocity of the drive. The Vlasov-Poisson simulations are used to confirm the results of the fluid model, and Whitham's averaged variational principle is applied for analyzing the evolution of autoresonant ion acoustic waves.

  10. Causes of Extremely Fast CMEs

    NASA Technical Reports Server (NTRS)

    Feynman, Joan; Ruzmaikin, Alexander

    2006-01-01

    We study CMEs observed by LASCO to have plane of the sky velocities exceeding 1500 km/sec. We find that these extremely fast CMEs are typically associated with flares accompanied by erupting prominences. Our results are consistent with a single CME initiation process that consists of three stages. The initial stage is brought about by the emergence of new magnetic flux, which interacts with the pre-existing magnetic configuration and results in a slow rise of the magnetic structure. The second stage is a fast reconnection phase with flaring, filament eruption and a sudden increase of the rise velocity of the magnetic structure (CME). The third stage consists of propagation in the corona. We discuss the sources of these CMEs and the need for improved understanding of the first and third stages.

  11. Extreme solar energetic particle events

    NASA Astrophysics Data System (ADS)

    Vainio, Rami; Afanasiev, Alexandr; Battarbee, Markus

    2016-04-01

    Properties of extreme solar energetic particle (SEP) events, here defined as those leading to ground level enhancements (GLEs) of cosmic rays, are reviewed. We review recent efforts on modeling SEP acceleration to relativistic energies and present simulation results on particle acceleration at shocks driven by fast coronal mass ejections (CMEs) in different types of coronal magnetic structures and turbulent downstream compression regions. Based on these modeling results, we discuss the possible role of solar and CME parameters in the lack of GLEs during the present sunspot cycle. This work has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 637324 (HESPERIA). The Academy of Finland is thanked for financial support.

  12. Extreme ultraviolet Talbot interference lithography.

    PubMed

    Li, Wei; Marconi, Mario C

    2015-10-05

    Periodic nanopatterns can be generated using lithography based on the Talbot effect or optical interference. However, these techniques have restrictions that limit their performance. High resolution Talbot lithography is limited by the very small depth of focus and the demanding requirements in the fabrication of the master mask. Interference lithography, with large DOF and high resolution, is limited to simple periodic patterns. This paper describes a hybrid extreme ultraviolet lithography approach that combines Talbot lithography and interference lithography to render an interference pattern with a lattice determined by a Talbot image. As a result, the method enables filling the arbitrary shaped cells produced by the Talbot image with interference patterns. Detailed modeling, system design and experimental results using a tabletop EUV laser are presented.

  13. Weather extremes could affect agriculture

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2012-05-01

    As Earth's climate warms, agricultural producers will need to adapt. Changes, especially increases in extreme events, are already having an impact on food production, according to speakers at a 1 May session on agriculture and food security at the AGU Science Policy Conference. Christopher Field, director of the Department of Global Ecology at the Carnegie Institution for Science of Washington, D. C., pointed out the complex factors that come into play in understanding food security, including spatially varying controls and stresses, incomplete models, and the potential for threshold responses. Factors that are likely to cause problems include increasing population; increasing preference for meat, which needs more land and energy inputs to produce; climate change; and increasing use of agricultural lands for biomass energy.

  14. Extreme Hyperpyrexia of Uncertain Origin.

    PubMed

    Shah, Nikita T; Habtegebriel, Yordanos A; Bloomfield, Dennis A

    2016-09-01

    The definition of hyperpyrexia is currently limited to temperatures reaching 106.7°F. A wide range of etiologies have been identified in the literature for an insidious onset of hyperpryexia, however a rapid ascent higher than temperatures of 106.7°F has never been reported nor evaluated. We present the case of a young paraplegic who developed an extreme hyperpyrexia, which to our knowledge is the highest occurring temperature reported in contemporary medical literature. He had a number of medical conditions, none of which are known to produce fever. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Fever, although a common presentation in the ER in the presence of various symptoms and comorbidities can obscure the diagnosis and lead to unwarranted evaluations. As such this patients case identifies a diagnosis of a fatal ascension of fever. Published by Elsevier Inc.

  15. Extreme resilience in cochleate nanoparticles.

    PubMed

    Bozó, Tamás; Brecska, Richárd; Gróf, Pál; Kellermayer, Miklós S Z

    2015-01-20

    Cochleates, prospective nanoscale drug delivery vehicles, are rolls of negatively charged phospholipid membrane layers. The membrane layers are held together by calcium ions; however, neither the magnitude of membrane interaction forces nor the overall mechanical properties of cochleates have been known. Here, we manipulated individual nanoparticles with atomic force microscopy to characterize their nanomechanical behavior. Their stiffness (4.2-12.5 N/m) and membrane-rupture forces (45.3-278 nN) are orders of magnitude greater than those of the tough viral nanoshells. Even though the fundamental building material of cochleates is a fluid membrane, the combination of supramolecular geometry, the cross-linking action of calcium, and the tight packing of the ions apparently lead to extreme mechanical resilience. The supramolecular design of cochleates may provide efficient protection for encapsulated materials and give clues to understanding biomolecular structures of similar design, such as the myelinated axon.

  16. Extremely red quasars in BOSS

    NASA Astrophysics Data System (ADS)

    Hamann, Fred; Zakamska, Nadia L.; Ross, Nicholas; Paris, Isabelle; Alexandroff, Rachael M.; Villforth, Carolin; Richards, Gordon T.; Herbst, Hanna; Brandt, W. Niel; Cook, Ben; Denney, Kelly D.; Greene, Jenny E.; Schneider, Donald P.; Strauss, Michael A.

    2017-01-01

    Red quasars are candidate young objects in an early transition stage of massive galaxy evolution. Our team recently discovered a population of extremely red quasars (ERQs) in the Baryon Oscillation Spectroscopic Survey (BOSS) that has a suite of peculiar emission-line properties including large rest equivalent widths (REWs), unusual `wingless' line profiles, large N V/Lyα, N V/C IV, Si IV/C IV and other flux ratios, and very broad and blueshifted [O III] λ5007. Here we present a new catalogue of C IV and N V emission-line data for 216 188 BOSS quasars to characterize the ERQ line properties further. We show that they depend sharply on UV-to-mid-IR colour, secondarily on REW(C IV), and not at all on luminosity or the Baldwin Effect. We identify a `core' sample of 97 ERQs with nearly uniform peculiar properties selected via i-W3 ≥ 4.6 (AB) and REW(C IV) ≥ 100 Å at redshifts 2.0-3.4. A broader search finds 235 more red quasars with similar unusual characteristics. The core ERQs have median luminosity ˜ 47.1, sky density 0.010 deg-2, surprisingly flat/blue UV spectra given their red UV-to-mid-IR colours, and common outflow signatures including BALs or BAL-like features and large C IV emission-line blueshifts. Their SEDs and line properties are inconsistent with normal quasars behind a dust reddening screen. We argue that the core ERQs are a unique obscured quasar population with extreme physical conditions related to powerful outflows across the line-forming regions. Patchy obscuration by small dusty clouds could produce the observed UV extinctions without substantial UV reddening.

  17. Acquired Upper Extremity Growth Arrest.

    PubMed

    Gauger, Erich M; Casnovsky, Lauren L; Gauger, Erica J; Bohn, Deborah C; Van Heest, Ann E

    2017-01-01

    This study reviewed the clinical history and management of acquired growth arrest in the upper extremity in pediatric patients. The records of all patients presenting from 1996 to 2012 with radiographically proven acquired growth arrest were reviewed. Records were examined to determine the etiology and site of growth arrest, management, and complications. Patients with tumors or hereditary etiology were excluded. A total of 44 patients (24 boys and 20 girls) with 51 physeal arrests who presented at a mean age of 10.6 years (range, 0.8-18.2 years) were included in the study. The distal radius was the most common site (n=24), followed by the distal humerus (n=8), metacarpal (n=6), distal ulna (n=5), proximal humerus (n=4), radial head (n=3), and olecranon (n=1). Growth arrest was secondary to trauma (n=22), infection (n=11), idiopathy (n=6), inflammation (n=2), compartment syndrome (n=2), and avascular necrosis (n=1). Twenty-six patients (59%) underwent surgical intervention to address deformity caused by the physeal arrest. Operative procedures included ipsilateral unaffected bone epiphysiodesis (n=21), shortening osteotomy (n=10), lengthening osteotomy (n=8), excision of physeal bar or bone fragment (n=2), angular correction osteotomy (n=1), and creation of single bone forearm (n=1). Four complications occurred; 3 of these required additional procedures. Acquired upper extremity growth arrest usually is caused by trauma or infection, and the most frequent site is the distal radius. Growth disturbances due to premature arrest can be treated effectively with epiphysiodesis or osteotomy. In this series, the specific site of anatomic growth arrest was the primary factor in determining treatment. [Orthopedics. 2017; 40(1):e95-e103.]. Copyright 2016, SLACK Incorporated.

  18. Gut Microbiota and Extreme Longevity.

    PubMed

    Biagi, Elena; Franceschi, Claudio; Rampelli, Simone; Severgnini, Marco; Ostan, Rita; Turroni, Silvia; Consolandi, Clarissa; Quercia, Sara; Scurti, Maria; Monti, Daniela; Capri, Miriam; Brigidi, Patrizia; Candela, Marco

    2016-06-06

    The study of the extreme limits of human lifespan may allow a better understanding of how human beings can escape, delay, or survive the most frequent age-related causes of morbidity, a peculiarity shown by long-living individuals. Longevity is a complex trait in which genetics, environment, and stochasticity concur to determine the chance to reach 100 or more years of age [1]. Because of its impact on human metabolism and immunology, the gut microbiome has been proposed as a possible determinant of healthy aging [2, 3]. Indeed, the preservation of host-microbes homeostasis can counteract inflammaging [4], intestinal permeability [5], and decline in bone and cognitive health [6, 7]. Aiming at deepening our knowledge on the relationship between the gut microbiota and a long-living host, we provide for the first time the phylogenetic microbiota analysis of semi-supercentenarians, i.e., 105-109 years old, in comparison to adults, elderly, and centenarians, thus reconstructing the longest available human microbiota trajectory along aging. We highlighted the presence of a core microbiota of highly occurring, symbiotic bacterial taxa (mostly belonging to the dominant Ruminococcaceae, Lachnospiraceae, and Bacteroidaceae families), with a cumulative abundance decreasing along with age. Aging is characterized by an increasing abundance of subdominant species, as well as a rearrangement in their co-occurrence network. These features are maintained in longevity and extreme longevity, but peculiarities emerged, especially in semi-supercentenarians, describing changes that, even accommodating opportunistic and allochthonous bacteria, might possibly support health maintenance during aging, such as an enrichment and/or higher prevalence of health-associated groups (e.g., Akkermansia, Bifidobacterium, and Christensenellaceae).

  19. Functional recovery following stroke: Capturing changes in upper extremity function

    PubMed Central

    Simpson, Lisa A

    2015-01-01

    Background and Purpose Augmenting changes in recovery is core to the rehabilitation process following a stroke. Hence, it is essential that outcome measures are able to detect change as it occurs; a property known as responsiveness. This paper critically reviewed the responsiveness of functional outcome measures following stroke, specifically examining tools that captured upper extremity functional recovery. Methods A systematic search of the literature was undertaken to identify articles providing responsiveness data for three types of change (observed, detectable, important). Results Data from 68 articles for 14 upper extremity functional outcome measures were retrieved. Larger percent changes were required to be considered important when obtained through anchor-based methods (eg. based on patient opinion or comparative measure) compared to distribution methods (eg. statistical estimates). Larger percent changes were required to surpass the measurement error for patient-perceived functional measures (eg. Motor Activity Log) compared to lab-based performance measures (eg. Action Research Arm Test). The majority of rehabilitation interventions have similarly sized effects on patient-perceived upper extremity function versus lab-based upper extremity function. Conclusions The magnitude of important change or change that surpasses measurement error can vary substantially depending on the method of calculation. Rehabilitation treatments can affect patient perceptions of functional change as effectively as lab-based functional measures; however higher sample sizes may be required to account for the larger measurement error associated with patient-perceived functional measures. PMID:23077144

  20. Point precipitation observation extremes in the world and Japan

    NASA Astrophysics Data System (ADS)

    Kiguchi, Masashi; Oki, Taikan

    2010-05-01

    In the discussion about the increase and decrease of the frequency of an extreme heavy precipitation, it is necessary to evaluate the rainfall extreme value record that has been observed up to now correctly. In this paper, the source and the observational data of the rainfall extreme value record in the world and Japan were revealed, and it revalued it including the reliability and the uncertainty. A lot of things with an indefinite source were included though it was brought together by WMO and NOAA/NWS in the rainfall extreme value record of the world. The case where the value in the thesis was different from the data of local agency and the case where there is a problem in the interpretation based on the content of the description of the quotation thesis were seen, and moreover, these were corrected and annotated as much as possible. Though the extreme value record including the observation of another government and municipal offices excluding the Japanese Meteorological Agency and a private company was described in various books, because data that mis-described and was uncertain that was included, that data was verified, corrected, and annotated for Japanese rainfall extreme value records. The relationship between the period and the depth of the extreme record is interestingly close to the line accordance with regression formula which is give by exponential value 0.5. The close examination concerning the precipitation extreme value which is advanced including other meteorological elements extreme events by WMO/CCl is expected to be promoted more by showing reliability and the uncertainty shown with this paper. This study cannot directory to make an impact assessment by climate change. On the other hand, it is possible to evaluate the effect of climate change on an extreme rainfall phenomenon that becomes the index through the evaluation of the estimation approach of the rainfall potential used for the probability precipitation that plays an important role to the

  1. Modeling the Pineapple Express phenomenon via Multivariate Extreme Value Theory

    NASA Astrophysics Data System (ADS)

    Weller, G.; Cooley, D. S.

    2011-12-01

    The pineapple express (PE) phenomenon is responsible for producing extreme winter precipitation events in the coastal and mountainous regions of the western United States. Because the PE phenomenon is also associated with warm temperatures, the heavy precipitation and associated snowmelt can cause destructive flooding. In order to study impacts, it is important that regional climate models from NARCCAP are able to reproduce extreme precipitation events produced by PE. We define a daily precipitation quantity which captures the spatial extent and intensity of precipitation events produced by the PE phenomenon. We then use statistical extreme value theory to model the tail dependence of this quantity as seen in an observational data set and each of the six NARCCAP regional models driven by NCEP reanalysis. We find that most NCEP-driven NARCCAP models do exhibit tail dependence between daily model output and observations. Furthermore, we find that not all extreme precipitation events are pineapple express events, as identified by Dettinger et al. (2011). The synoptic-scale atmospheric processes that drive extreme precipitation events produced by PE have only recently begun to be examined. Much of the current work has focused on pattern recognition, rather than quantitative analysis. We use daily mean sea-level pressure (MSLP) fields from NCEP to develop a "pineapple express index" for extreme precipitation, which exhibits tail dependence with our observed precipitation quantity for pineapple express events. We build a statistical model that connects daily precipitation output from the WRFG model, daily MSLP fields from NCEP, and daily observed precipitation in the western US. Finally, we use this model to simulate future observed precipitation based on WRFG output driven by the CCSM model, and our pineapple express index derived from future CCSM output. Our aim is to use this model to develop a better understanding of the frequency and intensity of extreme

  2. Survey of upper extremity injuries among martial arts participants.

    PubMed

    Diesselhorst, Matthew M; Rayan, Ghazi M; Pasque, Charles B; Peyton Holder, R

    2013-01-01

    To survey participants at various experience levels of different martial arts (MA) about upper extremity injuries sustained during training and fighting. A 21-s question survey was designed and utilised. The survey was divided into four groups (Demographics, Injury Description, Injury Mechanism, and Miscellaneous information) to gain knowledge about upper extremity injuries sustained during martial arts participation. Chi-square testing was utilised to assess for significant associations. Males comprised 81% of respondents. Involvement in multiple forms of MA was the most prevalent (38%). The hand/wrist was the most common area injured (53%), followed by the shoulder/upper arm (27%) and the forearm/elbow (19%). Joint sprains/muscle strains were the most frequent injuries reported overall (47%), followed by abrasions/bruises (26%). Dislocations of the upper extremity were reported by 47% of participants while fractures occurred in 39%. Surgeries were required for 30% of participants. Females were less likely to require surgery and more likely to have shoulder and elbow injuries. Males were more likely to have hand injuries. Participants of Karate and Tae Kwon Do were more likely to have injuries to their hands, while participants of multiple forms were more likely to sustain injuries to their shoulders/upper arms and more likely to develop chronic upper extremity symptoms. With advanced level of training the likelihood of developing chronic upper extremity symptoms increases, and multiple surgeries were required. Hand protection was associated with a lower risk of hand injuries. Martial arts can be associated with substantial upper extremity injuries that may require surgery and extended time away from participation. Injuries may result in chronic upper extremity symptoms. Hand protection is important for reducing injuries to the hand and wrist.

  3. New Insights into the Estimation of Extreme Geomagnetic Storm Occurrences

    NASA Astrophysics Data System (ADS)

    Ruffenach, Alexis; Winter, Hugo; Lavraud, Benoit; Bernardara, Pietro

    2017-04-01

    Space weather events such as intense geomagnetic storms are major disturbances of the near-Earth environment that may lead to serious impacts on our modern society. As such, it is of great importance to estimate their probability, and in particular that of extreme events. One approach largely used in statistical sciences for extreme events probability estimates is Extreme Value Analysis (EVA). Using this rigorous statistical framework, estimations of the occurrence of extreme geomagnetic storms are performed here based on the most relevant global parameters related to geomagnetic storms, such as ground parameters (e.g. geomagnetic Dst and aa indexes), and space parameters related to the characteristics of Coronal Mass Ejections (CME) (velocity, southward magnetic field component, electric field). Using our fitted model, we estimate the annual probability of a Carrington-type event (Dst = -850nT) to be on the order of 10-3, with a lower limit of the uncertainties on the return period of ˜500 years. Our estimate is significantly higher than that of most past studies, which typically had a return period of a few 100 years at maximum. Thus precautions are required when extrapolating intense values. Currently, the complexity of the processes and the length of available data inevitably leads to significant uncertainties in return period estimates for the occurrence of extreme geomagnetic storms. However, our application of extreme value models for extrapolating into the tail of the distribution provides a mathematically justified framework for the estimation of extreme return periods, thereby enabling the determination of more accurate estimates and reduced associated uncertainties.

  4. Lower-extremity burn reconstruction in the child.

    PubMed

    Barbour, John R; Schweppe, Mark; O, Seung-Jun

    2008-07-01

    Lower-extremity burns in a pediatric patient require special consideration. The management of burn reconstruction in pediatric patients is often complex, requiring multiple reconstructive operations, and the primary intention of the surgeon is to prevent burn scar deformities. Timely management of the burn wound and postburn scars has decreased the incidence of burn scar deformities and contractures of the lower extremity in recent years. We present an overview of the principles of reconstruction techniques using skin grafting and biologic skin substitutes to restore the important barrier lost secondary to burns. In addition, we address methods of repairing scar contracture, a common occurrence in burn patients, at specific locations on the lower extremity. Finally, special scenarios such as burns associated with fractures, burn injury in insensate children, and Marjolin ulcer are discussed.

  5. xSim: The Extreme-Scale Simulator

    SciTech Connect

    Boehm, Swen; Engelmann, Christian

    2011-01-01

    Investigating parallel application performance properties at scale is becoming an important part of high-performance computing (HPC) application development and deployment. The Extreme-scale Simulator (xSim) is a performance investigation toolkit that permits running an application in a controlled environment at extreme scale without the need for a respective extreme-scale HPC system. Using a lightweight parallel discrete event simulation, xSim executes a parallel application with a virtual wall clock time, such that performance data can be extracted based on a processor model and a network model. This paper presents significant enhancements to the xSim toolkit prototype that provide a more complete Message Passing Interface (MPI) support and improve its versatility. These enhancements include full virtual MPI group, communicator and collective communication support, and global variables support. The new capabilities are demonstrated by executing the entire NAS Parallel Benchmark suite in a simulated HPC environment.

  6. Impact of climate extremes on wildlife plant flowering over Germany

    NASA Astrophysics Data System (ADS)

    Siegmund, J. F.; Wiedermann, M.; Donges, J. F.; Donner, R. V.

    2015-11-01

    Ongoing climate change is known to cause an increase in the frequency and amplitude of local temperature and precipitation extremes in many regions of the Earth. While gradual changes in the climatological conditions are known to strongly influence plant flowering dates, the question arises if and how extremes specifically impact the timing of this important phenological phase. In this study, we systematically quantify simultaneities between meteorological extremes and the timing of flowering of four shrub species across Germany by means of event coincidence analysis, a novel statistical tool that allows assessing whether or not two types of events exhibit similar sequences of occurrences. Our systematic investigation supports previous findings of experimental studies by highlighting the impact of early spring temperatures on the flowering of wildlife plants. In addition, we find statistically significant indications for some long-term relations reaching back to the previous year.

  7. Extreme solar particle events: The worst case scenario

    NASA Astrophysics Data System (ADS)

    Usoskin, Ilya; Kovaltsov, Gennady

    2016-04-01

    Sporadic eruptive energetic events on the Sun may occur during periods of high solar activity. Sometimes such events can be strong or even extreme posing serious hazards for the modern technology and communication dependent society. It is important to asses the worst case scenario for an extreme solar particle event and what the probability of its occurrence. The era of direct scientific exploration of the Sun is short - from few decades to a century, and yet several strong harmful events took place during that time. Can we expect even greater events? How often? What shall we prepare for? In order to answer these questions, one has to rely upon indirect methods by analyzing natural proxy archives. Here we present an overview of the history of extreme solar events in the past, from hundreds to millions of year, based on an analysis of cosmogenic isotopes in terrestrial archives (polar ice cores and tree rings) and in lunar rocks.

  8. Flood protection diversification to reduce probabilities of extreme losses.

    PubMed

    Zhou, Qian; Lambert, James H; Karvetski, Christopher W; Keisler, Jeffrey M; Linkov, Igor

    2012-11-01

    Recent catastrophic losses because of floods require developing resilient approaches to flood risk protection. This article assesses how diversification of a system of coastal protections might decrease the probabilities of extreme flood losses. The study compares the performance of portfolios each consisting of four types of flood protection assets in a large region of dike rings. A parametric analysis suggests conditions in which diversifications of the types of included flood protection assets decrease extreme flood losses. Increased return periods of extreme losses are associated with portfolios where the asset types have low correlations of economic risk. The effort highlights the importance of understanding correlations across asset types in planning for large-scale flood protection. It allows explicit integration of climate change scenarios in developing flood mitigation strategy.

  9. Characterization of extreme precipitation within atmospheric river events over California

    DOE PAGES

    Jeon, S.; Prabhat,; Byna, S.; ...

    2015-11-17

    Atmospheric rivers (ARs) are large, spatially coherent weather systems with high concentrations of elevated water vapor. These systems often cause severe downpours and flooding over the western coastal United States – and with the availability of more atmospheric moisture in the future under global warming we expect ARs to play an important role as potential causes of extreme precipitation changes. Therefore, we aim to investigate changes in extreme precipitation properties correlated with AR events in a warmer climate, which are large-scale meteorological patterns affecting the weather and climate of California. We have recently developed the TECA (Toolkit for Extreme Climatemore » Analysis) software for automatically identifying and tracking features in climate data sets. Specifically, we can now identify ARs that make landfall on the western coast of North America. Based on this detection procedure, we can investigate the impact of ARs by exploring the spatial extent of AR precipitation using climate model (CMIP5) simulations and characterize spatial patterns of dependence for future projections between AR precipitation extremes under climate change within the statistical framework. Our results show that AR events in the future RCP (Representative Concentration Pathway)8.5 scenario (2076–2100) tend to produce heavier rainfall with higher frequency and longer days than events from the historical run (1981–2005). We also find that the dependence between extreme precipitation events has a shorter spatial range, within localized areas in California, under the high future emissions scenario than under the historical run.« less

  10. Changes in extreme regional sea level under global warming

    NASA Astrophysics Data System (ADS)

    Brunnabend, S.-E.; Dijkstra, H. A.; Kliphuis, M. A.; Bal, H. E.; Seinstra, F.; van Werkhoven, B.; Maassen, J.; van Meersbergen, M.

    2017-01-01

    An important contribution to future changes in regional sea level extremes is due to the changes in intrinsic ocean variability, in particular ocean eddies. Here, we study a scenario of future dynamic sea level (DSL) extremes using a high-resolution version of the Parallel Ocean Program and generalized extreme value theory. This model is forced with atmospheric fluxes from a coupled climate model which has been integrated under the IPCC-SRES-A1B scenario over the period 2000-2100. Changes in 10-year return time DSL extremes are very inhomogeneous over the globe and are related to changes in ocean currents and corresponding regional shifts in ocean eddy pathways. In this scenario, several regions in the North Atlantic experience an increase in mean DSL of up to 0.4 m over the period 2000-2100. DSL extremes with a 10-year return time increase up to 0.2 m with largest values in the northern and eastern Atlantic.

  11. Characterizing extreme and oppressive heat waves in Illinois

    NASA Astrophysics Data System (ADS)

    Ford, Trent W.; Schoof, Justin T.

    2017-01-01

    Heat waves are characteristic features of summertime climate in the Midwest United States and can have significant agricultural, hydrological, and societal impacts. Historically, heat waves in the Midwest state of Illinois have been either extreme (high temperature and low humidity) or oppressive (high temperature and high humidity) in nature, but our knowledge of the factors determining which heat wave type occurs is limited. We use self-organizing maps to classify synoptic-scale atmospheric circulation patterns associated with oppressive and extreme heat events and analysis of variance to evaluate the atmospheric and land surface features responsible for differences in humidity that characterize the two. We find that the majority of extreme and oppressive heat events are associated with similar synoptic-scale atmospheric conditions. Additionally, both locally evaporated moisture and advected moisture sources were important for determining which of the two heat wave types occurred. Specifically, oppressive heat waves were characterized by abundant antecedent precipitation, surplus soil moisture, and elevated evapotranspiration and related atmospheric humidity. Lower humidity levels during extreme heat wave events were driven by relative reductions in evapotranspiration due to limited soil water content. Overall, our results suggest that the onset of heat waves in Illinois is primarily driven by circulation features in the upper atmosphere; however, the distinction of extreme or oppressive heat wave is due to differences in boundary layer humidity, driven in part by land surface moisture availability for evapotranspiration.

  12. Characterization of extreme precipitation within atmospheric river events over California

    NASA Astrophysics Data System (ADS)

    Jeon, S.; Prabhat; Byna, S.; Gu, J.; Collins, W. D.; Wehner, M. F.

    2015-11-01

    Atmospheric rivers (ARs) are large, spatially coherent weather systems with high concentrations of elevated water vapor. These systems often cause severe downpours and flooding over the western coastal United States - and with the availability of more atmospheric moisture in the future under global warming we expect ARs to play an important role as potential causes of extreme precipitation changes. Therefore, we aim to investigate changes in extreme precipitation properties correlated with AR events in a warmer climate, which are large-scale meteorological patterns affecting the weather and climate of California. We have recently developed the TECA (Toolkit for Extreme Climate Analysis) software for automatically identifying and tracking features in climate data sets. Specifically, we can now identify ARs that make landfall on the western coast of North America. Based on this detection procedure, we can investigate the impact of ARs by exploring the spatial extent of AR precipitation using climate model (CMIP5) simulations and characterize spatial patterns of dependence for future projections between AR precipitation extremes under climate change within the statistical framework. Our results show that AR events in the future RCP (Representative Concentration Pathway)8.5 scenario (2076-2100) tend to produce heavier rainfall with higher frequency and longer days than events from the historical run (1981-2005). We also find that the dependence between extreme precipitation events has a shorter spatial range, within localized areas in California, under the high future emissions scenario than under the historical run.

  13. Operational early warning platform for extreme meteorological events

    NASA Astrophysics Data System (ADS)

    Mühr, Bernhard; Kunz, Michael

    2015-04-01

    Operational early warning platform for extreme meteorological events Most natural disasters are related to extreme weather events (e.g. typhoons); weather conditions, however, are also highly relevant for humanitarian and disaster relief operations during and after other natural disaster like earthquakes. The internet service "Wettergefahren-Frühwarnung" (WF) provides various information on extreme weather events, especially when these events are associated with a high potential for large damage. The main focus of the platform is on Central Europe, but major events are also monitored worldwide on a daily routine. WF provides high-resolution forecast maps for many weather parameters which allow detailed and reliable predictions about weather conditions during the next days in the affected areas. The WF service became operational in February 2004 and is part of the Center for Disaster Management and Risk Reduction Technology (CEDIM) since 2007. At the end of 2011, CEDIM embarked a new type of interdisciplinary disaster research termed as forensic disaster analysis (FDA) in near real time. In case of an imminent extreme weather event WF plays an important role in CEDIM's FDA group. It provides early and precise information which are always available and updated several times during a day and gives advice and assists with articles and reports on extreme events.

  14. Extremal Regions Detection Guided by Maxima of Gradient Magnitude.

    PubMed

    Faraji, Mehdi; Shanbehzadeh, Jamshid; Nasrollahi, Kamal; Moeslund, Thomas Baltzer

    2015-12-01

    A problem of computer vision applications is to detect regions of interest under different imaging conditions. The state-of-the-art maximally stable extremal regions (MSERs) detects affine covariant regions by applying all possible thresholds on the input image, and through three main steps including: (1) making a component tree of extremal regions' evolution; (2) obtaining region stability criterion; and (3) cleaning up. The MSER performs very well, but, it does not consider any information about the boundaries of the regions, which are important for detecting repeatable extremal regions. We have shown in this paper that employing prior information about boundaries of regions results in a novel region detector algorithm that not only outperforms MSER, but avoids the MSER's rather complicated steps of enumeration and the cleaning up. To employ the information about the region boundaries, we introduce maxima of gradient magnitudes (MGMs) which are shown to be points that are mostly around the boundaries of the regions. Having found the MGMs, the method obtains a global criterion for each level of the input image which is used to find extremum levels (ELs). The found ELs are then used to detect extremal regions. The proposed algorithm which is called extremal regions of extremum levels (EREL) has been tested on the public benchmark data set of Mikolajczyk. The obtained experimental results show that the inclusion of region boundaries through MGMs, results in a detector that detects regions with high repeatability scores and is more robust against noise compared with MSER.

  15. Estimating the extreme low-temperature event using nonparametric methods

    NASA Astrophysics Data System (ADS)

    D'Silva, Anisha

    This thesis presents a new method of estimating the one-in-N low temperature threshold using a non-parametric statistical method called kernel density estimation applied to daily average wind-adjusted temperatures. We apply our One-in-N Algorithm to local gas distribution companies (LDCs), as they have to forecast the daily natural gas needs of their consumers. In winter, demand for natural gas is high. Extreme low temperature events are not directly related to an LDCs gas demand forecasting, but knowledge of extreme low temperatures is important to ensure that an LDC has enough capacity to meet customer demands when extreme low temperatures are experienced. We present a detailed explanation of our One-in-N Algorithm and compare it to the methods using the generalized extreme value distribution, the normal distribution, and the variance-weighted composite distribution. We show that our One-in-N Algorithm estimates the one-in- N low temperature threshold more accurately than the methods using the generalized extreme value distribution, the normal distribution, and the variance-weighted composite distribution according to root mean square error (RMSE) measure at a 5% level of significance. The One-in- N Algorithm is tested by counting the number of times the daily average wind-adjusted temperature is less than or equal to the one-in- N low temperature threshold.

  16. A Classification Framework for Sub-Daily Extreme Rainfall Events

    NASA Astrophysics Data System (ADS)

    Johnson, F.; Li, J.; Westra, S.

    2016-12-01

    The statistics of extreme rainfall data are used in hydrologic engineering for the design and analysis of flooding and drainage infrastructure. However the mechanisms that lead to these extreme rainfall events are rarely examined. With expected increases in extreme rainfalls due to anthropogenic climate change, understanding the meteorological conditions that generate extremes will become particularly important. Improved understanding of these meteorological mechanisms will firstly help to verify the performance of dynamic downscaling models. The information will also assist in determining the potential changes in the overall extreme event statistics by considering changes in the frequency and amount of different classes of rainfall events. This presentation compares the effectiveness of a number of different classification systems using fine resolution rainfall data for Sydney and Darwin, Australia. Classification systems include the use of reanalysis data, radar reflectivity and co-located climate data including cloud cover, humidity and wind velocity. Rainfall events for a range of durations from 5 minutes to 5 days have been considered, and seasonal and annual variations in event types were examined. The most effective classification methods have been identified and recommendations on how these could be used applied in regional climate model evaluations have also been made.

  17. The role of climate variability in extreme floods in Europe

    NASA Astrophysics Data System (ADS)

    Guimarães Nobre, G.; Jongman, B.; Aerts, J.; Ward, P. J.

    2017-08-01

    Climate variability is shown to be an important driver of spatial and temporal changes in hydrometereological variables in Europe. However, the influence of climate variability on flood damage has received little attention. We investigated the El Niño Southern Oscillation (ENSO), the North Atlantic Oscillation (NAO), and the East Atlantic pattern (EA) during their neutral, positive, and negative phases, to understand their relationships with four flood indicators: Occurrence of Extreme Rainfall, Intensity of Extreme Rainfall, Flood Occurrence, and Flood Damage. We found that positive and negative phases of NAO and EA are associated with more (or less) frequent and intense seasonal extreme rainfall over large areas of Europe. The relationship between ENSO and the Occurrence of Extreme Rainfall and Intensity of Extreme Rainfall in Europe is much smaller than the relationship with NAO or EA, but still significant in some regions. We show that Flood Damage and Flood Occurrence have strong links with climate variability, especially in southern and eastern Europe. Therefore, when investigating flooding across Europe, all three indices of climate variability should be considered. Future research should focus on their joint influence on flood risk. The potential inclusion of seasonal forecasts of indices of climate variability could be effective in forecasting flood damage.

  18. Focus issue on the Study of Matter at Extreme Conditions

    NASA Astrophysics Data System (ADS)

    Saini, Naurang L.; Saxena, Surendra K.; Bansil, Arun

    2015-09-01

    Study of matter at extreme conditions encompasses many different approaches for understanding the physics, chemistry and materials science underlying processes, products and technologies important for society. Although extreme conditions have been associated traditionally with research in areas of geology, mineral and earth sciences, the field has expanded in the recent years to include work on energy related materials and quantum functional materials from hard to soft matter. With the motivation to engage a large number of scientists with various disciplinary interests, ranging from physics, chemistry, geophysics to materials science, the study of matter at extreme conditions has been the theme of a series of conferences hosted by the High Pressure Science Society of America (HiPSSA) and the Center for the Study of Matter at Extreme Conditions (CeSMEC) of Florida International University (FIU), Miami. These SMEC (Study of Matter at Extreme Conditions) conferences are aimed at providing a unique platform for leading researchers to meet and share cutting-edge developments, and to bridge established fields under this interdisciplinary umbrella for research on materials. The seventh meeting in the SMEC series was held during March 23-30, 2013, while sailing from Miami to the Caribbean Islands, and concluded with great enthusiasm.

  19. The Extreme and Variable High Energy Sky

    NASA Astrophysics Data System (ADS)

    A critically important region of the astrophysical spectrum is the hard X-ray/gamma-ray band, from the keV to the GeV energy range. In this band, an unusually rich range of astrophysical processes occur: this is the energy domain where fundamental changes from thermal to non-thermal sources/phenomena are expected, where the effects of absorption are drastically reduced and a clearer picture of the Universe is possible. This is also the energy range where most of the extreme astrophysical behavior is taking place, e.g. cosmic acceleration, explosions and accretion onto black holes and neutron stars; where variability is more the rule than the exception and where a number of instruments are actively working (e.g. INTEGRAL, SWIFT, Suzaku, MAXI, AGILE, Fermi and HESS). These telescopes are providing an unprecedented view of the high energy sky. Combined with data obtained at lower energies from a number of satellites and ground based telescopes we have for the first time the possibility of studying this extreme and variable sky over a very broad energy band and with unprecedented sensitivity.The workshop is aimed at bringing together scientists active across the field of high energy astrophysics in order to focus on the opportunities offered by the high energy window both from the observational and theoretical viewpoints, while a dedicated section will also be devoted to discuss the current status of planned and future missions. The meeting will consist of invited talks and contributions which are welcome as either posters or as short presentations. There will be time for open discussions throughout.We intend to cover the most extreme phenomena associated with acceleration, explosions and accretion onto galactic and extragalactic objects as well as to study variability in all types of objects and environments. In view of the extension of INTEGRAL operational lifetime, the workshop will provide a unique opportunity to prepare for extra observational possibility and to

  20. Towards a European Extremely Large Telescope

    NASA Astrophysics Data System (ADS)

    2006-07-01

    ESO, the European Organisation for Astronomical Research in the Southern Hemisphere, is taking an important step towards the realisation of a new, giant telescope for Europe's astronomers, by creating the ESO Extremely Large Telescope Project Office. It will be headed by Jason Spyromilio, formerly La Silla Paranal Observatory Director. "We believe that the European Extremely Large Telescope (E-ELT) is essential if we are to ensure the continued competitiveness of the astronomical community in ESO's member-states. This goal can be achieved in a timely manner through ESO and the community working closely together, and the establishment of the ELT project office is a significant step in this direction", says Catherine Cesarsky, ESO's Director General. "In its December 2004 Resolution, ESO's Council requested ESO to launch the construction of an ELT on a competitive timescale", says Jason Spyromilio. "The creation of the ELT Project Office is thus the logical step, following on the large amount of preparatory work on ELTs carried out in Europe, for instance in the framework of the OWL Conceptual Study [1], the EU co-funded ELT Design Study project [2] and more recently by the five ELT thematic working groups established by the Director General." The ESO ELT Project Office, which is part of the ESO Telescope Systems Division (TSD), will work closely together with experts, from both ESO and the European scientific community, represented in the ELT Science and Engineering Working Group and in a Standing Review Committee established by the ESO Council. "ESO aims to put the European Extremely Large Telescope on a 'fast-track', within a wide collaboration with its community and with the direct involvement of industry", says Roberto Gilmozzi, head of the ESO TSD and E-ELT Principal Investigator. A baseline design is to be presented to the ESO Council at the end of 2006. The plan is a telescope with a primary mirror between 30 and 60 metres in diameter and a financial envelope

  1. (When and where) Do extreme climate events trigger extreme ecosystem responses? - Development and initial results of a holistic analysis framework

    NASA Astrophysics Data System (ADS)

    Hauber, Eva K.; Donner, Reik V.

    2015-04-01

    In the context of ongoing climate change, extremes are likely to increase in magnitude and frequency. One of the most important consequences of these changes is that the associated ecological risks and impacts are potentially rising as well. In order to better anticipate and understand these impacts, it therefore becomes more and more crucial to understand the general connection between climate extremes and the response and functionality of ecosystems. Among other region of the world, Europe presents an excellent test case for studies concerning the interaction between climate and biosphere, since it lies in the transition region between cold polar and warm tropical air masses and thus covers a great variety of different climatic zones and associated terrestrial ecosystems. The large temperature differences across the continent make this region particularly interesting for investigating the effects of climate change on biosphere-climate interactions. However, previously used methods for defining an extreme event typically disregard the necessity of taking seasonality as well as seasonal variance appropriately into account. Furthermore, most studies have focused on the impacts of individual extreme events instead of considering a whole inventory of extremes with their respective spatio-temporal extents. In order to overcome the aforementioned research gaps, this work introduces a new approach to studying climate-biosphere interactions associated with extreme events, which comprises three consecutive steps: (1) Since Europe exhibits climatic conditions characterized by marked seasonality, a novel method is developed to define extreme events taking into account the seasonality in all quantiles of the probability distribution of the respective variable of interest. This is achieved by considering kernel density estimates individually for each observation date during the year, including the properly weighted information from adjacent dates. By this procedure, we obtain

  2. An 'extreme' future for estuaries? Effects of extreme climatic events on estuarine water quality and ecology.

    PubMed

    Wetz, Michael S; Yoskowitz, David W

    2013-04-15

    Recent climate observations suggest that extreme climatic events (ECE; droughts, floods, tropical cyclones, heat waves) have increased in frequency and/or intensity in certain world regions, consistent with climate model projections that account for man's influence on the global climate system. A synthesis of existing literature is presented and shows that ECE affect estuarine water quality by altering: (1) the delivery and processing of nutrients and organic matter, (2) physical-chemical properties of estuaries, and (3) ecosystem structure and function. From the standpoint of estuarine scientists and resource managers, a major scientific challenge will be to project the estuarine response to ECE that will co-occur with other important environmental changes (i.e., natural climate variability, global warming, sea level rise, eutrophication), as this will affect the provisioning of important ecosystem services provided by estuaries.

  3. On the nature of extreme Of supergiants

    NASA Astrophysics Data System (ADS)

    Crowther, P. A.; Bohannan, B.

    1997-01-01

    Astrophysically there is a clear distinction between extreme Of supergiants and WNL-type Wolf-Rayet stars, though the morphological distinction is often in the eye of the beholder, even for the most discriminating practitioner. Our spectroscopic analysis of the two extreme O supergiants, HD152408 and HD152386, and the morphologically related stars, HD151804 (O8Iaf), HDE313846 (WN9a), NS4 (WN9) and HD177230 (WN8) indicates that the astrophysical discrimination between Of and WNL is the surface mass flux (dotM /4pi R_{*}(2) ), with stellar temperature and surface helium abundance secondary effects. Above a surface mass flux of ~ 10(-8.8) Msunyr(-1) Rsun(-2) stars are classified as Wolf-Rayet. We conclude that OIafpe stars should be re-classified as WN9a stars from their overall spectral appearance, blue shifted absorption lines (e.g. Heii lambda 5412), their highly helium enriched atmospheres, and we suggest an evolutionary sequence between OIaf and WNLa stars, without direct observational evidence in favour of an intermediate Luminous Blue Variable phase (no ejecta nebulae, different morphologies, spatial locations). From new, high-resolution CTIO--IRS line profiles we find that given sufficient spectral resolution (R>=1000) over a suitable range in wavelength, the near-IR is a excellent region for quantatitive studies. We find good agreement between wind velocities derived from Hei 1.0830mu m and the usual ultraviolet P Cyg profiles. Overall our model analyses indicate good consistency between stellar parameters (mass-loss rates, luminosities, surface abundances) based on either near-IR or optical diagnostics, a question of importance to investigating stars obscured by interstellar dust (e.g. in the Galactic Center) or in crowded regions where IR spectroscopy and low-order adaptive optics provides spatial discrimination (e.g. stars in Local Group galaxies).

  4. Seasonal Climate Extremes : Mechanism, Predictability and Responses to Global Warming

    NASA Astrophysics Data System (ADS)

    Shongwe, M. E.

    2010-01-01

    Climate extremes are rarely occurring natural phenomena in the climate system. They often pose one of the greatest environmental threats to human and natural systems. Statistical methods are commonly used to investigate characteristics of climate extremes. The fitted statistical properties are often interpolated or extrapolated to give an indication of the likelihood of a certain event within a given period or interval. Under changing climatic conditions, the statistical properties of climate extremes are also changing. It is an important scientific goal to predict how the properties of extreme events change. To achieve this goal, observational and model studies aimed at revealing important features are a necessary prerequisite. Notable progress has been made in understanding mechanisms that influence climate variability and extremes in many parts of the globe including Europe. However, some of the recently observed unprecedented extremes cannot be fully explained from the already identified forcing factors. A better understanding of why these extreme events occur and their sensitivity to certain reinforcing and/or competing factors is useful. Understanding their basic form as well as their temporal variability is also vital and can contribute to global scientific efforts directed at advancing climate prediction capabilities, particularly making skilful forecasts and realistic projections of extremes. In this thesis temperature and precipitation extremes in Europe and Africa, respectively, are investigated. Emphasis is placed on the mechanisms underlying the occurrence of the extremes, their predictability and their likely response to global warming. The focus is on some selected seasons when extremes typically occur. An atmospheric energy budget analysis for the record-breaking European Autumn 2006 event has been carried out with the goal to identify the sources of energy for the extreme event. Net radiational heating is compared to surface turbulent fluxes of

  5. Characterizing differences in precipitation regimes of extreme wet and dry years: implications for climate change experiments.

    PubMed

    Knapp, Alan K; Hoover, David L; Wilcox, Kevin R; Avolio, Meghan L; Koerner, Sally E; La Pierre, Kimberly J; Loik, Michael E; Luo, Yiqi; Sala, Osvaldo E; Smith, Melinda D

    2015-02-03

    Climate change is intensifying the hydrologic cycle and is expected to increase the frequency of extreme wet and dry years. Beyond precipitation amount, extreme wet and dry years may differ in other ways, such as the number of precipitation events, event size, and the time between events. We assessed 1614 long-term (100 year) precipitation records from around the world to identify key attributes of precipitation regimes, besides amount, that distinguish statistically extreme wet from extreme dry years. In general, in regions where mean annual precipitation (MAP) exceeded 1000 mm, precipitation amounts in extreme wet and dry years differed from average years by ~40% and 30%, respectively. The magnitude of these deviations increased to >60% for dry years and to >150% for wet years in arid regions (MAP<500 mm). Extreme wet years were primarily distinguished from average and extreme dry years by the presence of multiple extreme (large) daily precipitation events (events >99th percentile of all events); these occurred twice as often in extreme wet years compared to average years. In contrast, these large precipitation events were rare in extreme dry years. Less important for distinguishing extreme wet from dry years were mean event size and frequency, or the number of dry days between events. However, extreme dry years were distinguished from average years by an increase in the number of dry days between events. These precipitation regime attributes consistently differed between extreme wet and dry years across 12 major terrestrial ecoregions from around the world, from deserts to the tropics. Thus, we recommend that climate change experiments and model simulations incorporate these differences in key precipitation regime attributes, as well as amount into treatments. This will allow experiments to more realistically simulate extreme precipitation years and more accurately assess the ecological consequences. © 2015 John Wiley & Sons Ltd.

  6. Hydrological extreme events with Mike Basin

    NASA Astrophysics Data System (ADS)

    Pereira, M. G.; Carvalho, S.; Fernandes, L.; Caramelo, L.; Alencoão, A.

    2012-04-01

    This work is part of a broader project which aims to develop an integrated system to model and simulate of the hydrological cycle processes at river basin scale. All these processes involved in the dynamics of a watershed, which play an important role in the proper management and sustainable use of water resources, are influenced by many factors (e.g. soil use, vegetation cover, weather and climate) being of particular importance, all aspects related to the occurrence, amount and the spatial-temporal distribution of precipitation. We focus our work on the use of the MIKE Basin model and apply it to the Corgo River basin, which is a tributary of the Douro river, located in the Portuguese region of Trás-os-Montes and Alto Douro. Different datasets were used to characterize and model the river basin catchment hydrological processes, namely temperature, precipitation and runoff registered in several weather/hydrometric stations from the Institute of Information System for Water Resources (http://snirh.pt/) as well as land use/soil occupation and topography maps. The MIKE BASIN model runs on a Geographic Information System (GIS) to perform hydrologic modeling at basin-scale. This software allows a set of multisectoral water demands (domestic and industrial water supply, irrigation, hydropower generation, among others) and provides simulation and visualization in both space and time. We start by using the topography, soil type, soil use and vegetation cover of the region. Then the model is calibrated and tested, comparing model runoff estimates with observed data. Finally, the model is used to simulate the river basin catchment behavior to the typical conditions of the hydrological extreme events namely, heavy precipitation and drought. We present the geologic, hydrologic and climatologic characterization of the Corgo river catchment, list the most important factors that control the water availability in the river basin, describe the MIKE BASIN model calibration process

  7. Remembrance of ecohydrologic extremes past

    NASA Astrophysics Data System (ADS)

    Band, L. E.; Hwang, T.

    2013-12-01

    Ecohydrological systems operate at time scales that span several orders of magnitude. Significant processes and feedbacks range from subdaily physiologic response to meteorological drivers, to soil forming and geomorphic processes ranging up through 10^3-10^4 years. While much attention in ecohydrology has focused on ecosystem optimization paradigms, these systems can show significant transience in structure and function, with apparent memory of hydroclimate extremes and regime shifts. While optimization feedbacks can be reconciled with system transience, a better understanding of the time scales and mechanisms of adjustment to increased hydroclimate variability and to specific events is required to understand and predict dynamics and vulnerability of ecosystems. Under certain circumstances of slowly varying hydroclimate, we hypothesize that ecosystems can remain adjusted to changing climate regimes, without displaying apparent system memory. Alternatively, rapid changes in hydroclimate and increased hydroclimate variability, amplified with well expressed non-linearity in the processes controlling feedbacks between water, carbon and nutrients, can move ecosystems far from adjusted states. The Coweeta Hydrological Laboratory is typical of humid, broadleaf forests in eastern North America, with a range of forest biomes from northern hardwoods at higher elevations, to oak-pine assemblages at lower elevations. The site provides almost 80 years of rainfall-runoff records for a set of watersheds under different management, along with multi-decadal forest plot structural information, soil moisture conditions and stream chemistry. An initial period of multi-decadal cooling, was followed by three decades of warming and increased hydroclimate variability. While mean temperature has risen over this time period, precipitation shows no long term trends in the mean, but has had a significant rise in variability with repeated extreme drought and wet periods. Over this latter

  8. Polyimide Resins Resist Extreme Temperatures

    NASA Technical Reports Server (NTRS)

    2009-01-01

    Spacecraft and aerospace engines share a common threat: high temperature. The temperatures experienced during atmospheric reentry can reach over 2,000 F, and the temperatures in rocket engines can reach well over 5,000 F. To combat the high temperatures in aerospace applications, Dr. Ruth Pater of Langley Research Center developed RP-46, a polyimide resin capable of withstanding the most brutal temperatures. The composite material can push the service temperature to the limits of organic materials. Designed as an environmentally friendly alternative to other high-temperature resins, the RP-46 polyimide resin system was awarded a 1992 "R&D 100" award, named a "2001 NASA Technology of the Year," and later, due to its success as a spinoff technology, "2004 NASA Commercial Invention of the Year." The technology s commercial success also led to its winning the Langley s "Paul F. Holloway Technology Transfer Award" as well as "Richard T. Whitcom Aerospace Technology Transfer Award" both for 2004. RP-46 is relatively inexpensive and it can be readily processed for use as an adhesive, composite, resin molding, coating, foam, or film. Its composite materials can be used in temperatures ranging from minus 150 F to 2,300 F. No other organic materials are known to be capable of such wide range and extreme high-temperature applications. In addition to answering the call for environmentally conscious high-temperature materials, RP-46 provides a slew of additional advantages: It is extremely lightweight (less than half the weight of aluminum), chemical and moisture resistant, strong, and flexible. Pater also developed a similar technology, RP-50, using many of the same methods she used with RP-46, and very similar in composition to RP-46 in terms of its thermal capacity and chemical construction, but it has different applications, as this material is a coating as opposed to a buildable composite. A NASA license for use of this material outside of the Space Agency as well as

  9. Sexual activity after dysvascular lower extremity amputation.

    PubMed

    Henderson, Alison W; Turner, Aaron P; Williams, Rhonda M; Norvell, Daniel C; Hakimi, Kevin N; Czerniecki, Joseph M

    2016-08-01

    This study examined the prevalence and correlates of sexual activity among individuals experiencing their first dysvascular lower extremity amputation. A prospective cohort was recruited from 4 Veterans Affairs Medical Centers. Of 198 potential participants who met inclusion criteria, 113 (57%) agreed to participate within 7 days of amputation (baseline) and 6 weeks, 4 months, and 12 months post-amputation; 105 completed the sexual activity items at baseline. Measures included self-reported frequency of sexual activity; desire for more or less sexual activity; importance of sexual activity to satisfaction with life; Patient Health Questionnaire-9; Locomotor Capability Index-5; pain intensity/frequency; quality of life. Depending on the time period post-amputation, 11%-24% reported engaging in any sexual activity, although a majority indicated that sexual activity is very important to their satisfaction with life. Frequency of sexual activity increased between 6 weeks and 4 and 12 months post-amputation. In univariate analyses, older age was associated with decreased sexual activity at all time points; at 4 and 12 months, greater mobility was associated with increased sexual activity. In multivariable models, mobility was associated with sexual activity at 4 and 12 months; age and race remained associated with sexual activity at 4 and 12 months, respectively. At all time points, frequency and importance of sexual activity were significantly associated with one another. Although a minority of individuals engaged in any sexual activity during the study period, it remained an important factor in overall satisfaction with life. Younger age and improved mobility were associated with increased sexual activity. Rehabilitation specialists are encouraged to address sexuality and, if relevant, incorporate it into rehabilitation goals. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  10. Probabilistic Büchi Automata with Non-extremal Acceptance Thresholds

    NASA Astrophysics Data System (ADS)

    Chadha, Rohit; Sistla, A. Prasad; Viswanathan, Mahesh

    This paper investigates the power of Probabilistic Büchi Automata (PBA) when the threshold probability of acceptance is non-extremal, i.e., is a value strictly between 0 and 1. Many practical randomized algorithms are designed to work under non-extremal threshold probabilities and thus it is important to study power of PBAs for such cases.

  11. Lower Extremity Limb Salvage: Lessons Learned From 14 Years at War.

    PubMed

    Blair, James A; Eisenstein, Emmanuel D; Pierrie, Sarah N; Gordon, Wade; Owens, Johnny G; Hsu, Joseph R

    2016-10-01

    American survivability during the current conflicts in Iraq and Afghanistan continues to improve, though the rate of extremity injury remains quite high. The decision to proceed with amputation versus limb salvage remains controversial. Exposure to combat wound with severe high-energy lower extremity trauma during the previous 14 years at war has incited important advances in limb salvage technique and rehabilitation.

  12. Analyzing phenological extreme events over the past five decades in Germany

    NASA Astrophysics Data System (ADS)

    Schleip, Christoph; Menzel, Annette; Estrella, Nicole; Graeser, Philipp

    2010-05-01

    , 1990 and 2007 whereas exceptionally extreme late events are seen in the year 1970. Summer phases such as fruit ripening exhibit stronger shifts to early extremes than spring phases. Leaf colouring phases reveal increasing probability for late extremes. The with GEV estimated 100-year event of Picea, Pinus and Larix amount to extreme early events of about -27, -31.48 and -32.79 days, respectively. If we assume non-stationary minimum data we get a more extreme 100-year event of about -35.40 for Picea but associated with wider confidence intervals. The GEV is simply another probability distribution but for purposes of extreme analysis in phenology it should be considered as equally important as (if not more important than) the Gaussian PDF approach.

  13. Extreme Programming in a Research Environment

    NASA Technical Reports Server (NTRS)

    Wood, William A.; Kleb, William L.

    2002-01-01

    This article explores the applicability of Extreme Programming in a scientific research context. The cultural environment at a government research center differs from the customer-centric business view. The chief theoretical difficulty lies in defining the customer to developer relationship. Specifically, can Extreme Programming be utilized when the developer and customer are the same person? Eight of Extreme Programming's 12 practices are perceived to be incompatible with the existing research culture. Further, six of the nine 'environments that I know don't do well with XP' apply. A pilot project explores the use of Extreme Programming in scientific research. The applicability issues are addressed and it is concluded that Extreme Programming can function successfully in situations for which it appears to be ill-suited. A strong discipline for mentally separating the customer and developer roles is found to be key for applying Extreme Programming in a field that lacks a clear distinction between the customer and the developer.

  14. Extreme Light Infrastructure: nuclear physics

    NASA Astrophysics Data System (ADS)

    Zamfir, N. V.; Habs, D.; Negoita, F.; Ursescu, D.

    2011-06-01

    The spectacular progress of electron and heavy-ions acceleration driven by ultra-short high-power laser has opened the way for new methods of investigations in nuclear physics and related fields. On the other hand, upshifting the photon energies of a high repetition TW-class laser through inverse Compton scattering on electron bunches classically accelerated, a high-flux narrow bandwidth gamma beam can be produced. With such a gamma beam in the 1-20 MeV energy range and a two-arms 10-PW class laser system, the pillar of "Extreme Light Infrastructure" to be built in Bucharest will focus on nuclear phenomena and their practical applications. Nuclear structure, nuclear astrophysics, fundamental QED aspects as well as applications in material and life sciences, radioactive waste management and homeland security will be studied using the high-power laser, the gamma beam or combining the two. The article includes a general description of ELI-Nuclear Physics (ELI-NP) facility, an overview of the Physics Case and some details on the few, most representative proposed experiments.

  15. The Diffuse Extreme Ultraviolet Background

    NASA Technical Reports Server (NTRS)

    Vallerga, John; Slavin, Jonathan

    1996-01-01

    Observations of the diffuse EUV background towards 138 different directions using the spectrometers aboard the Extreme Ultraviolet Explorer satellite (EUVE) have been combined into a spectrum from 150A to 730A and represent an effective exposure of 18 million seconds. There is no significant evidence of any non-local line flux in the resultant spectrum such as that from a hot coronal plasma. These results are inconsistent with the Wisconsin C and B broad-band surveys assuming the source is a logT = 5.8 - 6.1 hot plasma in ionization equilibrium with solar abundances, confirming the previous result of Jelinksy, Vallerga and Edelstein) (hereafter Paper 1) using an observation along the ecliptic with the same instrument. To make these results consistent with the previous broad-band surveys, the plasma responsible for the emission must either be depleted in Fe by a factor of approximately 6, be behind an absorbing slab of neutral H with a column of 2 x 10(exp 19)/sq cm, or not be in collisional ionization equilibrium (CIE). One such non-CIE model (Breitswerdt and Schmutzier) that explains the soft x-ray results is also inconsistent with this EUV data.

  16. Extreme Mechanics of Growing Matter

    NASA Astrophysics Data System (ADS)

    Kuhl, Ellen

    2013-03-01

    Growth is a distinguishing feature of all living things. Unlike standard materials, living matter can autonomously respond to alterations in its environment. As a result of a continuous ultrastructural turnover and renewal of cells and extracellular matrix, living matter can undergo extreme changes in composition, size, and shape within the order of months, weeks, or days. While hard matter typically adapts by increasing its density to grow strong, soft matter adapts by increasing its volume to grow large. Here we provide a state-of-the-art review of growing matter, and compare existing mathematical models for growth and remodeling of living systems. Applications are plentiful ranging from plant growth to tumor growth, from asthma in the lungs to restenosis in the vasculature, from plastic to reconstructive surgery, and from skeletal muscle adaptation to heart failure. Using these examples, we discuss current challenges and potential future directions. We hope to initiate critical discussions around the biophysical modeling of growing matter as a powerful tool to better understand biological systems in health and disease. This research has been supported by the NSF CAREER award CMMI 0952021.

  17. Driving Extreme Efficiency to Market

    NASA Astrophysics Data System (ADS)

    Garbesi, Karina

    2014-03-01

    The rapid development of extremely energy efficient appliances and equipment is essential to curtail catastrophic climate disruption. This will require the on-going development of products that apply all best-practices and that take advantage of the synergies of hybridization and building integration. Beyond that, it requires the development of new disruptive technologies and concepts. To facilitate these goals, in 2011 the Lawrence Berkeley National Laboratory and the U.S. Department of Energy launched the Max Tech and Beyond Design Competition for Ultra-Low-Energy-Use Appliances and Equipment. Now in its third year, the competition supports faculty-lead student design teams at U.S. universities to develop and test new technology prototypes. This talk describes what the competition and the Max Tech Program are doing to drive such rapid technology progress and to facilitate the entry to the market of successful Max Tech prototypes. The talk also initiates a discussion of physicists' unique role in driving that technology progress faster and farther. Emerging Technologies, Building Technologies Office, U.S. Department of Energy.

  18. Gravity and Extreme Magnetism SMEX

    NASA Technical Reports Server (NTRS)

    Swank, Jean; Kallman, Timothy R.; Jahoda, Keith M.

    2008-01-01

    Gas accreting ont,o black holes and neutron stars form a dynamic system generating X-rays with spectroscopic signatures and varying on time scales determined by the system. The radiation from various parts of these systems is surely polarized and compact sources have been calculated to give rise to net polarization from the unresolved sum of the radiation from the systems. Polarization has been looked to for some time as also bearing the imprint of strong gravity and providing complementary information that could resolve ambiguities between the physical models that can give rise to frequencies, time delays, and spectra. In the cases of both stellar black holes and supermassive black holes the net polarizations predicted for probable disk and corona models are less than 10 needed. This sensitivity can be achieved, even for sources as faint as 1 milliCrab, in the Gravity and Extreme Magnetism SMEX (GEMS) mission that uses foil mirrors and Time Projection Chamber detectors. Similarities have been pointed out between the timing and the spectral characteristics of low mass X-ray binaries and stellar black hole sources. Polarization measurements for these sources could play a role in determining the configuration of the disk and the neutron star.

  19. Magnetic slippery extreme icephobic surfaces.

    PubMed

    Irajizad, Peyman; Hasnain, Munib; Farokhnia, Nazanin; Sajadi, Seyed Mohammad; Ghasemi, Hadi

    2016-11-08

    Anti-icing surfaces have a critical footprint on daily lives of humans ranging from transportation systems and infrastructure to energy systems, but creation of these surfaces for low temperatures remains elusive. Non-wetting surfaces and liquid-infused surfaces have inspired routes for the development of icephobic surfaces. However, high freezing temperature, high ice adhesion strength, and high cost have restricted their practical applications. Here we report new magnetic slippery surfaces outperforming state-of-the-art icephobic surfaces with a ice formation temperature of -34 °C, 2-3 orders of magnitude higher delay time in ice formation, extremely low ice adhesion strength (≈2 Pa) and stability in shear flows up to Reynolds number of 10(5). In these surfaces, we exploit the magnetic volumetric force to exclude the role of solid-liquid interface in ice formation. We show that these inexpensive surfaces are universal and can be applied to all types of solids (no required micro/nano structuring) with no compromise to their unprecedented properties.

  20. Magnetic slippery extreme icephobic surfaces

    PubMed Central

    Irajizad, Peyman; Hasnain, Munib; Farokhnia, Nazanin; Sajadi, Seyed Mohammad; Ghasemi, Hadi

    2016-01-01

    Anti-icing surfaces have a critical footprint on daily lives of humans ranging from transportation systems and infrastructure to energy systems, but creation of these surfaces for low temperatures remains elusive. Non-wetting surfaces and liquid-infused surfaces have inspired routes for the development of icephobic surfaces. However, high freezing temperature, high ice adhesion strength, and high cost have restricted their practical applications. Here we report new magnetic slippery surfaces outperforming state-of-the-art icephobic surfaces with a ice formation temperature of −34 °C, 2–3 orders of magnitude higher delay time in ice formation, extremely low ice adhesion strength (≈2 Pa) and stability in shear flows up to Reynolds number of 105. In these surfaces, we exploit the magnetic volumetric force to exclude the role of solid–liquid interface in ice formation. We show that these inexpensive surfaces are universal and can be applied to all types of solids (no required micro/nano structuring) with no compromise to their unprecedented properties. PMID:27824053

  1. Magnetic slippery extreme icephobic surfaces

    NASA Astrophysics Data System (ADS)

    Irajizad, Peyman; Hasnain, Munib; Farokhnia, Nazanin; Sajadi, Seyed Mohammad; Ghasemi, Hadi

    2016-11-01

    Anti-icing surfaces have a critical footprint on daily lives of humans ranging from transportation systems and infrastructure to energy systems, but creation of these surfaces for low temperatures remains elusive. Non-wetting surfaces and liquid-infused surfaces have inspired routes for the development of icephobic surfaces. However, high freezing temperature, high ice adhesion strength, and high cost have restricted their practical applications. Here we report new magnetic slippery surfaces outperforming state-of-the-art icephobic surfaces with a ice formation temperature of -34 °C, 2-3 orders of magnitude higher delay time in ice formation, extremely low ice adhesion strength (~2 Pa) and stability in shear flows up to Reynolds number of 105. In these surfaces, we exploit the magnetic volumetric force to exclude the role of solid-liquid interface in ice formation. We show that these inexpensive surfaces are universal and can be applied to all types of solids (no required micro/nano structuring) with no compromise to their unprecedented properties.

  2. Gravity and Extreme Magnetism SMEX

    NASA Technical Reports Server (NTRS)

    Swank, Jean; Kallman, Timothy R.; Jahoda, Keith M.

    2008-01-01

    Gas accreting ont,o black holes and neutron stars form a dynamic system generating X-rays with spectroscopic signatures and varying on time scales determined by the system. The radiation from various parts of these systems is surely polarized and compact sources have been calculated to give rise to net polarization from the unresolved sum of the radiation from the systems. Polarization has been looked to for some time as also bearing the imprint of strong gravity and providing complementary information that could resolve ambiguities between the physical models that can give rise to frequencies, time delays, and spectra. In the cases of both stellar black holes and supermassive black holes the net polarizations predicted for probable disk and corona models are less than 10 needed. This sensitivity can be achieved, even for sources as faint as 1 milliCrab, in the Gravity and Extreme Magnetism SMEX (GEMS) mission that uses foil mirrors and Time Projection Chamber detectors. Similarities have been pointed out between the timing and the spectral characteristics of low mass X-ray binaries and stellar black hole sources. Polarization measurements for these sources could play a role in determining the configuration of the disk and the neutron star.

  3. Pushing particles in extreme fields

    NASA Astrophysics Data System (ADS)

    Gordon, Daniel F.; Hafizi, Bahman; Palastro, John

    2017-03-01

    The update of the particle momentum in an electromagnetic simulation typically employs the Boris scheme, which has the advantage that the magnetic field strictly performs no work on the particle. In an extreme field, however, it is found that onerously small time steps are required to maintain accuracy. One reason for this is that the operator splitting scheme fails. In particular, even if the electric field impulse and magnetic field rotation are computed exactly, a large error remains. The problem can be analyzed for the case of constant, but arbitrarily polarized and independent electric and magnetic fields. The error can be expressed in terms of exponentials of nested commutators of the generators of boosts and rotations. To second order in the field, the Boris scheme causes the error to vanish, but to third order in the field, there is an error that has to be controlled by decreasing the time step. This paper introduces a scheme that avoids this problem entirely, while respecting the property that magnetic fields cannot change the particle energy.

  4. The Extreme Case of Magnetars

    NASA Technical Reports Server (NTRS)

    Kouveliotou, Chryssa

    2011-01-01

    Magnetars are magnetically powered rotating neutron stars with extreme magnetic fields (over 10(exp 14) Gauss). They were discovered in the X- and gamma-rays where they predominantly emit their radiation. Very few sources (roughly 18) have been found since their discovery in 1987. NASA's Fermi Gamma-ray Space Telescope was launched June 11, 2009; since then the Fermi Gamma-ray Burst Monitor (GBM) recorded emission from four magnetar sources. Two of these were brand new sources, SGR J0501+4516, discovered with Swift and extensively monitored with Swift and GBM, SGR J0418+5729, discovered with GBM and the Interplanetary Network (IPN). A third was SGR J1550-5418, a source originally classified as an Anomalous X-ray Pulsar (AXP 1E1547.0-5408), but exhibiting a very prolific outburst with over 400 events recorded in January 2009. In my talk I will give a short history of magnetars and describe how this, once relatively esoteric field, has emerged as a link between several astrophysical areas including Gamma-Ray Bursts. Finally, I will describe the exciting new results of Fermi in this field and the current status of our knowledge of the magnetar population properties and magnetic fields.

  5. The epidemiology of injury in adventure and extreme sports.

    PubMed

    Caine, Dennis J

    2012-01-01

    The objective of this article is to provide an overview of the current knowledge related to the epidemiology of injury in selected adventure and extreme sports. PubMed and Google Scholar were searched using the terms 'epidemiology', 'injury,' 'adventure sports' and 'extreme sports'. Publications from the past 10 years were largely selected, but commonly referenced or highly regarded older publications were also included. References lists of articles identified in the search strategy were also searched and articles selected that were judged to be relevant. Important aspects of the epidemiology of injury related to adventure and extreme sports are discussed including occurrence of injury, who is affected by injury, where and when injury occurs, injury outcome, risk factors, inciting events, prevention and further research. Given the life-changing impact injury can have in sports (personal, social, financial, psychological, political, and medical), the current paucity of well-designed descriptive and particularly analytical epidemiological studies in some adventure and extreme sports is disturbing. The importance of denominator-based and longitudinal data collection in obtaining an accurate picture of injury risk and severity and as a basis for testing risk factors and evaluating preventive measures is emphasized. Copyright © 2012 S. Karger AG, Basel.

  6. Changes in extreme dry and wet precipitation spell

    NASA Astrophysics Data System (ADS)

    Papalexiou, Simon Michael; Foufoula-Georgiou, Efi; Onof, Chris

    2016-04-01

    Global warming is expected to alter the behavior of hydroclimatic variables in various ways. Therefore, it is of great importance not only to identify which hydroclimatic variables are going through changes but also which of their specific characteristics change and in what way. For example the major focus regarding precipitation has been on changes or trends in extreme events or in annual totals, obviously, not without a reason. Yet one of the aspects of precipitation we believe is of equal importance and has not been extensively studied is extreme dry and wet spells. Changes in dry and wet spells can severely impact all aspects of human lives, ranging from infrastructure planning and water resources management to agriculture and infectious disease spread. In this study we perform an extensive analysis of extreme dry and wet precipitation spells using tenths of thousands of daily precipitation records in order to identify trends or variability changes in the maximum number of consecutive dry or wet days of each year. Our final goal is to evaluate the percentage of stations globally with positive/negative trends either in the mean value or in variability of extreme dry and wet spells and assess if this percentage is statistically justifiable.

  7. Python import replacement

    SciTech Connect

    2011-10-01

    SmartImport.py is a Python source-code file that implements a replacement for the standard Python module importer. The code is derived from knee.py, a file in the standard Python diestribution , and adds functionality to improve the performance of Python module imports in massively parallel contexts.

  8. Python import replacement

    SciTech Connect

    2011-10-01

    SmartImport.py is a Python source-code file that implements a replacement for the standard Python module importer. The code is derived from knee.py, a file in the standard Python diestribution , and adds functionality to improve the performance of Python module imports in massively parallel contexts.

  9. Investigation on rainfall extremes events trough a geoadditive model

    NASA Astrophysics Data System (ADS)

    Bocci, C.; Caporali, E.; Petrucci, A.; Rossi, G.

    2012-04-01

    Rainfall can be considered a very important variable, and rainfall extreme events analysis of great concern for the enormous impacts that they may have on everyday life particularly when related to intense rainfalls and floods, and hydraulic risk management. On the catchment area of Arno River in Tuscany, Central Italy, a geoadditive mixed model of rainfall extremes is developed. Most of the territory of Arno River has suffered in the past of many severe hydro-geological events, with high levels of risk due to the vulnerability of a unique artistic and cultural heritage. The area has a complex topography that greatly influences the precipitation regime. The dataset is composed by the time series of the annual maxima of daily rainfall recorded in about 400 rain gauges, spatially distributed over the catchment area of about 8.800 km2. The record period covers mainly the second half of 20th century. The rainfall observations are assumed to follow generalized extreme value distributions whose locations are spatially dependent and where the dependence is captured using a geoadditive model. In particular, since rainfall has a natural spatial domain and a significant spatial variability, a spatial hierarchical model for extremes is used. The spatial hierarchical models, in fact, take into account data from all locations, borrowing strength from neighbouring locations when they estimate parameters and are of great interest when small set of data is available, as in the case of rainfall extreme values. Together with rain gauges location variables further physiographic variables are investigated as explanation variables. The implemented geoadditive mixed model of spatially referenced time series of rainfall extreme values, is able to capture the spatial dynamics of the rainfall extreme phenomenon. Since the model shows evidence of a spatial trend in the rainfall extreme dynamic, the temporal dynamic and the time influence can be also taken into account. The implemented

  10. Characteristics of Extreme Summer Convection over equatorial America and Africa

    NASA Astrophysics Data System (ADS)

    Zuluaga, M. D.; Houze, R.

    2013-12-01

    cases over tropical America. Over Africa the monsoon is also important in modulating the occurrence of extreme convection; however, diurnal heating and the passage of African Easterly Waves are of primary importance in distributing the extreme convection zonally across the tropical African savannas.

  11. Exclusive lower extremity mirror movements and diastematomyelia.

    PubMed

    Tubbs, R Shane; Smyth, Matthew D; Dure, Leon S; Oakes, W Jerry

    2004-01-01

    Mirror movements usually seen in the Klippel-Feil syndrome are most commonly appreciated in the upper extremities. Lower extremity involvement is seen rarely and when observed, is found in conjunction with upper extremity mirror movements. We report what we believe to be the first case of mirror movements found exclusively in the lower extremities in a female patient presenting with tethered cord syndrome. Our hopes are that this report will help elucidate mechanisms involved with these anomalous movements, as currently there is no commonly accepted etiology.

  12. Against objective statistical analysis of hydrological extremes

    NASA Astrophysics Data System (ADS)

    Bardsley, W. E.

    1994-11-01

    Random-variable models are frequently applied to recorded sequences of hydrological extremes. However, even if the recorded extremes behave like random variables the underlying probability distribution still remains unknown. It follows that better extrapolations of extreme hydrological events will never be achieved by comparing permutations of the latest estimation techniques and specified probability distributions. Yet such estimation/distribution comparisons continue to proliferate through the hydrological literature in the vain hope that some 'best' extrapolation method will emerge in time. The questionable value of the whole comparison process calls into question the worth of objectivity as a desirable attribute in techniques for analysing hydrological extremes.

  13. The limits for life under multiple extremes.

    PubMed

    Harrison, Jesse P; Gheeraert, Nicolas; Tsigelnitskiy, Dmitry; Cockell, Charles S

    2013-04-01

    Life on Earth is limited by physical and chemical extremes that define the 'habitable space' within which it operates. Aside from its requirement for liquid water, no definite limits have been established for life under any extreme. Here, we employ growth data published for 67 prokaryotic strains to explore the limitations for microbial life under combined extremes of temperature, pH, salt (NaCl) concentrations, and pressure. Our review reveals a fundamental lack of information on the tolerance of microorganisms to multiple extremes that impedes several areas of science, ranging from environmental and industrial microbiology to the search for extraterrestrial life.

  14. Real World: Analog Testing in Extreme Environments

    NASA Image and Video Library

    See how NASA uses analog testing to simulate space exploration. Explore extreme environments like the Aquarius underwater laboratory in Key Largo, Florida. Find out how scientists use mathematical ...

  15. Statistical modeling and trend detection of extreme sea level records in the Pearl River Estuary

    NASA Astrophysics Data System (ADS)

    Wang, Weiwen; Zhou, Wen

    2017-03-01

    Sea level rise has become an important issue in global climate change studies. This study investigates trends in sea level records, particularly extreme records, in the Pearl River Estuary, using measurements from two tide gauge stations in Macau and Hong Kong. Extremes in the original sea level records (daily higher high water heights) and in tidal residuals with and without the 18.6-year nodal modulation are investigated separately. Thresholds for defining extreme sea levels are calibrated based on extreme value theory. Extreme events are then modeled by peaks-over-threshold models. The model applied to extremes in original sea level records does not include modeling of their durations, while a geometric distribution is added to model the duration of extremes in tidal residuals. Realistic modeling results are recommended in all stationary models. Parametric trends of extreme sea level records are then introduced to nonstationary models through a generalized linear model framework. The result shows that, in recent decades, since the 1960s, no significant trends can be found in any type of extreme at any station, which may be related to a reduction in the influence of tropical cyclones in the region. For the longer-term record since the 1920s at Macau, a regime shift of tidal amplitudes around the 1970s may partially explain the diverse trend of extremes in original sea level records and tidal residuals.

  16. Effect of extreme value loss on long-term correlated time series

    NASA Astrophysics Data System (ADS)

    Yuan, Naiming; Fu, Zuntao; Li, Huiqun; Mao, Jiangyu

    2012-07-01

    Effects of extreme value loss on long-term correlated time series are analyzed by means of detrended fluctuation analysis (DFA) and power spectral density analysis. Weaker memory can be detected after removing of extreme values for the artificial long-term correlated data, indicating the emergence of extreme events may be closely related to long-term memory. For observational temperature records, similar results are obtained, but not in all stations. For example, in some stations, only extending of scaling range to smaller time scales occurs, which may be due to the asymmetric distribution of values in the record. By comparing our findings with previous works, clustered positions of the extreme events are recognized as an important property in long-term correlated records. Through a simple numerical test, close relations between extreme events and long-term memory are discovered, which is helpful for our understanding of the effects of extreme value loss on long-term correlated records.

  17. Recent high mountain rockfalls and warm daily temperature extremes

    NASA Astrophysics Data System (ADS)

    Allen, S. K.; Huggel, C.

    2012-04-01

    temperatures in the 7 days prior to failure, (between 6 - 9°C above average), and in three of these cases, temperatures exceeded even the 99th percentile. A further 3 events occurring in this region during the longer term heatwave of 2003 similarly were also preceded by extreme daily maximum temperatures. This relationship holds for other failures analysed in the northern, and eastern regions of the central Alps. Most interestingly, the weekly temperature anomaly, and the proportion of 'extreme' days, generally decreases as the analyses are extended from 1, 2, 3 and 4 weeks out from each failure. In other words, there is a notable warming, and conditions become increasingly extreme in the lead-up to slope failure. In addition to extreme summer temperatures, our analyses points towards a possible role of unusually warm autumn and spring days influencing slope stability. A linkage between short term periods of extremely warm temperatures and rock failure may be reasonably facilitated through melt water operating within rock discontinues, processes that have recently been measured in high-mountain rock faces, and are considered to be particularly important in spring/early summer melt periods. It is not clear whether slope failures during warm autumn periods can be linked to the same processes. Rockfalls in the winter months remain rare, however, the 27 December 2011 rock avalanche at Piz Cengalo, Val Bregaglia, Switzerland (ca 2-3million m3), occurred following the warmest year on record, potentially reinforcing the role of longer term warming destabilising bedrock with permafrost at depth.

  18. War injuries of the extremities.

    PubMed

    Korzinek, K

    1993-05-01

    This paper describes experience acquired during the war against Croatia under improvised conditions at the Kutina War Hospital in the immediate vicinity of the first front lines. Over a period of almost 6 months a total of 701 soldiers and civilians, 546 of whom had been wounded by firearm missiles, were treated at the Kutina War Hospital, which has a capacity of 30-40 beds. As many as 87% of the injuries were due to mine, bomb or artillery shell shrapnel. The percentage of gunshot wounds was very low, mainly caused by sniper shots. Most patients (419, or 76.7%) were admitted with injuries to the extremities, including 893 severe soft tissue injuries and 182 fractures (32.3%). Soft tissue injuries were treated by routine procedures of war surgery, associated with ample use of Lavasept, an antiseptic solution (Fresenius, Stans, Switzerland), which has proved to be highly efficacious in preventing and decontaminating infection without disturbance of the wound healing process. Long bone fractures were fixed with the aid of external fixators of various designs, including the CMC external fixator of our own construction. External fixators have once again proved indispensable in the treatment of open fractures sustained in war settings. Amputations were performed in 10.4% of cases, including fingers and toes. Only 8 patients died during or immediately after surgery, corresponding to a very low mortality rate of 1.46%. The main prerequisites for successful treatment are a professional relationship to war surgery and its specific requirements, satisfactory technical equipment, and excellent organization of medical and non-medical services.

  19. Magnetotactic Bacteria from Extreme Environments

    NASA Astrophysics Data System (ADS)

    Bazylinski, Dennis A.; Lefère, Christopher T.

    2013-03-01

    Magnetotactic bacteria (MTB) represent a diverse collection of motile prokaryotes that biomineralize intracellular, membrane-bounded, tens-of-nanometer-sized crystals of a magnetic mineral called magnetosomes. Magnetosome minerals consist of either magnetite (Fe3O4) or greigite (Fe3S4) and cause cells to align along the Earth's geomagnetic field lines as they swim, a trait called magnetotaxis. MTB are known to mainly inhabit the oxic-anoxic interface (OAI) in water columns or sediments of aquatic habitats and it is currently thought that magnetosomes function as a means of making chemotaxis more efficient in locating and maintaining an optimal position for growth and survival at the OAI. Known cultured and uncultured MTB are phylogenetically associated with the Alpha-, Gamma- and Deltaproteobacteria classes of the phylum Proteobacteria, the Nitrospirae phylum and the candidate division OP3, part of the Planctomycetes-Verrucomicrobia-Chlamydiae (PVC) bacterial superphylum. MTB are generally thought to be ubiquitous in aquatic environments as they are cosmopolitan in distribution and have been found in every continent although for years MTB were thought to be restricted to habitats with pH values near neutral and at ambient temperature. Recently, however, moderate thermophilic and alkaliphilic MTB have been described including: an uncultured, moderately thermophilic magnetotactic bacterium present in hot springs in northern Nevada with a probable upper growth limit of about 63 °C; and several strains of obligately alkaliphilic MTB isolated in pure culture from different aquatic habitats in California, including the hypersaline, extremely alkaline Mono Lake, with an optimal growth pH of >9.0.

  20. Extreme Adaptive Optics Planet Imager

    NASA Astrophysics Data System (ADS)

    Macintosh, B.; Graham, J. R.; Ghez, A.; Kalas, P.; Lloyd, J.; Makidon, R.; Olivier, S.; Patience, J.; Perrin, M.; Poyneer, L.; Severson, S.; Sheinis, A.; Sivaramakrishnan, A.; Troy, M.; Wallace, J.; Wilhelmsen, J.

    2002-12-01

    Direct detection of photons emitted or reflected by extrasolar planets is the next major step in extrasolar planet studies. Current adaptive optics (AO) systems, with <300 subapertures and Strehl ratio 0.4-0.7, can achieve contrast levels of 106 at 2" separations; this is sufficient to see very young planets in wide orbits but insufficient to detect solar systems more like our own. Contrast levels of 107 - 108 in the near-IR are needed to probe a significant part of the extrasolar planet phase space. The NSF Center for Adaptive Optics is carrying out a design study for a dedicated ultra-high-contrast "Extreme" adaptive optics system for an 8-10m telescope. With 3000 controlled subapertures it should achieve Strehl ratios > 0.9 in the near-IR. Using a spatially filtered wavefront sensor, the system will be optimized to control scattered light over a large radius and suppress artifacts caused static errors. We predict that it will achieve contrast levels of 107-108 around a large sample of stars (R<7-10), sufficient to detect Jupiter-like planets through their near-IR emission over a wide range of ages and masses. The system will be capable of a variety of high-contrast science including studying circumstellar dust disks at densities a factor of 10-100 lower than currently feasible and a systematic inventory of other solar systems on 10-100 AU scale. This work was supported by the NSF Science and Technology Center for Adaptive Optics, managed by UC Santa Cruz under AST-9876783. Portions of this work was performed under the auspices of the U.S. Department of Energy, under contract No. W-7405-Eng-48.

  1. Magnetotactic Bacteria from Extreme Environments

    PubMed Central

    Bazylinski, Dennis A.; Lefèvre, Christopher T.

    2013-01-01

    Magnetotactic bacteria (MTB) represent a diverse collection of motile prokaryotes that biomineralize intracellular, membrane-bounded, tens-of-nanometer-sized crystals of a magnetic mineral called magnetosomes. Magnetosome minerals consist of either magnetite (Fe3O4) or greigite (Fe3S4) and cause cells to align along the Earth’s geomagnetic field lines as they swim, a trait called magnetotaxis. MTB are known to mainly inhabit the oxic–anoxic interface (OAI) in water columns or sediments of aquatic habitats and it is currently thought that magnetosomes function as a means of making chemotaxis more efficient in locating and maintaining an optimal position for growth and survival at the OAI. Known cultured and uncultured MTB are phylogenetically associated with the Alpha-, Gamma- and Deltaproteobacteria classes of the phylum Proteobacteria, the Nitrospirae phylum and the candidate division OP3, part of the Planctomycetes-Verrucomicrobia-Chlamydiae (PVC) bacterial superphylum. MTB are generally thought to be ubiquitous in aquatic environments as they are cosmopolitan in distribution and have been found in every continent although for years MTB were thought to be restricted to habitats with pH values near neutral and at ambient temperature. Recently, however, moderate thermophilic and alkaliphilic MTB have been described including: an uncultured, moderately thermophilic magnetotactic bacterium present in hot springs in northern Nevada with a probable upper growth limit of about 63 °C; and several strains of obligately alkaliphilic MTB isolated in pure culture from different aquatic habitats in California, including the hypersaline, extremely alkaline Mono Lake, with an optimal growth pH of >9.0. PMID:25369742

  2. Black breast cancer survivors experience greater upper extremity disability.

    PubMed

    Dean, Lorraine T; DeMichele, Angela; LeBlanc, Mously; Stephens-Shields, Alisa; Li, Susan Q; Colameco, Chris; Coursey, Morgan; Mao, Jun J

    2015-11-01

    Over one-third of breast cancer survivors experience upper extremity disability. Black women present with factors associated with greater upper extremity disability, including: increased body mass index (BMI), more advanced disease stage at diagnosis, and varying treatment type compared with Whites. No prior research has evaluated the relationship between race and upper extremity disability using validated tools and controlling for these factors. Data were drawn from a survey study among 610 women with stage I-III hormone receptor positive breast cancer. The disabilities of the arm, shoulder and hand (QuickDASH) is an 11-item self-administered questionnaire that has been validated for breast cancer survivors to assess global upper extremity function over the past 7 days. Linear regression and mediation analysis estimated the relationships between race, BMI and QuickDASH score, adjusting for demographics and treatment types. Black women (n = 98) had 7.3 points higher average QuickDASH scores than White (n = 512) women (p < 0.001). After adjusting for BMI, age, education, cancer treatment, months since diagnosis, and aromatase inhibitor status, Black women had an average 4-point (95 % confidence interval 0.18-8.01) higher QuickDASH score (p = 0.04) than White women. Mediation analysis suggested that BMI attenuated the association between race and disability by 40 %. Even several years post-treatment, Black breast cancer survivors had greater upper extremity disability, which was partially mediated by higher BMIs. Close monitoring of high BMI Black women may be an important step in reducing disparities in cancer survivorship. More research is needed on the relationship between race, BMI, and upper extremity disability.

  3. Amplification of Heat Extremes by CO2 Physiological Forcing

    NASA Astrophysics Data System (ADS)

    Skinner, C. B.; Poulsen, C. J.

    2016-12-01

    Continued increases in anthropogenic emissions of CO2 are expected to enhance the magnitude and frequency of extreme temperature events. Given the potential acute impacts on human and natural systems, a process-based understanding of where and how extreme temperature events may change in response to elevated CO2 is critical. In this work, we utilize a set of idealized AOGCM simulations from the carbon-climate feedback experiment within CMIP5 and a suite of AGCM simulations with the Community Climate System Model 4 to identify and elucidate the processes linked to projected future high-impact temperature extremes. Model simulations reveal that CO2 physiological forcing, the response of plant physiology to CO2, has an important role in shaping the geographic distribution and intensity of extreme heat events under projected elevated CO2. Specifically, we find that reduced stomatal conductance from projected physiological forcing limits evaporative cooling at the Earth's surface and increases the flux of sensible heat to the atmosphere, making vegetated regions of the tropics and Northern Hemisphere mid-latitudes particularly susceptible to increases in future heat extremes. Robust increases in excess of 15 extreme heat days per year (greater than 99th percentile temperature events) are common throughout tropical forests, northern North America and Eurasia in response to CO2 physiological forcing alone. Our results point to a critical role for vegetation in shaping future climate change impacts, and highlight the need to further refine our understanding of the relationship between leaf-level and ecosystem-level vegetation responses to CO2.

  4. Extreme precipitation patterns reduced terrestrial ecosystem production across biomes

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Moran, S. M.; Nearing, M.; Ponce Campos, G. E.; Huete, A. R.; Buda, A. R.; Bosch, D. D.; Gunter, S. A.; Kitchen, S. G.; McNab, W.; Morgan, J. A.; McClaran, M. P.; Montoya, D. S.; Peters, D. P.; Starks, P. J.

    2012-12-01

    Precipitation regimes are predicted to shift to more extreme patterns that are characterized by more intense rainfall events and longer dry intervals, yet their ecological impacts on vegetation production remain uncertain across biomes in natural climatic conditions. This in situ study investigated the effects of novel climatic conditions on aboveground net primary production (ANPP) by combining a greenness index from satellite measurements and climatic records during 2000 to 2009 from 11 long-term experimental sites in multiple biomes and climates. Results showed that extreme precipitation patterns decreased the sensitivity of ANPP to total annual precipitation (PT), at the regional and decadal scales, leading to a mean 20% decrease in rain-use efficiency across biomes. Relative decreases in ANPP were greatest for arid grassland (16%) and Mediterranean forest (20%), and less for mesic grassland and temperate forest (3%). The co-occurrence of more heavy rainfall events and longer dry intervals caused greater water stress that resulted in reduced vegetation production. A new generalized model was developed to improve predictions of the ANPP response to changes in extreme precipitation patterns by using a function of both PT and an index of precipitation extremes. These findings suggest that extreme precipitation patterns have more substantial and complex effects on vegetation production across biomes, and are as important as total annual precipitation in understanding vegetation processes. With predictions of more extreme weather events, forecasts of ecosystem production should consider these non-linear responses to altered precipitation patterns associated with climate change. Figure. Relation of production across precipitation gradients for 11 sites for two groups (Low: R95p% < 20%, High: R95p% ≥ 20%). See Table 2 for R95p% definitions. The relations were significantly different for the two groups (F2, 106 = 18.51, P < 0.0001).

  5. Adolescent baseball pitching technique: lower extremity biomechanical analysis.

    PubMed

    Milewski, Matthew D; Õunpuu, Sylvia; Solomito, Matthew; Westwell, Melany; Nissen, Carl W

    2012-11-01

    Documentation of the lower extremity motion patterns of adolescent pitchers is an important part of understanding the pitching motion and the implication of lower extremity technique on upper extremity loads, injury and performance. The purpose of this study was to take the initial step in this process by documenting the biomechanics of the lower extremities during the pitching cycle in adolescent pitchers and to compare these findings with the published data for older pitchers. Three-dimensional motion analysis using a comprehensive lower extremity model was used to evaluate the fast ball pitch technique in adolescent pitchers. Thirty-two pitchers with a mean age of 12.4 years (range 10.5-14.7 years) and at least 2 years of experience were included in this study. The pitchers showed a mean of 49 ± 12° of knee flexion of the lead leg at foot contact. They tended to maintain this position through ball release, and then extended their knee during the follow through phase (ball release to maximal internal glenohumeral rotation). The lead leg hip rapidly progressed into adduction and flexion during the arm cocking phase with a range of motion of 40 ± 10° adduction and 30 ± 13° flexion. The lead hip mean peak adduction velocity was 434 ± 83°/s and flexion velocity was 456 ± 156°/s. Simultaneously, the trailing leg hip rapidly extended approaching to a mean peak extension of -8 ± 5° at 39% of the pitch cycle, which is close to passive range of motion constraints. Peak hip abduction of the trailing leg at foot contact was -31 ± 12°, which also approached passive range of motion constraints. Differences and similarities were also noted between the adolescent lower extremity kinematics and adult pitchers; however, a more comprehensive analysis using similar methods is needed for a complete comparison.

  6. Extreme evolutionary conservation of functionally important regions in H1N1 influenza proteome.

    PubMed

    Warren, Samantha; Wan, Xiu-Feng; Conant, Gavin; Korkin, Dmitry

    2013-01-01

    The H1N1 subtype of influenza A virus has caused two of the four documented pandemics and is responsible for seasonal epidemic outbreaks, presenting a continuous threat to public health. Co-circulating antigenically divergent influenza strains significantly complicates vaccine development and use. Here, by combining evolutionary, structural, functional, and population information about the H1N1 proteome, we seek to answer two questions: (1) do residues on the protein surfaces evolve faster than the protein core residues consistently across all proteins that constitute the influenza proteome? and (2) in spite of the rapid evolution of surface residues in influenza proteins, are there any protein regions on the protein surface that do not evolve? To answer these questions, we first built phylogenetically-aware models of the patterns of surface and interior substitutions. Employing these models, we found a single coherent pattern of faster evolution on the protein surfaces that characterizes all influenza proteins. The pattern is consistent with the events of inter-species reassortment, the worldwide introduction of the flu vaccine in the early 80's, as well as the differences caused by the geographic origins of the virus. Next, we developed an automated computational pipeline to comprehensively detect regions of the protein surface residues that were 100% conserved over multiple years and in multiple host species. We identified conserved regions on the surface of 10 influenza proteins spread across all avian, swine, and human strains; with the exception of a small group of isolated strains that affected the conservation of three proteins. Surprisingly, these regions were also unaffected by genetic variation in the pandemic 2009 H1N1 viral population data obtained from deep sequencing experiments. Finally, the conserved regions were intrinsically related to the intra-viral macromolecular interaction interfaces. Our study may provide further insights towards the identification of novel protein targets for influenza antivirals.

  7. Lower extremity vasculitis in giant cell arteritis: important differential diagnosis in patients with lower limb claudication.

    PubMed

    Sigl, Martin; Hsu, Eric; Scheffel, Hans; Haneder, Stefan; Rümenapf, Gerhard; Amendt, Klaus

    2014-09-01

    Most patients with peripheral arterial disease suffer from arteriosclerosis, the prevalence of which increases with age. In some of these patients, however, the ischemic symptoms are not caused by stenotic arteriosclerosis, but by large vessel giant cell arteritis (LV-GCA), a disease also predominantly affecting patients of the older generation. Identifying large vessel vasculitis is a challenge for all physicians caring for patients with peripheral artery disease. The results of invasive treatment such as bypass surgery and angioplasty of inflammatory vascular lesions differ fundamentally from those of patients with atherosclerosis. Duplex ultrasound is a widely available diagnostic method for examining patients with lower limb claudication and pathological ankle-/toe- brachial index or pulse volume recording with or without exercise. Knowledge of characteristic sonographic findings suspicious about large vessel vasculitis is essential for a differential diagnosis of vasculitis versus atherosclerosis. In addition to clinical and laboratory findings, further imaging techniques, e.g. contrast-enhanced computed tomography, magnetic resonance imaging or a combination of positron emission tomography and computed tomography (PET-CT) can provide information on further vessel involvement and inflammatory activity. The present study focuses on diagnostic imaging of LV-GCA in patients presenting with claudication, illustrated by a series of cases.

  8. Extreme Evolutionary Conservation of Functionally Important Regions in H1N1 Influenza Proteome

    PubMed Central

    Warren, Samantha; Wan, Xiu-Feng; Conant, Gavin; Korkin, Dmitry

    2013-01-01

    The H1N1 subtype of influenza A virus has caused two of the four documented pandemics and is responsible for seasonal epidemic outbreaks, presenting a continuous threat to public health. Co-circulating antigenically divergent influenza strains significantly complicates vaccine development and use. Here, by combining evolutionary, structural, functional, and population information about the H1N1 proteome, we seek to answer two questions: (1) do residues on the protein surfaces evolve faster than the protein core residues consistently across all proteins that constitute the influenza proteome? and (2) in spite of the rapid evolution of surface residues in influenza proteins, are there any protein regions on the protein surface that do not evolve? To answer these questions, we first built phylogenetically-aware models of the patterns of surface and interior substitutions. Employing these models, we found a single coherent pattern of faster evolution on the protein surfaces that characterizes all influenza proteins. The pattern is consistent with the events of inter-species reassortment, the worldwide introduction of the flu vaccine in the early 80’s, as well as the differences caused by the geographic origins of the virus. Next, we developed an automated computational pipeline to comprehensively detect regions of the protein surface residues that were 100% conserved over multiple years and in multiple host species. We identified conserved regions on the surface of 10 influenza proteins spread across all avian, swine, and human strains; with the exception of a small group of isolated strains that affected the conservation of three proteins. Surprisingly, these regions were also unaffected by genetic variation in the pandemic 2009 H1N1 viral population data obtained from deep sequencing experiments. Finally, the conserved regions were intrinsically related to the intra-viral macromolecular interaction interfaces. Our study may provide further insights towards the identification of novel protein targets for influenza antivirals. PMID:24282564

  9. SOMs-Based Analysis of WRF Extreme Daily Precipitation in Alaska

    NASA Astrophysics Data System (ADS)

    Glisan, J. M.

    2015-12-01

    We analyze daily extremes of precipitation produced with a polar-optimized version of the Advanced Weather Research and Forecasting (ARW-WRF) model that simulated 19 years on the domain developed for the Regional Arctic System (RASM) model. Analysis focuses on Alaska, because of its proximity to the Pacific and Arctic oceans, both of which provide a large moisture fetch inland. Alaska's topography also has an important impact on orographically-forced precipitation. In order to understand the circulation characteristics conducive for extreme precipitation events, we use Self-Organizing Maps (SOMs) to find general patterns of circulation behavior. The SOM algorithm employs an artificial neural network that uses an unsupervised training process. In our analysis, we use mean sea level pressure (MSLP) anomalies to train the SOM. We examine daily widespread extreme precipitation events, defined as at least 25 grid points experiencing 99th percentile precipitation. Using the SOM procedure, we map days with widespread extremes onto the SOM's array of circulation patterns. This mapping aids in determining which nodes are being accessed at higher frequencies, and hence, which circulations are more conducive to extreme events. We show that there are multiple circulation patterns responsible for extreme precipitation differentiated by where they produce extreme events in our analysis region. Additionally, we plot composites of several meteorological fields for SOM nodes being accessed by both extreme and non-extreme events to determine what specific conditions are necessary for a widespread extreme event. Composites of individual nodes (or of adjacent nodes in SOM space) produce more physically reasonable circulations as opposed to composites of all extreme events, which can include multiple synoptic circulation regimes. We also trace the temporal evolution of extreme events through SOM space. Thus, our analysis lays the groundwork for diagnosing differences in atmospheric

  10. Extreme sports: extreme physiology. Exercise-induced pulmonary oedema.

    PubMed

    Ma, Joyce Lok Gee; Dutch, Martin John

    2013-08-01

    We report five patients who presented to an on-site medical team with concurrent haemoptysis and shortness of breath at a recent triathlon event. After initial management in the field, three of the five patients were transported to hospital via ambulance for further management, resulting in patients with haemoptysis and dyspnoea being 17 times more likely to require hospital transport. It is important to consider the differential diagnoses for this presentation, particularly exercise-induced pulmonary oedema.

  11. Discrete extremal lengths of graph approximations of Sierpinski carpets

    NASA Astrophysics Data System (ADS)

    Malo, Robert Jason

    The study of mathematical objects that are not smooth or regular has grown in importance since Benoit Mandelbrot's foundational work in the in the late 1960s. The geometry of fractals has many of its roots in that work. An important measurement of the size and structure of fractals is their dimension. We discuss various ways to describe a fractal in its canonical form. We are most interested in a concept of dimension introduced by Pierre Pansu in 1989, that of the conformal dimension. We focus on an open question: what is the conformal dimension of the Sierpinski carpet? In this work we adapt an algorithm by Oded Schramm to calculate the discrete extremal length in graph approximations of the Sierpinski carpet. We apply a result by Matias Piaggio to relate the extremal length to the Ahlfors-regular conformal dimension. We find strong numeric evidence suggesting both a lower and upper bound for this dimension.

  12. Thermodynamics of extremal rotating thin shells in an extremal BTZ spacetime and the extremal black hole entropy

    NASA Astrophysics Data System (ADS)

    Lemos, José P. S.; Minamitsuji, Masato; Zaslavskii, Oleg B.

    2017-02-01

    In a (2 +1 )-dimensional spacetime with a negative cosmological constant, the thermodynamics and the entropy of an extremal rotating thin shell, i.e., an extremal rotating ring, are investigated. The outer and inner regions with respect to the shell are taken to be the Bañados-Teitelbom-Zanelli (BTZ) spacetime and the vacuum ground state anti-de Sitter spacetime, respectively. By applying the first law of thermodynamics to the extremal thin shell, one shows that the entropy of the shell is an arbitrary well-behaved function of the gravitational area A+ alone, S =S (A+). When the thin shell approaches its own gravitational radius r+ and turns into an extremal rotating BTZ black hole, it is found that the entropy of the spacetime remains such a function of A+, both when the local temperature of the shell at the gravitational radius is zero and nonzero. It is thus vindicated by this analysis that extremal black holes, here extremal BTZ black holes, have different properties from the corresponding nonextremal black holes, which have a definite entropy, the Bekenstein-Hawking entropy S (A+)=A/+4G , where G is the gravitational constant. It is argued that for extremal black holes, in particular for extremal BTZ black holes, one should set 0 ≤S (A+)≤A/+4G;i.e., the extremal black hole entropy has values in between zero and the maximum Bekenstein-Hawking entropy A/+4 G . Thus, rather than having just two entropies for extremal black holes, as previous results have debated, namely, 0 and A/+4 G , it is shown here that extremal black holes, in particular extremal BTZ black holes, may have a continuous range of entropies, limited by precisely those two entropies. Surely, the entropy that a particular extremal black hole picks must depend on past processes, notably on how it was formed. A remarkable relation between the third law of thermodynamics and the impossibility for a massive body to reach the velocity of light is also found. In addition, in the procedure, it

  13. The Nature and Characteristics of Youthful Extremism

    ERIC Educational Resources Information Center

    Zubok, Iu. A.; Chuprov, V. I.

    2010-01-01

    Extremism is an acute problem of the present day. Moods of extremism are manifested in all spheres of the life and activities of young people--in education, work, business, political life, and leisure activity. They can be found in both individual and group social self-determination and are influenced by the immediate social environment as well as…

  14. Ionosphere Response to Extreme Space Weather

    NASA Astrophysics Data System (ADS)

    Viereck, R. A.

    2016-12-01

    In this presentation, we will evaluate the ionosphere response to extreme space weather events. There are many external factors that modify and drive the ionosphere. The ionosphere is highly coupled to the thermosphere which also responds to extreme space weather conditions. For some types of space weather, such as extreme solar x-ray flares, or solar energetic proton events, the response of the ionosphere D-Region can be predicted based on the empirical relationships determined from moderate flares and proton events. Predicting how the ionosphere will respond to an extreme geomagnetic storm is more challenging. First, estimating the extremes of the IMF and solar wind will introduce some level of uncertainty. The magnetosphere response to extreme solar wind condistions will also introduce unknowns and uncertainties. The conditions of the thermosphere under extreme conditions will strongly drive the ionospheric response as will the level of solar EUV irradiance. Even the variability of the lower atmosphere will influence how the ionosphere responds. We will try to establish the current state of knowledge and then suggest the next steps towards improvements in quantifying the ionospheric response to extreme space weather conditions.

  15. How Vulnerable Is Nigeria to Islam Extremism?

    DTIC Science & Technology

    2011-06-01

    38  c.  Triggers of Violence ................................................................40  2...MOVEMENT THEORY, DRIVERS OF VIOLENT EXTREMISM AND NIGERIAN VIOLENCE ...........................................55  viii LIST OF REFERENCES...intolerance, hatred, and violence .1 The factors that determine why people resort to religious extremism vary from one nation to another. Nowadays, the

  16. Generalized IRT Models for Extreme Response Style

    ERIC Educational Resources Information Center

    Jin, Kuan-Yu; Wang, Wen-Chung

    2014-01-01

    Extreme response style (ERS) is a systematic tendency for a person to endorse extreme options (e.g., strongly disagree, strongly agree) on Likert-type or rating-scale items. In this study, we develop a new class of item response theory (IRT) models to account for ERS so that the target latent trait is free from the response style and the tendency…

  17. Quantum corrections and extremal black holes

    NASA Astrophysics Data System (ADS)

    Alejandro, G.; Mazzitelli, F. D.; Núñez, C.

    1995-02-01

    We consider static solutions of two dimensional dilaton gravity models as toy laboratories to address the question of the final fate of black holes. A nonperturbative correction to the CGHS potential term is shown to lead classically to an extremal black hole geometry, thus providing a plausible solution to the Hawking evaporation paradox. However, the full quantum theory does not admit an extremal solution.

  18. Surface atmospheric extremes (Launch and transportation areas)

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The effects of extreme values of surface and low altitude atmospheric parameters on space vehicle design, tests, and operations are discussed. Atmospheric extremes from the surface to 150 meters for geographic locations of interest to NASA are given. Thermal parameters (temperature and solar radiation), humidity, pressure, and atmospheric electricity (lighting and static) are presented. Weather charts and tables are included.

  19. Complex Plasma Research Under Extreme Conditions

    SciTech Connect

    Ishihara, Osamu

    2008-09-07

    Complex plasma research under extreme conditions is described. The extreme conditions include low-dimensionality for self-organized structures of dust particles, dust magnetization in high magnetic field, criticality in phase transition, and cryogenic environment for Coulomb crystals and dust dynamics.

  20. Infectious disease and the extreme sport athlete.

    PubMed

    Young, Craig C; Niedfeldt, Mark W; Gottschlich, Laura M; Peterson, Charles S; Gammons, Matthew R

    2007-07-01

    Extreme sport competition often takes place in locations that may harbor atypical diseases. This article discusses infections that may be more likely to occur in the extreme sport athlete, such as selected parasitic infections, marine infections, freshwater-borne diseases, tick-borne disease, and zoonoses. Epidemiology, presentation, treatment, complications, and return-to-sport issues are discussed for each of these diseases.

  1. The Nature and Characteristics of Youthful Extremism

    ERIC Educational Resources Information Center

    Zubok, Iu. A.; Chuprov, V. I.

    2010-01-01

    Extremism is an acute problem of the present day. Moods of extremism are manifested in all spheres of the life and activities of young people--in education, work, business, political life, and leisure activity. They can be found in both individual and group social self-determination and are influenced by the immediate social environment as well as…

  2. Britain Sets Guidelines on Islamic Extremism

    ERIC Educational Resources Information Center

    Labi, Aisha

    2006-01-01

    The British government has published a long-anticipated report containing guidelines designed to help higher-education institutions combat Islamic extremism. The report entitled "Promoting Good Campus Relations: Working With Staff and Students to Build Community Cohesion and Tackle Violent Extremism in the Name of Islam at Universities and…

  3. Christian Extremism as a Domestic Terror Threat

    DTIC Science & Technology

    2011-05-19

    extremism with cultural relativism to universally deem extremist actions as justified.8 Religious extremism and conflict are not new. Conceivably, as...health care program? The questions above reflect the ongoing ethical and legal debate on abortion, a social issue that remains controversial and heavily

  4. Generalized IRT Models for Extreme Response Style

    ERIC Educational Resources Information Center

    Jin, Kuan-Yu; Wang, Wen-Chung

    2014-01-01

    Extreme response style (ERS) is a systematic tendency for a person to endorse extreme options (e.g., strongly disagree, strongly agree) on Likert-type or rating-scale items. In this study, we develop a new class of item response theory (IRT) models to account for ERS so that the target latent trait is free from the response style and the tendency…

  5. Contrasting responses of mean and extreme snowfall to climate change.

    PubMed

    O'Gorman, Paul A

    2014-08-28

    Snowfall is an important element of the climate system, and one that is expected to change in a warming climate. Both mean snowfall and the intensity distribution of snowfall are important, with heavy snowfall events having particularly large economic and human impacts. Simulations with climate models indicate that annual mean snowfall declines with warming in most regions but increases in regions with very low surface temperatures. The response of heavy snowfall events to a changing climate, however, is unclear. Here I show that in simulations with climate models under a scenario of high emissions of greenhouse gases, by the late twenty-first century there are smaller fractional changes in the intensities of daily snowfall extremes than in mean snowfall over many Northern Hemisphere land regions. For example, for monthly climatological temperatures just below freezing and surface elevations below 1,000 metres, the 99.99th percentile of daily snowfall decreases by 8% in the multimodel median, compared to a 65% reduction in mean snowfall. Both mean and extreme snowfall must decrease for a sufficiently large warming, but the climatological temperature above which snowfall extremes decrease with warming in the simulations is as high as -9 °C, compared to -14 °C for mean snowfall. These results are supported by a physically based theory that is consistent with the observed rain-snow transition. According to the theory, snowfall extremes occur near an optimal temperature that is insensitive to climate warming, and this results in smaller fractional changes for higher percentiles of daily snowfall. The simulated changes in snowfall that I find would influence surface snow and its hazards; these changes also suggest that it may be difficult to detect a regional climate-change signal in snowfall extremes.

  6. EPE The Extreme Physics Explorer

    NASA Technical Reports Server (NTRS)

    Garcia, Michael; Elvis, Martin; Bookbinder, Jay; Brenneman, Laura; Bulbul, Esra; Nulsen, Paul; Patnaude, Dan; Smith, Randall; Bandler, Simon; Okajima, Takashi; hide

    2012-01-01

    The Extreme Physics Explorer (EPE) is a mission concept that will address fundamental and timely questions in astrophysics which are primary science objectives of IXO. The reach of EPE to the areas outlined in NASA RFI NNH11ZDA018L is shown as a table. The dark green indicates areas in which EPE can do the basic IXO science, and the light green areas where EPE can contribute but will not reach the full IXO capability. To address these science questions, EPE will trace orbits close to the event horizon of black holes, measure black hole spin in active galactic nuclei (AGN), use spectroscopy to characterize outflows and the environment of AGN, map bulk motions and turbulence in galaxy clusters, and observe the process of cosmic feedback where black holes inject energy on galactic and intergalactic scales. EPE gives up the high resolution imaging of IXO in return for lightweight, high TRL foil mirrors which will provide >20 times the effective area of ASTRO-H and similar spatial resolution, with a beam sufficient to study point sources and nearby galaxies and clusters. Advances in micro-calorimeters allow improved performance at high rates with twice the energy resolution of ASTRO-H. A lower TRL option would provide 200 times the area of ASTRO-H using a micro-channel plate optic (MCPO) and a deployable optical bench. Both options are in the middle range of RFI missions at between $600M and $1000M. The EPE foil optic has direct heritage to ASTRO-H, allowing robust cost estimates. The spacecraft is entirely off the shelf and introduces no difficult requirements. The mission could be started and launched in this decade to an L2 orbit, with a three-year lifetime and consumables for 5 years. While ASTRO-H will give us the first taste of high-resolution, non-dispersive X-ray spectroscopy, it will be limited to small numbers of objects in many categories. EPE will give us the first statistically significant samples in each of these categories.

  7. [Crossing borders. The motivation of extreme sportsmen].

    PubMed

    Opaschowski, H W

    2005-08-01

    In his article "Crossing borders -- the motivation of extreme sportsmen" the author gets systematically to the bottom of the question of why extreme sportsmen voluntarily take risks and endanger themselves. Within the scope of a representative sampling 217 extreme sportsmen -- from the fields of mountain biking, trekking and free climbing, canoyning, river rafting and deep sea diving, paragliding, parachuting, bungee jumping and survival training -- give information about their personal motives. What fascinates them? The attraction of risk? The search for sensation? Or the drop out of everyday life? And what comes afterwards? Does in the end the whole life become an extreme sport? Fact is: they live extremely, because they want to move beyond well-trodden paths. To escape the boredom of everyday life they are searching for the kick, the thrill, the no-limit experience. It's about calculated risk between altitude flight and deep sea adventure.

  8. Statistics of Extreme Events with Application to Climate

    DTIC Science & Technology

    1992-01-01

    costs associated with global warming will be measured in terms of changes in the frequency and intensity of extreme events such as droughts, floods...in climate studies or in discussions of greenhouse warming despite the obvious importance of large deviations from 1 the mean. The theory and...examining 33 7.60 Globa Averaged Temerture Range for Gaussian Distributi, Dew oin Tepertur 6.40 r5-0Sea Surface Temperature - 5.20 4.60 4,00

  9. Update: nonhuman primate importation.

    PubMed

    1991-10-11

    Beginning in November 1989, a number of cynomolgus monkeys (Macaca fascicularis) imported into the United States were found to have been infected with a previously unrecognized Ebola-like filovirus. This report summarizes findings of surveillance and serologic testing of nonhuman primates imported under special permits from June 1990 through September 1991.

  10. Emergy and Its Importance

    EPA Science Inventory

    Emergy is an important quantity needed for public policy analysis that is based on a complex methodology. The intent of this Environmental Research Brief is to define emergy and its importance in a manner that is accessible to everyone with at least a high school education. Emer...

  11. Emergy and Its Importance

    EPA Science Inventory

    Emergy is an important quantity needed for public policy analysis that is based on a complex methodology. The intent of this Environmental Research Brief is to define emergy and its importance in a manner that is accessible to everyone with at least a high school education. Emer...

  12. Mangrove species' responses to winter air temperature extremes in China

    USGS Publications Warehouse

    Chen, Luzhen; Wang, Wenqing; Li, Qingshun Q.; Zhang, Yihui; Yang, Shengchang; Osland, Michael J.; Huang, Jinliang; Peng, Congjiao

    2017-01-01

    The global distribution and diversity of mangrove forests is greatly influenced by the frequency and intensity of winter air temperature extremes. However, our understanding of how different mangrove species respond to winter temperature extremes has been lacking because extreme freezing and chilling events are, by definition, relatively uncommon and also difficult to replicate experimentally. In this study, we investigated species-specific variation in mangrove responses to winter temperature extremes in China. In 10 sites that span a latitudinal gradient, we quantified species-specific damage and recovery following a chilling event, for mangrove species within and outside of their natural range (i.e., native and non-native species, respectively). To characterize plant stress, we measured tree defoliation and chlorophyll fluorescence approximately one month following the chilling event. To quantify recovery, we measured chlorophyll fluorescence approximately nine months after the chilling event. Our results show high variation in the geographic- and species-specific responses of mangroves to winter temperature extremes. While many species were sensitive to the chilling temperatures (e.g., Bruguiera sexangula and species in the Sonneratia and Rhizophora genera), the temperatures during this event were not cold enough to affect certain species (e.g., Kandelia obovata, Aegiceras corniculatum, Avicennia marina, and Bruguiera gymnorrhiza). As expected, non-native species were less tolerant of winter temperature extremes than native species. Interestingly, tidal inundation modulated the effects of chilling. In comparison with other temperature-controlled mangrove range limits across the world, the mangrove range limit in China is unique due to the combination of the following three factors: (1) Mangrove species diversity is comparatively high; (2) winter air temperature extremes, rather than means, are particularly intense and play an important ecological

  13. Extreme Weather and Climate: Workshop Report

    NASA Technical Reports Server (NTRS)

    Sobel, Adam; Camargo, Suzana; Debucquoy, Wim; Deodatis, George; Gerrard, Michael; Hall, Timothy; Hallman, Robert; Keenan, Jesse; Lall, Upmanu; Levy, Marc; hide

    2016-01-01

    Extreme events are the aspects of climate to which human society is most sensitive. Due to both their severity and their rarity, extreme events can challenge the capacity of physical, social, economic and political infrastructures, turning natural events into human disasters. Yet, because they are low frequency events, the science of extreme events is very challenging. Among the challenges is the difficulty of connecting extreme events to longer-term, large-scale variability and trends in the climate system, including anthropogenic climate change. How can we best quantify the risks posed by extreme weather events, both in the current climate and in the warmer and different climates to come? How can we better predict them? What can we do to reduce the harm done by such events? In response to these questions, the Initiative on Extreme Weather and Climate has been created at Columbia University in New York City (extreme weather.columbia.edu). This Initiative is a University-wide activity focused on understanding the risks to human life, property, infrastructure, communities, institutions, ecosystems, and landscapes from extreme weather events, both in the present and future climates, and on developing solutions to mitigate those risks. In May 2015,the Initiative held its first science workshop, entitled Extreme Weather and Climate: Hazards, Impacts, Actions. The purpose of the workshop was to define the scope of the Initiative and tremendously broad intellectual footprint of the topic indicated by the titles of the presentations (see Table 1). The intent of the workshop was to stimulate thought across disciplinary lines by juxtaposing talks whose subjects differed dramatically. Each session concluded with question and answer panel sessions. Approximately, 150 people were in attendance throughout the day. Below is a brief synopsis of each presentation. The synopses collectively reflect the variety and richness of the emerging extreme event research agenda.

  14. Extreme Weather and Climate: Workshop Report

    NASA Technical Reports Server (NTRS)

    Sobel, Adam; Camargo, Suzana; Debucquoy, Wim; Deodatis, George; Gerrard, Michael; Hall, Timothy; Hallman, Robert; Keenan, Jesse; Lall, Upmanu; Levy, Marc; Orlove, Ben; Rosenzweig, Cynthia; Seager, Richard; Shaman, Jeffrey; Tippett, Michael

    2016-01-01

    Extreme events are the aspects of climate to which human society is most sensitive. Due to both their severity and their rarity, extreme events can challenge the capacity of physical, social, economic and political infrastructures, turning natural events into human disasters. Yet, because they are low frequency events, the science of extreme events is very challenging. Among the challenges is the difficulty of connecting extreme events to longer-term, large-scale variability and trends in the climate system, including anthropogenic climate change. How can we best quantify the risks posed by extreme weather events, both in the current climate and in the warmer and different climates to come? How can we better predict them? What can we do to reduce the harm done by such events? In response to these questions, the Initiative on Extreme Weather and Climate has been created at Columbia University in New York City (extreme weather.columbia.edu). This Initiative is a University-wide activity focused on understanding the risks to human life, property, infrastructure, communities, institutions, ecosystems, and landscapes from extreme weather events, both in the present and future climates, and on developing solutions to mitigate those risks. In May 2015,the Initiative held its first science workshop, entitled Extreme Weather and Climate: Hazards, Impacts, Actions. The purpose of the workshop was to define the scope of the Initiative and tremendously broad intellectual footprint of the topic indicated by the titles of the presentations (see Table 1). The intent of the workshop was to stimulate thought across disciplinary lines by juxtaposing talks whose subjects differed dramatically. Each session concluded with question and answer panel sessions. Approximately, 150 people were in attendance throughout the day. Below is a brief synopsis of each presentation. The synopses collectively reflect the variety and richness of the emerging extreme event research agenda.

  15. Extreme low temperature tolerance in woody plants

    PubMed Central

    Strimbeck, G. Richard; Schaberg, Paul G.; Fossdal, Carl G.; Schröder, Wolfgang P.; Kjellsen, Trygve D.

    2015-01-01

    Woody plants in boreal to arctic environments and high mountains survive prolonged exposure to temperatures below -40°C and minimum temperatures below -60°C, and laboratory tests show that many of these species can also survive immersion in liquid nitrogen at -196°C. Studies of biochemical changes that occur during acclimation, including recent proteomic and metabolomic studies, have identified changes in carbohydrate and compatible solute concentrations, membrane lipid composition, and proteins, notably dehydrins, that may have important roles in survival at extreme low temperature (ELT). Consideration of the biophysical mechanisms of membrane stress and strain lead to the following hypotheses for cellular and molecular mechanisms of survival at ELT: (1) Changes in lipid composition stabilize membranes at temperatures above the lipid phase transition temperature (-20 to -30°C), preventing phase changes that result in irreversible injury. (2) High concentrations of oligosaccharides promote vitrification or high viscosity in the cytoplasm in freeze-dehydrated cells, which would prevent deleterious interactions between membranes. (3) Dehydrins bind membranes and further promote vitrification or act stearically to prevent membrane–membrane interactions. PMID:26539202

  16. Colors of extreme exo-Earth environments.

    PubMed

    Hegde, Siddharth; Kaltenegger, Lisa

    2013-01-01

    The search for extrasolar planets has already detected rocky planets and several planetary candidates with minimum masses that are consistent with rocky planets in the habitable zone of their host stars. A low-resolution spectrum in the form of a color-color diagram of an exoplanet is likely to be one of the first post-detection quantities to be measured for the case of direct detection. In this paper, we explore potentially detectable surface features on rocky exoplanets and their connection to, and importance as, a habitat for extremophiles, as known on Earth. Extremophiles provide us with the minimum known envelope of environmental limits for life on our planet. The color of a planet reveals information on its properties, especially for surface features of rocky planets with clear atmospheres. We use filter photometry in the visible as a first step in the characterization of rocky exoplanets to prioritize targets for follow-up spectroscopy. Many surface environments on Earth have characteristic albedos and occupy a different color space in the visible waveband (0.4-0.9 μm) that can be distinguished remotely. These detectable surface features can be linked to the extreme niches that support extremophiles on Earth and provide a link between geomicrobiology and observational astronomy. This paper explores how filter photometry can serve as a first step in characterizing Earth-like exoplanets for an aerobic as well as an anaerobic atmosphere, thereby prioritizing targets to search for atmospheric biosignatures.

  17. Prospects for quantum computing: Extremely doubtful

    NASA Astrophysics Data System (ADS)

    Dyakonov, M. I.

    2014-09-01

    The quantum computer is supposed to process information by applying unitary transformations to 2N complex amplitudes defining the state of N qubits. A useful machine needing N 103 or more, the number of continuous parameters describing the state of a quantum computer at any given moment is at least 21000 10300 which is much greater than the number of protons in the Universe. However, the theorists believe that the feasibility of large-scale quantum computing has been proved via the “threshold theorem”. Like for any theorem, the proof is based on a number of assumptions considered as axioms. However, in the physical world none of these assumptions can be fulfilled exactly. Any assumption can be only approached with some limited precision. So, the rather meaningless “error per qubit per gate” threshold must be supplemented by a list of the precisions with which all assumptions behind the threshold theorem should hold. Such a list still does not exist. The theory also seems to ignore the undesired free evolution of the quantum computer caused by the energy differences of quantum states entering any given superposition. Another important point is that the hypothetical quantum computer will be a system of 103 -106 qubits PLUS an extremely complex and monstrously sophisticated classical apparatus. This huge and strongly nonlinear system will generally exhibit instabilities and chaotic behavior.

  18. Imaging the Injured Pediatric Athlete: Upper Extremity.

    PubMed

    Delgado, Jorge; Jaramillo, Diego; Chauvin, Nancy A

    2016-10-01

    Increased physical activity in childhood has resulted in a large number of sports-related injuries. Although there is overlap between the sports-related injuries seen in pediatric and adult patients, important differences exist in the injury patterns of pediatric patients. These differences are related to the continuous changes in the developing skeleton and its relationship with adjacent soft tissues. The imbalance in strength between the growing bones and the nearby tendons and ligaments makes the bones prone to acute and chronic injuries. Acute injuries are more common in contact sports such as football and wrestling, whereas chronic injuries are often seen in baseball pitchers and gymnasts. Acute injuries unique to pediatric athletes include physeal fractures of the proximal and distal portions of the clavicle (periosteal sleeve fracture), the proximal humeral physis, and the coracoid process, as well as supracondylar, lateral condylar, and medial condylar fractures around the elbow. Chronic injuries, most commonly caused by repetitive microtrauma, include acromial apophyseolysis, Little Leaguer's shoulder, the constellation of findings seen in Little Leaguer's elbow, and injuries to the medial, lateral, and posterior elbow compartments. In addition, trochlear osteochondral lesions, gymnast's wrist, and rock climber's finger are less-common injuries that may be seen in children. In this article, the normal osseous development of the upper extremity is reviewed, with emphasis on the structures that are most commonly injured. The pathophysiology, imaging appearance, and imaging findings of pediatric athletic injuries are described, along with the prognostic implications. (©)RSNA, 2016.

  19. Fiber Scrambling for Extreme Doppler Precision

    NASA Astrophysics Data System (ADS)

    Spronck, Julien; Kaplan, Z.; Fischer, D.

    2011-09-01

    The detection of Earth-like exoplanets with the radial velocity method requires extreme Doppler precision and long-term stability in order to measure tiny reflex velocities in the host star. Recent planet searches have led to the detection of so called “super-Earths” (up to a few Earth masses) that induce radial velocity changes of about 1 m/s. However, the detection of true Earth analogs requires a precision of 10 cm/s. One of the factors limiting Doppler precision is variation in the Point Spread Function (PSF) from observation to observation due to changes in the illumination of the slit and spectrograph optics. Thus, this stability has become a focus of current instrumentation work. Fiber optics have been used since the 1980’s to couple telescopes to high-precision spectrographs, initially for simpler mechanical design and control. However, fiber optics are also naturally efficient scramblers. Scrambling refers to a fiber’s ability to produce an output beam independent of input. Our research is focused on understanding the scrambling properties of fibers with different geometries (circular, square, octagonal), different lengths and fiber sizes. Another important parameter when it comes to fibers is the so-called focal ratio degradation (FRD), which accounts for a different (faster) focal ratio after the fiber than the one sent into the fiber. In this paper, we will present new insight on fiber scrambling, FRD and what we call fiber personality, which describes differing behaviors for supposedly identical fiber.

  20. Colors of Extreme Exo-Earth Environments

    NASA Astrophysics Data System (ADS)

    Hegde, Siddharth; Kaltenegger, Lisa

    2013-07-01

    The search for extrasolar planets has already detected rocky planets and several planetary candidates with minimum masses that are consistent with rocky planets in the habitable zone of their host stars. A low-resolution spectrum in the form of a color-color diagram of an exoplanet is likely to be one of the first post-detection quantities to be measured for the case of direct detection. In this poster, we explore potentially detectable surface features on rocky exoplanets and their connection to, and importance as, a habitat for extremophiles, as known on Earth. Extremophiles provide us with the minimum known envelope of environmental limits for life on our planet. The color of a planet reveals information on its properties, especially for surface features of rocky planets with clear atmospheres. We use filter photometry in the visible as a first step in the characterization of rocky exoplanets to prioritize targets for follow-up spectroscopy. Many surface environments on Earth have characteristic albedos and occupy a different color space in the visible waveband (0.4-0.9 microns) that can be distinguished remotely. These detectable surface features can be linked to the extreme niches that support extremophiles on Earth and provide a link between geomicrobiology and observational astronomy. This poster explores how filter photometry can serve as a first step in characterizing Earth-like exoplanets for an aerobic as well as an anaerobic atmosphere, thereby prioritizing targets to search for atmospheric biosignatures.

  1. Extreme winds and tornadoes: an overview

    SciTech Connect

    McDonald, J.R.

    1985-01-01

    The objective of this course on extreme winds, hurricanes and tornadoes is to provide an overview of these natural phenomenon from the perspective of design of new buildings and structures or the evaluation of existing ones. Information is directly applicable to design and evaluation processes. The premise is that the facility under consideration, which may consist of various buildings, structures, processing equipment, stacks, ventilation ducts, etc., can be classified into certain categories, depending on the importance of the mission performed in the facility or the hazard that is presented by the particular operation. Having classified the facility into an appropriate category will automatically define certain design goals for the facility. The design goals are then met by selecting a design wind speed that is appropriate for the specified exceedance probability and by following certain specified design procedures. The problem then is to determine appropriate wind loads and other applicable loads, including dead loads, live loads, seismic loads and other loads that may act on the structures. The design process can then proceed in the usual manner. In the case of existing facilities the strengths of the various structural elements, subsystems and systems are evaluated and these strengths are related to wind speeds that would result in failure to meet the design goals. 12 refs.

  2. [Assessment of animal welfare aspects in extreme breeds of pet animals: principles, rules and other measures].

    PubMed

    Steiger, A

    2008-05-01

    The review deals with fundamental aspects of the problems and the assessment of animal welfare aspects in extreme breeds of companion and pet animals, with legislation and with other measures to avoid breeding animals with extreme characteristics. Efforts are important in particular by breeding organisations to adapt breeding standards and to improve the education of judges and breeders. Furthermore adequate activities to correctly inform animal keepers are important.

  3. Management of Lower Extremity and Pelvic Tumors Using Computer Assisted Modeling (CAM) A Case Series.

    PubMed

    Haskoor, John; Sinno, Sammy; Blank, Alan; Saadeh, Pierre; Rapp, Timothy

    2016-06-01

    Computer assisted modeling (CAM) has become an important tool in surgical oncology and reconstructive surgery. The preservation of the limb is an important consideration when approaching the treatment of lower extremity and pelvic tumors. The use of cutting guides allows for optimal conservation of disease-free bone and maintenance of function. We present a small case series that illustrates the use of CAM in patients with lower extremity and pelvic bone tumors.

  4. Synoptic and meteorological drivers of extreme ozone concentrations over Europe

    NASA Astrophysics Data System (ADS)

    Otero, N.; Sillmann, J.; Schnell, J. L.; Rust, H. W.; Butler, T.

    2016-02-01

    The present work assesses the relationship between local and synoptic meteorological conditions and surface ozone concentration over Europe in spring and summer months, during the period 1998-2012 using a new interpolated data set of observed surface ozone concentrations over the European domain. Along with local meteorological conditions, the influence of large-scale atmospheric circulation on surface ozone is addressed through a set of airflow indices computed with a novel implementation of a grid-by-grid weather type classification across Europe. Drivers of surface ozone over the full distribution of maximum daily 8 h average values are investigated, along with drivers of the extreme high percentiles and exceedances or air quality guideline thresholds. Three different regression techniques are applied: multiple linear regression to assess the drivers of maximum daily ozone, logistic regression to assess the probability of threshold exceedances and quantile regression to estimate the meteorological influence on extreme values, as represented by the 95th percentile. The relative importance of the input parameters (predictors) is assessed by a backward stepwise regression procedure that allows the identification of the most important predictors in each model. Spatial patterns of model performance exhibit distinct variations between regions. The inclusion of the ozone persistence is particularly relevant over southern Europe. In general, the best model performance is found over central Europe, where the maximum temperature plays an important role as a driver of maximum daily ozone as well as its extreme values, especially during warmer months.

  5. Synoptic and meteorological drivers of extreme ozone concentrations over Europe

    NASA Astrophysics Data System (ADS)

    Otero, Noelia Felipe; Sillmann, Jana; Schnell, Jordan L.; Rust, Henning W.; Butler, Tim

    2016-04-01

    The present work assesses the relationship between local and synoptic meteorological conditions and surface ozone concentration over Europe in spring and summer months, during the period 1998-2012 using a new interpolated data set of observed surface ozone concentrations over the European domain. Along with local meteorological conditions, the influence of large-scale atmospheric circulation on surface ozone is addressed through a set of airflow indices computed with a novel implementation of a grid-by-grid weather type classification across Europe. Drivers of surface ozone over the full distribution of maximum daily 8-hour average values are investigated, along with drivers of the extreme high percentiles and exceedances or air quality guideline thresholds. Three different regression techniques are applied: multiple linear regression to assess the drivers of maximum daily ozone, logistic regression to assess the probability of threshold exceedances and quantile regression to estimate the meteorological influence on extreme values, as represented by the 95th percentile. The relative importance of the input parameters (predictors) is assessed by a backward stepwise regression procedure that allows the identification of the most important predictors in each model. Spatial patterns of model performance exhibit distinct variations between regions. The inclusion of the ozone persistence is particularly relevant over Southern Europe. In general, the best model performance is found over Central Europe, where the maximum temperature plays an important role as a driver of maximum daily ozone as well as its extreme values, especially during warmer months.

  6. Large Extremity Peripheral Nerve Repair

    DTIC Science & Technology

    2016-12-01

    tissue engineering and regenerative medicine . Although many of these roles are of historical interest only, an awareness of this history is an important... medicine is also discussed. Biological wound dressing Burns The history of amnion use for the management of burns is extensive. The use of amnion for...epithelial and chorionic surfaces bond equally well Task 1i. Data analysis, conclusions and consideration of alternative wrap materials, if required

  7. Detection of trends in precipitation extremes in Zhejiang, east China

    NASA Astrophysics Data System (ADS)

    Tian, Ye; Xu, Yue-Ping; Booij, M. J.; Lin, Shengji; Zhang, Qingqing; Lou, Zhanghua

    2012-01-01

    Extreme weather exerts a huge impact on human beings and it is of vital importance to study the regular pattern of meteorological and hydrological factors. In this paper, a selection of seven extreme indices is used to analyze the trend of precipitation extremes of 18 meteorological stations located in Zhejiang Province, east China using the Mann-Kendall test. Then the precipitation trends in the plum season (from May to July) and typhoon season (from August to October) are studied separately. The results show that the precipitation trend varies from east to west. There is a positive trend in the east and a negative one in the west. The largest part of Zhejiang Province shows a positive trend in heavy precipitation and the most significant upward trend is detected in Dinghai with 3.4 mm/year for precipitation on very wet days. Although the upward trend of extreme precipitation is not prevailing, the range of increase in specific areas is apparent, like Dinghai with 1.3 mm/year. Precipitation intensity exhibits an upward trend in most areas and a typical upward trend can be found in Dachendao, Tianmushan, and Yuhuan with 0.04, 0.02, and 0.05 mm/year respectively. Precipitation intensity in both plum and typhoon seasons has increased too, especially for the coastal stations.

  8. Extremely Cold Winter Months in Europe (1951-2010)

    NASA Astrophysics Data System (ADS)

    Twardosz, Robert; Kossowska-Cezak, Urszula; Pełech, Sebastian

    2016-12-01

    Investigation of extreme thermal conditions is important from the perspective of global warming. Therefore, this study has been undertaken in order to determine the frequency, timing and spatial extent of extremely cold months in winter time at 60 weather stations across Europe over a sixty-year period from 1951 to 2010. Extremely cold months (ECMs) are defined as months in which the average air temperature is lower than the corresponding multi-annual average by at least 2 standard deviations. Half of all the ECMs occurred in the years 1951-1970 (33 out of 67). The lowest number of ECMs was recorded in the decade 1991-2000, but since the beginning of the 21st century, their density and territorial extent has started to increase again. The extremely cold months with ECMs of the greatest spatial extent, covering at least one third of the stations (over 20 stations), included: February 1954 (22), February 1956 (36), January 1963 (25), and January 1987 (23 stations).

  9. Mekong River flow and hydrological extremes under climate change

    NASA Astrophysics Data System (ADS)

    Phi Hoang, Long; Lauri, Hannu; Kummu, Matti; Koponen, Jorma; van Vliet, Michelle T. H.; Supit, Iwan; Leemans, Rik; Kabat, Pavel; Ludwig, Fulco

    2016-07-01

    Climate change poses critical threats to water-related safety and sustainability in the Mekong River basin. Hydrological impact signals from earlier Coupled Model Intercomparison Project phase 3 (CMIP3)-based assessments, however, are highly uncertain and largely ignore hydrological extremes. This paper provides one of the first hydrological impact assessments using the CMIP5 climate projections. Furthermore, we model and analyse changes in river flow regimes and hydrological extremes (i.e. high-flow and low-flow conditions). In general, the Mekong's hydrological cycle intensifies under future climate change. The scenario's ensemble mean shows increases in both seasonal and annual river discharges (annual change between +5 and +16 %, depending on location). Despite the overall increasing trend, the individual scenarios show differences in the magnitude of discharge changes and, to a lesser extent, contrasting directional changes. The scenario's ensemble, however, shows reduced uncertainties in climate projection and hydrological impacts compared to earlier CMIP3-based assessments. We further found that extremely high-flow events increase in both magnitude and frequency. Extremely low flows, on the other hand, are projected to occur less often under climate change. Higher low flows can help reducing dry season water shortage and controlling salinization in the downstream Mekong Delta. However, higher and more frequent peak discharges will exacerbate flood risks in the basin. Climate-change-induced hydrological changes will have important implications for safety, economic development, and ecosystem dynamics and thus require special attention in climate change adaptation and water management.

  10. Regional tendencies of extreme wind characteristics in Hungary

    NASA Astrophysics Data System (ADS)

    Radics, Dr.; Bartholy, Dr.; Péliné

    2009-09-01

    Human activities have substantial effects on climate system. It has already accepted that change in the long-term climatic mean state will have significant consequences in the global economy and society, but the most important effects of climate change may come from changes in the intensity and frequency of climatic extremes. It is therefore of great interest to document the extremes of surface wind that could assist in estimating the regional effects of climate change. The research presented is based on 34-year-long (1975-2008) wind (speed, direction, and wind gust) data sets of 36 Hungarian synoptic meteorological stations. After processing (including digitalisation of old instrumental records, quality control and homogenisation of wind time series) the measured wind data sets, time series and complex wind climate analysis were carried out. Spatial and temporal distributions of mean and extreme wind climate characteristics were estimated, wind extremes and trends were interpolated and mapped over the country. Finally, measured and reanalysed (ERA40) wind data were compared over Hungary, in order to verify not only the validity of ERA40 reanalysed data sets, but the adaptability of climate simulation results in estimation of regional climate change effects.

  11. New Options for Vascularized Bone Reconstruction in the Upper Extremity

    PubMed Central

    Houdek, Matthew T.; Wagner, Eric R.; Wyles, Cody C.; Nanos, George P.; Moran, Steven L.

    2015-01-01

    Originally described in the 1970s, vascularized bone grafting has become a critical component in the treatment of bony defects and non-unions. Although well established in the lower extremity, recent years have seen many novel techniques described to treat a variety of challenging upper extremity pathologies. Here the authors review the use of different techniques of vascularized bone grafts for the upper extremity bone pathologies. The vascularized fibula remains the gold standard for the treatment of large bone defects of the humerus and forearm, while also playing a role in carpal reconstruction; however, two other important options for larger defects include the vascularized scapula graft and the Capanna technique. Smaller upper extremity bone defects and non-unions can be treated with the medial femoral condyle (MFC) free flap or a vascularized rib transfer. In carpal non-unions, both pedicled distal radius flaps and free MFC flaps are viable options. Finally, in skeletally immature patients, vascularized fibular head epiphyseal transfer can provide growth potential in addition to skeletal reconstruction. PMID:25685100

  12. Extreme Precipitation and Runoff under Changing Climate in Southern Maine

    SciTech Connect

    Yan, Eugene; Jared, Alissa; Mahat, Vinod; Picel, Mark; Verner, Duane; Wall, Thomas; Moges, Edom M.; Demissie, Yonas K.; Pierce, Julia

    2016-12-01

    The quantification of extreme precipitation events is vitally important for designing and engineering water and flood sensitive infrastructure. Since this kind of infrastructure is usually built to last much longer than 10, 50, or even 100 years, there is great need for statistically sound estimates of the intensity of 10-, 50-, 100-, and 500-year rainstorms and associated floods. The recent assessment indicated that the intensity of the most extreme precipitation events (or the heaviest 1% of all daily events) have increased in every region of the contiguous states since the 1950s (Melillo et al. 2014). The maximum change in precipitation intensity of extreme events occurred in the northeast region reaching 71%. The precipitation extremes can be characterized using intensity-duration-frequency analysis (IDF). However, the current IDFs in this region were developed around the assumption that climate condition remains stationary over the next 50 or 100 years. To better characterize the potential flood risk, this project will (1) develop precipitation IDFs on the basis of both historical observations and future climate projections from dynamic downscaling with Argonne National Laboratory’s (Argonne’s) regional climate model and (2) develop runoff IDFs using precipitation IDFs for the Casco Bay Watershed. IDF development also considers non-stationary distribution models and snowmelt effects that are not incorporated in the current IDFs.

  13. Regional frequency analysis of extreme precipitation for Sicily (Italy)

    NASA Astrophysics Data System (ADS)

    Forestieri, Angelo; Blenkinsop, Stephen; Fowler, Hayley; Lo Conti, Francesco; Noto, Leonardo

    2016-04-01

    The analysis of extreme precipitation has always been included among most relevant hydrological applications because of the several important activities linked to the availability of tools for the estimation of extreme rainfall quantiles. These activities include the design of hydraulic civil structures and the evaluation and management of hydraulic and hydrological risk. In this study a frequency analysis of annual maxima precipitation measurements has been carried out for the area of Sicily (Italy). A typical hierarchical regional approach has been adopted for the parameter estimation procedure based on the L-moments method. The identification of homogeneous regions within the procedure has been pursued with a data driven procedure constituted by a principal component analysis of an ensemble of selected auxiliary variables, and a K-means cluster analysis algorithm. Auxiliary variables comprise meteo-climatic information and a representation of the average seasonal distribution of intense events. Results have been evaluated by means of a Monte Carlo experiment based on the comparison between at-site and regional fitted frequency distributions. Moreover, results have been compared with previous analyses performed for the same area. The study provides an updated tool for the modelling of extreme precipitation for the area of Sicily (Italy), with different features respect to previous tools both in terms of definition of homogeneous zones and in terms of parameters of the frequency distribution. Meteo-climatic information and the seasonality of extreme events retrieved from the dataset has been proficuously exploited in the analysis.

  14. Nonlinear processes reinforce extreme Indian Ocean Dipole events.

    PubMed

    Ng, Benjamin; Cai, Wenju; Walsh, Kevin; Santoso, Agus

    2015-06-26

    Under global warming, climate models show an almost three-fold increase in extreme positive Indian Ocean Dipole (pIOD) events by 2100. These extreme pIODs are characterised by a westward extension of cold sea surface temperature anomalies (SSTAs) which push the downstream atmospheric convergence further west. This induces severe drought and flooding in the surrounding countries, but the processes involved in this projected increase have not been fully examined. Here we conduct a detailed heat budget analysis of 19 models from phase 5 of the Coupled Model Intercomparison Project and show that nonlinear zonal and vertical heat advection are important for reinforcing extreme pIODs. Under greenhouse warming, these nonlinear processes do not change significantly in amplitude, but the frequency of occurrences surpassing a threshold increases. This is due to the projected weakening of the Walker circulation, which leads to the western tropical Indian Ocean warming faster than the east. As such, the magnitude of SSTAs required to shift convection westward is relatively smaller, allowing these convection shifts to occur more frequently in the future. The associated changes in wind and ocean current anomalies support the zonal and vertical advection terms in a positive feedback process and consequently, moderate pIODs become more extreme-like.

  15. Geophysical Hazards and Preventive Disaster Management of Extreme Natural Events

    NASA Astrophysics Data System (ADS)

    Ismail-Zadeh, A.; Takeuchi, K.

    2007-12-01

    Geophysical hazard is potentially damaging natural event and/or phenomenon, which may cause the loss of life or injury, property damage, social and economic disruption, or environmental degradation. Extreme natural hazards are a key manifestation of the complex hierarchical nonlinear Earth system. An understanding, accurate modeling and forecasting of the extreme hazards are most important scientific challenges. Several recent extreme natural events (e.g., 2004 Great Indian Ocean Earthquake and Tsunami and the 2005 violent Katrina hurricane) demonstrated strong coupling between solid Earth and ocean, and ocean and atmosphere. These events resulted in great humanitarian tragedies because of a weak preventive disaster management. The less often natural events occur (and the extreme events are rare by definition), the more often the disaster managers postpone the preparedness to the events. The tendency to reduce the funding for preventive disaster management of natural catastrophes is seldom follows the rules of responsible stewardship for future generations neither in developing countries nor in highly developed economies where it must be considered next to malfeasance. Protecting human life and property against earthquake disasters requires an uninterrupted chain of tasks: from (i) understanding of physics of the events, analysis and monitoring, through (ii) interpretation, modeling, hazard assessment, and prediction, to (iii) public awareness, preparedness, and preventive disaster management.

  16. Nonlinear processes reinforce extreme Indian Ocean Dipole events

    NASA Astrophysics Data System (ADS)

    Ng, Benjamin; Cai, Wenju; Walsh, Kevin; Santoso, Agus

    2015-06-01

    Under global warming, climate models show an almost three-fold increase in extreme positive Indian Ocean Dipole (pIOD) events by 2100. These extreme pIODs are characterised by a westward extension of cold sea surface temperature anomalies (SSTAs) which push the downstream atmospheric convergence further west. This induces severe drought and flooding in the surrounding countries, but the processes involved in this projected increase have not been fully examined. Here we conduct a detailed heat budget analysis of 19 models from phase 5 of the Coupled Model Intercomparison Project and show that nonlinear zonal and vertical heat advection are important for reinforcing extreme pIODs. Under greenhouse warming, these nonlinear processes do not change significantly in amplitude, but the frequency of occurrences surpassing a threshold increases. This is due to the projected weakening of the Walker circulation, which leads to the western tropical Indian Ocean warming faster than the east. As such, the magnitude of SSTAs required to shift convection westward is relatively smaller, allowing these convection shifts to occur more frequently in the future. The associated changes in wind and ocean current anomalies support the zonal and vertical advection terms in a positive feedback process and consequently, moderate pIODs become more extreme-like.

  17. Limitations of Extreme Nonlinear Ultrafast Nanophotonics

    NASA Astrophysics Data System (ADS)

    Kern, Christian; Zürch, Michael; Spielmann, Christian

    2015-01-01

    High-harmonic generation (HHG) has been established as an indispensable tool in optical spectroscopy. This effect arises for instance upon illumination of a noble gas with sub-picosecond laser pulses at focussed intensities significantly greater than 1012W/cm2. HHG provides a coherent light source in the extreme ultraviolet (XUV) spectral region, which is of importance in inner shell photo ionization of many atoms and molecules. Additionally, it intrinsically features light fields with unique temporal properties. Even in its simplest realization, XUV bursts of sub-femtosecond pulse lengths are released. More sophisticated schemes open the path to attosecond physics by offering single pulses of less than 100 attoseconds duration. Resonant optical antennas are important tools for coupling and enhancing electromagnetic fields on scales below their free-space wavelength. In a special application, placing field-enhancing plasmonic nano antennas at the interaction site of an HHG experiment has been claimed to boost local laser field strengths, from insufficient initial intensities to sufficient values. This was achieved with the use of arrays of bow-tie-shaped antennas of ˜ 100nm in length. However, the feasibility of this concept depends on the vulnerability of these nano-antennas to the still intense driving laser light.We show, by looking at a set of exemplary metallic structures, that the threshold fluence Fth of laser-induced damage (LID) is a greatly limiting factor for the proposed and tested schemes along these lines.We present our findings in the context of work done by other groups, giving an assessment of the feasibility and effectiveness of the proposed scheme.

  18. "Extreme events" in STT-MRAM speed retention and reliability (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Wang, Xiaobin; Zhang, Jing; Wang, Zihui; Hao, Xiaojie; Zhou, Yuchen; Gan, Huadong; Jun, Dongha; Satoh, Kimihiro; Yen, Bing K.; Huai, Yiming

    2016-10-01

    Fast operation speed, high retention and high reliability are the most attractive features of the spin transfer torque magnetic random access memory (STT-MRAM) based upon perpendicular magnetic tunneling junction (pMTJ). For state-of-the-art pMTJ STT-MRAM, its device performance is fundamentally determined by material "extreme events" physics. For example, nanosecond write bit error rate is determined by extremely high probability (>(1-10^(-7))) stochastic magnetization switching events, retention is determined by magnetization configurations with extremely low switching probability, reliability is determined by extremely low probability (<10^(-15)) tunneling junction break-down events. Despite their critical importance, accurately modeling, testing and prediction of "extreme events" have been a long-standing challenging physics and engineering issue due to their low occurrence rates. In this presentation, we will discuss our unique modeling and testing approaches to understand and predict "extreme events" in STT-MRAM write, read, retention and reliability. Specifically, we will present our model that accurately calculates extremely low write BER for various magnetization configurations. We will review our study of thermal magnetization switching through the dynamic optimal reversal path approach, capable of characterizing extreme thermal magnetization switching events under both low frequency (e.g. static retention) and high frequency (e.g. fast read) excitations. We will also discuss a new MTJ breakdown reliability model that quantifies extreme events uniformly at different failure mode regions.

  19. The Climatology of Climate Extremes in the World's Major Growing Regions

    NASA Astrophysics Data System (ADS)

    Troy, T.; Zhu, X.

    2015-12-01

    A stable food supply is increasingly important as global populations grow and climate variability and extremes affect crop yields. It is therefore critical to quantify the occurrence of extremes in major growing regions globally to understand the vulnerability of the global food supply to climate. First, we grid the GHCN historical climate data and evaluate the effect of gridding on estimation of agriculturally relevant climate extremes, such as heat waves, consecutive dry days, and precipitation intensity. We find that the differences between gridded indices and the raw station indices are small, mostly less than 10%. We then evaluate the climatology of climate extremes and the probability of concurrent extremes, both within one growing region and across multiple regions globally. We find that the correlation of two precipitation or temperature related indices are quite strong, such that the probability of another extreme occurring increases given the occurrence of one extreme. These results provide estimations of the global food supply's vulnerability to climate variability and extremes, which is critical for planning in the coming decades with projections of more frequent and more intense climate extremes.

  20. Sensitivity of UK butterflies to local climatic extremes: which life stages are most at risk?

    PubMed

    McDermott Long, Osgur; Warren, Rachel; Price, Jeff; Brereton, Tom M; Botham, Marc S; Franco, Aldina M A

    2017-01-01

    There is growing recognition as to the importance of extreme climatic events (ECEs) in determining changes in species populations. In fact, it is often the extent of climate variability that determines a population's ability to persist at a given site. This study examined the impact of ECEs on the resident UK butterfly species (n = 41) over a 37-year period. The study investigated the sensitivity of butterflies to four extremes (drought, extreme precipitation, extreme heat and extreme cold), identified at the site level, across each species' life stages. Variations in the vulnerability of butterflies at the site level were also compared based on three life-history traits (voltinism, habitat requirement and range). This is the first study to examine the effects of ECEs at the site level across all life stages of a butterfly, identifying sensitive life stages and unravelling the role life-history traits play in species sensitivity to ECEs. Butterfly population changes were found to be primarily driven by temperature extremes. Extreme heat was detrimental during overwintering periods and beneficial during adult periods and extreme cold had opposite impacts on both of these life stages. Previously undocumented detrimental effects were identified for extreme precipitation during the pupal life stage for univoltine species. Generalists were found to have significantly more negative associations with ECEs than specialists. With future projections of warmer, wetter winters and more severe weather events, UK butterflies could come under severe pressure given the findings of this study.

  1. Importance of Family Routines

    MedlinePlus

    ... Pediatrician Family Life Medical Home Family Dynamics Adoption & Foster Care Communication & Discipline Types of Families Media Work & Play Getting Involved in Your Community Healthy Children > Family Life > Family Dynamics > The Importance of Family ...

  2. Threshold modeling of extreme spatial rainfall

    NASA Astrophysics Data System (ADS)

    Thibaud, E.; Davison, A.

    2013-12-01

    Complex events such as sustained extreme precipitation have major effects on human populations and environmental sustainability, and there is a growing interest in modeling them realistically. For risk assessment based on spatial quantities such as the total amount of rainfall falling over a region, it is necessary to properly model the dependence among extremes over that region, based on data from perhaps only a few sites within it. We propose an approach to spatial modeling of extreme rainfall, based on max-stable processes fitted using partial duration series and a censored threshold likelihood function. The resulting models are coherent with classical extreme-value theory and allow the consistent treatment of spatial dependence of rainfall using ideas related to those of classical geostatistics. The method can be used to produce simulations needed for hydrological models, and in particular for the generation of spatially heterogeneous extreme rainfall fields over catchments. We illustrate the ideas through data from the Val Ferret watershed in the Swiss Alps, based on daily cumulative rainfall totals recorded at 24 stations for four summers, augmented by a longer series from nearby. References: Davison, A. C., Huser, R., Thibaud, E. (2013). Geostatistics of Dependent and Asymptotically Independent Extremes, Mathematical Geosciences, vol. 45, num. 5, p. 511-529, 2013, doi:10.1007/s11004-013-9469-y Thibaud, E., Mutzner, R., Davison A. C. (2013, to appear). Threshold modeling of extreme spatial rainfall, Water Resources Research, doi:10.1002/wrcr.20329

  3. Changes in Concurrent Precipitation and Temperature Extremes

    SciTech Connect

    Hao, Zengchao; AghaKouchak, Amir; Phillips, Thomas J.

    2013-08-01

    While numerous studies have addressed changes in climate extremes, analyses of concurrence of climate extremes are scarce, and climate change effects on joint extremes are rarely considered. This study assesses the occurrence of joint (concurrent) monthly continental precipitation and temperature extremes in Climate Research Unit (CRU) and University of Delaware (UD) observations, and in 13 Coupled Model Intercomparison Project Phase 5 (CMIP5) global climate simulations. Moreover, the joint occurrences of precipitation and temperature extremes simulated by CMIP5 climate models are compared with those derived from the CRU and UD observations for warm/wet, warm/dry, cold/wet, and cold/dry combinations of joint extremes. The number of occurrences of these four combinations during the second half of the 20th century (1951–2004) is assessed on a common global grid. CRU and UD observations show substantial increases in the occurrence of joint warm/dry and warm/wet combinations for the period 1978–2004 relative to 1951–1977. The results show that with respect to the sign of change in the concurrent extremes, the CMIP5 climate model simulations are in reasonable overall agreement with observations. The results reveal notable discrepancies between regional patterns and the magnitude of change in individual climate model simulations relative to the observations of precipitation and temperature.

  4. Sea level extremes in the Caribbean Sea

    NASA Astrophysics Data System (ADS)

    Torres, R. Ricardo; Tsimplis, Michael N.

    2014-08-01

    Sea level extremes in the Caribbean Sea are analyzed on the basis of hourly records from 13 tide gauges. The largest sea level extreme observed is 83 cm at Port Spain. The largest nontidal residual in the records is 76 cm, forced by a category 5 hurricane. Storm surges in the Caribbean are primarily caused by tropical storms and stationary cold fronts intruding the basin. However, the seasonal signal and mesoscale eddies also contribute to the creation of extremes. The five stations that have more than 20 years of data show significant trends in the extremes suggesting that flooding events are expected to become more frequent in the future. The observed trends in extremes are caused by mean sea level rise. There is no evidence of secular changes in the storm activity. Sea level return periods have also been estimated. In the south Colombian Basin, where large hurricane-induced surges are rare, stable estimates can be obtained with 30 years of data or more. For the north of the basin, where large hurricane-induced surges are more frequent, at least 40 years of data are required. This suggests that the present data set is not sufficiently long for robust estimates of return periods. ENSO variability correlates with the nontidal extremes, indicating a reduction of the storm activity during positive ENSO events. The period with the highest extremes is around October, when the various sea level contributors' maxima coincide.

  5. Understanding hydrological extremes in the Anthropocene

    NASA Astrophysics Data System (ADS)

    Mård, Johanna; Di Baldassarre, Giuliano

    2016-04-01

    Hydrological extremes, from floods to droughts, pose one of the greatest challenges of the 21st century. Many of these challenges are associated with societal interactions with water, as people control or impact hydrological systems in a multitude of ways while they are also being affected and shaped by hydrological extremes, depending on their response to drought and flood events. However, the fact that the human and natural components of freshwater systems interact and co-evolve over time is often not taken into account. There is a need to study the two-way coupling between hydrology and society within a more comprehensive framework for hydrological extremes to anticipate future trajectories in a rapidly changing world. We present an interdisciplinary framework (and concepts) to identify internal controlling variables, processes and feedbacks, and the external system drivers and disturbances of the coupled human-water system with regard to hydrological extremes. To achieve this, the study (i) synthesizes existing research on coupled human-water system focusing on floods and droughts, (ii) analyzes hydrological extremes that have already occurred and their spatiotemporal patterns to investigate what patterns are observed in different regions of the world, and (iii) systematically describe the observed hydrological extremes, their causes and the interactions and feedbacks between hydrology and society. Advancing our understanding of mechanisms and feedbacks driving hydrological extremes is essential to better anticipate how the coupled human-water system will respond to future environmental change.

  6. Changes in Concurrent Precipitation and Temperature Extremes

    DOE PAGES

    Hao, Zengchao; AghaKouchak, Amir; Phillips, Thomas J.

    2013-08-01

    While numerous studies have addressed changes in climate extremes, analyses of concurrence of climate extremes are scarce, and climate change effects on joint extremes are rarely considered. This study assesses the occurrence of joint (concurrent) monthly continental precipitation and temperature extremes in Climate Research Unit (CRU) and University of Delaware (UD) observations, and in 13 Coupled Model Intercomparison Project Phase 5 (CMIP5) global climate simulations. Moreover, the joint occurrences of precipitation and temperature extremes simulated by CMIP5 climate models are compared with those derived from the CRU and UD observations for warm/wet, warm/dry, cold/wet, and cold/dry combinations of joint extremes.more » The number of occurrences of these four combinations during the second half of the 20th century (1951–2004) is assessed on a common global grid. CRU and UD observations show substantial increases in the occurrence of joint warm/dry and warm/wet combinations for the period 1978–2004 relative to 1951–1977. The results show that with respect to the sign of change in the concurrent extremes, the CMIP5 climate model simulations are in reasonable overall agreement with observations. The results reveal notable discrepancies between regional patterns and the magnitude of change in individual climate model simulations relative to the observations of precipitation and temperature.« less

  7. DNA Import into Mitochondria.

    PubMed

    Konstantinov, Yu M; Dietrich, A; Weber-Lotfi, F; Ibrahim, N; Klimenko, E S; Tarasenko, V I; Bolotova, T A; Koulintchenko, M V

    2016-10-01

    In recent decades, it has become evident that the condition for normal functioning of mitochondria in higher eukaryotes is the presence of membrane transport systems of macromolecules (proteins and nucleic acids). Natural competence of the mitochondria in plants, animals, and yeasts to actively uptake DNA may be directly related to horizontal gene transfer into these organelles occurring at much higher rate compared to the nuclear and chloroplast genomes. However, in contrast with import of proteins and tRNAs, little is known about the biological role and molecular mechanism underlying import of DNA into eukaryotic mitochondria. In this review, we discuss current state of investigations in this area, particularly specificity of DNA import into mitochondria and its features in plants, animals, and yeasts; a tentative mechanism of DNA import across the mitochondrial outer and inner membranes; experimental data evidencing several existing, but not yet fully understood mechanisms of DNA transfer into mitochondria. Currently available data regarding transport of informational macromolecules (DNA, RNA, and proteins) into the mitochondria do not rule out that the mechanism of protein and tRNA import as well as tRNA and DNA import into the mitochondria may partially overlap.

  8. [Injury mechanisms in extreme violence settings].

    PubMed

    Arcaute-Velazquez, Fernando Federico; García-Núñez, Luis Manuel; Noyola-Vilallobos, Héctor Faustino; Espinoza-Mercado, Fernando; Rodríguez-Vega, Carlos Eynar

    2016-01-01

    Extreme violence events are consequence of current world-wide economic, political and social conditions. Injury patterns found among victims of extreme violence events are very complex, obeying several high-energy injury mechanisms. In this article, we present the basic concepts of trauma kinematics that regulate the clinical approach to victims of extreme violence events, in the hope that clinicians increase their theoretical armamentarium, and reflecting on obtaining better outcomes. Copyright © 2016. Published by Masson Doyma México S.A.

  9. Amniotic band sequence: an extreme case.

    PubMed

    Kahramaner, Zelal; Cosar, Hese; Turkoglu, Ebru; Erdemir, Aydin; Kanik, Ali; Sutcuoglu, Sumer; Ozer, Esra Arun

    2012-03-01

    Amniotic band sequence (ABS) is a rare cause of fetal disruptions associated with fibrous bands that entrap various fetal parts in utero and lead to abnormalities. Fetal disruptions of ABS are influenced by the timing of the amnion rupture and the site of amnion adherence. Herein we report an extreme case of ABS presented with dysmorphic face, amputation of four extremities and fusion of legs and genitalia with a fibrotic band. This is an extreme case of ABS characterized by an unusual combination of multiple fetal anomalies.

  10. Extremely thermophilic energy metabolisms: biotechnological prospects.

    PubMed

    Straub, Christopher T; Zeldes, Benjamin M; Schut, Gerrit J; Adams, Michael Ww; Kelly, Robert M

    2017-03-16

    New strategies for metabolic engineering of extremely thermophilic microorganisms to produce bio-based fuels and chemicals could leverage pathways and physiological features resident in extreme thermophiles for improved outcomes. Furthermore, very recent advances in genetic tools for these microorganisms make it possible for them to serve as metabolic engineering hosts. Beyond providing a higher temperature alternative to mesophilic platforms, exploitation of strategic metabolic characteristics of high temperature microorganisms grants new opportunities for biotechnological products. This review considers recent developments in extreme thermophile biology as they relate to new horizons for energy biotechnology.

  11. American coal imports 2015

    SciTech Connect

    Frank Kolojeski

    2007-09-15

    As 2007 ends, the US coal industry passes two major milestones - the ending of the Synfuel tax break, affecting over 100M st annually, and the imposition of tighter and much more expensive safety measures, particularly in deep mines. Both of these issues, arriving at a time of wretched steam coal price levels, promise to result in a major shake up in the Central Appalachian mining sector. The report utilizes a microeconomic regional approach to determine whether either of these two schools of thought have any validity. Transport, infrastructure, competing fuels and regional issues are examined in detail and this forecasts estimates coal demand and imports on a region by region basis for the years 2010 and 2015. Some of the major highlights of the forecast are: Import growth will be driven by steam coal demand in the eastern and southern US; Transport will continue to be the key driver - we believe that inland rail rates will deter imports from being railed far inland and that the great majority of imports will be delivered directly by vessel, barge or truck to end users; Colombian coal will be the overwhelmingly dominant supply source and possesses a costs structure to enable it to compete with US-produced coal in any market conditions; Most of the growth will come from existing power plants - increasing capacity utilization at existing import facilities and other plants making investments to add imports to the supply portfolio - the growth is not dependent upon a lot of new coal fired capacity being built. Contents of the report are: Key US market dynamics; International supply dynamics; Structure of the US coal import market; and Geographic analysis.

  12. Extreme Geohazards: Reducing Disaster Risk and Increasing Resilience

    NASA Astrophysics Data System (ADS)

    Plag, Hans-Peter; Stein, Seth; Brocklebank, Sean; Jules-Plag, Shelley; Campus, Paola

    2014-05-01

    damage on a global scale for a globally connected and stressed society. In particular, large volcanic eruptions could impact climate, damage anthropogenic infrastructure and interrupt resource supplies on a global scale. The occurrence of one or more of the largest volcanic eruptions that took place during the last 2,000 years under today's conditions would likely cause global disasters or catastrophes challenging civilization. Integration of these low-probability, high-impact events in DRR requires an approach focused on resilience and antifragility, as well as the ability to cope with, and recover from failure of infrastructures and social systems. Resilience results from social capital even more than from the robustness of infrastructure. While it is important to understand the hazards through the contribution of geosciences, it is equally important to understand through the contribution of social sciences and engineering the societal processes involved with coping with hazards or leading to failure. For comprehensive development of resilience to natural hazards and, in particular, extreme geohazards, synergy between geosciences, engineering and social sciences, jointed to an improved science-policy relationship is key to success. For example, a simple cost-benefit analysis shows that a comprehensive monitoring system that could identify the onset of an extreme volcanic eruption with sufficient lead time to allow for a globally coordinated preparation makes economic sense. The WP recommends implementation of such a monitoring system with global coverage, assesses the existing assets in current monitoring systems, and illustrates many benefits, besides providing early warning for extreme volcanic eruptions. However, such a monitoring system can provide resilience only via the capability of the global community to react to early warnings. The WP recommends achieving this through the establishment of a global coordination platform comparable to IPCC's role in addressing

  13. Observed and Projected Climate Extremities in Chennai Metropolitan Area

    NASA Astrophysics Data System (ADS)

    Anushiya, j.; Andimuthu, R.

    2013-12-01

    Analyses of observed climate throughout world revealed some significant changes in the extremes. Any change in the frequency or severity of extreme climate events would have profound impacts on the resilience of nature and society. It is thus very important to analyze extreme events to reliably monitor and detect climate change. Chennai is the fourth largest metropolis in India and one of the fastest growing economic and Industrial growth centers in South Asia. Population has grown rapidly in the last 20 years due to its major industrialization and tremendous growth. Already Chennai's day and night time Temperature shows an increasing trend. The past incidence of catastrophic flooding was observed in the city due to heavy rains associated with depressions and cyclonic storm lead floods in major rivers. After 2000, the incidents were reported repeatedly. The effort has made in this study to find the observed climate extremities over the past years and in the future. For observed changes, IMD gridded data set, and station data are used. Future high resolution climate scenarios (0.220x0.220) are developed through RCM using PRECIS. The boundary data have provided by the UK Met office. The selected members are simulated under the A1B scenario (a mid range emission scenario) for a continuous run till 2100. Climate indices listed by Expert Team (ET) on Climate Change Detection and Indices (ETCCDI) by the CLIVAR are considered in this study. The indices were obtained using the software package RClimDex. Kendall's tau based slope estimator has been used to find the significance lavel. The results shows the significant increasing tendency of warm days (TX90P) in the past and in future. The trends in extreme wet days (R99P) are also increased. The growth in population, urban and industrial area, economic activities, depletion of natural resources along with changing climate are forced to develop the infrastructure includes climate friendly policies to adopt and to ensure the

  14. EXTREME: an online EM algorithm for motif discovery

    PubMed Central

    Quang, Daniel; Xie, Xiaohui

    2014-01-01

    Motivation: Identifying regulatory elements is a fundamental problem in the field of gene transcription. Motif discovery—the task of identifying the sequence preference of transcription factor proteins, which bind to these elements—is an important step in this challenge. MEME is a popular motif discovery algorithm. Unfortunately, MEME’s running time scales poorly with the size of the dataset. Experiments such as ChIP-Seq and DNase-Seq are providing a rich amount of information on the binding preference of transcription factors. MEME cannot discover motifs in data from these experiments in a practical amount of time without a compromising strategy such as discarding a majority of the sequences. Results: We present EXTREME, a motif discovery algorithm designed to find DNA-binding motifs in ChIP-Seq and DNase-Seq data. Unlike MEME, which uses the expectation-maximization algorithm for motif discovery, EXTREME uses the online expectation-maximization algorithm to discover motifs. EXTREME can discover motifs in large datasets in a practical amount of time without discarding any sequences. Using EXTREME on ChIP-Seq and DNase-Seq data, we discover many motifs, including some novel and infrequent motifs that can only be discovered by using the entire dataset. Conservation analysis of one of these novel infrequent motifs confirms that it is evolutionarily conserved and possibly functional. Availability and implementation: All source code is available at the Github repository http://github.com/uci-cbcl/EXTREME. Contact: xhx@ics.uci.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:24532725

  15. Extreme Ultraviolet Imaging Telescope (EIT)

    NASA Technical Reports Server (NTRS)

    Lemen, J. R.; Freeland, S. L.

    1997-01-01

    Efforts concentrated on development and implementation of the SolarSoft (SSW) data analysis system. From an EIT analysis perspective, this system was designed to facilitate efficient reuse and conversion of software developed for Yohkoh/SXT and to take advantage of a large existing body of software developed by the SDAC, Yohkoh, and SOHO instrument teams. Another strong motivation for this system was to provide an EIT analysis environment which permits coordinated analysis of EIT data in conjunction with data from important supporting instruments, including Yohkoh/SXT and the other SOHO coronal instruments; CDS, SUMER, and LASCO. In addition, the SSW system will support coordinated EIT/TRACE analysis (by design) when TRACE data is available; TRACE launch is currently planned for March 1998. Working with Jeff Newmark, the Chianti software package (K.P. Dere et al) and UV /EUV data base was fully integrated into the SSW system to facilitate EIT temperature and emission analysis.

  16. Are recent severe floods in Xiang River basin of China linked with the increase extreme precipitation?

    NASA Astrophysics Data System (ADS)

    Cheng, L.; Du, J.

    2015-12-01

    The Xiang River, a main tributary of the Yangtze River, is subjected to high floods frequently in recent twenty years. Climate change, including abrupt shifts and fluctuations in precipitation is an important factor influencing hydrological extreme conditions. In addition, human activities are widely recognized as another reasons leading to high flood risk. With the effects of climate change and human interventions on hydrological cycle, there are several questions that need to be addressed. Are floods in the Xiang River basin getting worse? Whether the extreme streamflow shows an increasing tendency? If so, is it because the extreme rainfall events have predominant effect on floods? To answer these questions, the article detected existing trends in extreme precipitation and discharge using Mann-Kendall test. Continuous wavelet transform method was employed to identify the consistency of changes in extreme precipitation and discharge. The Pearson correlation analysis was applied to investigate how much degree of variations in extreme discharge can be explained by climate change. The results indicate that slightly upward trends can be detected in both extreme rainfalls and discharge in the upper region of Xiang River basin. For the most area of middle and lower river basin, the extreme rainfalls show significant positive trends, but the extreme discharge displays slightly upward trends with no significance at 90% confidence level. Wavelet transform analysis results illustrate that highly similar patterns of signal changes can be seen between extreme precipitation and discharge in upper section of the basin, while the changes in extreme precipitation for the middle and lower reaches do not always coincide with the extreme streamflow. The correlation coefficients of the wavelet transforms for the precipitation and discharge signals in most area of the basin pass the significance test. The conclusion may be drawn that floods in recent years are not getting worse in

  17. Forecaster's dilemma: Extreme events and forecast evaluation

    NASA Astrophysics Data System (ADS)

    Lerch, Sebastian; Thorarinsdottir, Thordis; Ravazzolo, Francesco; Gneiting, Tilmann

    2015-04-01

    In discussions of the quality of forecasts in the media and public, attention often focuses on the predictive performance in the case of extreme events. Intuitively, accurate predictions on the subset of extreme events seem to suggest better predictive ability. However, it can be demonstrated that restricting conventional forecast verification methods to subsets of observations might have unexpected and undesired effects and may discredit even the most skillful forecasters. Hand-picking extreme events is incompatible with the theoretical assumptions of established forecast verification methods, thus confronting forecasters with what we refer to as the forecaster's dilemma. For probabilistic forecasts, weighted proper scoring rules provide suitable alternatives for forecast evaluation with an emphasis on extreme events. Using theoretical arguments, simulation experiments and a case study on probabilistic forecasts of wind speed over Germany, we illustrate the forecaster's dilemma and the use of weighted proper scoring rules.

  18. Astronomy and the Extreme Ultraviolet Explorer satellite.

    PubMed

    Bowyer, S

    1994-01-07

    The extreme ultraviolet wave band (100 to 912 angstroms) was thought until recently to be useless to astronomy, primarily because the opacity of the interstellar medium would prevent observations at these wavelengths. However, the interstellar medium has been found to be markedly inhomogeneous in both density and ionization state and the sun is fortunately located in a region of low extreme ultraviolet opacity. The Extreme Ultraviolet Explorer, launched in June 1992, has surveyed the sky in this wave band and has detected a wide variety of astronomical sources at considerable distances, including some extragalactic objects. Studies in the extreme ultraviolet band have already begun to increase our understanding of the contents of the universe.

  19. Astronomy and the Extreme Ultraviolet Explorer satellite

    NASA Technical Reports Server (NTRS)

    Bowyer, S.

    1994-01-01

    The extreme ultraviolet wave band (100 to 912 angstroms) was thought until recently to be useless to astronomy, primarily because the opacity of the interstellar medium would prevent observations at these wavelengths. However, the interstellar medium has been found to be markedly inhomogeneous in both density and ionization state and the sun is fortunately located in a region of low extreme ultraviolet opacity. The Extreme Ultraviolet Explorer, launched in June 1992, has surveyed the sky in this wave band and has detected a wide variety of astronomical sources at considerable distances, including some extragalactic objects. Studies in the extreme ultraviolet band have already begun to increase our understanding of the contents of the universe.

  20. Frequently Asked Questions (FAQ) about Extreme Heat

    MedlinePlus

    ... Centers Extreme Heat PSAs Related Links MMWR Bibliography Floods Flood Readiness Personal Hygiene After a Disaster Reentering Your Flooded Home Cleanup of Flood Water After a Flood Worker Safety Educational Materials ...

  1. Extremal vacuum black holes in higher dimensions

    SciTech Connect

    Figueras, Pau; Lucietti, James; Rangamani, Mukund; Kunduri, Hari K.

    2008-08-15

    We consider extremal black hole solutions to the vacuum Einstein equations in dimensions greater than five. We prove that the near-horizon geometry of any such black hole must possess an SO(2,1) symmetry in a special case where one has an enhanced rotational symmetry group. We construct examples of vacuum near-horizon geometries using the extremal Myers-Perry black holes and boosted Myers-Perry strings. The latter lead to near-horizon geometries of black ring topology, which in odd spacetime dimensions have the correct number of rotational symmetries to describe an asymptotically flat black object. We argue that a subset of these correspond to the near-horizon limit of asymptotically flat extremal black rings. Using this identification we provide a conjecture for the exact 'phase diagram' of extremal vacuum black rings with a connected horizon in odd spacetime dimensions greater than five.

  2. Technology of planetary extreme environment simulation

    NASA Technical Reports Server (NTRS)

    Wakefield, M. E.; Apodaca, L. E.; Hall, C. A.

    1972-01-01

    Four test chamber systems were devleoped to simulate the extreme atmospheric environs of Venus and Jupiter, in order to assure satisfactory performance of scientific entry probes and their experiments.

  3. Extreme Heat and Human Health (Invited)

    NASA Astrophysics Data System (ADS)

    Rood, R. B.; O'Neill, M.

    2010-12-01

    Climate projections tell us that there will be more heat waves in the future; that is, periods of sustained, extreme heat. Extreme heat is, presently, the greatest cause of human death of any weather-related human health threat. It is natural, therefore, to expect such threats to increase in the future. This straightforward logic is challenged, however, by the complex relationship between heat extremes and human health. For example, temperatures that are dangerous in Chicago, Paris, or Moscow, are often not of note in Houston or New Delhi. This suggests, perhaps, societal adaptation or human acclimatization. In this talk we explore current measures of extreme heat and how to best incorporate knowledge which informs the potential of increased danger to humans. The goal of this work is to improve the usefulness of climate projections for public health applications.

  4. Upper extremity trauma: current trends in management.

    PubMed

    Stone, W M; Fowl, R J; Money, S R

    2007-10-01

    Upper extremity trauma can be penetrating or blunt in etiology. The close proximity of vein, artery and nerve makes for a complicated presentation and potentially complicated reconstruction. Orthopedic and neurologic injuries can cause the more long term disability of these patients, but vascular injuries are initially more life threatening. Control of vascular injuries can be particularly difficult due to anatomic issues in the upper extremities. The intervention carried significant morbidity until evolution to endovascular approaches occurred. By reconstructing the injury from a more ''remote'' access site, less concomitant injury to the extremity can be encountered. However, although control of vascular injuries may result in greater survival rates with less morbidity from the procedure, long term outcome remains dependent upon concomitant injuries. This review will encompass both vascular and neurologic injuries secondary to trauma to the upper extremity and outline some of the trends in management.

  5. NASA Measures Extreme Precipitation From Space

    NASA Image and Video Library

    From Jan. 25 through Feb. 3, IMERG data estimated that the most extreme precipitation over the United States during this period was over 200mm (7.9 inches) in an area where stormy weather frequentl...

  6. Threshold modeling of extreme spatial rainfall

    NASA Astrophysics Data System (ADS)

    Thibaud, E.; Mutzner, R.; Davison, A. C.

    2013-08-01

    We propose an approach to spatial modeling of extreme rainfall, based on max-stable processes fitted using partial duration series and a censored threshold likelihood function. The resulting models are coherent with classical extreme-value theory and allow the consistent treatment of spatial dependence of rainfall using ideas related to those of classical geostatistics. We illustrate the ideas through data from the Val Ferret watershed in the Swiss Alps, based on daily cumulative rainfall totals recorded at 24 stations for four summers, augmented by a longer series from nearby. We compare the fits of different statistical models appropriate for spatial extremes, select that best fitting our data, and compare return level estimates for the total daily rainfall over the stations. The method can be used in other situations to produce simulations needed for hydrological models, and in particular, for the generation of spatially heterogeneous extreme rainfall fields over catchments.

  7. Golf injuries of the upper extremity.

    PubMed

    Wiesler, Ethan R; Lumsden, Boyd

    2005-01-01

    Golf has demonstrated increasing popularity and with this heightened enthusiasm has come an increased awareness of the significant number of injuries associated with playing golf. While back injuries represent the most commonly injured specific body part, upper extremity injuries are most frequent overall and the most likely to result in loss of play. Patterns of injury differ based on level of play and time spent playing or practicing golf. Among golf professionals, the hand/wrist is the most commonly injured upper extremity structure. Among amateurs, the elbow is most commonly injured. The vast majority of upper extremity injuries are due to overuse. Age, ability, equipment, and swing mechanics also play contributing roles. Most upper extremity golf injuries can be successfully treated with appropriate cessation or modification of play, anti-inflammatory modalities, and rehabilitation. Surgical treatment is rarely required, but if needed can prove successful in a high percentage of patients.

  8. Isolation of Extreme Halophiles from Seawater

    PubMed Central

    Rodriguez-Valera, F.; Ruiz-Berraquero, F.; Ramos-Cormenzana, A.

    1979-01-01

    Extreme halophilic bacteria were isolated from the ocean off the coast of Spain. All were gram-negative cocci. One isolate was compared to Halococcus sp. NCMB 757 and was found to have similar characteristics. PMID:16345409

  9. Isolation of extreme halophiles from seawater.

    PubMed

    Rodriguez-Valera, F; Ruiz-Berraquero, F; Ramos-Cormenzana, A

    1979-07-01

    Extreme halophilic bacteria were isolated from the ocean off the coast of Spain. All were gram-negative cocci. One isolate was compared to Halococcus sp. NCMB 757 and was found to have similar characteristics.

  10. Extreme heat effects on wheat senescence in India

    NASA Astrophysics Data System (ADS)

    Lobell, David B.; Sibley, Adam; Ivan Ortiz-Monasterio, J.

    2012-03-01

    An important source of uncertainty in anticipating the effects of climate change on agriculture is limited understanding of crop responses to extremely high temperatures. This uncertainty partly reflects the relative lack of observations of crop behaviour in farmers' fields under extreme heat. We used nine years of satellite measurements of wheat growth in northern India to monitor rates of wheat senescence following exposure to temperatures greater than 34°C. We detect a statistically significant acceleration of senescence from extreme heat, above and beyond the effects of increased average temperatures. Simulations with two commonly used process-based crop models indicate that existing models underestimate the effects of heat on senescence. As the onset of senescence is an important limit to grain filling, and therefore grain yields, crop models probably underestimate yield losses for +2°C by as much as 50% for some sowing dates. These results imply that warming presents an even greater challenge to wheat than implied by previous modelling studies, and that the effectiveness of adaptations will depend on how well they reduce crop sensitivity to very hot days.

  11. Possible future changes in extreme events over Northern Eurasia

    NASA Astrophysics Data System (ADS)

    Monier, Erwan; Sokolov, Andrei; Scott, Jeffery

    2013-04-01

    In this study, we investigate possible future climate change over Northern Eurasia and its impact on extreme events. Northern Eurasia is a major player in the global carbon budget because of boreal forests and peatlands. Circumpolar boreal forests alone contain more than five times the amount of carbon of temperate forests and almost double the amount of carbon of the world's tropical forests. Furthermore, severe permafrost degradation associated with climate change could result in peatlands releasing large amounts of carbon dioxide and methane. Meanwhile, changes in the frequency and magnitude of extreme events, such as extreme precipitation, heat waves or frost days are likely to have substantial impacts on Northern Eurasia ecosystems. For this reason, it is very important to quantify the possible climate change over Northern Eurasia under different emissions scenarios, while accounting for the uncertainty in the climate response and changes in extreme events. For several decades, the Massachusetts Institute of Technology (MIT) Joint Program on the Science and Policy of Global Change has been investigating uncertainty in climate change using the MIT Integrated Global System Model (IGSM) framework, an integrated assessment model that couples an earth system model of intermediate complexity (with a 2D zonal-mean atmosphere) to a human activity model. In this study, regional change is investigated using the MIT IGSM-CAM framework that links the IGSM to the National Center for Atmospheric Research (NCAR) Community Atmosphere Model (CAM). New modules were developed and implemented in CAM to allow climate parameters to be changed to match those of the IGSM. The simulations presented in this paper were carried out for two emission scenarios, a "business as usual" scenario and a 660 ppm of CO2-equivalent stabilization, which are similar to, respectively, the Representative Concentration Pathways RCP8.5 and RCP4.5 scenarios. Values of climate sensitivity and net aerosol

  12. A Weather climate change Impact Study at Extreme Resolution (WISER)

    NASA Astrophysics Data System (ADS)

    Gadian, A.; Burton, R.; Bruyere, C. L.; Done, J.; Tye, M. R.; Holland, G. J.; Thielen, J.; Blyth, A. M.

    2014-12-01

    Understanding and simulation of weather scale processes is required to understand extremes in the rapidly changing climate. The resolution required to include meso-scale features, is still out of the reach of climate model resolution, and this project attempts to include the important meso-scale features. WISER (Weather climate change Impact Study at Extreme Resolution) is a regional climate study to use a numerical weather model (WRF), in a channel formulation (+/- 68 degrees latitude) at a resolution of 20 km at the equator reducing to 9 km at the Northern and Southern boundaries. The inner domain nested regional model at a resolution of 3-4 km over Western Europe aims at resolving the larger convective scale precipitation events statistically. (see figure for geometrical domain set up). The outer domain is driven by ERA interim climate reanalysis global fields for recent decades 1989-2001; the nested inner domain d02 is driven by the outer domain. The inner model climatological statistics are compared with observations and with those from the outer domain, with particular reference for the statistical convective precipitation extremes. The extremes of the pdfs are shown to be better represented by the increase in resolution and suggest that this could be a tool useful in examining the likely extremes in future climates. The data also provides an assessment of the uncertainty in the precipitation extremes and an alternative approach to ownscaling. The overall aim is to examine statistical changes in(a) general precipitation over western Europe and the UK,(b) in quantity and frequency of severe and hazardous convective rainfall events. The future work-plan is(i) to complete simulations for the decade 1989-2000 driven by ERA-Interim reanalysis data(ii) to complete simulations for the same decade with boundary CESM/CAM climate model data to compute offset and bias corrections(iii) to complete climate scenarios for decadal periods, 2020-2030 initially and later 2050

  13. Hierarchical Spatial Analysis of Extreme Precipitation in Urban Areas

    NASA Astrophysics Data System (ADS)

    Rajulapati, C. R.; Mujumdar, P.

    2015-12-01

    Quantification of extreme precipitation is important for hydrologic designs. Due to lack of availability of extreme precipitation data for sufficiently large number of years, estimating the probability of extreme events is difficult and extrapolating the distributions to locations where observations are not available is challenging. In an urban setting, the spatial variation of precipitation can be high; the precipitation amounts and patterns often vary within short distances of less than 10 km. Therefore it is crucial to study the uncertainties in the spatial variation of precipitation in urban areas. In this work, the extreme precipitation is modeled spatially using the Bayesian hierarchical spatial analysis and the spatial variation of return levels is studied. The analysis is carried out with both the Peak over Threshold (PoT) and the Block Maxima approaches for defining the extreme precipitation. The study area is Bangalore city, India. Daily data for seventeen stations in and around Bangalore city are considered in the study. The threshold exceedences are modeled using a Generalized Pareto (GP) distribution and the block maxima are modeled using Generalized Extreme Value (GEV) distribution. In the hierarchical analysis, the statistical model is specified in three layers. The data layer models the data (either block maxima or the threshold exceedences) at each station. In the process layer, the latent spatial process characterized by geographical and climatological covariates (lat-lon, elevation, mean temperature etc.) which drives the extreme precipitation is modeled and in the prior level, the prior distributions that govern the latent process are modeled. Markov Chain Monte Carlo (MCMC) algorithm is used to obtain the samples of parameters from the posterior distribution of parameters. The spatial maps of return levels for specified return periods, along with the associated uncertainties, are obtained. The results show that there is significant variation in

  14. Extreme Ultraviolet Explorer Bright Source List

    NASA Technical Reports Server (NTRS)

    Malina, Roger F.; Marshall, Herman L.; Antia, Behram; Christian, Carol A.; Dobson, Carl A.; Finley, David S.; Fruscione, Antonella; Girouard, Forrest R.; Hawkins, Isabel; Jelinsky, Patrick

    1994-01-01

    Initial results from the analysis of the Extreme Ultraviolet Explorer (EUVE) all-sky survey (58-740 A) and deep survey (67-364 A) are presented through the EUVE Bright Source List (BSL). The BSL contains 356 confirmed extreme ultraviolet (EUV) point sources with supporting information, including positions, observed EUV count rates, and the identification of possible optical counterparts. One-hundred twenty-six sources have been detected longward of 200 A.

  15. Performance of Portable Ventilators at Temperature Extremes

    DTIC Science & Technology

    2015-03-30

    shipped and stored at ambient conditions. The effect of storage at hot and cold temperature extremes on ventilator performance is unknown. We evaluated...The effect of storage at hot and cold temperature extremes on ventilator performance is unknown. We evaluated three portable ventilators currently...operated immediately after 30 minutes of acclimation to room temperature but displayed either a “battery too hot ” or “battery too cold” alert at

  16. EXTREME VALUE THEORY WITH OPERATOR NORMING

    PubMed Central

    MEERSCHAERT, MARK M.; SCHEFFLER, HANS-PETER; STOEV, STILIAN A.

    2013-01-01

    A new approach to extreme value theory is presented for vector data with heavy tails. The tail index is allowed to vary with direction, where the directions are not necessarily along the coordinate axes. Basic asymptotic theory is developed, using operator regular variation and extremal integrals. A test is proposed to judge whether the tail index varies with direction in any given data set. PMID:24443640

  17. Prevention of Lower Extremity Injuries in Basketball

    PubMed Central

    Taylor, Jeffrey B.; Ford, Kevin R.; Nguyen, Anh-Dung; Terry, Lauren N.; Hegedus, Eric J.

    2015-01-01

    Context: Lower extremity injuries are common in basketball, yet it is unclear how prophylactic interventions affect lower extremity injury incidence rates. Objective: To analyze the effectiveness of current lower extremity injury prevention programs in basketball athletes, focusing on injury rates of (1) general lower extremity injuries, (2) ankle sprains, and (3) anterior cruciate ligament (ACL) tears. Data Sources: PubMed, MEDLINE, CINAHL, SPORTDiscus, and the Cochrane Register of Controlled Trials were searched in January 2015. Study Selection: Studies were included if they were randomized controlled or prospective cohort trials, contained a population of competitive basketball athletes, and reported lower extremity injury incidence rates specific to basketball players. In total, 426 individual studies were identified. Of these, 9 met the inclusion criteria. One other study was found during a hand search of the literature, resulting in 10 total studies included in this meta-analysis. Study Design: Systematic review and meta-analysis. Level of Evidence: Level 2. Data Extraction: Details of the intervention (eg, neuromuscular vs external support), size of control and intervention groups, and number of injuries in each group were extracted from each study. Injury data were classified into 3 groups based on the anatomic diagnosis reported (general lower extremity injury, ankle sprain, ACL rupture). Results: Meta-analyses were performed independently for each injury classification. Results indicate that prophylactic programs significantly reduced the incidence of general lower extremity injuries (odds ratio [OR], 0.69; 95% CI, 0.57-0.85; P < 0.001) and ankle sprains (OR, 0.45; 95% CI, 0.29-0.69; P < 0.001), yet not ACL ruptures (OR, 1.09; 95% CI, 0.36-3.29; P = 0.87) in basketball athletes. Conclusion: In basketball players, prophylactic programs may be effective in reducing the risk of general lower extremity injuries and ankle sprains, yet not ACL injuries. PMID

  18. Preconditioned iterations to calculate extreme eigenvalues

    SciTech Connect

    Brand, C.W.; Petrova, S.

    1994-12-31

    Common iterative algorithms to calculate a few extreme eigenvalues of a large, sparse matrix are Lanczos methods or power iterations. They converge at a rate proportional to the separation of the extreme eigenvalues from the rest of the spectrum. Appropriate preconditioning improves the separation of the eigenvalues. Davidson`s method and its generalizations exploit this fact. The authors examine a preconditioned iteration that resembles a truncated version of Davidson`s method with a different preconditioning strategy.

  19. Extreme weather and the impacts on agriculture

    NASA Astrophysics Data System (ADS)

    Rowhani, Pedram; Lesk, Corey; Ramankutty, Navin

    2017-04-01

    Climate change is estimated to have already affected crop production adversely. The major way in which climate influences crop production is through extreme weather events such as droughts, floods and extreme temperature (heat and frosts). Numerous studies have examined the influence of historical and potential future climate means on crop production. However few have quantified the influence of extreme weather events. We used a statistical approach, "superposed epoch analysis" or compositing, to estimate for the first time national crop production losses across the globe due to historical weather-related disasters from 1961-2007. We obtained historical data on floods, droughts, extreme heat, and extreme cold events from the Emergency Events Database, EM-DAT and related these to historical national-level harvested area, yield, and production statistics for cereal crops from the FAOSTAT database. We found that droughts and extreme heat events have had a substantial influence on cereal crops, on average reducing crop production by 9-10%, while cold waves and extreme cold events exhibit no statistically discernible influence. We further find that the influence of droughts is through a combination of reduced harvested area and yields, while extreme heat seems to have mainly affected yields. The underlying reasons for these different crop responses are unknown, as the statistical approach only estimates the revealed relationships and does not explore causes. Nevertheless these findings raise new questions on why certain weather events seem to have had substantial production impacts while others have not. We suggest that greater attention should be paid to studying the influence of actual weather events on crops, rather than the influence of mean climate alone.

  20. Test fields cannot destroy extremal black holes

    NASA Astrophysics Data System (ADS)

    Natário, José; Queimada, Leonel; Vicente, Rodrigo

    2016-09-01

    We prove that (possibly charged) test fields satisfying the null energy condition at the event horizon cannot overspin/overcharge extremal Kerr-Newman or Kerr-Newman-anti de Sitter black holes, that is, the weak cosmic censorship conjecture cannot be violated in the test field approximation. The argument relies on black hole thermodynamics (without assuming cosmic censorship), and does not depend on the precise nature of the fields. We also discuss generalizations of this result to other extremal black holes.

  1. Flexible diaphragm-extreme temperature usage

    NASA Technical Reports Server (NTRS)

    Lerma, Guillermo (Inventor)

    1991-01-01

    A diaphragm suitable for extreme temperature usage, such as encountered in critical aerospace applications, is fabricated by a unique method, and of a unique combination of materials. The materials include multilayered lay-ups of diaphragm materials sandwiched between layers of bleeder fabrics. After being formed in the desired shape on a mold, they are vacuum sealed and then cured under pressure, in a heated autoclave. A bond capable of withstanding extreme temperatures are produced.

  2. Regional Changes in Extreme Climatic Events

    NASA Astrophysics Data System (ADS)

    Bell, J. L.; Sloan, L. C.; Snyder, M. A.

    2002-12-01

    This study focuses on California as a climatically complex region that is vulnerable to changes in water supply and delivery. A regional climate model is employed to assess changes in the frequency and intensity of extreme temperatures and precipitation. Significant increases in daily minimum and maximum temperatures occur with a doubling of atmospheric carbon dioxide concentration. Increases in daily temperatures lead to increases in prolonged heat waves and length of the growing season. Changes in total and extreme precipitation vary by geographic region.

  3. Minimal Pairs: Minimal Importance?

    ERIC Educational Resources Information Center

    Brown, Adam

    1995-01-01

    This article argues that minimal pairs do not merit as much attention as they receive in pronunciation instruction. There are other aspects of pronunciation that are of greater importance, and there are other ways of teaching vowel and consonant pronunciation. (13 references) (VWL)

  4. SMOS data and extreme events

    NASA Astrophysics Data System (ADS)

    Kerr, Yann; Wigneron, Jean-Pierre; Ferrazzoli, Paolo; Mahmoodi, Ali; Al-Yaari, Amen; Parrens, Marie; Bitar, Ahmad Al; Rodriguez-Fernandez, Nemesio; Bircher, Simone; Molero-rodenas, Beatriz; Drusch, Matthias; Mecklenburg, Susanne

    2017-04-01

    The SMOS (Soil Moisture and Ocean Salinity) satellite was successfully launched in November 2009. This ESA led mission for Earth Observation is dedicated to provide soil moisture over continental surface (with an accuracy goal of 0.04 m3/m3), vegetation water content over land, and ocean salinity. These geophysical features are important as they control the energy balance between the surface and the atmosphere. Their knowledge at a global scale is of interest for climatic and weather researches, and in particular in improving model forecasts. The Soil Moisture and Ocean Salinity mission has now been collecting data for over 7 years. The whole data set has been reprocessed (Version 620 for levels 1 and 2 and version 3 for level 3 CATDS) while operational near real time soil moisture data is now available and assimilation of SMOS data in NWP has proved successful. After 7 years it seems important to start using data for having a look at anomalies and see how they can relate to large scale events. We have also produced a 15 year soil moisture data set by merging SMOS and AMSR using a neural network approach. The purpose of this communication is to present the mission results after more than seven years in orbit in a climatic trend perspective, as through such a period anomalies can be detected. Thereby we benefit from consistent datasets provided through the latest reprocessing using most recent algorithm enhancements. Using the above mentioned products it is possible to follow large events such as the evolution of the droughts in North America, or water fraction evolution over the Amazonian basin. In this occasion we will focus on the analysis of SMOS and ancillary products anomalies to reveal two climatic trends, the temporal evolution of water storage over the Indian continent in relation to rainfall anomalies, and the global impact of El Nino types of events on the general water storage distribution. This presentation shows in detail the use of long term data sets

  5. Extreme events monitoring from space

    NASA Astrophysics Data System (ADS)

    Kerr, Yann; Bitar, Ahmad Al; Mahmoodi, Ali; Richaume, Philippe; Al-Yaari, Amen; Wigneron, Jean-Pierre

    2016-04-01

    The SMOS (Soil Moisture and Ocean Salinity) satellite was successfully launched in November 2009. This ESA led mission for Earth Observation is dedicated to provide soil moisture over continental surface (with an accuracy goal of 0.04 m3/m3), vegetation water content over land, and ocean salinity. These geophysical features are important as they control the energy balance between the surface and the atmosphere. Their knowledge at a global scale is of interest for climatic and weather researches, and in particular in improving model forecasts. The Soil Moisture and Ocean Salinity mission has now been collecting data for 6 years. The whole data set has just been reprocessed (Version 620 for levels 1 and 2 and version 3 for level 3 CATDS). After 6 years it seems important to start using data for having a look at anomalies and see how they can relate to large scale events The purpose of this communication is to present the mission results after more than six years in orbit in a climatic trend perspective, as through such a period anomalies can be detected. Thereby we benefit from consistent datasets provided through the latest reprocessing using most recent algorithm enhancements. Using the above mentioned products it is possible to follow large events such as the evolution of the droughts in North America, or water fraction evolution over the Amazonian basin. In this occasion we will focus on the analysis of SMOS and ancillary products anomalies to reveal two climatic trends, the temporal evolution of water storage over the Indian continent in relation to rainfall anomalies, and the global impact of El Nino types of events on the general water storage distribution. This presentation shows in detail the use of long term data sets of L-band microwave radiometry in two specific cases, namely droughts and water budget over a large basin. Several other analyses are under way currently. Obviously, vegetation water content, but also dielectric constant, are carrying a wealth

  6. Are healthcare middle management jobs extreme jobs?

    PubMed

    Buchanan, David A; Parry, Emma; Gascoigne, Charlotte; Moore, Cíara

    2013-01-01

    The purpose of this paper is to explore the incidence of "extreme jobs" among middle managers in acute hospitals, and to identify individual and organizational implications. The paper is based on interviews and focus groups with managers at six hospitals, a "proof of concept" pilot with an operations management team, and a survey administered at five hospitals. Six of the original dimensions of extreme jobs, identified in commercial settings, apply to hospital management: long hours, unpredictable work patterns, tight deadlines with fast pace, broad responsibility, "24/7 availability", mentoring and coaching. Six healthcare-specific dimensions were identified: making life or death decisions, conflicting priorities, being required to do more with fewer resources, responding to regulatory bodies, the need to involve many people before introducing improvements, fighting a negative climate. Around 75 per cent of hospital middle managers have extreme jobs. This extreme healthcare management job model was derived inductively from a qualitative study involving a small number of respondents. While the evidence suggests that extreme jobs are common, further research is required to assess the antecedents, incidence, and implications of these working practices. A varied, intense, fast-paced role with responsibility and long hours can be rewarding, for some. However, multi-tasking across complex roles can lead to fatigue, burnout, and mistakes, patient care may be compromised, and family life may be adversely affected. As far as the authors can ascertain, there are no other studies exploring acute sector management roles through an extreme jobs lens.

  7. The future intensification of hourly precipitation extremes

    NASA Astrophysics Data System (ADS)

    Prein, Andreas F.; Rasmussen, Roy M.; Ikeda, Kyoko; Liu, Changhai; Clark, Martyn P.; Holland, Greg J.

    2017-01-01

    Extreme precipitation intensities have increased in all regions of the Contiguous United States (CONUS) and are expected to further increase with warming at scaling rates of about 7% per degree Celsius (ref. ), suggesting a significant increase of flash flood hazards due to climate change. However, the scaling rates between extreme precipitation and temperature are strongly dependent on the region, temperature, and moisture availability, which inhibits simple extrapolation of the scaling rate from past climate data into the future. Here we study observed and simulated changes in local precipitation extremes over the CONUS by analysing a very high resolution (4 km horizontal grid spacing) current and high-end climate scenario that realistically simulates hourly precipitation extremes. We show that extreme precipitation is increasing with temperature in moist, energy-limited, environments and decreases abruptly in dry, moisture-limited, environments. This novel framework explains the large variability in the observed and modelled scaling rates and helps with understanding the significant frequency and intensity increases in future hourly extreme precipitation events and their interaction with larger scales.

  8. Extreme Weather Events and Climate Change Attribution

    SciTech Connect

    Thomas, Katherine

    2016-03-31

    A report from the National Academies of Sciences, Engineering, and Medicine concludes it is now possible to estimate the influence of climate change on some types of extreme events. The science of extreme event attribution has advanced rapidly in recent years, giving new insight to the ways that human-caused climate change can influence the magnitude or frequency of some extreme weather events. This report examines the current state of science of extreme weather attribution, and identifies ways to move the science forward to improve attribution capabilities. Confidence is strongest in attributing types of extreme events that are influenced by climate change through a well-understood physical mechanism, such as, the more frequent heat waves that are closely connected to human-caused global temperature increases, the report finds. Confidence is lower for other types of events, such as hurricanes, whose relationship to climate change is more complex and less understood at present. For any extreme event, the results of attribution studies hinge on how questions about the event's causes are posed, and on the data, modeling approaches, and statistical tools chosen for the analysis.

  9. Sensitivity of precipitation extremes to radiative forcing of greenhouse gases and aerosols

    NASA Astrophysics Data System (ADS)

    Lin, Lei; Wang, Zhili; Xu, Yangyang; Fu, Qiang

    2016-09-01

    Greenhouse gases (GHGs) and aerosols are the two most important anthropogenic forcing agents in the 21st century. The expected declines of anthropogenic aerosols in the 21st century from present-day levels would cause an additional warming of the Earth's climate system, which would aggravate the climate extremes caused by GHG warming. We examine the increased rate of precipitation extremes with global mean surface warming in the 21st century caused by anthropogenic GHGs and aerosols, using an Earth system model ensemble simulation. Similar to mean precipitation, the increased rate of precipitation extremes caused by aerosol forcing is significantly larger than that caused by GHG forcing. The aerosol forcing in the coming decades can play a critical role in inducing change in precipitation extremes if a lower GHG emission pathway is adopted. Our results have implications for policy-making on climate adaptation to extreme precipitation events.

  10. Slow and fast responses of mean and extreme precipitation to different forcing in CMIP5 simulations

    NASA Astrophysics Data System (ADS)

    Sillmann, Jana; Stjern, Camilla Weum; Myhre, Gunnar; Forster, Piers M.

    2017-06-01

    We are investigating the fast and slow responses of changes in mean and extreme precipitation to different climate forcing mechanisms, such as greenhouse gas and solar forcing, to understand whether rapid adjustments are important for extreme precipitation. To disentangle the effect of rapid adjustment to a given forcing on the overall change in extreme precipitation, we use a linear regression method that has been previously applied to mean precipitation. Equilibrium experiments with preindustrial CO2 concentrations and reduced solar constant were compared with a four times CO2 concentration experiment for 10 state-of-the-art climate models. We find that the two forcing mechanisms, greenhouse gases and solar, impose clearly different rapid adjustment signals in the mean precipitation, while such difference is difficult to discern for extreme precipitation due to large internal variability. In contrast to mean precipitation, changes in extreme precipitation scale with surface temperature trends and do not seem to depend on the forcing mechanism.

  11. Numerical study of extreme events in a laser diode with phase-conjugate optical feedback

    NASA Astrophysics Data System (ADS)

    Mercier, Émeric; Even, Armelle; Mirisola, Elodie; Wolfersberger, Delphine; Sciamanna, Marc

    2015-04-01

    Extreme intensity pulses sharing statistical properties similar to rogue waves have been recently observed in a laser diode with phase-conjugate feedback [A. Karsaklian Dal Bosco, D. Wolfersberger, and M. Sciamanna, Opt. Lett. 38, 703 (2013), 10.1364/OL.38.000703], but remain unexplained. We demonstrate here that a rate equation model of a laser diode that includes an instantaneous phase-conjugate feedback field reproduces qualitatively well the statistical features of these extreme events as identified in the experiment, i.e., the deviation of the intensity statistics to a Gaussian-shape statistics and the statistics of the time separating extreme events. The numerical simulations confirm the importance of the feedback strength in increasing the number of such extreme events and allow us to explain how extreme events emerge from a sequence of bifurcations on self-pulsating solutions, the so-called external cavity modes.

  12. Extremity shortness in obstetric brachial plexus lesion and its relationship to root avulsion.

    PubMed

    Uysal, Hilmi; Demir, Sibel Ozbudak; Oktay, Fügen; Selcuk, Barin; Akyüz, Müfit

    2007-12-01

    A total of 73 patients with obstetric brachial plexus palsy and extremity shortness were evaluated clinically, electrophysiologically, and with cervical magnetic resonance imaging. Patients were separated into groups according to age and the level of lesion. The differences of the length of the humerus, ulna, radius, and the second and fifth metacarpal bones were significant between the involved and uninvolved extremities. The difference in shortness increased in relation to the age of the groups and stabilized to approximately 10% in the groups aged 4 to 8 years and 8+ years. A significant relationship was observed between bone length differences and lesion levels. Differences in bone lengths were statistically significant in patients with avulsion in the group aged 8+ years. Extremity shortness appears to be related to avulsion and the level of lesion. The effect of avulsion on extremity shortness gradually increases with age. Finally, root avulsion can be an important factor in extremity shortness of obstetric brachial plexus palsy patients.

  13. Increasing climate extremes under global warming - What is the driving force?

    NASA Astrophysics Data System (ADS)

    Yoon, Jin-Ho

    2017-04-01

    More climate extreme events have occurred in recent years, including the continual development of extreme drought in California, the severe cold winters in the eastern U.S. since 2014, 2015 Washington drought, and excessive wildfire events over Alaska in 2015. These have been casually attributed to global warming. However, a need for further understanding of mechanisms responsible for climate extremes is growing. In this presentation, we'll use sets of climate model simulation that designed to identify the role of the oceanic feedback in increasing climate extremes under global warming. One is with a fully coupled climate model forced by 1% ramping CO2, and the other is with an atmosphere only model forced by the same CO2 forcing. By contrasting these two, an importance of the oceanic feedback in increasing climate extremes under global warming can be diagnosed.

  14. Seasonal and regional variations in extreme precipitation event frequency using CMIP5

    NASA Astrophysics Data System (ADS)

    Janssen, E.; Sriver, R. L.; Wuebbles, D. J.; Kunkel, K. E.

    2016-05-01

    Understanding how the frequency and intensity of extreme precipitation events are changing is important for regional risk assessments and adaptation planning. Here we use observational data and an ensemble of climate change model experiments (from the Coupled Model Intercomparison Project Phase 5 (CMIP5)) to examine past and potential future seasonal changes in extreme precipitation event frequency over the United States. Using the extreme precipitation index as a metric for extreme precipitation change, we find key differences between models and observations. In particular, the CMIP5 models tend to overestimate the number of spring events and underestimate the number of summer events. This seasonal shift in the models is amplified in projections. These results provide a basis for evaluating climate model skill in simulating observed seasonality and changes in regional extreme precipitation. Additionally, we highlight key sources of variability and uncertainty that can potentially inform regional impact analyses and adaptation planning.

  15. Increasing climate extremes under global warming - What is the driving force?

    NASA Astrophysics Data System (ADS)

    Yoon, J.; Wang, S. Y.; Gillies, R. R.; Hipps, L.; Kravitz, B.; Rasch, P. J.

    2015-12-01

    More climate extreme events have occurred in recent years, including the continual development of extreme drought in California, the severe cold winters in the eastern U.S. since 2014, 2015 Washington drought, and excessive wildfire events over Alaska in 2015. These have been casually attributed to global warming. However, a need for further understanding of mechanisms responsible for climate extremes is growing. In this presentation, we'll use sets of climate model simulation that designed to identify the role of the oceanic feedback in increasing climate extremes under global warming. One is with a fully coupled climate model forced by 1% ramping CO2, and the other is with an atmosphere only model forced by the same CO2 forcing. By contrasting these two, an importance of the oceanic feedback in increasing climate extremes under global warming can be diagnosed.

  16. Extreme adaptations for aquatic ectoparasitism in a Jurassic fly larva.

    PubMed

    Chen, Jun; Wang, Bo; Engel, Michael S; Wappler, Torsten; Jarzembowski, Edmund A; Zhang, Haichun; Wang, Xiaoli; Zheng, Xiaoting; Rust, Jes

    2014-06-24

    The reconstruction of ancient insect ectoparasitism is challenging, mostly because of the extreme scarcity of fossils with obvious ectoparasitic features such as sucking-piercing mouthparts and specialized attachment organs. Here we describe a bizarre fly larva (Diptera), Qiyia jurassica gen. et sp. nov., from the Jurassic of China, that represents a stem group of the tabanomorph family Athericidae. Q. jurassica exhibits adaptations to an aquatic habitat. More importantly, it preserves an unusual combination of features including a thoracic sucker with six radial ridges, unique in insects, piercing-sucking mouthparts for fluid feeding, and crocheted ventral prolegs with upward directed bristles for anchoring and movement while submerged. We demonstrate that Q. jurassica was an aquatic ectoparasitic insect, probably feeding on the blood of salamanders. The finding reveals an extreme morphological specialization of fly larvae, and broadens our understanding of the diversity of ectoparasitism in Mesozoic insects.DOI: http://dx.doi.org/10.7554/eLife.02844.001.

  17. Seasonal extreme value statistics for precipitation in Germany

    NASA Astrophysics Data System (ADS)

    Fischer, Madlen; Rust, Henning W.; Ulbrich, Uwe

    2013-04-01

    Extreme precipitation has a strong influence on environment, society and economy. It leads to large damage due to floods, mudslides, increased erosion or hail. While standard annual return levels are important for hydrological structures, seasonaly resolved return levels provide additional information for risk managment, e.g., for the agricultural sector. For 1208 stations in Germany, we calculate monthly resolved return levels. Instead of estimating parameters separately for every month in the year, we use a non-stationary approach and benefit from smoothly varying return levels throughout the year. This natural approach is more suitable to characterise seasonal variability of extreme precipitation and leads to more accurate return level estimates. Harmonic functions of different orders are used to describe the seasonal variation of GEV parameters and crossvalidation is used to determine a suitable model forall stations. Finally particularly vulnerable regions and associated month are investigated in more detail.

  18. Dramatic increases in likelihoods of extreme seasonal temperatures since 2003.

    NASA Astrophysics Data System (ADS)

    Stott, P.; Christidis, N.; Ciavarella, A.

    2014-12-01

    Severe heatwaves in the last decade like the ones in Russia in 2010, Texas in 2011 and the Australian "angry summer" of 2012-13 were characterised by long duration, large spatial extent and catastrophic impacts. We have updated the analysis that attributed a human contribution to the European heatwave of 2003 and now show that the likelihood of such a summer has increased dramatically since then. Such events are set to become the norm in only a few decades underlining the importance of developing our capacity to adapt to such extremes. In order to meet this developing challenge, a new European initiative, EUCLEIA (EUropean CLimate and weather Events : Inerpretation and Attribution) seeks to lay the groundwork for an operational attribution service for Europe. This will provide updated assessments of the extent to which human and natural drivers of climate have contributed to the magnitude or probability of extreme weather and climate events.

  19. Lower extremity finite element model for crash simulation

    SciTech Connect

    Schauer, D.A.; Perfect, S.A.

    1996-03-01

    A lower extremity model has been developed to study occupant injury mechanisms of the major bones and ligamentous soft tissues resulting from vehicle collisions. The model is based on anatomically correct digitized bone surfaces of the pelvis, femur, patella and the tibia. Many muscles, tendons and ligaments were incrementally added to the basic bone model. We have simulated two types of occupant loading that occur in a crash environment using a non-linear large deformation finite element code. The modeling approach assumed that the leg was passive during its response to the excitation, that is, no active muscular contraction and therefore no active change in limb stiffness. The approach recognized that the most important contributions of the muscles to the lower extremity response are their ability to define and modify the impedance of the limb. When nonlinear material behavior in a component of the leg model was deemed important to response, a nonlinear constitutive model was incorporated. The accuracy of these assumptions can be verified only through a review of analysis results and careful comparison with test data. As currently defined, the model meets the objective for which it was created. Much work remains to be done, both from modeling and analysis perspectives, before the model can be considered complete. The model implements a modeling philosophy that can accurately capture both kinematic and kinetic response of the lower limb. We have demonstrated that the lower extremity model is a valuable tool for understanding the injury processes and mechanisms. We are now in a position to extend the computer simulation to investigate the clinical fracture patterns observed in actual crashes. Additional experience with this model will enable us to make a statement on what measures are needed to significantly reduce lower extremity injuries in vehicle crashes. 6 refs.

  20. Extreme events of perceived temperature over Europe: a projected northward extension of dangerous areas

    NASA Astrophysics Data System (ADS)

    Scoccimarro, Enrico; Fogli, Pier Giuseppe; Gualdi, Silvio

    2017-04-01

    It is well known that an increase of temperature over Europe, both in terms of averages and extremes, is expected within the current century. In order to consider health impacts under warm conditions, it is important to take into account the combined effect of temperature and humidity on the human body. To this aim a basic index - the humindex - representative of the perceived temperature, under different scenarios and periods, has been investigated in this study. A very low concomitance of extreme temperature events and extreme humindex events is found over the present climate, reinforcing the importance to investigate not only extreme temperature and relative humidity future projections but also the combination of the two parameters. A set of 10-km resolution regional climate simulations provided within the EUR-11 EURO-CORDEX multi-model effort, demonstrates ability in representing the intense and extreme events of the humindex over the present climate and to be eligible as a tool to quantify future changes in geographical patterns of exposed areas over Europe. An enlargement of the domain subject to dangerous conditions is found since the middle of the current century, reaching 60 degrees North when considering really extreme events. The most significant increase in humindex extreme events is found when comparing the 2066-2095 projections under rcp8.5 scenario, to the 1966-2005 period: bearing in mind that changes in relative humidity may either amplify or offset the health effects of temperature extremes, a less pronounced projected reduction of relative humidity intensity in the Northern part of the European domain, associated to extreme temperature and humindex, makes Northern Europe the most prone region to a local increase of the humindex extremes.

  1. Conditional probability of rainfall extremes across multiple durations

    NASA Astrophysics Data System (ADS)

    Le, Phuong Dong; Leonard, Michael; Westra, Seth

    2017-04-01

    estimate marginal parameters across the full spatial domain. Finally, spatial interpolation result is used as initial condition to estimate dependence parameters via a likelihood function of max-stable model for multiple durations. The Hawkesbury-Nepean catchment near Sydney in Australia was selected as case study for this research. This catchment has 25 sub-daily rain gauges with the minimum record length of 24 years over a region of 300 km × 300 km area. The re-parameterization was applied for each station for durations from 1 hour to 24 hours and then is evaluated by comparing with the at-site fitted GEV. The evaluation showed that the average R2 for all station is around 0.80 with the range from 0.26 to 1.0. The output of re-parameterization then was used to construct the spatial surface based on covariates including longitude, latitude, and elevation. The dependence model showed good agreements between empirical extremal coefficient and theoretical extremal coefficient for multiple durations. For the overall model, a leave-one-out cross-validation for all stations showed it works well for 20 out of 25 stations. The potential application of this model framework was illustrated through a conditional map of return period and return level across multiple durations, both of which are important for engineering design and management.

  2. Large Scale Meteorological Pattern of Extreme Rainfall in Indonesia

    NASA Astrophysics Data System (ADS)

    Kuswanto, Heri; Grotjahn, Richard; Rachmi, Arinda; Suhermi, Novri; Oktania, Erma; Wijaya, Yosep

    2014-05-01

    Extreme Weather Events (EWEs) cause negative impacts socially, economically, and environmentally. Considering these facts, forecasting EWEs is crucial work. Indonesia has been identified as being among the countries most vulnerable to the risk of natural disasters, such as floods, heat waves, and droughts. Current forecasting of extreme events in Indonesia is carried out by interpreting synoptic maps for several fields without taking into account the link between the observed events in the 'target' area with remote conditions. This situation may cause misidentification of the event leading to an inaccurate prediction. Grotjahn and Faure (2008) compute composite maps from extreme events (including heat waves and intense rainfall) to help forecasters identify such events in model output. The composite maps show large scale meteorological patterns (LSMP) that occurred during historical EWEs. Some vital information about the EWEs can be acquired from studying such maps, in addition to providing forecaster guidance. Such maps have robust mid-latitude meteorological patterns (for Sacramento and California Central Valley, USA EWEs). We study the performance of the composite approach for tropical weather condition such as Indonesia. Initially, the composite maps are developed to identify and forecast the extreme weather events in Indramayu district- West Java, the main producer of rice in Indonesia and contributes to about 60% of the national total rice production. Studying extreme weather events happening in Indramayu is important since EWEs there affect national agricultural and fisheries activities. During a recent EWE more than a thousand houses in Indramayu suffered from serious flooding with each home more than one meter underwater. The flood also destroyed a thousand hectares of rice plantings in 5 regencies. Identifying the dates of extreme events is one of the most important steps and has to be carried out carefully. An approach has been applied to identify the

  3. [Diagnosing imported helminthiasis].

    PubMed

    Pardo, Javier; Pérez-Arellano, José Luis; Galindo, Inmaculada; Belhassen, Moncef; Cordero, Miguel; Muro, Antonio

    2007-05-01

    In recent years, there has been an increase in cases of imported helminthiasis in Spain because of two complementary causes: immigration and international travel. Although the prevalence of helminthiasis is high in the immigrant population, the risk of transmission to the Spanish population is low. In this review, we provide clues to aid in the diagnosis of the helminthiasis, highlighting the geographic characteristics, clinical findings and analytical results of the most frequent types. The low sensitivity of the classic parasitological diagnostic test, mainly in tissue helminthiasis, is described. In addition, the advantages and limitations of the common serological methods for detecting related circulating antigens and antibodies are presented. Certain molecular methods used in the diagnosis of imported helminthiasis and the best strategies for screening of this condition are discussed.

  4. [Imported cases of histoplasmosis].

    PubMed

    Nyffenegger, Laurent; Abbas, Mohamed; Gex, Grégoire; Boffi, Emmanuelle; Schrenzel, Jacques; Bouchuiguir-Wafa, Kalthum; Hirschel, Bernard

    2009-11-25

    Histoplasmosis is a fungal infection that may be opportunistic in the context of HIV. Rare in Europe, it is always imported. The two variants of histoplasmosis are encountered in defined geographic areas: var. capsulatum in Americas, Africa and Asia; and var duboisii in Africa only. In immuno-competent patients, acute infection is often asymptomatic, or it may cause a pulmonary syndrome of variable severity. Among immuno-compromised patients, histoplasmosis is disseminated and life-threatening. Diagnosis is typically made by cultures. The treatment of the disseminated form must be started immediately with anti-fungal therapy and highly active anti-retroviral treatment. In a globalized world, one has to remember the importation of unusual exotic diseases.

  5. The Pace of Perceivable Extreme Climate Change

    NASA Astrophysics Data System (ADS)

    Tan, X.; Gan, T. Y.

    2015-12-01

    When will the signal of obvious changes in extreme climate emerge over climate variability (Time of Emergence, ToE) is a key question for planning and implementing measures to mitigate the potential impact of climate change to natural and human systems that are generally adapted to potential changes from current variability. We estimated ToEs for the magnitude, duration and frequency of global extreme climate represented by 24 extreme climate indices (16 for temperature and 8 for precipitation) with different thresholds of the signal-to-noise (S/N) ratio based on projections of CMIP5 global climate models under RCP8.5 and RCP4.5 for the 21st century. The uncertainty of ToE is assessed by using 3 different methods to calculate S/N for each extreme index. Results show that ToEs of the projected extreme climate indices based on the RCP4.5 climate scenarios are generally projected to happen about 20 years later than that for the RCP8.5 climate scenarios. Under RCP8.5, the projected magnitude, duration and frequency of extreme temperature on Earth will all exceed 2 standard deviations by 2100, and the empirical 50th percentile of the global ToE for the frequency and magnitude of hot (cold) extreme are about 2040 and 2054 (2064 and 2054) for S/N > 2, respectively. The 50th percentile of global ToE for the intensity of extreme precipitation is about 2030 and 2058 for S/N >0.5 and S/N >1, respectively. We further evaluated the exposure of ecosystems and human societies to the pace of extreme climate change by determining the year of ToE for various extreme climate indices projected to occur over terrestrial biomes, marine realms and major urban areas with large populations. This was done by overlaying terrestrial, ecoregions and population maps with maps of ToE derived, to extract ToEs for these regions. Possible relationships between GDP per person and ToE are also investigated by relating the mean ToE for each country and its average value of GDP per person.

  6. Neurodevelopmental problems and extremes in BMI

    PubMed Central

    Tajnia, Armin; Lichtenstein, Paul; Lundström, Sebastian; Anckarsäter, Henrik; Nilsson, Thomas; Råstam, Maria

    2015-01-01

    Background. Over the last few decades, an increasing number of studies have suggested a connection between neurodevelopmental problems (NDPs) and body mass index (BMI). Attention deficit/hyperactivity disorder (ADHD) and autism spectrum disorders (ASD) both seem to carry an increased risk for developing extreme BMI. However, the results are inconsistent, and there have been only a few studies of the general population of children. Aims. We had three aims with the present study: (1) to define the prevalence of extreme (low or high) BMI in the group of children with ADHD and/or ASDs compared to the group of children without these NDPs; (2) to analyze whether extreme BMI is associated with the subdomains within the diagnostic categories of ADHD or ASD; and (3) to investigate the contribution of genetic and environmental factors to BMI in boys and girls at ages 9 and 12. Method. Parents of 9- or 12-year-old twins (n = 12,496) were interviewed using the Autism—Tics, ADHD and other Comorbidities (A-TAC) inventory as part of the Child and Adolescent Twin Study in Sweden (CATSS). Univariate and multivariate generalized estimated equation models were used to analyze associations between extremes in BMI and NDPs. Results. ADHD screen-positive cases followed BMI distributions similar to those of children without ADHD or ASD. Significant association was found between ADHD and BMI only among 12-year-old girls, where the inattention subdomain of ADHD was significantly associated with the high extreme BMI. ASD scores were associated with both the low and the high extremes of BMI. Compared to children without ADHD or ASD, the prevalence of ASD screen-positive cases was three times greater in the high extreme BMI group and double as much in the low extreme BMI group. Stereotyped and repetitive behaviors were significantly associated with high extreme BMIs. Conclusion. Children with ASD, with or without coexisting ADHD, are more prone to have low or high extreme BMIs than children

  7. Ongoing climatic extreme dynamics in Siberia

    NASA Astrophysics Data System (ADS)

    Gordov, E. P.; Shulgina, T. M.; Okladnikov, I. G.; Titov, A. G.

    2013-12-01

    Ongoing global climate changes accompanied by the restructuring of global processes in the atmosphere and biosphere are strongly pronounced in the Northern Eurasia regions, especially in Siberia. Recent investigations indicate not only large changes in averaged climatic characteristics (Kabanov and Lykosov, 2006, IPCC, 2007; Groisman and Gutman, 2012), but more frequent occurrence and stronger impacts of climatic extremes are reported as well (Bulygina et al., 2007; IPCC, 2012: Climate Extremes, 2012; Oldenborh et al., 2013). This paper provides the results of daily temperature and precipitation extreme dynamics in Siberia for the last three decades (1979 - 2012). Their seasonal dynamics is assessed using 10th and 90th percentile-based threshold indices that characterize frequency, intensity and duration of climatic extremes. To obtain the geographical pattern of these variations with high spatial resolution, the sub-daily temperature data from ECMWF ERA-Interim reanalysis and daily precipitation amounts from APHRODITE JMA dataset were used. All extreme indices and linear trend coefficients have been calculated using web-GIS information-computational platform Climate (http://climate.scert.ru/) developed to support collaborative multidisciplinary investigations of regional climatic changes and their impacts (Gordov et al., 2012). Obtained results show that seasonal dynamics of daily temperature extremes is asymmetric for tails of cold and warm temperature extreme distributions. Namely, the intensity of warming during cold nights is higher than during warm nights, especially at high latitudes of Siberia. The similar dynamics is observed for cold and warm day-time temperatures. Slight summer cooling was observed in the central part of Siberia. It is associated with decrease in warm temperature extremes. In the southern Siberia in winter, we also observe some cooling mostly due to strengthening of the cold temperature extremes. Changes in daily precipitation extremes

  8. [Myiases of economic importance].

    PubMed

    Touré, S M

    1994-12-01

    A simplified list of the principal Diptera capable of causing myiasis is followed by a brief presentation of the biology, lesions inflicted, and methods of treatment and control of the myiases of economic importance. Cochliomyiasis caused by Cochliomyia hominivorax is of greatest interest, in view of the damage and losses caused by this disease. A brief account of the outbreak of infestation in Libya illustrates the danger of this parasite. Other important traumatic myiases are described: that due to Chrysomya bezziana, which causes an African myiasis similar to cochliomyiasis, and those due to Lucilia cuprina and related species. Hypodermyiasis (warble fly infestation) and oestrosis (nasal bot fly infestation in sheep) still cause major economic losses in domestic animals, justifying their inclusion in control campaigns. The same applies to stomach bot flies of the family Gasterophilidae. The account of each myiasis includes notes on parasiticides which have been found to be effective. Given the rapidity with which a parasite can now be transported from one continent to another, it is important for Veterinary Services to be well-informed and vigilant.

  9. Charged Matter Tests of Cosmic Censorship for Extremal and Nearly-Extremal Black Holes

    NASA Astrophysics Data System (ADS)

    Sorce, Jonathan; Wald, Robert

    2017-01-01

    We investigate scenarios in which adding electrically charged matter to a black hole may cause it to become over-extremal, violating cosmic censorship. It has previously been shown that when the matter is localized as a point particle, no violation occurs for extremal black holes to lowest nonvanishing order in the particle's charge and mass. However, recent work has suggested that violations may be possible when the black hole deviates from extremality. We show that these potential violations always occur above lowest nonvanishing order, and conclude that no lowest-order violation can occur in the nearly-extremal case unless a violation also occurs in the extremal case. We also extend the previous results on point particles to show that no violations occur to second order in charge when an arbitrary charged matter configuration is added to an extremal Kerr black hole, provided only that the matter satisfies the null energy condition.

  10. The role of land use change in the recent warming of daily extreme temperatures

    NASA Astrophysics Data System (ADS)

    Christidis, Nikolaos; Stott, Peter A.; Hegerl, Gabriele C.; Betts, Richard A.

    2013-02-01

    Abstract Understanding how temperature <span class="hlt">extremes</span> respond in a climate forced by human activity is of great <span class="hlt">importance</span>, as <span class="hlt">extreme</span> temperatures are detrimental to health and often responsible for mortality increases. While previous detection and attribution studies demonstrated a significant human influence on the recent warming of daily <span class="hlt">extremes</span>, contributions of individual anthropogenic forcings like changes in land use have not yet been investigated in such studies. Here we apply an optimal fingerprinting technique to data from observations and experiments with a new earth system model to examine whether changing land use has led to detectable changes in daily <span class="hlt">extreme</span> temperatures on a quasi-global scale. We find that loss of trees and increase of grassland since preindustrial times has caused an overall cooling trend in both mean and <span class="hlt">extreme</span> temperatures which is detectable in the observed changes of warm but not cold <span class="hlt">extremes</span>. The warming in both mean and <span class="hlt">extreme</span> temperatures due to anthropogenic forcings other than land use is detected in all cases, whereas the weaker effect of natural climatic forcings is not detected in any. This is the first formal attribution of observed climatic changes to changing land use, suggesting further investigations are justified, particularly in studies of warm <span class="hlt">extremes</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ISPAr.XL7b.195O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ISPAr.XL7b.195O"><span>Analyzing Spatiotemporal Patterns of <span class="hlt">Extreme</span> Precipitation Events in Southeastern Anatolia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ozcan, O.; Bookhagen, B.; Musaoglu, N.</p> <p>2013-10-01</p> <p><span class="hlt">Extreme</span> environmental events, such as floods, droughts, rainstorms, and strong winds have severe consequences for human society. Changes in <span class="hlt">extreme</span> weather and climate events have significant impacts and are among the most serious challenges to society in coping with a changing climate. The cost of damage caused by <span class="hlt">extreme</span> climate events is rising all over the world. The European Environment Agency (EEA) report ("Climate Change, Impacts and Vulnerabilities in Europe 2012") stated that the cost of damage had increased from € 9 billion in the 1980s to € 13 billions in the 2000s. In the United States, the National Oceanic and Atmospheric Administration (NOAA) reported that 188 billion in damage was caused by the severe weather events in 2011 and 2012. Understanding and identifying hydrometeorologic <span class="hlt">extreme</span> events and their changes through time are key in sustaining agriculture and socio-economic development. Planning for weather-related emergencies, agricultural and reservoir management and insurance risk calculations, all rely on knowledge of the frequency of these <span class="hlt">extreme</span> events. The assessment of <span class="hlt">extreme</span> precipitation is an <span class="hlt">important</span> problem in hydrologic risk analysis and design. Erosion and removal of the fertile soil layer through hydroclimatic <span class="hlt">extreme</span> events is also a serious problem in semi-arid to arid regions, especially in mediterranean climates. Accurate measurements of precipitation on a variety of space and time scales are <span class="hlt">important</span> to climate scientists and decision makers, including hydrologists, agriculturalists and emergency managers. The historical record of precipitation observations is limited mostly to land areas where rain gauges can be deployed, and measurements from those instruments are sparse over large and meteorologically <span class="hlt">important</span> regions of the Turkey, such as over the Southeastern Anatolia Region. While rain gauge measurements are often used to tune hydrologic models, they are limited by their spatial coverage. Remote sensing</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3547282','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3547282"><span>Eukaryotic diversity at pH <span class="hlt">extremes</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Amaral-Zettler, Linda A.</p> <p>2013-01-01</p> <p><span class="hlt">Extremely</span> acidic (pH < 3) and <span class="hlt">extremely</span> alkaline (pH > 9) environments support a diversity of single-cell and to a lesser extent, multicellular eukaryotic life. This study compared alpha and beta diversity in eukaryotic communities from seven diverse aquatic environments with pH values ranging from 2 to 11 using massively-parallel pyrotag sequencing targeting the V9 hypervariable region of the 18S ribosomal RNA (rRNA) gene. A total of 946 operational taxonomic units (OTUs) were recovered at a 6% cut-off level (94% similarity) across the sampled environments. Hierarchical clustering of the samples segregated the communities into acidic and alkaline groups. Similarity percentage (SIMPER) analysis followed by indicator OTU analysis (IOA) and non-metric multidimensional scaling (NMDS) were used to determine which characteristic groups of eukaryotic taxa typify acidic or alkaline <span class="hlt">extremes</span> and the extent to which pH explains eukaryotic community structure in these environments. Spain's Rio Tinto yielded the fewest observed OTUs while Nebraska Sandhills alkaline lakes yielded the most. Distinct OTUs, including metazoan OTUs, numerically dominated pH <span class="hlt">extreme</span> sites. Indicator OTUs included the diatom Pinnularia and unidentified opisthokonts (Fungi and Filasterea) in the <span class="hlt">extremely</span> acidic environments, and the ciliate Frontonia across the <span class="hlt">extremely</span> alkaline sites. Inferred from NMDS, pH explained only a modest fraction of the variation across the datasets, indicating that other factors influence the underlying community structure in these environments. The findings from this study suggest that the ability for eukaryotes to adapt to pH <span class="hlt">extremes</span> over a broad range of values may be rare, but further study of taxa that can broadly adapt across diverse acidic and alkaline environments, respectively present good models for understanding adaptation and should be targeted for future investigations. PMID:23335919</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23335919','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23335919"><span>Eukaryotic diversity at pH <span class="hlt">extremes</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Amaral-Zettler, Linda A</p> <p>2012-01-01</p> <p><span class="hlt">Extremely</span> acidic (pH < 3) and <span class="hlt">extremely</span> alkaline (pH > 9) environments support a diversity of single-cell and to a lesser extent, multicellular eukaryotic life. This study compared alpha and beta diversity in eukaryotic communities from seven diverse aquatic environments with pH values ranging from 2 to 11 using massively-parallel pyrotag sequencing targeting the V9 hypervariable region of the 18S ribosomal RNA (rRNA) gene. A total of 946 operational taxonomic units (OTUs) were recovered at a 6% cut-off level (94% similarity) across the sampled environments. Hierarchical clustering of the samples segregated the communities into acidic and alkaline groups. Similarity percentage (SIMPER) analysis followed by indicator OTU analysis (IOA) and non-metric multidimensional scaling (NMDS) were used to determine which characteristic groups of eukaryotic taxa typify acidic or alkaline <span class="hlt">extremes</span> and the extent to which pH explains eukaryotic community structure in these environments. Spain's Rio Tinto yielded the fewest observed OTUs while Nebraska Sandhills alkaline lakes yielded the most. Distinct OTUs, including metazoan OTUs, numerically dominated pH <span class="hlt">extreme</span> sites. Indicator OTUs included the diatom Pinnularia and unidentified opisthokonts (Fungi and Filasterea) in the <span class="hlt">extremely</span> acidic environments, and the ciliate Frontonia across the <span class="hlt">extremely</span> alkaline sites. Inferred from NMDS, pH explained only a modest fraction of the variation across the datasets, indicating that other factors influence the underlying community structure in these environments. The findings from this study suggest that the ability for eukaryotes to adapt to pH <span class="hlt">extremes</span> over a broad range of values may be rare, but further study of taxa that can broadly adapt across diverse acidic and alkaline environments, respectively present good models for understanding adaptation and should be targeted for future investigations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA.....8987L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA.....8987L"><span>Hydrometeorological <span class="hlt">extremes</span> in the Mediterranean area</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Llasat, M. C.; Rigo, T.</p> <p>2003-04-01</p> <p>Between the 9th and 18th of November of 2001, a succession of hydrometeorological hazards affected the West of the Mediterranean area. High rainfalls above 200mm /24 h gave place to catastrophic floods in Algeria, Balearic Islands, Morocco and the Northeast of the Iberian Peninsula; <span class="hlt">extreme</span> winds of more than 30 m/s of sustained speed uprooted thousands of trees, removed up to 50 per cent of the sand in a great number of beaches of the Balearic Islands and Catalonia and made waves over 11 m high; combined with the wind, the hail destroyed the crops in the littoral region of Catalonia, whereas a cold wave affected the rest of Spain, with the snow arriving to Catalonia. Over 600 people died in Algeria and up to 10 in Spain, with material damage up to 150M euros. In this case a strong cyclone was identified as one of the main causes of the severe weather produced. A study developed into the framework of the MEDEX project shows that the Gulf of Genoa (mainly medium and deep cyclones) and the Iberian Peninsula (mainly shallow cyclones) are the most cyclogenesis prone areas in the West Mediterranean (Campins et al, 2002). Although the West part of the Mediterranean shows the maximum number of cyclones, it is also <span class="hlt">important</span> in the Eastern part (smoothed values are, respectively, 437 and 353, following the results of Gil et al, 2002). Although the events of November 2001 are not usual in the Mediterranean area, hydrometeorological hazards that affect more than one country (usually Spain, France and Italy) are frequent. But not all the catastrophic events are so vast. On the 25th of September of 1962 a catastrophic flash-flood produced 815 casualties in less than 150 km2 and on the 10th of June of 2000, more than 200 mm were recorded in less than 3 hours. Although the Mediterranean climate is identified with dry summers, that season shows the greatest rate of convective events (Llasat, 2001) that can lead to flash floods in little catchments, usually in mountain and coastal</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/3898482','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/3898482"><span><span class="hlt">Imported</span> malaria in Kuwait.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hira, P R; Behbehani, K; Al-Kandari, S</p> <p>1985-01-01</p> <p>The number of <span class="hlt">imported</span> malaria cases in Kuwait rose from 87 in 1980 to 504 in 1983, an increase of 579%. The continued resurgence of malaria in endemic zones, improved diagnostic techniques and a heightened awareness of <span class="hlt">imported</span> malaria have contributed to the increase in the number of microscopically proved cases. Thick blood films fixed in acetone and stained in Giemsa proved a rapid method of diagnosis; species identification on the basis of a thin film on the same slide was performed with ease. Malaria was acquired in 38 countries. Most patients were young male adults. Most of the cases were due to Plasmodium vivax originating from India, although an increasing number of P. falciparum cases are also now being diagnosed from there. P. falciparum infections were evenly distributed throughout the year and most cases presented within 14 days of their arrival in the country. The highest number of P. vivax cases were diagnosed between May and October, when heat stress might have been a factor in precipitating a clinical attack of an infection previously acquired in the endemic zone. Attention is drawn to the <span class="hlt">importance</span> of delayed attacks of P. vivax and, in semi-immunes, of P. falciparum. The time interval involved in establishing a history of "recent" travel in clinically suspected cases of malaria needs to be more clearly defined in each geographical area. Cases of induced malaria due to transfusion, accidental and congenital infections were identified. The fatality rate due to P. falciparum infections was low. In terms of the risk of renewed transmission, Kuwait may be considered a vulnerable area.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.3922G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.3922G"><span>The influence of physics parameterizations on precipitation <span class="hlt">extremes</span> in the Newcastle east coast low of 2007</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gilmore, J. B.; Evans, J. P.; Sherwood, S. C.</p> <p>2012-04-01</p> <p>East coast low (ECL) events are one of the major sources of <span class="hlt">extreme</span> precipitation on the eastern Australian seaboard. In fact, it is not uncommon for a location to receive a significant portion of its average yearly rainfall in one to two days from an ECL event. Because of this, developing ways to accurately simulate ECL events and compare modeled <span class="hlt">extreme</span> precipitation to observations is an <span class="hlt">important</span> and challenging goal. We investigate how the Weather Research and Forecasting (WRF) model simulates <span class="hlt">extreme</span> precipitation for ECL events with an emphasis on understanding the connection to model physics. We focus on the Newcastle ECL of 2007, which was one of the most powerful ECLs in recent memory, with high precipitation and strong winds in the Newcastle area. We examine the sensitivity of precipitation <span class="hlt">extremes</span> to microphysical schemes, radiation schemes, boundary and surface layer physics, and cumulus parametrizations. Using the Bureau of Meteorology rain gauge network, we compare the observed hourly accumulations to the model precipitation fields using an ensemble based approach. This comparison shows that WRF, when appropriately configured, does simulate the <span class="hlt">extreme</span> precipitation well, although there are <span class="hlt">important</span> differences between the physics parametrizations. Also, we show how the cumulus parametrization, and to a lesser extent the boundary layer, can have a significant impact on the most <span class="hlt">extreme</span> hourly accumulations. <span class="hlt">Extreme</span> accumulations on daily and longer time scales are less sensitive to the choice of physical parametrization.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.A34E..06G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.A34E..06G"><span>The influence of physics parameterizations on precipitation <span class="hlt">extremes</span> in the Newcastle east coast low of 2007</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gilmore, J.; Evans, J. P.; Sherwood, S. C.</p> <p>2012-12-01</p> <p>East coast low (ECL) events are one of the major sources of <span class="hlt">extreme</span> precipitation on the eastern Australian seaboard. In fact, it is not uncommon for a location to receive a significant portion of its average yearly rainfall in one to two days from an ECL event. Because of this, developing ways to accurately simulate ECL events and compare modeled <span class="hlt">extreme</span> precipitation to observations is an <span class="hlt">important</span> and challenging goal. We investigate how the Weather Research and Forecasting (WRF) model simulates <span class="hlt">extreme</span> precipitation for ECL events with an emphasis on understanding the connection to model physics. We focus on the Newcastle ECL of 2007, which was one of the most powerful ECLs in recent memory, with high precipitation and strong winds in the Newcastle area. We examine the sensitivity of precipitation <span class="hlt">extremes</span> to microphysical schemes, radiation schemes, boundary and surface layer physics, and cumulus parameterizations. Using the Bureau of Meteorology rain gauge network, we compare the observed hourly accumulations to the model precipitation fields using an ensemble based approach. This comparison shows that WRF, when appropriately configured, does simulate the <span class="hlt">extreme</span> precipitation well, although there are <span class="hlt">important</span> differences between the physics parameterizations. Also, we show how the cumulus parametrization, and to a lesser extent the boundary layer, can have a significant impact on the most <span class="hlt">extreme</span> hourly accumulations. <span class="hlt">Extreme</span> accumulations on daily and longer time scales are less sensitive to the choice of physical parametrization.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28719992','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28719992"><span>Does Mindfulness Correlate With Physical Function and Pain Intensity in Patients With Upper <span class="hlt">Extremity</span> Illness?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Beks, Reinier B; Mellema, Jos J; Menendez, Mariano E; Chen, Neal C; Ring, David; Vranceanu, Ana Maria</p> <p>2017-03-01</p> <p>Mindfulness skills training interventions seem efficacious in increasing physical function and decreasing pain intensity in patients with chronic pain. The relationship of mindfulness and upper <span class="hlt">extremity</span> complaints in patients presenting to orthopedic surgical practices is not known. The aim of this study was to assess if mindfulness has a relationship to physical function and pain intensity in patients with upper <span class="hlt">extremity</span> illness. In this cross-sectional study, a total of 126 patients with a nontraumatic upper <span class="hlt">extremity</span> condition were asked to fill out questionnaires assessing the 5 facets of mindfulness, pain intensity, and upper <span class="hlt">extremity</span> physical function, along with clinical and demographic variables prior to their visit with the surgeon. Nonreactivity to inner experiences was the only facet of mindfulness that was correlated with upper <span class="hlt">extremity</span> physical function and pain intensity. The overall mindfulness score was correlated with pain intensity only. In multivariable analyses, mindfulness was not associated with either physical function or with pain intensity. Pain interference was the most <span class="hlt">important</span> predictor of both pain intensity and physical function. Greater overall mindfulness was associated with lower pain intensity, and greater ability to be nonreactive to inner experiences was associated with both pain intensity and upper <span class="hlt">extremity</span> physical function in bivariate but not multivariable analyses. Pain interference was the most <span class="hlt">important</span> predictor of both pain intensity and upper <span class="hlt">extremity</span> physical function. Psychosocial interventions focused on improving physical function and decreasing pain intensity in this population should focus primarily on reducing pain interference, and secondarily on teaching patients mindfulness skills.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1513897W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1513897W"><span>Multidecadal oscillations in rainfall and hydrological <span class="hlt">extremes</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Willems, Patrick</p> <p>2013-04-01</p> <p>Many studies have anticipated a worldwide increase in the frequency and intensity of precipitation <span class="hlt">extremes</span> and floods since the last decade(s). Natural variability by climate oscillations partly determines the observed evolution of precipitation <span class="hlt">extremes</span>. Based on a technique for the identification and analysis of changes in <span class="hlt">extreme</span> quantiles, it is shown that hydrological <span class="hlt">extremes</span> have oscillatory behaviour at multidecadal time scales. Results are based on nearly independent <span class="hlt">extremes</span> extracted from long-term historical time series of precipitation intensities and river flows. Study regions include Belgium - The Netherlands (Meuse basin), Ethiopia (Blue Nile basin) and Ecuador (Paute basin). For Belgium - The Netherlands, the past 100 years showed larger and more hydrological <span class="hlt">extremes</span> around the 1910s, 1950-1960s, and more recently during the 1990-2000s. Interestingly, the oscillations for southwestern Europe are anti-correlated with these of northwestern Europe, thus with oscillation highs in the 1930-1940s and 1970s. The precipitation oscillation peaks are explained by persistence in atmospheric circulation patterns over the North Atlantic during periods of 10 to 15 years. References: Ntegeka V., Willems P. (2008), 'Trends and multidecadal oscillations in rainfall <span class="hlt">extremes</span>, based on a more than 100 years time series of 10 minutes rainfall intensities at Uccle, Belgium', Water Resources Research, 44, W07402, doi:10.1029/2007WR006471 Mora, D., Willems, P. (2012), 'Decadal oscillations in rainfall and air temperature in the Paute River Basin - Southern Andes of Ecuador', Theoretical and Applied Climatology, 108(1), 267-282, doi:0.1007/s00704-011-0527-4 Taye, M.T., Willems, P. (2011). 'Influence of climate variability on representative QDF predictions of the upper Blue Nile Basin', Journal of Hydrology, 411, 355-365, doi:10.1016/j.jhydrol.2011.10.019 Taye, M.T., Willems, P. (2012). 'Temporal variability of hydro-climatic <span class="hlt">extremes</span> in the Blue Nile basin', Water</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.H21D0888I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.H21D0888I"><span><span class="hlt">Extreme</span> Rainfall Impacts in Fractured Permeable Catchments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ireson, A. M.; Butler, A. P.</p> <p>2009-12-01</p> <p> of recharge: under low rainfall intensities recharge is slow (lags of > 100 days) and through the matrix; under moderate intensities recharge is via the matrix and partially saturated fractures (lags of 10s of days) and, if sustained, can lead to flooding (as in 2000/1); under high intensity rainfall fractures transmit rainfall preferentially, leading to a large, rapid (<1 day) water table response. Given the expectation that <span class="hlt">extreme</span> rainfall events are likely to become more frequent and intense, our main focus is the preferential recharge mechanism, which has the potential to cause rapid flooding. By examining rainfall-water table response patterns, we demonstrate how the combined intensity-duration characteristics of rainfall events can be used to predict when preferential recharge is likely to occur. A 2D physically based, dual permeability Richards' equation model of the Chalk, which fully couples the unsaturated/saturated zones was developed and conditioned on field observations. This was used in a sensitivity study of water table response to a wide range of rainfall conditions, such as might be expected under future climate scenarios. The model also demonstrated the <span class="hlt">importance</span> of the soil and weathered chalk layers on matrix and fracture flow response to rainfall infiltration.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. 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