Counter-Discursive and Erotic Agency: The Case of the Black Slaves in Miguel De Cervantes's "El Celoso Extremeño"

ERIC Educational Resources Information Center

Ruiz, Eduardo

2014-01-01

Cervantes's "novela" creates a complex protagonist due in part to the involvement of the slaves' destructive and creative energies: a linguistic and erotic paradox. Linguistically the female slave foregrounds the historical dichotomy between "ladinos" and "bozales" and the related problematic of conversion,…

The patellofemoral joint: from dysplasia to dislocation

PubMed Central

Zaffagnini, Stefano; Grassi, Alberto; Zocco, Gianluca; Rosa, Michele Attilo; Signorelli, Cecilia; Muccioli, Giulio Maria Marcheggiani

2017-01-01

Patellofemoral dysplasia is a major predisposing factor for instability of the patellofemoral joint. However, there is no consensus as to whether patellofemoral dysplasia is genetic in origin, caused by imbalanced forces producing maltracking and remodelling of the trochlea during infancy and growth, or due to other unknown and unexplored factors. The biomechanical effects of patellofemoral dysplasia on patellar stability and on surgical procedures have not been fully investigated. Also, different anatomical and demographic risk factors have been suggested, in an attempt to identify the recurrent dislocators. Therefore, a comprehensive evaluation of all the radiographic, MRI and CT parameters can help the clinician to assess patients with primary and recurrent patellar dislocation and guide management. Patellofemoral dysplasia still represents an extremely challenging condition to manage. Its controversial aetiology and its complex biomechanical behaviour continue to pose more questions than answers to the research community, which reflects the lack of universally accepted guidelines for the correct treatment. However, due to the complexity of this condition, an extremely personalised approach should be reserved for each patient, in considering and addressing the anatomical abnormalities responsible for the symptoms. Cite this article: EFORT Open Rev 2017;2. DOI: 10.1302/2058-5241.2.160081. Originally published online at www.efortopenreviews.org PMID:28630757

Data-assisted reduced-order modeling of extreme events in complex dynamical systems

PubMed Central

Koumoutsakos, Petros

2018-01-01

The prediction of extreme events, from avalanches and droughts to tsunamis and epidemics, depends on the formulation and analysis of relevant, complex dynamical systems. Such dynamical systems are characterized by high intrinsic dimensionality with extreme events having the form of rare transitions that are several standard deviations away from the mean. Such systems are not amenable to classical order-reduction methods through projection of the governing equations due to the large intrinsic dimensionality of the underlying attractor as well as the complexity of the transient events. Alternatively, data-driven techniques aim to quantify the dynamics of specific, critical modes by utilizing data-streams and by expanding the dimensionality of the reduced-order model using delayed coordinates. In turn, these methods have major limitations in regions of the phase space with sparse data, which is the case for extreme events. In this work, we develop a novel hybrid framework that complements an imperfect reduced order model, with data-streams that are integrated though a recurrent neural network (RNN) architecture. The reduced order model has the form of projected equations into a low-dimensional subspace that still contains important dynamical information about the system and it is expanded by a long short-term memory (LSTM) regularization. The LSTM-RNN is trained by analyzing the mismatch between the imperfect model and the data-streams, projected to the reduced-order space. The data-driven model assists the imperfect model in regions where data is available, while for locations where data is sparse the imperfect model still provides a baseline for the prediction of the system state. We assess the developed framework on two challenging prototype systems exhibiting extreme events. We show that the blended approach has improved performance compared with methods that use either data streams or the imperfect model alone. Notably the improvement is more significant in regions associated with extreme events, where data is sparse. PMID:29795631

Data-assisted reduced-order modeling of extreme events in complex dynamical systems.

PubMed

Wan, Zhong Yi; Vlachas, Pantelis; Koumoutsakos, Petros; Sapsis, Themistoklis

2018-01-01

The prediction of extreme events, from avalanches and droughts to tsunamis and epidemics, depends on the formulation and analysis of relevant, complex dynamical systems. Such dynamical systems are characterized by high intrinsic dimensionality with extreme events having the form of rare transitions that are several standard deviations away from the mean. Such systems are not amenable to classical order-reduction methods through projection of the governing equations due to the large intrinsic dimensionality of the underlying attractor as well as the complexity of the transient events. Alternatively, data-driven techniques aim to quantify the dynamics of specific, critical modes by utilizing data-streams and by expanding the dimensionality of the reduced-order model using delayed coordinates. In turn, these methods have major limitations in regions of the phase space with sparse data, which is the case for extreme events. In this work, we develop a novel hybrid framework that complements an imperfect reduced order model, with data-streams that are integrated though a recurrent neural network (RNN) architecture. The reduced order model has the form of projected equations into a low-dimensional subspace that still contains important dynamical information about the system and it is expanded by a long short-term memory (LSTM) regularization. The LSTM-RNN is trained by analyzing the mismatch between the imperfect model and the data-streams, projected to the reduced-order space. The data-driven model assists the imperfect model in regions where data is available, while for locations where data is sparse the imperfect model still provides a baseline for the prediction of the system state. We assess the developed framework on two challenging prototype systems exhibiting extreme events. We show that the blended approach has improved performance compared with methods that use either data streams or the imperfect model alone. Notably the improvement is more significant in regions associated with extreme events, where data is sparse.

Comparative outcome of bomb explosion injuries versus high-powered gunshot injuries of the upper extremity in a civilian setting.

PubMed

Luria, Shai; Rivkin, Gurion; Avitzour, Malka; Liebergall, Meir; Mintz, Yoav; Mosheiff, Ram

2013-03-01

Explosion injuries to the upper extremity have specific clinical characteristics that differ from injuries due to other mechanisms. To evaluate the upper extremity injury pattern of attacks on civilian targets, comparing bomb explosion injuries to gunshot injuries and their functional recovery using standard outcome measures. Of 157 patients admitted to the hospital between 2000 and 2004, 72 (46%) sustained explosion injuries and 85 (54%) gunshot injuries. The trauma registry files were reviewed and the patients completed the DASH Questionnaire (Disabilities of Arm, Shoulder and Hand) and SF-12 (Short Form-12) after a minimum period of 1 year. Of the 157 patients, 72 (46%) had blast injuries and 85 (54%) had shooting injuries. The blast casualties had higher Injury Severity Scores (47% vs. 22% with a score of > 16, P = 0.02) and higher percent of patients treated in intensive care units (47% vs. 28%, P = 0.02). Although the Abbreviated Injury Scale score of the upper extremity injury was similar in the two groups, the blast casualties were found to have more bilateral and complex soft tissue injuries and were treated surgically more often. No difference was found in the SF-12 or DASH scores between the groups at follow up. The casualties with upper extremity blast injuries were more severely injured and sustained more bilateral and complex soft tissue injuries to the upper extremity. However, the rating of the local injury to the isolated limb is similar, as was the subjective functional recovery.

Reconstructive challenges in war wounds

PubMed Central

Bhandari, Prem Singh; Maurya, Sanjay; Mukherjee, Mrinal Kanti

2012-01-01

War wounds are devastating with extensive soft tissue and osseous destruction and heavy contamination. War casualties generally reach the reconstructive surgery centre after a delayed period due to additional injuries to the vital organs. This delay in their transfer to a tertiary care centre is responsible for progressive deterioration in wound conditions. In the prevailing circumstances, a majority of war wounds undergo delayed reconstruction, after a series of debridements. In the recent military conflicts, hydrosurgery jet debridement and negative pressure wound therapy have been successfully used in the preparation of war wounds. In war injuries, due to a heavy casualty load, a faster and reliable method of reconstruction is aimed at. Pedicle flaps in extremities provide rapid and reliable cover in extremity wounds. Large complex defects can be reconstructed using microvascular free flaps in a single stage. This article highlights the peculiarities and the challenges encountered in the reconstruction of these ghastly wounds. PMID:23162233

Non-Algorithmic Issues in Automated Computational Mechanics

DTIC Science & Technology

1991-04-30

Tworzydlo, Senior Research Engineer and Manager of Advanced Projects Group I. Professor I J. T. Oden, President and Senior Scientist of COMCO, was project...practical applications of the systems reported so far is due to the extremely arduous and complex development and management of a realistic knowledge base...software, designed to effectively implement deep, algorithmic knowledge, * and 0 "intelligent" software, designed to manage shallow, heuristic

External human factors in incident management team decisionmaking and their effect on large fire suppression expenditures

Treesearch

Janie Canton-Tompson; Krista M. Gebert; Brooke Thompson; Greg Jones; David Calkin; Geoff Donovan

2008-01-01

Large wildland fires are complex, costly events influenced by a vast array of physical, climatic, and social factors. Changing climate, fuel buildup due to past suppression, and increasing populations in the wildland-urban interface have all been blamed for the extreme fire seasons and rising suppression expenditures of recent years. With each high-cost year comes a...

Mapping upland hardwood site quality and productivity with GIS and FIA in the Blue Ridge of North Carolina

Treesearch

Claudia A. Cotton; Stephen R. Prisley; Thomas R. Fox

2009-01-01

The forested ecosystems of the southern Appalachians are some of the most diverse in North America due to the variability in climate, soils, and geologic parent material coupled with the complex topography found throughout the region. These same characteristics cause stands of upland hardwoods to be extremely variable with regard to site quality and productivity. Site...

CRUX: A compliant robotic upper-extremity exosuit for lightweight, portable, multi-joint muscular augmentation.

PubMed

Lessard, Steven; Pansodtee, Pattawong; Robbins, Ash; Baltaxe-Admony, Leya Breanna; Trombadore, James M; Teodorescu, Mircea; Agogino, Adrian; Kurniawan, Sri

2017-07-01

Wearable robots can potentially offer their users enhanced stability and strength. These augmentations are ideally designed to actuate harmoniously with the user's movements and provide extra force as needed. The creation of such robots, however, is particularly challenging due to the underlying complexity of the human body. In this paper, we present a compliant, robotic exosuit for upper extremities called CRUX. This exosuit, inspired by tensegrity models of the human arm, features a lightweight (1.3 kg), flexible multi-joint design for portable augmentation. We also illustrate how CRUX maintains the full range of motion of the upper-extremities for its users while providing multi-DoF strength amplification to the major muscles of the arm, as evident by tracking the heart rate of an individual exercising said arm. Exosuits such as CRUX may be useful in physical therapy and in extreme environments where users are expected to exert their bodies to the fullest extent.

Intrathecal Bupivacaine Monotherapy with a Retrograde Catheter for the Management of Complex Regional Pain Syndrome of the Lower Extremity.

PubMed

McRoberts, W Porter; Apostol, Catalina; Haleem, Abdul

2016-01-01

Complex regional pain syndrome (CRPS) presents a therapeutic challenge due to its many presentations and multifaceted pathophysiology. There is no approved treatment algorithm and clinical interventions are often applied empirically. In cases of CRPS where symptoms are localized to an extremity, a targeted treatment is indicated. We describe the use of intrathecal bupivacaine monotherapy, delivered through a retrograde catheter, in the treatment of CRPS affecting the lower extremity. The patient, a 57-year-old woman with a history of failed foot surgery, was seen in our office after 2 years of ineffective treatments with local blocks and neurolytic procedures. We advanced therapy to moderately invasive procedures with an emphasis on neuromodulation. A combined central and peripheral stimulation technique that initially provided 75% pain relief, failed to provide lasting analgesia. We proceeded with an intrathecal pump implant. Based on the results of dorsal root ganglion (DRG) mapping, L5-S1 was identified as the optimal target for therapy and a retrograde catheter was placed at this level. Various intrathecal medications were tested individually. An intrathecal morphine trial was ineffective (visual analog scale [VAS] 7), while intrathecal clonidine provided excellent pain relief (VAS 0) that was limited by severe side effects. Bupivacaine provided 100% analgesia with tolerable side effects (lower extremity weakness and minor bladder incontinence) and was selected for intrathecal infusion. After 14 months, bupivacaine treatment continued to control pain exacerbations. We conclude that CRPS patients benefit from early identification of the predominant underlying symptoms and a targeted treatment with moderately invasive techniques when less invasive techniques fail. Intrathecal bupivacaine, bupivacaine monotherapy, retrograde catheter, complex regional pain syndrome (CRPS), dual stimulation, dosal root ganglion (DRG) testing.

Floating Offshore WTG Integrated Load Analysis & Optimization Employing a Tuned Mass Damper

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rodriguez Tsouroukdissian, Arturo; Lackner, Matt; Cross-Whiter, John

2015-09-25

Floating offshore wind turbines (FOWTs) present complex design challenges due to the coupled dynamics of the platform motion, mooring system, and turbine control systems, in response to wind and wave loading. This can lead to higher extreme and fatigue loads than a comparable fixed bottom or onshore system. Previous research[1] has shown the potential to reduced extreme and fatigue loads on FOWT using tuned mass dampers (TMD) for structural control. This project aims to reduce maximum loads using passive TMDs located at the tower top during extreme storm events, when grid supplied power for other controls systems may not bemore » available. The Alstom Haliade 6MW wind turbine is modelled on the Glosten Pelastar tension-leg platform (TLP). The primary objectives of this project are to provide a preliminary assessment of the load reduction potential of passive TMDs on real wind turbine and TLP designs.« less

Vibrational dephasing and frequency shifts of hydrogen-bonded pyridine-water complexes

NASA Astrophysics Data System (ADS)

Kalampounias, A. G.; Tsilomelekis, G.; Boghosian, S.

2015-01-01

In this paper we present the picosecond vibrational dynamics and Raman shifts of hydrogen-bonded pyridine-water complexes present in aqueous solutions in a wide concentration range from dense to extreme dilute solutions. We studied the vibrational dephasing and vibrational frequency modulation by calculating time correlation functions of vibrational relaxation by fits in the frequency domain. The concentration induced variations in bandwidths, band frequencies and characteristic dephasing times have been estimated and interpreted as effects due to solute-solvent interactions. The time-correlation functions of vibrational dephasing were obtained for the ring breathing mode of both "free" and hydrogen-bonded pyridine molecules and it was found that sufficiently deviate from the Kubo model. There is a general agreement in the whole concentration range with the modeling proposed by the Rothschild approach, which applies to complex liquids. The results have shown that the reorientation of pyridine aqueous solutions is very slow and hence in both scattering geometries only vibrational dephasing is probed. It is proposed that the spectral changes depend on the perturbations induced by the dynamics of the water molecules in the first hydration cell and water in bulk, while at extreme dilution conditions, the number of bulk water molecules increases and the interchange between molecules belonging to the first hydration cell may not be the predominant modulation mechanism. The evolution of several parameters, such as the characteristic times, the percentage of Gaussian character in the peak shape and the a parameter are indicative of drastic variations at extreme dilution revealing changes in the vibrational relaxation of the pyridine complexes in the aqueous environment. The higher dilution is correlated to diffusion of water molecules into the reference pyridine system in agreement with the jump diffusion model, while at extreme dilutions, almost all pyridine molecules are elaborated in hydrogen bonding. The results are discussed in the framework of the current phenomenological status of the field.

Extreme Storm Surges in the North Sea

NASA Astrophysics Data System (ADS)

Goennert, G.; Buß, Th.; Mueller, O.; Thumm, S.

2009-04-01

Extreme Storm Surges in the North Sea Gabriele Gönnert, Olaf Müller, Thomas Buß and Sigrid Thumm Climate Change will cause a rise of the sea level and probably more frequent and more violent storm surges. This has serious consequences for the safety of people as well as for their values and assets behind the dikes. It is therefore inevitable to first assess how sea level rise and an extreme storm surge event designes. In a second step it is possible to determine the risk for specific locations and develop strategies. The Project XtremRisk - Extreme Storm Surges at the North Sea Coast and in Estuaries. Risk calculation and risk strategies, funded by the German Federal Government will help answering these questions. The „Source-Pathway-Receptor" Concept will be used as a basis for risk analysis and development of new strategies. The Project offers methods to assess the development of extreme events under the conditions of today. Under conditions reflecting the climate change it will be tried to design an extreme event. For these three main points will be considered: a) Analysis and calculation of each factor, which produce a storm surge and its maximum level occurring in the last 100 years. These are: - maximum surge level: surge (due to the wind), - influence of the tide and the interaction between surge and tide, - influence of external surges , b) The hydrodynamics of a storm surge cause nonlinear effects in the interaction of the named factors. These factors and effects will both be taken into account to calculate the magnitude of the extreme storm surge. This step is very complex and need additional examination by numerical models. c) Analysis of the different scenarios to mean sea level rise and to the increase of wind speed due to the climate change. The presentation will introduce methods and show first results of the analysis of extreme events and the mean sea level rise.

Ovarian hyperstimulation, hyperprolactinaemia and LH gonadotroph adenoma.

PubMed

Castelo-Branco, Camil; del Pino, Marta; Valladares, Esther

2009-08-01

This report considers a highly exceptional case of ovarian hyperstimulation syndrome due to a gonadotroph adenoma secreting LH in a 31-year-old patient who presented with amenorrhoea and galactorrhoea syndrome and a complex bilateral ovarian mass. Magnetic resonance imaging revealed a pituitary adenoma, and laboratory tests corroborated the hyperprolactinaemia without other hormonal pituitary abnormalities. Ovarian hyperstimulation syndrome due to a gonadotroph adenoma with normal gonadotrophins is extremely rare. Most of the described cases are caused by FSH adenomas. Due to the originality of the case, it was considered useful for understanding the management of this entity, and it is proposed that LH adenomas should also be considered in the differential diagnosis of patients with spontaneous ovarian hyperstimulation syndrome.

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.

Non-senescent Hydra tolerates severe disturbances in the nuclear lamina.

PubMed

Klimovich, Alexander; Rehm, Arvid; Wittlieb, Jörg; Herbst, Eva-Maria; Benavente, Ricardo; Bosch, Thomas C G

2018-05-10

The cnidarian Hydra is known for its unlimited lifespan and non-senescence, due to the indefinite self-renewal capacity of its stem cells. While proteins of the Lamin family are recognized as critical factors affecting senescence and longevity in human and mice, their putative role in the extreme longevity and non-senescence in long-living animals remains unknown. Here we analyze the role of a single lamin protein in non-senescence of Hydra . We demonstrate that proliferation of stem cells in Hydra is robust against the disturbance of Lamin expression and localization. While Lamin is indispensable for Hydra , the stem cells tolerate overexpression, downregulation and mislocalization of Lamin, and disturbances in the nuclear envelope structure. This extraordinary robustness may underlie the indefinite self-renewal capacity of stem cells and the non-senescence of Hydra . A relatively low complexity of the nuclear envelope architecture in basal Metazoa might allow for their extreme lifespans, while an increasing complexity of the nuclear architecture in bilaterians resulted in restricted lifespans.

Non-senescent Hydra tolerates severe disturbances in the nuclear lamina

PubMed Central

Rehm, Arvid; Wittlieb, Jörg; Herbst, Eva-Maria; Benavente, Ricardo

2018-01-01

The cnidarian Hydra is known for its unlimited lifespan and non-senescence, due to the indefinite self-renewal capacity of its stem cells. While proteins of the Lamin family are recognized as critical factors affecting senescence and longevity in human and mice, their putative role in the extreme longevity and non-senescence in long-living animals remains unknown. Here we analyze the role of a single lamin protein in non-senescence of Hydra. We demonstrate that proliferation of stem cells in Hydra is robust against the disturbance of Lamin expression and localization. While Lamin is indispensable for Hydra, the stem cells tolerate overexpression, downregulation and mislocalization of Lamin, and disturbances in the nuclear envelope structure. This extraordinary robustness may underlie the indefinite self-renewal capacity of stem cells and the non-senescence of Hydra. A relatively low complexity of the nuclear envelope architecture in basal Metazoa might allow for their extreme lifespans, while an increasing complexity of the nuclear architecture in bilaterians resulted in restricted lifespans. PMID:29754147

Endogenous versus Exogenous Origins of Crises

NASA Astrophysics Data System (ADS)

Sornette, Didier

Are large biological extinctions such as the Cretaceous/Tertiary KT boundary due to a meteorite, extreme volcanic activity or self-organized critical extinction cascades? Are commercial successes due to a progressive reputation cascade or the result of a well orchestrated advertisement? Determining the chain of causality for Xevents in complex systems requires disentangling interwoven exogenous and endogenous contributions with either no clear signature or too many signatures. Here, I review several efforts carried out with collaborators which suggest a general strategy for understanding the organizations of several complex systems under the dual effect of endogenous and exogenous fluctuations. The studied examples are: internet download shocks, book sale shocks, social shocks, financial volatility shocks, and financial crashes. Simple models are offered to quantitatively relate the endogenous organization to the exogenous response of the system. Suggestions for applications of these ideas to many other systems are offered.

Germination and seedling establishment in orchids: a complex of requirements

PubMed Central

Rasmussen, Hanne N.; Dixon, Kingsley W.; Jersáková, Jana; Těšitelová, Tamara

2015-01-01

Background Seedling recruitment is essential to the sustainability of any plant population. Due to the minute nature of seeds and early-stage seedlings, orchid germination in situ was for a long time practically impossible to observe, creating an obstacle towards understanding seedling site requirements and fluctuations in orchid populations. The introduction of seed packet techniques for sowing and retrieval in natural sites has brought with it important insights, but many aspects of orchid seed and germination biology remain largely unexplored. Key Considerations The germination niche for orchids is extremely complex, because it is defined by requirements not only for seed lodging and germination, but also for presence of a fungal host and its substrate. A mycobiont that the seedling can parasitize is considered an essential element, and a great diversity of Basidiomycota and Ascomycota have now been identified for their role in orchid seed germination, with fungi identifiable as imperfect Rhizoctonia species predominating. Specificity patterns vary from orchid species employing a single fungal lineage to species associating individually with a limited selection of distantly related fungi. A suitable organic carbon source for the mycobiont constitutes another key requirement. Orchid germination also relies on factors that generally influence the success of plant seeds, both abiotic, such as light/shade, moisture, substrate chemistry and texture, and biotic, such as competitors and antagonists. Complexity is furthermore increased when these factors influence seeds/seedling, fungi and fungal substrate differentially. Conclusions A better understanding of germination and seedling establishment is needed for conservation of orchid populations. Due to the obligate association with a mycobiont, the germination niches in orchid species are extremely complex and varied. Microsites suitable for germination can be small and transient, and direct observation is difficult. An experimental approach using several levels of environmental manipulation/control is recommended. PMID:26271118

Geomorphic Complexity of Sequential Fire and Floods in Mountain Watersheds

NASA Astrophysics Data System (ADS)

Brogan, D. J.; Nelson, P. A.; MacDonald, L. H.; Morgan, J. A.

2017-12-01

Fires and floods are important drivers of fluvial geomorphic changes. While each has been studied independently, there have been almost no situations where the hydrologic and geomorphic effects of fires and extreme floods could be compared at the watershed scale. Following the 2012 High Park fire in montane northcentral Colorado we began intensively monitoring channel changes in two 15 km2 watersheds (Skin Gulch and Hill Gulch) burned primarily at moderate to high severity. Summer thunderstorms resulted in extensive hillslope erosion and deposition in the valley bottoms, and subsequent incision through these deposits occurred due to spring snowmelt and elevated baseflows. The complex response associated with this state change from unburned to burned can be completely disrupted and overwhelmed by the larger changes resulting from extreme floods. Fifteen months after burning, both watersheds experienced an extreme flood resulting from a long-duration rainstorm; however, the geomorphic changes resulting from this flood differed markedly between the two watersheds. In Skin Gulch, sustained high flows from the September 2013 flood excavated nearly all of the accumulated sediment, expanded the active channel, and either scoured to bedrock or armored the bed with coarser substrate. Geomorphic changes in Hill Gulch due to the September 2013 flood, however, were small. The disparity between watersheds is likely the legacy of the catastrophic 1976 Big Thompson flood, which scoured out much of the previously accumulated sediment in Hill Gulch but did not appreciably impact Skin Gulch. These different sequences of disturbances indicate that fires in the Rocky Mountains often generate significant and dynamic geomorphic changes over sub-decadal timescales, while extreme floods can result in much longer lasting geomorphic changes. Our results allow us to compare the geomorphic sensitivity for different sequences of fire and floods, and propose a new conceptual model to explain the complicated interactions between the effects of fires and floods on the landscape.

Chronic Conjunctivitis due to Nocardia nova Complex Formation on a Silicone Stent: A Case Report and Review of the Literature.

PubMed

Micheletti, John M; Agrawal, Megha; Matoba, Alice Y; Marx, Douglas P

2015-01-01

Nocardial conjunctivitis associated with silicone tubing is an extremely rare finding. The authors present a case of a 52-year-old woman with previous dacryocystorhinostomy and silicone tube placement 3 years prior who presented with OD redness and discharge for 1 week. On examination, the patient was noted to have mucoid discharge and crusting surrounding the silicone tube. The tube debris was sampled, and the culture was positive for Nocardia nova complex sensitive to trimethoprim/sulfamethoxazole and amikacin. Silicone tube colonization and N. nova complex conjunctivitis are both rare but should be considered in the differential diagnosis of patients with indwelling silicone tubes presenting with chronic conjunctivitis resistant to fluoroquinolones and tobramycin.

Highly specialized microbial diversity in hyper-arid polar desert

PubMed Central

Pointing, Stephen B.; Chan, Yuki; Lacap, Donnabella C.; Lau, Maggie C. Y.; Jurgens, Joel A.; Farrell, Roberta L.

2009-01-01

The McMurdo Dry Valleys in Antarctica are a cold hyperarid polar desert that present extreme challenges to life. Here, we report a culture-independent survey of multidomain microbial biodiversity in McKelvey Valley, a pristine example of the coldest desert on Earth. We demonstrate that life has adapted to form highly-specialized communities in distinct lithic niches occurring concomitantly within this terrain. Endoliths and chasmoliths in sandstone displayed greatest diversity, whereas soil was relatively depauperate and lacked a significant photoautotrophic component, apart from isolated islands of hypolithic cyanobacterial colonization on quartz rocks in soil contact. Communities supported previously unreported polar bacteria and fungi, but archaea were absent from all niches. Lithic community structure did not vary significantly on a landscape scale and stochastic moisture input due to snowmelt resulted in increases in colonization frequency without significantly affecting diversity. The findings show that biodiversity near the cold-arid limit for life is more complex than previously appreciated, but communities lack variability probably due to the high selective pressures of this extreme environment. PMID:19850879

Molecular-dynamics simulation of Richtmyer-Meshkov instability on a Li-H2 interface at extreme compressing conditions

NASA Astrophysics Data System (ADS)

Huang, Shenghong; Wang, Weirong; Luo, Xisheng

2018-06-01

The new characteristics of Richtmyer-Meshkov instability (RMI) under extreme shock conditions are numerically studied by using molecular dynamics simulation incorporated with the electron force field model. The emphasis is placed on the ionization effects caused by different impacting speeds (6-30 km/s) on the microscale RMI on a Li-H2 interface. The linear region of the amplitude growth rate of the shocked interface under extreme shock conditions is observed to be much longer than that at the ordinary impact, which is in good accord with experimental results obtained with a Nova laser. It is also found that the amplitude of the nonlinear region is larger than the ordinary counterpart or the prediction by theory without considering the ionization effect. The two new characteristics are attributed to the ambipolar acceleration induced by the extra electric field due to the electron/ion separation under extreme shock conditions. These new findings may shed new light on the very complex physical process of the inertial confinement fusion on nanoscales.

Joint Interpretation of Insar and GPS Data Related To The Eruptive Event of July 2001 At Mt. Etna

NASA Astrophysics Data System (ADS)

Ferretti, A.; Colesanti, C.; Basilico, M.; Locatelli, R.; Novali, F.; Bonforte, A.; Coltelli, M.; Guglielmino, F.; Palano, M.; Puglisi, G.

The eruptive background of the July 2001 eruption at Mt. Etna, proved extremely complex and dynamic from the very beginning. The development of the ground defor- mation pattern due to the eruptive event was monitored through both GPS continuous measurements on network of permanent and static stations, and daily measurements both static and kinematic GPS, made by INGV-CT on geodetic network. These mea- surements show diffuse and intense ground deformations on large part of volcanic area. After the ERS-2 gyroscope problems in January 2001, the attitude accuracy of the platform was compromised due to the variability of the baseline and Doppler cen- troid values. Since January, a dedicated and passionate ESA team started a complex recovery procedure aimed at improving the satellite stability. The results obtained are extremely promising. In fact, POLIMI team, in cooperation with TRE (POLIMI com- mercial spin-off), was able to obtain, albeit with a very simple ad hoc processing, a clear surface deformation map related to the 11 July-15 August 2001 passages. Fur- ther work, after this preliminary interferogram, could be carried out to unwrap the very crowded fringe pattern on the top of the volcano. A preliminary analysis of the differential product shows an extremely interesting pattern that will appear associated to a decimetres ground deformation at the summit area of the volcano and at the Valle del Bove area. The GPS data and the preliminary results of SAR interferogram are in agreement with the deformation pattern expected in such kind of event, where the displacements are caused by deep magmatic sources and locally modulated by major structural features.

Long survival in patients with leigh syndrome and the m.10191T>C mutation in MT-ND3 : a case report and review of the literature.

PubMed

Levy, Rebecca J; Ríos, Purificación Gutierrez; Akman, Hasan O; Sciacco, Monica; Vivo, Darryl C De; DiMauro, Salvatore

2014-10-01

We report an unusual case of Leigh syndrome due to the m.10191T>C mutation in the complex I gene MT-ND3. This mutation has been associated with a spectrum of clinical phenotypes ranging from infant lethality to adult onset. Despite infantile onset and severe symptoms, our patient has survived to early adulthood because of a strict dietary regimen and parental care. This patient is an extreme example of the frequently prolonged course of Leigh syndrome due to this particular mutation. © The Author(s) 2013.

Dry seasons identified in oak tree-ring chronology in the Czech Lands over the last millennium

NASA Astrophysics Data System (ADS)

Dobrovolny, Petr; Brazdil, Rudolf; Büntgen, Ulf; Rybnicek, Michal; Kolar, Tomas; Reznickova, Ladislava; Valasek, Hubert; Kotyza, Oldrich

2015-04-01

There is growing evidence on amplification of hydrological regimes as a consequence of rising temperatures, increase in evaporation and changes in circulation patterns. These processes may be responsible for higher probability of hydroclimatic extremes occurrence in regional scale. Extreme events such as floods or droughts are rare from their definition and for better understanding of possible changes in the frequency and intensity of their occurrence, long-term proxy archives may be analysed. Recently several tree ring width chronologies were compiled from hardwood species occurring in lowland positions and their analysis proved that they are moisture-sensitive and suitable for hydroclimate reconstructions. Here, we introduce a new oak (Quercus sp) ring width (RW) dataset for the Czech Republic and the last 1250 years. We explain the process of oak chronology standardization that was based on several only slightly different de-trending techniques and subsequent chronology development steps. We hypothesize that the most severe RW increment reductions (negative extremes) reflect extremely dry spring-summer conditions. Negative extremes were assigned for years in which transformed oak RWs were lower than the minus 1.5 standard deviation. To verify our hypothesis, we compare typical climatic conditions in negative extreme years with climatology of the reference period 1961-1990. Comparison was done for various instrumental measurements (1805-2012), existing proxy reconstructions (1500-1804) and also for documentary evidence from historical archives (before 1500). We found that years of negative extremes are characterized with distinctly above average spring (MAM) and summer (JJA) air temperatures and below average precipitation amounts. Typical sea level pressure spatial distribution in those years shows positive pressure anomaly over British Isles and Northern Sea, the pattern that synoptically corresponds to blocking anticyclone bringing to Central Europe warm air from SW and low precipitation totals with higher probability of drought occurrence. Our results provide consistent physical explanation of extremely dry seasons occurring in Central Europe. However, direct comparisons of individual RW extreme seasons with existing documentary evidence show the complexity the problem as some extremes identified in oak RW chronology were not confirmed in documentary archives and vice versa. We discuss possible causes of such differences related to the fact that various proxies may have problems to record real intensity or duration of extreme events e.g. due to non-linear response of proxy data to climate drivers or due to shift in seasonality.

Environmental health aspects of drinking water-borne outbreak due to karst flooding: case study.

PubMed

Dura, Gyula; Pándics, Tamás; Kádár, Mihály; Krisztalovics, Katalin; Kiss, Zoltánné; Bodnár, Judit; Asztalos, Agnes; Papp, Erzsébet

2010-09-01

Climate change may increase the incidence of waterborne diseases due to extreme rainfall events, and consequent microbiological contamination of the water source and supply. As a result of the complexity of the pathways from the surface to the consumer, it is difficult to detect an association between rainfall and human disease. The water supply of a Hungarian city, Miskolc (174,000 inhabitant), is mainly based on karstic water, a vulnerable underground water body. A large amount of precipitation fell on the catchment area of the karstic water source, causing an unusually strong karstic water flow and flooding, and subsequent microbiological contamination. The presence of several potential sources of contamination in the protective zone of the karstic water source should be emphasized. The water supplier was unprepared to treat the risk of waterborne outbreak caused by an extreme weather event. Public health intervention and hygienic measures were taken in line with epidemiological actions, focusing on the protection of consumers by providing safe drinking water. The contamination was identified, and measures were taken for risk reduction and prevention. This case study underlines the increasing importance of preparedness for extreme water events in order to protect the karstic water sources and to avoid waterborne outbreaks.

Extreme fluctuations in stochastic network coordination with time delays

NASA Astrophysics Data System (ADS)

Hunt, D.; Molnár, F.; Szymanski, B. K.; Korniss, G.

2015-12-01

We study the effects of uniform time delays on the extreme fluctuations in stochastic synchronization and coordination problems with linear couplings in complex networks. We obtain the average size of the fluctuations at the nodes from the behavior of the underlying modes of the network. We then obtain the scaling behavior of the extreme fluctuations with system size, as well as the distribution of the extremes on complex networks, and compare them to those on regular one-dimensional lattices. For large complex networks, when the delay is not too close to the critical one, fluctuations at the nodes effectively decouple, and the limit distributions converge to the Fisher-Tippett-Gumbel density. In contrast, fluctuations in low-dimensional spatial graphs are strongly correlated, and the limit distribution of the extremes is the Airy density. Finally, we also explore the effects of nonlinear couplings on the stability and on the extremes of the synchronization landscapes.

Variations of trends of indicators describing complex systems: Change of scaling precursory to extreme events

NASA Astrophysics Data System (ADS)

Keilis-Borok, V. I.; Soloviev, A. A.

2010-09-01

Socioeconomic and natural complex systems persistently generate extreme events also known as disasters, crises, or critical transitions. Here we analyze patterns of background activity preceding extreme events in four complex systems: economic recessions, surges in homicides in a megacity, magnetic storms, and strong earthquakes. We use as a starting point the indicators describing the system's behavior and identify changes in an indicator's trend. Those changes constitute our background events (BEs). We demonstrate a premonitory pattern common to all four systems considered: relatively large magnitude BEs become more frequent before extreme event. A premonitory change of scaling has been found in various models and observations. Here we demonstrate this change in scaling of uniformly defined BEs in four real complex systems, their enormous differences notwithstanding.

Fluctuating residual limb volume accommodated with an adjustable, modular socket design: A novel case report.

PubMed

Mitton, Kay; Kulkarni, Jai; Dunn, Kenneth William; Ung, Anthony Hoang

2017-10-01

This novel case report describes the problems of prescribing a prosthetic socket in a left transfemoral amputee secondary to chronic patellofemoral instability compounded by complex regional pain syndrome. Case Description and Methods: Following the amputation, complex regional pain syndrome symptoms recurred in the residual limb, presenting mainly with oedema. Due to extreme daily volume fluctuations of the residual limb, a conventional, laminated thermoplastic socket fitting was not feasible. Findings and Outcomes: An adjustable, modular socket design was trialled. The residual limb volume fluctuations were accommodated within the socket. Amputee rehabilitation could be continued, and the rehabilitation goals were achieved. The patient was able to wear the prosthesis for 8 h daily and to walk unaided indoors and outdoors. An adjustable, modular socket design accommodated the daily residual limb volume fluctuations and provided a successful outcome in this case. It demonstrates the complexities of socket fitting and design with volume fluctuations. Clinical relevance Ongoing complex regional pain syndrome symptoms within the residual limb can lead to fitting difficulties in a conventional, laminated thermoplastic socket due to volume fluctuations. An adjustable, modular socket design can accommodate this and provide a successful outcome.

Extreme events and natural hazards: The complexity perspective

NASA Astrophysics Data System (ADS)

Schultz, Colin

2012-10-01

Advanced societies have become quite proficient at defending against moderate-size earthquakes, hurricanes, floods, or other natural assaults. What still pose a significant threat, however, are the unknowns, the extremes, the natural phenomena encompassed by the upper tail of the probability distribution. Alongside the large or powerful events, truly extreme natural disasters are those that tie different systems together: an earthquake that causes a tsunami, which leads to flooding, which takes down a nuclear reactor. In the geophysical monograph Extreme Events and Natural Hazards: The Complexity Perspective, editors A. Surjalal Sharma, Armin Bunde, Vijay P. Dimro, and Daniel N. Baker present a lens through which such multidisciplinary phenomena can be understood. In this interview, Eos talks to Sharma about complexity science, predicting extreme events and natural hazards, and the push for "big data."

On Predictive Understanding of Extreme Events: Pattern Recognition Approach; Prediction Algorithms; Applications to Disaster Preparedness

NASA Astrophysics Data System (ADS)

Keilis-Borok, V. I.; Soloviev, A.; Gabrielov, A.

2011-12-01

We describe a uniform approach to predicting different extreme events, also known as critical phenomena, disasters, or crises. The following types of such events are considered: strong earthquakes; economic recessions (their onset and termination); surges of unemployment; surges of crime; and electoral changes of the governing party. A uniform approach is possible due to the common feature of these events: each of them is generated by a certain hierarchical dissipative complex system. After a coarse-graining, such systems exhibit regular behavior patterns; we look among them for "premonitory patterns" that signal the approach of an extreme event. We introduce methodology, based on the optimal control theory, assisting disaster management in choosing optimal set of disaster preparedness measures undertaken in response to a prediction. Predictions with their currently realistic (limited) accuracy do allow preventing a considerable part of the damage by a hierarchy of preparedness measures. Accuracy of prediction should be known, but not necessarily high.

Anticipating Future Extreme Climate Events for Alaska Using Dynamical Downscaling and Quantile Mapping

NASA Astrophysics Data System (ADS)

Lader, R.; Walsh, J. E.

2016-12-01

Alaska is projected to experience major changes in extreme climate during the 21st century, due to greenhouse warming and exacerbated by polar amplification, wherein the Arctic is warming at twice the rate compared to the Northern Hemisphere. Given its complex topography, Alaska displays extreme gradients of temperature and precipitation. However, global climate models (GCMs), which typically have a spatial resolution on the order of 100km, struggle to replicate these extremes. To help resolve this issue, this study employs dynamically downscaled regional climate simulations and quantile-mapping methodologies to provide a full suite of daily model variables at 20 km spatial resolution for Alaska, from 1970 to 2100. These data include downscaled products of the: ERA-Interim reanalysis from 1979 to 2015, GFDL-CM3 historical from 1970 to 2005, and GFDL-CM3 RCP 8.5 from 2006 to 2100. Due to the limited nature of long-term observations and high-resolution modeling in Alaska, these data enable a broad expansion of extremes analysis. This study uses these data to highlight a subset of the 27 climate extremes indices, previously defined by the Expert Team on Climate Change Detection and Indices, as they pertain to climate change in Alaska. These indices are based on the statistical distributions of daily surface temperature and precipitation and focus on threshold exceedance, and percentiles. For example, the annual number of days with a daily maximum temperature greater than 25°C is anticipated to triple in many locations in Alaska by the end of the century. Climate extremes can also refer to long duration events, such as the record-setting warmth that defined the 2015-16 cold season in Alaska. The downscaled climate model simulations indicate that this past winter will be considered normal by as early as the mid-2040s, if we continue to warm according to the business-as-usual RCP 8.5 emissions scenario. This represents an accelerated warming as compared to projections form the coarse scale GCMs, and this greater rate of change in the downscaled products is noted with other extremes indices as well.

Carbonate-H2O2 Leaching for Sequestering Uranium from Seawater

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pan, Horng-Bin; Weisheng, Liao; Wai, Chien

Uranium adsorbed on amidoxime-based polyethylene fiber in simulated seawater can be quantitatively eluted at room temperature using 1M Na2CO3 containing 0.1 M H2O2. This efficient elution process is probably due to formation of an extremely stable uranyl-peroxo-carbonato complex in the carbonate solution. After washing with water, the sorbent can be reused with little loss of uranium loading capacity. Possible existence of this stable uranyl species in ocean water is also discussed.

Carbonate-H₂O₂ leaching for sequestering uranium from seawater.

PubMed

Pan, Horng-Bin; Liao, Weisheng; Wai, Chien M; Oyola, Yatsandra; Janke, Christopher J; Tian, Guoxin; Rao, Linfeng

2014-07-28

Uranium adsorbed on amidoxime-based polyethylene fiber in simulated seawater can be quantitatively eluted at room temperature using 1 M Na2CO3 containing 0.1 M H2O2. This efficient elution process is probably due to the formation of an extremely stable uranyl-peroxo-carbonato complex in the carbonate solution. After washing with water, the sorbent can be reused with minimal loss of uranium loading capacity. Possible existence of this stable uranyl species in ocean water is also discussed.

Liquid-Phase Laser Induced Forward Transfer for Complex Organic Inks and Tissue Engineering.

PubMed

Nguyen, Alexander K; Narayan, Roger J

2017-01-01

Laser induced forward transfer (LIFT) acts as a novel alternative to incumbent plotting techniques such as inkjet printing due to its ability to precisely deposit and position picoliter-sized droplets while being gentle enough to preserve sensitive structures within the ink. Materials as simple as screen printing ink to complex eukaryotic cells have been printed with applications spanning from microelectronics to tissue engineering. Biotechnology can benefit from this technique due to the efficient use of low volumes of reagent and the compatibility with a wide range of rheological properties. In addition, LIFT can be performed in a simple lab environment, not requiring vacuum or other extreme conditions. Although the basic apparatus is simple, many strategies exist to optimize the performance considering the ink and the desired pattern. The basic mechanism is similar between studies so the large number of variants can be summarized into a couple of categories and reported on with respect to their specific applications. In particular, precise and gentle deposition of complex molecules and eukaryotic cells represent the unique abilities of this technology. LIFT has demonstrated not only marked improvements in the quality of sensors and related medical devices over those manufactured with incumbent technologies but also great applicability in tissue engineering due to the high viability of printed cells.

Penetrating Injury to Cauda Equina from a Missile Fragment, Completely Recovered after Delayed Surgical Removal of Ballistic Fragment.

PubMed

Harsha, Kamble Jayaprakash; Thomas, Anu

2018-01-01

Penetrating injuries to cauda equina due to missile fragment are rare. The mechanism of injury may be more complex due to thermal effect of missile fragment, apart from mechanisms described in penetrating gunshot injuries or stab injuries. We report a case of a 42-year-old male with penetrating missile injury to cauda equina, improved completely after delayed surgical exploration and removal of ballistic fragment. Furthermore, his bowel and bladder dysfunction improved completely within 1 week of neurosurgical exploration. Although early neurosurgical intervention is recommended for penetrating injuries of the cauda equina, delayed intervention may also be beneficial in selected patients. Computed tomography (CT) scan and CT myelogram are extremely useful in surgical planning when magnetic resonance imaging contraindicated due to impregnated metal fragments.

Extremely pulsatile flow around a surface-mounted hemisphere: synergistic experiments and simulations

NASA Astrophysics Data System (ADS)

Carr, Ian A.; Beratlis, Nikolaos; Balaras, Elias; Plesniak, Michael W.

2017-11-01

Extremely pulsatile flow (where the amplitude of oscillation pulsation is of the same order as the mean flow) over a three-dimensional, surface-mounted bluff body gives rise a wealth of fluid dynamics phenomena. In this study, we extend our previous experimental work on extremely pulsatile flow around a surface-mounted hemisphere by performing a complementary direct numerical simulation. Results from the experiment and simulation will be presented and compared. After establishing the agreement between experiment and simulation, we will examine the morphology and dynamics of the vortex structures in the wake of the hemisphere, and the effects of extreme pulsatility. The dynamics of the arch-type recirculation vortex is of primary interest, in particular its upstream propagation due to self-induced velocity in the direction opposite to the freestream during deceleration. In addition to the velocity field, the surface pressure field throughout the pulsatile cycle will be presented. These synergistic experiments and simulations provide a detailed view into the complex flow fields associated with pulsatile flow over a surface-mounted hemisphere. This material is based upon work supported by the National Science Foundation under Grant Number CBET-1236351 and the GW Center for Biomimetics and Bioinspired Engineering.

Germination and seedling establishment in orchids: a complex of requirements.

PubMed

Rasmussen, Hanne N; Dixon, Kingsley W; Jersáková, Jana; Těšitelová, Tamara

2015-09-01

Seedling recruitment is essential to the sustainability of any plant population. Due to the minute nature of seeds and early-stage seedlings, orchid germination in situ was for a long time practically impossible to observe, creating an obstacle towards understanding seedling site requirements and fluctuations in orchid populations. The introduction of seed packet techniques for sowing and retrieval in natural sites has brought with it important insights, but many aspects of orchid seed and germination biology remain largely unexplored. The germination niche for orchids is extremely complex, because it is defined by requirements not only for seed lodging and germination, but also for presence of a fungal host and its substrate. A mycobiont that the seedling can parasitize is considered an essential element, and a great diversity of Basidiomycota and Ascomycota have now been identified for their role in orchid seed germination, with fungi identifiable as imperfect Rhizoctonia species predominating. Specificity patterns vary from orchid species employing a single fungal lineage to species associating individually with a limited selection of distantly related fungi. A suitable organic carbon source for the mycobiont constitutes another key requirement. Orchid germination also relies on factors that generally influence the success of plant seeds, both abiotic, such as light/shade, moisture, substrate chemistry and texture, and biotic, such as competitors and antagonists. Complexity is furthermore increased when these factors influence seeds/seedling, fungi and fungal substrate differentially. A better understanding of germination and seedling establishment is needed for conservation of orchid populations. Due to the obligate association with a mycobiont, the germination niches in orchid species are extremely complex and varied. Microsites suitable for germination can be small and transient, and direct observation is difficult. An experimental approach using several levels of environmental manipulation/control is recommended. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Diagnosis of mitochondrial disorders by concomitant next-generation sequencing of the exome and mitochondrial genome

PubMed Central

Dinwiddie, Darrell L.; Smith, Laurie D.; Miller, Neil A.; Atherton, Andrea M.; Farrow, Emily G.; Strenk, Meghan E.; Soden, Sarah E.; Saunders, Carol J.; Kingsmore, Stephen F.

2015-01-01

Mitochondrial diseases are notoriously difficult to diagnose due to extreme locus and allelic heterogeneity, with both nuclear and mitochondrial genomes potentially liable. Using exome sequencing we demonstrate the ability to rapidly and cost effectively evaluate both the nuclear and mitochondrial genomes to obtain a molecular diagnosis for four patients with three distinct mitochondrial disorders. One patient was found to have Leigh syndrome due to a mutation in MT-ATP6, two affected siblings were discovered to be compound heterozygous for mutations in the NDUFV1 gene, which causes mitochondrial complex I deficiency, and one patient was found to have coenzyme Q10 deficiency due to compound heterozygous mutations in COQ2. In all cases conventional diagnostic testing failed to identify a molecular diagnosis. We suggest that additional studies should be conducted to evaluate exome sequencing as a primary diagnostic test for mitochondrial diseases, including those due to mtDNA mutations. PMID:23631824

[Ecology of vector systems: a tangle of complexity].

PubMed

Rodhain, F

2008-06-01

The long co-evolutionary process between arthropods and microorganisms has resulted in a wide variety of relationships. One such relationship involves a wide range of infectious agents (virus, bacteria, protozoa, helminthes) that use blood-feeding arthropods (insects and mites) as vectors for transmission from one vertebrate to another. Transmission involves three components, i.e., microorganism, vector(s), and vertebrate host(s). Study under natural conditions has shown that the underlying mechanisms are extremely complex with circulation of the infectious agents depending on numerous conditions linked not only to bioecology but also to genetic factors in all three component populations. The role of arthropods sometimes goes beyond that of a transmitter of disease. In some cases they also serve as reservoirs or disseminators. In addition changes in the environment whether due to natural causes or human activities (e.g. pollution, agropastoralism, urbanization, transportation network development, and climate change) can have profound and rapid effects on the mechanisms underlying these vector systems. In short the ecology of vector systems closely reflects the extreme complexity of epidemiological studies on diseases caused by infectious agents depending on this type of transmission. As a result prediction of infectious risks and planning of preventive action are difficult. It appears obvious that a good understanding of vector systems in their natural context will require a truly ecological approach to the diseases that must be the focus of extremely close epidemiologic surveillance. Achieving this goal will necessitate more than the skills of physicians and veterinarians. It will require the contribution of specialists from a variety of fields such as microbiology, entomology, systematics, climatology, ecology, urbanism, social sciences, economic development, and many others.

Deformation of extremal black holes from stringy interactions

NASA Astrophysics Data System (ADS)

Chen, Baoyi; Stein, Leo C.

2018-04-01

Black holes are a powerful setting for studying general relativity and theories beyond GR. However, analytical solutions for rotating black holes in beyond-GR theories are difficult to find because of the complexity of such theories. In this paper, we solve for the deformation to the near-horizon extremal Kerr metric due to two example string-inspired beyond-GR theories: Einstein-dilaton-Gauss-Bonnet and dynamical Chern-Simons theory. We accomplish this by making use of the enhanced symmetry group of NHEK and the weak-coupling limit of EdGB and dCS. We find that the EdGB metric deformation has a curvature singularity, while the dCS metric is regular. From these solutions, we compute orbital frequencies, horizon areas, and entropies. This sets the stage for analytically understanding the microscopic origin of black hole entropy in beyond-GR theories.

Active disturbance rejection controller for chemical reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Both, Roxana; Dulf, Eva H.; Muresan, Cristina I., E-mail: roxana.both@aut.utcluj.ro

2015-03-10

In the petrochemical industry, the synthesis of 2 ethyl-hexanol-oxo-alcohols (plasticizers alcohol) is of high importance, being achieved through hydrogenation of 2 ethyl-hexenal inside catalytic trickle bed three-phase reactors. For this type of processes the use of advanced control strategies is suitable due to their nonlinear behavior and extreme sensitivity to load changes and other disturbances. Due to the complexity of the mathematical model an approach was to use a simple linear model of the process in combination with an advanced control algorithm which takes into account the model uncertainties, the disturbances and command signal limitations like robust control. However themore » resulting controller is complex, involving cost effective hardware. This paper proposes a simple integer-order control scheme using a linear model of the process, based on active disturbance rejection method. By treating the model dynamics as a common disturbance and actively rejecting it, active disturbance rejection control (ADRC) can achieve the desired response. Simulation results are provided to demonstrate the effectiveness of the proposed method.« less

Interdisciplinary challenges in the study of power grid resilience and stability and their relation to extreme weather events

NASA Astrophysics Data System (ADS)

Heitzig, J.; Fujiwara, N.; Aihara, K.; Kurths, J.

2014-10-01

This topical issue collects contributions to the interdisciplinary study of power grid stability in face of increasing volatility of energy production and consumption due to increasing renewable energy infeed and changing climatic conditions. The individual papers focus on different aspects of this field and bring together modern achievements from various disciplines, in particular complex systems science, nonlinear data analysis, control theory, electrical engineering, and climatology. Main topics considered here are prediction and volatility of renewable infeed, modelling and theoretical analysis of power grid topology, dynamics and stability, relationships between stability and complex network topology, and improvements via topological changes or control. Impacts for the design of smart power grids are discussed in detail.

Hawking radiation from a Reisner-Nordström domain wall

DOE Office of Scientific and Technical Information (OSTI.GOV)

Greenwood, Eric, E-mail: esg3@buffalo.edu

2010-01-01

We investigate the effect on the Hawking radiation given off during the time of collapse of a Reisner-Nordström domain wall. Using the functional Schrödinger formalism we are able to probe the time-dependent regime, which is out of the reach of the standard approximations like the Bogolyubov method. We calculate the occupation number of particles for a scalar field and complex scalar field. We demonstrate that the particles from the scalar field are unaffected by the charge of the Reisner-Nordström domain wall, as is expected since the scalar field doesn't carry any charge, which would couple to the charge of themore » Reisner-Nordström domain wall. Here the situation effectively reduces to the uncharged case, a spherically symmetric domain wall. To take the charge into account, we consider the complex scalar field which represents charged particles and anti-particles. Here investigate two different cases, first the non-extremal case and second the extremal case. In the non-extremal case we demonstrate that when the particle (anti-particle) carries charge opposite to that of the domain wall, the occupation number becomes suppressed during late times of the collapse. Therefore the dominate occupation number is when the particle (anti-particle) carries the same charge as the domain wall, as expected due to the Coulomb potential carried by the domain walls. In the extremal case we demonstrate that as time increases the temperature of the radiation decreases until when the domain wall reaches the horizon and the temperature then goes to zero. This is in agreement with the Hawking temperature for charged black holes.« less

An Assessment of Direct and Indirect Economic Losses of Climatic Extreme Events

NASA Astrophysics Data System (ADS)

Otto, C.; Willner, S. N.; Wenz, L.; Levermann, A.

2015-12-01

Risk of extreme weather events like storms, heat extremes, and floods has already risen due to anthropogenic climate change and is likely to increase further under future global warming. Additionally, the structure of the global economy has changed importantly in the last decades. In the process of globalization, local economies have become more and more interwoven forming a complex network. Together with a trend towards lean production, this has resulted in a strong dependency of local manufacturers on global supply and value added chains, which may render the economic network more vulnerable to climatic extremes; outages of local manufacturers trigger indirect losses, which spread along supply chains and can even outstrip direct losses. Accordingly, in a comprehensive climate risk assessment these inter-linkages should be considered. Here, we present acclimate, an agent based dynamic damage propagation model. Its agents are production and consumption sites, which are interlinked by economic flows accounting for the complexity as well as the heterogeneity of the global supply network. Assessing the economic response on the timescale of the adverse event, the model permits to study temporal and spatial evolution of indirect production losses during the disaster and in the subsequent recovery phase of the economy. In this study, we focus on the dynamic economic resilience defined here as the ratio of direct to total losses. This implies that the resilience of the system under consideration is low if the high indirect losses are high. We find and assess a nonlinear dependence of the resilience on the disaster size. Further, we analyze the influence of the network structure upon resilience and discuss the potential of warehousing as an adaptation option.

Tardigrades living in extreme environments have naturally selected prerequisites useful to space conquer

NASA Astrophysics Data System (ADS)

Guidetti, Roberto; Tiziana, Altiero; Cesari, Michele; Rizzo, Angela Maria; Bertolani, Roberto; Galletta, Giuseppe; Dalessandro, Maurizio; Rebecchi, Lorena

Extreme habitats are highly selective and can host only living organisms possessing specific adaptations to stressors. Among extreme habitats, space environment has particular charac-teristics of radiations, vacuum, microgravity and temperature, which induce rapid changes in living systems. Consequently, the response of multicellular complex organisms, able to colo-nize extreme environments, to space stresses can give very useful information on the ability to withstand a single stress or stress combinations. This knowledge on changes in living systems in space, with their similarity to the ageing processes, offers the opportunity to improve human life both on Earth and in space. Even though experimentation in space has often been carried out using unicellular organisms, multicellular organisms are very relevant in order to develop the appropriate countermeasures to avoid the risks imposed by environmental space in humans. The little attention received by multicellular organisms is probably due, other than to difficul-ties in the manipulation of biological materials in space, to the presence of only few organisms with the potential to tolerate environmental space stresses. Among them, tardigrades are small invertebrates representing an attractive animal model to study adaptive strategies for surviving extreme environments, including space environment. Tardigrades are little known microscopic aquatic animals (250-800 m in body length) distributed in different environments (from the deep sea to high mountains and deserts all over the world), and frequently inhabiting very unstable and unpredictable habitats (e.g. interstices of mosses, lichens, leaf litter, freshwater ponds, cryoconite holes). Their ability to live in the extreme environments is related to a wide variety of their life histories and adaptive strategies. A widespread and crucial strategy is cryptobiosis, a form of quiescence. It includes strategies such as anhydrobiosis and cryobiosis, characterized by a complete or almost complete metabolic standstill. The ability of tardigrades to colonize terrestrial habitats is linked to their well known ability to enter anhydrobiosis when their habi-tat desiccates. Tardigrades survive dehydration by entering a highly stable state of suspended animation due to complete desiccation (¿ 95Results on tardigrades open a window on the fu-ture perspective in astrobiology and in their applications. The discovery and identification of metabolites naturally synthesized by tardigrades to perform a remarkable protection against the damages to cellular components and DNA due to desiccation, radiation, microgravity and oxidation stresses, will be used to define the countermeasures to protect sensitive organisms, including humans, not naturally able to withstand extreme stresses under space conditions, for the future long-term explorations of our solar system, including Mars.

Penetrating Injury to Cauda Equina from a Missile Fragment, Completely Recovered after Delayed Surgical Removal of Ballistic Fragment

PubMed Central

Harsha, Kamble Jayaprakash; Thomas, Anu

2018-01-01

Penetrating injuries to cauda equina due to missile fragment are rare. The mechanism of injury may be more complex due to thermal effect of missile fragment, apart from mechanisms described in penetrating gunshot injuries or stab injuries. We report a case of a 42-year-old male with penetrating missile injury to cauda equina, improved completely after delayed surgical exploration and removal of ballistic fragment. Furthermore, his bowel and bladder dysfunction improved completely within 1 week of neurosurgical exploration. Although early neurosurgical intervention is recommended for penetrating injuries of the cauda equina, delayed intervention may also be beneficial in selected patients. Computed tomography (CT) scan and CT myelogram are extremely useful in surgical planning when magnetic resonance imaging contraindicated due to impregnated metal fragments. PMID:29682053

75 FR 8044 - Summer Undergraduate Research Program Extension of Due Date for Proposals

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-23

...: Due to extreme weather conditions in the Mid-Atlantic United States, NIST is extending the deadline.... Eastern Time, Tuesday, February 16, 2010. Due to extreme weather conditions and associated power outages...

Identifying and characterizing key nodes among communities based on electrical-circuit networks.

PubMed

Zhu, Fenghui; Wang, Wenxu; Di, Zengru; Fan, Ying

2014-01-01

Complex networks with community structures are ubiquitous in the real world. Despite many approaches developed for detecting communities, we continue to lack tools for identifying overlapping and bridging nodes that play crucial roles in the interactions and communications among communities in complex networks. Here we develop an algorithm based on the local flow conservation to effectively and efficiently identify and distinguish the two types of nodes. Our method is applicable in both undirected and directed networks without a priori knowledge of the community structure. Our method bypasses the extremely challenging problem of partitioning communities in the presence of overlapping nodes that may belong to multiple communities. Due to the fact that overlapping and bridging nodes are of paramount importance in maintaining the function of many social and biological networks, our tools open new avenues towards understanding and controlling real complex networks with communities accompanied with the key nodes.

Bayesian hierarchical modelling of North Atlantic windiness

NASA Astrophysics Data System (ADS)

Vanem, E.; Breivik, O. N.

2013-03-01

Extreme weather conditions represent serious natural hazards to ship operations and may be the direct cause or contributing factor to maritime accidents. Such severe environmental conditions can be taken into account in ship design and operational windows can be defined that limits hazardous operations to less extreme conditions. Nevertheless, possible changes in the statistics of extreme weather conditions, possibly due to anthropogenic climate change, represent an additional hazard to ship operations that is less straightforward to account for in a consistent way. Obviously, there are large uncertainties as to how future climate change will affect the extreme weather conditions at sea and there is a need for stochastic models that can describe the variability in both space and time at various scales of the environmental conditions. Previously, Bayesian hierarchical space-time models have been developed to describe the variability and complex dependence structures of significant wave height in space and time. These models were found to perform reasonably well and provided some interesting results, in particular, pertaining to long-term trends in the wave climate. In this paper, a similar framework is applied to oceanic windiness and the spatial and temporal variability of the 10-m wind speed over an area in the North Atlantic ocean is investigated. When the results from the model for North Atlantic windiness is compared to the results for significant wave height over the same area, it is interesting to observe that whereas an increasing trend in significant wave height was identified, no statistically significant long-term trend was estimated in windiness. This may indicate that the increase in significant wave height is not due to an increase in locally generated wind waves, but rather to increased swell. This observation is also consistent with studies that have suggested a poleward shift of the main storm tracks.

Phenology of mixed woody-herbaceous ecosystems following extreme events: net and differential responses.

PubMed

Rich, Paul M; Breshears, David D; White, Amanda B

2008-02-01

Ecosystem responses to key climate drivers are reflected in phenological dynamics such as the timing and degree of "green-up" that integrate responses over spatial scales from individual plants to ecosystems. This integration is clearest in ecosystems dominated by a single species or life form, such as seasonally dynamic grasslands or more temporally constant evergreen forests. Yet many ecosystems have substantial contribution of cover from both herbaceous and woody evergreen plants. Responses of mixed woody-herbaceous ecosystems to climate are of increasing concern due to their extensive nature, the potential for such systems to yield more complex responses than those dominated by a single life form, and projections that extreme climate and weather events will increase in frequency and intensity with global warming. We present responses of a mixed woody-herbaceous ecosystem type to an extreme event: regional-scale piñon pine mortality following an extended drought and the subsequent herbaceous green-up following the first wet period after the drought. This example highlights how reductions in greenness of the slower, more stable evergreen woody component can rapidly be offset by increases associated with resources made available to the relatively more responsive herbaceous component. We hypothesize that such two-phase phenological responses to extreme events are characteristic of many mixed woody-herbaceous ecosystems.

Gradient descent algorithm applied to wavefront retrieval from through-focus images by an extreme ultraviolet microscope with partially coherent source

DOE PAGES

Yamazoe, Kenji; Mochi, Iacopo; Goldberg, Kenneth A.

2014-12-01

The wavefront retrieval by gradient descent algorithm that is typically applied to coherent or incoherent imaging is extended to retrieve a wavefront from a series of through-focus images by partially coherent illumination. For accurate retrieval, we modeled partial coherence as well as object transmittance into the gradient descent algorithm. However, this modeling increases the computation time due to the complexity of partially coherent imaging simulation that is repeatedly used in the optimization loop. To accelerate the computation, we incorporate not only the Fourier transform but also an eigenfunction decomposition of the image. As a demonstration, the extended algorithm is appliedmore » to retrieve a field-dependent wavefront of a microscope operated at extreme ultraviolet wavelength (13.4 nm). The retrieved wavefront qualitatively matches the expected characteristics of the lens design.« less

Gradient descent algorithm applied to wavefront retrieval from through-focus images by an extreme ultraviolet microscope with partially coherent source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamazoe, Kenji; Mochi, Iacopo; Goldberg, Kenneth A.

The wavefront retrieval by gradient descent algorithm that is typically applied to coherent or incoherent imaging is extended to retrieve a wavefront from a series of through-focus images by partially coherent illumination. For accurate retrieval, we modeled partial coherence as well as object transmittance into the gradient descent algorithm. However, this modeling increases the computation time due to the complexity of partially coherent imaging simulation that is repeatedly used in the optimization loop. To accelerate the computation, we incorporate not only the Fourier transform but also an eigenfunction decomposition of the image. As a demonstration, the extended algorithm is appliedmore » to retrieve a field-dependent wavefront of a microscope operated at extreme ultraviolet wavelength (13.4 nm). The retrieved wavefront qualitatively matches the expected characteristics of the lens design.« less

[Shoulder injuries in golf].

PubMed

Liem, D; Gosheger, G; Schmidt, C

2014-03-01

Due to its growing popularity golf has now come into the focus of orthopedic sports medicine. With a wide range of age groups and playing levels, orthopedic surgeons will encounter a wide range of musculoskeletal problems which are usually the result of overuse rather than trauma. The shoulder joint plays an important role in the golf swing whereby not only the muscles around the glenohumeral joint but also the scapula stabilizing muscles are extremely important for an effective golf swing. Golf is strictly not considered to be an overhead sport; however, the extreme peak positions of the golf swing involve placing the shoulder joint in maximum abduction and adduction positions which can provoke impingement, lesions of the pulley system or even a special form of posterior shoulder instability. Even after complex shoulder operations, such as rotator cuff repair or shoulder arthroplasty, a return to the golf course at nearly the same level of play can be expected.

A complex multi-notch astronomical filter to suppress the bright infrared sky.

PubMed

Bland-Hawthorn, J; Ellis, S C; Leon-Saval, S G; Haynes, R; Roth, M M; Löhmannsröben, H-G; Horton, A J; Cuby, J-G; Birks, T A; Lawrence, J S; Gillingham, P; Ryder, S D; Trinh, C

2011-12-06

A long-standing and profound problem in astronomy is the difficulty in obtaining deep near-infrared observations due to the extreme brightness and variability of the night sky at these wavelengths. A solution to this problem is crucial if we are to obtain the deepest possible observations of the early Universe, as redshifted starlight from distant galaxies appears at these wavelengths. The atmospheric emission between 1,000 and 1,800 nm arises almost entirely from a forest of extremely bright, very narrow hydroxyl emission lines that varies on timescales of minutes. The astronomical community has long envisaged the prospect of selectively removing these lines, while retaining high throughput between them. Here we demonstrate such a filter for the first time, presenting results from the first on-sky tests. Its use on current 8 m telescopes and future 30 m telescopes will open up many new research avenues in the years to come.

The use of ERTS-1 satellite data in Great Lakes mesometeorological studies

NASA Technical Reports Server (NTRS)

Lyons, W. A. (Principal Investigator)

1972-01-01

The author has identified the following significant results. In the original proposal, it was hoped that ERTS could, with its extremely high resolution and multispectral capability, detect many meteorological phenomena occurring at the low end of the mesoscale motion spectrum (1 - 100 km). This included convective cloud phenomena, internal wave patterns, air pollution, snow squalls, etc. For meteorologists, ERTS-1 has more than lived up to initial hopes. First-look inspection of images has produced a large number of truly remarkable finds. Some of the most significant are: (1) Images of Lake Ontario during late summer have revealed several extremely good examples of lake breeze frontal cloud patterns. (2) Detection of suspended particulates from Chicago-Gary industrial complex in the 50,000 to 150,000 tons/year category. (3) Inadvertant weather modification due to anthropogenic condensation and ice nuclei from urban areas.

Integration of UAV photogrammetry and SPH modelling of fluids to study runoff on real terrains.

PubMed

Barreiro, Anxo; Domínguez, Jose M; C Crespo, Alejandro J; González-Jorge, Higinio; Roca, David; Gómez-Gesteira, Moncho

2014-01-01

Roads can experience runoff problems due to the intense rain discharge associated to severe storms. Two advanced tools are combined to analyse the interaction of complex water flows with real terrains. UAV (Unmanned Aerial Vehicle) photogrammetry is employed to obtain accurate topographic information on small areas, typically on the order of a few hectares. The Smoothed Particle Hydrodynamics (SPH) technique is applied by means of the DualSPHysics model to compute the trajectory of the water flow during extreme rain events. The use of engineering solutions to palliate flood events is also analysed. The study case simulates how the collected water can flow into a close road and how precautionary measures can be effective to drain water under extreme conditions. The amount of water arriving at the road is calculated under different protection scenarios and the efficiency of a ditch is observed to decrease when sedimentation reduces its depth.

Integration of UAV Photogrammetry and SPH Modelling of Fluids to Study Runoff on Real Terrains

PubMed Central

Barreiro, Anxo; Domínguez, Jose M.; C. Crespo, Alejandro J.; González-Jorge, Higinio; Roca, David; Gómez-Gesteira, Moncho

2014-01-01

Roads can experience runoff problems due to the intense rain discharge associated to severe storms. Two advanced tools are combined to analyse the interaction of complex water flows with real terrains. UAV (Unmanned Aerial Vehicle) photogrammetry is employed to obtain accurate topographic information on small areas, typically on the order of a few hectares. The Smoothed Particle Hydrodynamics (SPH) technique is applied by means of the DualSPHysics model to compute the trajectory of the water flow during extreme rain events. The use of engineering solutions to palliate flood events is also analysed. The study case simulates how the collected water can flow into a close road and how precautionary measures can be effective to drain water under extreme conditions. The amount of water arriving at the road is calculated under different protection scenarios and the efficiency of a ditch is observed to decrease when sedimentation reduces its depth. PMID:25372035

Mechanochemical Preparation of Stable Sub-100 nm γ-Cyclodextrin:Buckminsterfullerene (C60) Nanoparticles by Electrostatic or Steric Stabilization.

PubMed

Van Guyse, Joachim F R; de la Rosa, Victor R; Hoogenboom, Richard

2018-02-21

Buckminster fullerene (C 60 )'s main hurdle to enter the field of biomedicine is its low bioavailability, which results from its extremely low water solubility. A well-known approach to increase the water solubility of C 60 is by complexation with γ-cyclodextrins. However, the formed complexes are not stable in time as they rapidly aggregate and eventually precipitate due to attractive intermolecular forces, a common problem in inclusion complexes of cyclodextrins. In this study we attempt to overcome the attractive intermolecular forces between the complexes by designing custom γ-cyclodextrin (γCD)-based supramolecular hosts for C 60 that inhibit the aggregation found in native γCD-C 60 complexes. The approach entails the introduction of either repulsive electrostatic forces or increased steric hindrance to prevent aggregation, thus enhancing the biomedical application potential of C 60 . These modifications have led to new sub-100 nm nanostructures that show long-term stability in solution. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Low Complexity System Based on Multiple Weighted Decision Trees for Indoor Localization

PubMed Central

Sánchez-Rodríguez, David; Hernández-Morera, Pablo; Quinteiro, José Ma.; Alonso-González, Itziar

2015-01-01

Indoor position estimation has become an attractive research topic due to growing interest in location-aware services. Nevertheless, satisfying solutions have not been found with the considerations of both accuracy and system complexity. From the perspective of lightweight mobile devices, they are extremely important characteristics, because both the processor power and energy availability are limited. Hence, an indoor localization system with high computational complexity can cause complete battery drain within a few hours. In our research, we use a data mining technique named boosting to develop a localization system based on multiple weighted decision trees to predict the device location, since it has high accuracy and low computational complexity. The localization system is built using a dataset from sensor fusion, which combines the strength of radio signals from different wireless local area network access points and device orientation information from a digital compass built-in mobile device, so that extra sensors are unnecessary. Experimental results indicate that the proposed system leads to substantial improvements on computational complexity over the widely-used traditional fingerprinting methods, and it has a better accuracy than they have. PMID:26110413

OPTIMIZING THROUGH CO-EVOLUTIONARY AVALANCHES

DOE Office of Scientific and Technical Information (OSTI.GOV)

S. BOETTCHER; A. PERCUS

2000-08-01

We explore a new general-purpose heuristic for finding high-quality solutions to hard optimization problems. The method, called extremal optimization, is inspired by ''self-organized critically,'' a concept introduced to describe emergent complexity in many physical systems. In contrast to Genetic Algorithms which operate on an entire ''gene-pool'' of possible solutions, extremal optimization successively replaces extremely undesirable elements of a sub-optimal solution with new, random ones. Large fluctuations, called ''avalanches,'' ensue that efficiently explore many local optima. Drawing upon models used to simulate far-from-equilibrium dynamics, extremal optimization complements approximation methods inspired by equilibrium statistical physics, such as simulated annealing. With only onemore » adjustable parameter, its performance has proved competitive with more elaborate methods, especially near phase transitions. Those phase transitions are found in the parameter space of most optimization problems, and have recently been conjectured to be the origin of some of the hardest instances in computational complexity. We will demonstrate how extremal optimization can be implemented for a variety of combinatorial optimization problems. We believe that extremal optimization will be a useful tool in the investigation of phase transitions in combinatorial optimization problems, hence valuable in elucidating the origin of computational complexity.« less

Visual difficulty and employment status in the world.

PubMed

Harrabi, Hanen; Aubin, Marie-Josee; Zunzunegui, Maria Victoria; Haddad, Slim; Freeman, Ellen E

2014-01-01

Using a world-wide, population-based dataset, we sought to examine the relationship between visual difficulty and employment status. The World Health Survey was conducted in 70 countries throughout the world in 2003 using a random, multi-stage, stratified, cluster sampling design. Far vision was assessed by asking about the level of difficulty in seeing and recognizing a person you know across the road (i.e. from a distance of about 20 meters). Responses included none, mild, moderate, severe, or extreme/unable. Participants were asked about their current job, and if they were not working, the reason why (unable to find job, ill health, homemaker, studies, unpaid work, other). The occupation in the last 12 months was obtained. Multinomial regression was used accounting for the complex survey design. Of those who wanted to work, 79% of those with severe visual difficulty and 64% of those with extreme visual difficulty were actually working. People who had moderate, severe, or extreme visual difficulty had a higher odds of not working due to an inability to find a job and of not working due to ill health after adjusting for demographic and health factors (P<0.05). As the major causes of visual impairment in the world are uncorrected refractive error and cataract, countries are losing a great deal of labor productivity by failing to provide for the vision health needs of their citizens and failing to help them integrate into the workforce.

Optimizing Illumina next-generation sequencing library preparation for extremely AT-biased genomes.

PubMed

Oyola, Samuel O; Otto, Thomas D; Gu, Yong; Maslen, Gareth; Manske, Magnus; Campino, Susana; Turner, Daniel J; Macinnis, Bronwyn; Kwiatkowski, Dominic P; Swerdlow, Harold P; Quail, Michael A

2012-01-03

Massively parallel sequencing technology is revolutionizing approaches to genomic and genetic research. Since its advent, the scale and efficiency of Next-Generation Sequencing (NGS) has rapidly improved. In spite of this success, sequencing genomes or genomic regions with extremely biased base composition is still a great challenge to the currently available NGS platforms. The genomes of some important pathogenic organisms like Plasmodium falciparum (high AT content) and Mycobacterium tuberculosis (high GC content) display extremes of base composition. The standard library preparation procedures that employ PCR amplification have been shown to cause uneven read coverage particularly across AT and GC rich regions, leading to problems in genome assembly and variation analyses. Alternative library-preparation approaches that omit PCR amplification require large quantities of starting material and hence are not suitable for small amounts of DNA/RNA such as those from clinical isolates. We have developed and optimized library-preparation procedures suitable for low quantity starting material and tolerant to extremely high AT content sequences. We have used our optimized conditions in parallel with standard methods to prepare Illumina sequencing libraries from a non-clinical and a clinical isolate (containing ~53% host contamination). By analyzing and comparing the quality of sequence data generated, we show that our optimized conditions that involve a PCR additive (TMAC), produces amplified libraries with improved coverage of extremely AT-rich regions and reduced bias toward GC neutral templates. We have developed a robust and optimized Next-Generation Sequencing library amplification method suitable for extremely AT-rich genomes. The new amplification conditions significantly reduce bias and retain the complexity of either extremes of base composition. This development will greatly benefit sequencing clinical samples that often require amplification due to low mass of DNA starting material.

Materials Manufactured from 3D Printed Synthetic Biology Arrays

NASA Technical Reports Server (NTRS)

Gentry, Diana; Micks, Ashley

2013-01-01

Many complex, biologically-derived materials have extremely useful properties (think wood or silk), but are unsuitable for space-related applications due to production, manufacturing, or processing limitations. Large-scale ecosystem-based production, such as raising and harvesting trees for wood, is impractical in a self-contained habitat such as a space station or potential Mars colony. Manufacturing requirements, such as the specialized equipment needed to harvest and process cotton, add too much upmass for current launch technology. Cells in nature are already highly specialized for making complex biological materials on a micro scale. We envision combining these strengths with the recently emergent technologies of synthetic biology and 3D printing to create 3D-structured arrays of cells that are bioengineered to secrete different materials in a specified three-dimensional pattern.

Nanocrystalline coating design for extreme applications based on the concept of complex adaptive behavior

NASA Astrophysics Data System (ADS)

Fox-Rabinovich, G. S.; Veldhuis, S. C.; Dosbaeva, G. K.; Yamamoto, K.; Kovalev, A. I.; Wainstein, D. L.; Gershman, I. S.; Shuster, L. S.; Beake, B. D.

2008-04-01

The development of effective hard coatings for high performance dry machining, which is associated with high stress/temperatures during friction, is a major challenge. Newly developed synergistically alloyed nanocrystalline adaptive Ti0.2Al0.55Cr0.2Si0.03Y0.02N plasma vapor deposited hard coatings exhibit excellent tool life under conditions of high performance dry machining of hardened steel, especially under severe and extreme cutting conditions. The coating is capable of sustaining cutting speeds as high as 600 m/min. Comprehensive investigation of the microstructure and properties of the coating was performed. The structure of the coating before and after service has been characterized by high resolution transmission electron microscopy. Micromechanical characteristics of the coating have been investigated at elevated temperatures. Oxidation resistance of the coating has been studied by using thermogravimetry within a temperature range of 25-1100 °C in air. The coefficient of friction of the coatings was studied within a temperature range of 25-1200 °C. To determine the causes of excellent tool life and improved wear behavior of the TiAlCrSiYN coatings, its surface structure characteristics after service have been investigated by using x-ray photoelectron spectroscopy and extended energy-loss fine spectroscopy. One of the major features of this coating is the dynamic formation of the protective tribo-oxide films (dissipative structures) on the surface during friction with a sapphire and mullite crystal structure. Aluminum- and silicon-rich tribofilms with dangling bonds form on the surface as well. These tribofilms act in synergy and protect the surface so efficiently that it is able to sustain extreme operating conditions. Moreover, the Ti0.2Al0.55Cr0.2Si0.03Y0.02N coating possesses some features of a complex adaptive behavior because it has a number of improved characteristics (tribological adaptability, ultrafine nanocrystalline structure, hot hardness and plasticity, and oxidation stability) that work synergistically as a whole. Due to the complex adaptive behavior, this coating represents a higher ordered system that has an ability to achieve unattainable wear resistance under strongly intensifying and extreme tribological conditions.

Patterns of precipitation and soil moisture extremes in Texas, US: A complex network analysis

NASA Astrophysics Data System (ADS)

Sun, Alexander Y.; Xia, Youlong; Caldwell, Todd G.; Hao, Zengchao

2018-02-01

Understanding of the spatial and temporal dynamics of extreme precipitation not only improves prediction skills, but also helps to prioritize hazard mitigation efforts. This study seeks to enhance the understanding of spatiotemporal covariation patterns embedded in precipitation (P) and soil moisture (SM) by using an event-based, complex-network-theoretic approach. Events concurrences are quantified using a nonparametric event synchronization measure, and spatial patterns of hydroclimate variables are analyzed by using several network measures and a community detection algorithm. SM-P coupling is examined using a directional event coincidence analysis measure that takes the order of event occurrences into account. The complex network approach is demonstrated for Texas, US, a region possessing a rich set of hydroclimate features and is frequented by catastrophic flooding. Gridded daily observed P data and simulated SM data are used to create complex networks of P and SM extremes. The uncovered high degree centrality regions and community structures are qualitatively in agreement with the overall existing knowledge of hydroclimate extremes in the study region. Our analyses provide new visual insights on the propagation, connectivity, and synchronicity of P extremes, as well as the SM-P coupling, in this flood-prone region, and can be readily used as a basis for event-driven predictive analytics for other regions.

[A method for reproducing amnesia in mice by the complex extremal exposure].

PubMed

Iasnetsov, V V; Provornova, N A

2003-01-01

It is suggested to reproduce a retrograde amnesia in mice by means of a complex extremal action: emaciating swim in cold water with simultaneous wheel rotation. It was found that nootropes such as pyracetam, mexidol, semax, nooglutil, acephen, and noopept fully or completely prevent from the amnesia development.

Influence of Arbuscular Mycorrhizal Fungus (AMF) on degradation of iron-cyanide complexes

NASA Astrophysics Data System (ADS)

Sut, Magdalena; Boldt-Burisch, Katja; Raab, Thomas

2015-04-01

Soil contamination in the vicinities of former Manufactured Gas Plant (MGP) sites is a worldwide known environmental issue. The pollutants, in form of iron-cyanide complexes, originating from the gas purification process, create a risk for human health due to potential release of toxic free cyanide, CN(aq) and HCN(g), (aq).The management and remediation of cyanide contaminated soil can be very challenging due to the complex chemistry and toxicity of CN compounds. The employment of phytoremediation to remove or stabilize contaminants at a former MGP site is an inexpensive process, but can be limited through shallow rotting, decreased biomass, poor growing and the risk of secondary accumulation. However, this adaptation may be enhanced via arbuscular mycorrhizal fungi (AMF) activity, which may cooperate on the degradation, transformation or uptake of the contaminants. We would like to present our preliminary results from the ongoing project concerning toxic substrate-AMF-plant relation, based on studying the site of a former MGP site. In situ experiments contributed to identifying those fungi that are likely to persist in extremely acidic and toxic conditions. Subsequently, commercially available Rhizophagus irregularis was grown in sterilized, un-spiked soil with the roots of the host plant Calamagrostis epigejos. Extracted roots and AMF hyphae were used in the batch experiment, were the potential of this association on degradation of iron-cyanide complexes, in form of potassium ferrocyanide solution, was assessed.

Review of complex networks application in hydroclimatic extremes with an implementation to characterize spatio-temporal drought propagation in continental USA

NASA Astrophysics Data System (ADS)

Konapala, Goutam; Mishra, Ashok

2017-12-01

The quantification of spatio-temporal hydroclimatic extreme events is a key variable in water resources planning, disaster mitigation, and preparing climate resilient society. However, quantification of these extreme events has always been a great challenge, which is further compounded by climate variability and change. Recently complex network theory was applied in earth science community to investigate spatial connections among hydrologic fluxes (e.g., rainfall and streamflow) in water cycle. However, there are limited applications of complex network theory for investigating hydroclimatic extreme events. This article attempts to provide an overview of complex networks and extreme events, event synchronization method, construction of networks, their statistical significance and the associated network evaluation metrics. For illustration purpose, we apply the complex network approach to study the spatio-temporal evolution of droughts in Continental USA (CONUS). A different drought threshold leads to a new drought event as well as different socio-economic implications. Therefore, it would be interesting to explore the role of thresholds on spatio-temporal evolution of drought through network analysis. In this study, long term (1900-2016) Palmer drought severity index (PDSI) was selected for spatio-temporal drought analysis using three network-based metrics (i.e., strength, direction and distance). The results indicate that the drought events propagate differently at different thresholds associated with initiation of drought events. The direction metrics indicated that onset of mild drought events usually propagate in a more spatially clustered and uniform approach compared to onsets of moderate droughts. The distance metric shows that the drought events propagate for longer distance in western part compared to eastern part of CONUS. We believe that the network-aided metrics utilized in this study can be an important tool in advancing our knowledge on drought propagation as well as other hydroclimatic extreme events. Although the propagation of droughts is investigated using the network approach, however process (physics) based approaches is essential to further understand the dynamics of hydroclimatic extreme events.

The fluid dynamics of microjet explosions caused by extremely intense X-ray pulses

NASA Astrophysics Data System (ADS)

Stan, Claudiu; Laksmono, Hartawan; Sierra, Raymond; Milathianaki, Despina; Koglin, Jason; Messerschmidt, Marc; Williams, Garth; Demirci, Hasan; Botha, Sabine; Nass, Karol; Stone, Howard; Schlichting, Ilme; Shoeman, Robert; Boutet, Sebastien

2014-11-01

Femtosecond X-ray scattering experiments at free-electron laser facilities typically requires liquid jet delivery methods to bring samples to the region of interaction with X-rays. We have imaged optically the damage process in water microjets due to intense hard X-ray pulses at the Linac Coherent Light Source (LCLS), using time-resolved imaging techniques to record movies at rates up to half a billion frames per second. For pulse energies larger than a few percent of the maximum pulse energy available at LCLS, the X-rays deposit energies much larger than the latent heat of vaporization in water, and induce a phase explosion that opens a gap in the jet. The LCLS pulses last a few tens of femtoseconds, but the full evolution of the broken jet is orders of magnitude slower - typically in the microsecond range - due to complex fluid dynamics processes triggered by the phase explosion. Although the explosion results in a complex sequence of phenomena, they lead to an approximately self-similar flow of the liquid in the jet.

Diversity and function of prevalent symbiotic marine bacteria in the genus Endozoicomonas.

PubMed

Neave, Matthew J; Apprill, Amy; Ferrier-Pagès, Christine; Voolstra, Christian R

2016-10-01

Endozoicomonas bacteria are emerging as extremely diverse and flexible symbionts of numerous marine hosts inhabiting oceans worldwide. Their hosts range from simple invertebrate species, such as sponges and corals, to complex vertebrates, such as fish. Although widely distributed, the functional role of Endozoicomonas within their host microenvironment is not well understood. In this review, we provide a summary of the currently recognized hosts of Endozoicomonas and their global distribution. Next, the potential functional roles of Endozoicomonas, particularly in light of recent microscopic, genomic, and genetic analyses, are discussed. These analyses suggest that Endozoicomonas typically reside in aggregates within host tissues, have a free-living stage due to their large genome sizes, show signs of host and local adaptation, participate in host-associated protein and carbohydrate transport and cycling, and harbour a high degree of genomic plasticity due to the large proportion of transposable elements residing in their genomes. This review will finish with a discussion on the methodological tools currently employed to study Endozoicomonas and host interactions and review future avenues for studying complex host-microbial symbioses.

Surgical Management of Complex Lower-Extremity Trauma With a Long Hindfoot Fusion Nail: A Case Report.

PubMed

Jain, Nickul S; Lopez, Gregory D; Bederman, S Samuel; Wirth, Garrett A; Scolaro, John A

2016-08-01

High-energy injuries can result in complete or partial loss of the talus. Ipsilateral fractures to the lower limb increase the complexity of surgical management, and treatment is guided by previous case reports of similar injuries. A case of complex lower-extremity trauma with extruded and missing talar body and ipsilateral type IIIB open tibia fracture is presented. Surgical limb reconstruction and salvage was performed successfully with a single orthopaedic implant in a manner not described previously in the literature. The purpose of this case report is to present the novel use of a single orthopaedic implant for treatment of a complex, open traumatic injury. Previous case reports in the literature have described the management of complete or partial talar loss. We describe the novel use of a long hindfoot fusion nail and staged bone grafting to achieve tibiocalcaneal arthrodesis for the treatment of complex lower-extremity trauma. Therapeutic, Level IV: Case study. © 2015 The Author(s).

A Review of Computational Intelligence Methods for Eukaryotic Promoter Prediction.

PubMed

Singh, Shailendra; Kaur, Sukhbir; Goel, Neelam

2015-01-01

In past decades, prediction of genes in DNA sequences has attracted the attention of many researchers but due to its complex structure it is extremely intricate to correctly locate its position. A large number of regulatory regions are present in DNA that helps in transcription of a gene. Promoter is one such region and to find its location is a challenging problem. Various computational methods for promoter prediction have been developed over the past few years. This paper reviews these promoter prediction methods. Several difficulties and pitfalls encountered by these methods are also detailed, along with future research directions.

A Cellular Automata Model of Infection Control on Medical Implants

PubMed Central

Prieto-Langarica, Alicia; Kojouharov, Hristo; Chen-Charpentier, Benito; Tang, Liping

2011-01-01

S. epidermidis infections on medically implanted devices are a common problem in modern medicine due to the abundance of the bacteria. Once inside the body, S. epidermidis gather in communities called biofilms and can become extremely hard to eradicate, causing the patient serious complications. We simulate the complex S. epidermidis-Neutrophils interactions in order to determine the optimum conditions for the immune system to be able to contain the infection and avoid implant rejection. Our cellular automata model can also be used as a tool for determining the optimal amount of antibiotics for combating biofilm formation on medical implants. PMID:23543851

Robust intelligent flight control for hypersonic vehicles. Ph.D. Thesis - Massachusetts Inst. of Technology

NASA Technical Reports Server (NTRS)

Chamitoff, Gregory Errol

1992-01-01

Intelligent optimization methods are applied to the problem of real-time flight control for a class of airbreathing hypersonic vehicles (AHSV). The extreme flight conditions that will be encountered by single-stage-to-orbit vehicles, such as the National Aerospace Plane, present a tremendous challenge to the entire spectrum of aerospace technologies. Flight control for these vehicles is particularly difficult due to the combination of nonlinear dynamics, complex constraints, and parametric uncertainty. An approach that utilizes all available a priori and in-flight information to perform robust, real time, short-term trajectory planning is presented.

A fast isogeometric BEM for the three dimensional Laplace- and Helmholtz problems

NASA Astrophysics Data System (ADS)

Dölz, Jürgen; Harbrecht, Helmut; Kurz, Stefan; Schöps, Sebastian; Wolf, Felix

2018-03-01

We present an indirect higher order boundary element method utilising NURBS mappings for exact geometry representation and an interpolation-based fast multipole method for compression and reduction of computational complexity, to counteract the problems arising due to the dense matrices produced by boundary element methods. By solving Laplace and Helmholtz problems via a single layer approach we show, through a series of numerical examples suitable for easy comparison with other numerical schemes, that one can indeed achieve extremely high rates of convergence of the pointwise potential through the utilisation of higher order B-spline-based ansatz functions.

"Complex" Posttraumatic Stress Disorder/Disorders of Extreme Stress (CP/DES) in Sexually Abused Children: An Exloratory Study.

ERIC Educational Resources Information Center

Hall, Darlene Kordich

1999-01-01

Compares three groups of young sexually abused children on seven "Complex" Posttraumatic Stress Disorder/Disorders of Extreme Stress (CP/DES) indices. As cumulative number of types of trauma increased, the number of CP/DES symptoms rose. Results suggest that CP/DES also characterizes sexually abused children, especially those who have…

Predictability of Extreme Climate Events via a Complex Network Approach

NASA Astrophysics Data System (ADS)

Muhkin, D.; Kurths, J.

2017-12-01

We analyse climate dynamics from a complex network approach. This leads to an inverse problem: Is there a backbone-like structure underlying the climate system? For this we propose a method to reconstruct and analyze a complex network from data generated by a spatio-temporal dynamical system. This approach enables us to uncover relations to global circulation patterns in oceans and atmosphere. This concept is then applied to Monsoon data; in particular, we develop a general framework to predict extreme events by combining a non-linear synchronization technique with complex networks. Applying this method, we uncover a new mechanism of extreme floods in the eastern Central Andes which could be used for operational forecasts. Moreover, we analyze the Indian Summer Monsoon (ISM) and identify two regions of high importance. By estimating an underlying critical point, this leads to an improved prediction of the onset of the ISM; this scheme was successful in 2016 and 2017.

Rare events modeling with support vector machine: Application to forecasting large-amplitude geomagnetic substorms and extreme events in financial markets.

NASA Astrophysics Data System (ADS)

Gavrishchaka, V. V.; Ganguli, S. B.

2001-12-01

Reliable forecasting of rare events in a complex dynamical system is a challenging problem that is important for many practical applications. Due to the nature of rare events, data set available for construction of the statistical and/or machine learning model is often very limited and incomplete. Therefore many widely used approaches including such robust algorithms as neural networks can easily become inadequate for rare events prediction. Moreover in many practical cases models with high-dimensional inputs are required. This limits applications of the existing rare event modeling techniques (e.g., extreme value theory) that focus on univariate cases. These approaches are not easily extended to multivariate cases. Support vector machine (SVM) is a machine learning system that can provide an optimal generalization using very limited and incomplete training data sets and can efficiently handle high-dimensional data. These features may allow to use SVM to model rare events in some applications. We have applied SVM-based system to the problem of large-amplitude substorm prediction and extreme event forecasting in stock and currency exchange markets. Encouraging preliminary results will be presented and other possible applications of the system will be discussed.

Necrotizing Fasciitis of the Lower Extremity Caused by Serratia marcescens A Case Report.

PubMed

Heigh, Evelyn G; Maletta-Bailey, April; Haight, John; Landis, Gregg S

2016-03-01

Necrotizing fasciitis is a rare and potentially fatal infection, with mortality of up to 30%. This case report describes a patient recovering from a laryngectomy for laryngeal squamous cell cancer who developed nosocomial necrotizing fasciitis of the lower extremity due to Serratia marcescens . Only eight cases of necrotizing fasciitis exclusive to the lower extremity due to S marcescens have been previously reported. Patients with S marcescens necrotizing fasciitis of the lower extremity often have multiple comorbidities, are frequently immunosuppressed, and have a strikingly high mortality rate.

Magnetic storms and solar flares: can be analysed within similar mathematical framework with other extreme events?

NASA Astrophysics Data System (ADS)

Balasis, Georgios; Potirakis, Stelios M.; Papadimitriou, Constantinos; Zitis, Pavlos I.; Eftaxias, Konstantinos

2015-04-01

The field of study of complex systems considers that the dynamics of complex systems are founded on universal principles that may be used to describe a great variety of scientific and technological approaches of different types of natural, artificial, and social systems. We apply concepts of the nonextensive statistical physics, on time-series data of observable manifestations of the underlying complex processes ending up to different extreme events, in order to support the suggestion that a dynamical analogy characterizes the generation of a single magnetic storm, solar flare, earthquake (in terms of pre-seismic electromagnetic signals) , epileptic seizure, and economic crisis. The analysis reveals that all the above mentioned different extreme events can be analyzed within similar mathematical framework. More precisely, we show that the populations of magnitudes of fluctuations included in all the above mentioned pulse-like-type time series follow the traditional Gutenberg-Richter law as well as a nonextensive model for earthquake dynamics, with similar nonextensive q-parameter values. Moreover, based on a multidisciplinary statistical analysis we show that the extreme events are characterized by crucial common symptoms, namely: (i) high organization, high compressibility, low complexity, high information content; (ii) strong persistency; and (iii) existence of clear preferred direction of emerged activities. These symptoms clearly discriminate the appearance of the extreme events under study from the corresponding background noise.

Overwintering of herbaceous plants in a changing climate. Still more questions than answers.

PubMed

Rapacz, Marcin; Ergon, Ashild; Höglind, Mats; Jørgensen, Marit; Jurczyk, Barbara; Ostrem, Liv; Rognli, Odd Arne; Tronsmo, Anne Marte

2014-08-01

The increase in surface temperature of the Earth indicates a lower risk of exposure for temperate grassland and crop to extremely low temperatures. However, the risk of low winter survival rate, especially in higher latitudes may not be smaller, due to complex interactions among different environmental factors. For example, the frequency, degree and length of extreme winter warming events, leading to snowmelt during winter increased, affecting the risks of anoxia, ice encasement and freezing of plants not covered with snow. Future climate projections suggest that cold acclimation will occur later in autumn, under shorter photoperiod and lower light intensity, which may affect the energy partitioning between the elongation growth, accumulation of organic reserves and cold acclimation. Rising CO2 levels may also disturb the cold acclimation process. Predicting problems with winter pathogens is also very complex, because climate change may greatly influence the pathogen population and because the plant resistance to these pathogens is increased by cold acclimation. All these factors, often with contradictory effects on winter survival, make plant overwintering viability under future climates an open question. Close cooperation between climatologists, ecologists, plant physiologists, geneticists and plant breeders is strongly required to predict and prevent possible problems. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

The nature of selection on the major histocompatibility complex.

PubMed

Apanius, V; Penn, D; Slev, P R; Ruff, L R; Potts, W K

1997-01-01

Only natural selection can account for the extreme genetic diversity of genes of the major histocompatibility complex (MHC). Although the structure and function of classic MHC genes is well understood at the molecular and cellular levels, there is controversy about how MHC diversity is selectively maintained. The diversifying selection can be driven by pathogen interactions and inbreeding avoidance mechanisms. Pathogen-driven selection can maintain MHC polymorphism based on heterozygote advantage or frequency-dependent selection due to pathogen evasion of MHC-dependent immune recognition. Empirical evidence demonstrates that specific MHC haplotypes are resistant to certain infectious agents, while susceptible to others. These data are consistent with both heterozygote advantage and frequency-dependent models. Additional research is needed to discriminate between these mechanisms. Infectious agents can precipitate autoimmunity and can potentially contribute to MHC diversity through molecular mimicry and by favoring immunodominance. MHC-dependent abortion and mate choice, based on olfaction, can also maintain MHC diversity and probably functions both to avoid genome-wide inbreeding and produce MHC-heterozygous offspring with increased immune responsiveness. Although this diverse set of hypotheses are often treated as competing alternatives, we believe that they all fit into a coherent, internally consistent thesis. It is likely that at least in some species, all of these mechanisms operate, leading to the extreme diversification found in MHC genes.

Weather model performance on extreme rainfall events simulation's over Western Iberian Peninsula

NASA Astrophysics Data System (ADS)

Pereira, S. C.; Carvalho, A. C.; Ferreira, J.; Nunes, J. P.; Kaiser, J. J.; Rocha, A.

2012-08-01

This study evaluates the performance of the WRF-ARW numerical weather model in simulating the spatial and temporal patterns of an extreme rainfall period over a complex orographic region in north-central Portugal. The analysis was performed for the December month of 2009, during the Portugal Mainland rainy season. The heavy rainfall to extreme heavy rainfall periods were due to several low surface pressure's systems associated with frontal surfaces. The total amount of precipitation for December exceeded, in average, the climatological mean for the 1971-2000 time period in +89 mm, varying from 190 mm (south part of the country) to 1175 mm (north part of the country). Three model runs were conducted to assess possible improvements in model performance: (1) the WRF-ARW is forced with the initial fields from a global domain model (RunRef); (2) data assimilation for a specific location (RunObsN) is included; (3) nudging is used to adjust the analysis field (RunGridN). Model performance was evaluated against an observed hourly precipitation dataset of 15 rainfall stations using several statistical parameters. The WRF-ARW model reproduced well the temporal rainfall patterns but tended to overestimate precipitation amounts. The RunGridN simulation provided the best results but model performance of the other two runs was good too, so that the selected extreme rainfall episode was successfully reproduced.

Natural Hazards characterisation in industrial practice

NASA Astrophysics Data System (ADS)

Bernardara, Pietro

2017-04-01

The definition of rare hydroclimatic extremes (up to 10-4 annual probability of occurrence) is of the utmost importance for the design of high value industrial infrastructures, such as grids, power plants, offshore platforms. The underestimation as well as the overestimation of the risk may lead to huge costs (ex. mid-life expensive works or overdesign) which may even prevent the project to happen. Nevertheless, the uncertainty associated to the extrapolation towards the rare frequencies are huge and manifold. They are mainly due to the scarcity of observations, the lack of quality on the extreme value records and on the arbitrary choice of the models used for extrapolations. This often put the design engineers in uncomfortable situations when they must choose the design values to use. Providentially, the recent progresses in the earth observation techniques, information technology, historical data collection and weather and ocean modelling are making huge datasets available. A careful use of big datasets of observations and modelled data are leading towards a better understanding of the physics of the underlying phenomena, the complex interactions between them and thus of the extreme events frequency extrapolations. This will move the engineering practice from the single site, small sample, application of statistical analysis to a more spatially coherent, physically driven extrapolation of extreme values. Few examples, from the EDF industrial practice are given to illustrate these progresses and their potential impact on the design approaches.

Ship Detection from Ocean SAR Image Based on Local Contrast Variance Weighted Information Entropy

PubMed Central

Huang, Yulin; Pei, Jifang; Zhang, Qian; Gu, Qin; Yang, Jianyu

2018-01-01

Ship detection from synthetic aperture radar (SAR) images is one of the crucial issues in maritime surveillance. However, due to the varying ocean waves and the strong echo of the sea surface, it is very difficult to detect ships from heterogeneous and strong clutter backgrounds. In this paper, an innovative ship detection method is proposed to effectively distinguish the vessels from complex backgrounds from a SAR image. First, the input SAR image is pre-screened by the maximally-stable extremal region (MSER) method, which can obtain the ship candidate regions with low computational complexity. Then, the proposed local contrast variance weighted information entropy (LCVWIE) is adopted to evaluate the complexity of those candidate regions and the dissimilarity between the candidate regions with their neighborhoods. Finally, the LCVWIE values of the candidate regions are compared with an adaptive threshold to obtain the final detection result. Experimental results based on measured ocean SAR images have shown that the proposed method can obtain stable detection performance both in strong clutter and heterogeneous backgrounds. Meanwhile, it has a low computational complexity compared with some existing detection methods. PMID:29652863

Dynamic pathway modeling of signal transduction networks: a domain-oriented approach.

PubMed

Conzelmann, Holger; Gilles, Ernst-Dieter

2008-01-01

Mathematical models of biological processes become more and more important in biology. The aim is a holistic understanding of how processes such as cellular communication, cell division, regulation, homeostasis, or adaptation work, how they are regulated, and how they react to perturbations. The great complexity of most of these processes necessitates the generation of mathematical models in order to address these questions. In this chapter we provide an introduction to basic principles of dynamic modeling and highlight both problems and chances of dynamic modeling in biology. The main focus will be on modeling of s transduction pathways, which requires the application of a special modeling approach. A common pattern, especially in eukaryotic signaling systems, is the formation of multi protein signaling complexes. Even for a small number of interacting proteins the number of distinguishable molecular species can be extremely high. This combinatorial complexity is due to the great number of distinct binding domains of many receptors and scaffold proteins involved in signal transduction. However, these problems can be overcome using a new domain-oriented modeling approach, which makes it possible to handle complex and branched signaling pathways.

OVERFLOW Validation for Predicting Plume Impingement of Underexpanded Axisymmetric Jets onto Angled Flat Plates

NASA Technical Reports Server (NTRS)

Lee, Henry C.; Klopfer, Goetz

2011-01-01

This report documents how OVERFLOW, a computational fluid dynamics code, predicts plume impingement of underexpanded axisymmetric jets onto both perpendicular and inclined flat plates. The effects of the plume impinging on a range of plate inclinations varying from 90deg to 30deg are investigated and compared to the experimental results in Reference 1 and 2. The flow fields are extremely complex due to the interaction between the shock waves from the free jet and those deflected by the plate. Additionally, complex mixing effects create very intricate structures in the flow. The experimental data is very limited, so these validation studies will focus only on cold plume impingement on flat and inclined plates. This validation study will help quantify the error in the OVERFLOW simulation when applied to stage separation scenarios.

Forecasts and Warnings of Extreme Solar Storms at the Sun

NASA Astrophysics Data System (ADS)

Lundstedt, H.

2015-12-01

The most pressing space weather forecasts and warnings are those of the most intense solar flares and coronal mass ejections. However, in trying to develop these forecasts and warnings, we are confronted to many fundamental questions. Some of those are: How to define an observable measure for an extreme solar storm? How extreme can a solar storm become and how long is the build up time? How to make forecasts and warnings? Many have contributed to clarifying these general questions. In his presentation we will describe our latest results on the topological complexity of magnetic fields and the use of SDO SHARP parameters. The complexity concept will then be used to discuss the second question. Finally we will describe probability estimates of extreme solar storms.

Grid-converged solution and analysis of the unsteady viscous flow in a two-dimensional shock tube

NASA Astrophysics Data System (ADS)

Zhou, Guangzhao; Xu, Kun; Liu, Feng

2018-01-01

The flow in a shock tube is extremely complex with dynamic multi-scale structures of sharp fronts, flow separation, and vortices due to the interaction of the shock wave, the contact surface, and the boundary layer over the side wall of the tube. Prediction and understanding of the complex fluid dynamics are of theoretical and practical importance. It is also an extremely challenging problem for numerical simulation, especially at relatively high Reynolds numbers. Daru and Tenaud ["Evaluation of TVD high resolution schemes for unsteady viscous shocked flows," Comput. Fluids 30, 89-113 (2001)] proposed a two-dimensional model problem as a numerical test case for high-resolution schemes to simulate the flow field in a square closed shock tube. Though many researchers attempted this problem using a variety of computational methods, there is not yet an agreed-upon grid-converged solution of the problem at the Reynolds number of 1000. This paper presents a rigorous grid-convergence study and the resulting grid-converged solutions for this problem by using a newly developed, efficient, and high-order gas-kinetic scheme. Critical data extracted from the converged solutions are documented as benchmark data. The complex fluid dynamics of the flow at Re = 1000 are discussed and analyzed in detail. Major phenomena revealed by the numerical computations include the downward concentration of the fluid through the curved shock, the formation of the vortices, the mechanism of the shock wave bifurcation, the structure of the jet along the bottom wall, and the Kelvin-Helmholtz instability near the contact surface. Presentation and analysis of those flow processes provide important physical insight into the complex flow physics occurring in a shock tube.

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…

Predicting the effects of muscle activation on knee, thigh, and hip injuries in frontal crashes using a finite-element model with muscle forces from subject testing and musculoskeletal modeling.

PubMed

Chang, Chia-Yuan; Rupp, Jonathan D; Reed, Matthew P; Hughes, Richard E; Schneider, Lawrence W

2009-11-01

In a previous study, the authors reported on the development of a finite-element model of the midsize male pelvis and lower extremities with lower-extremity musculature that was validated using PMHS knee-impact response data. Knee-impact simulations with this model were performed using forces from four muscles in the lower extremities associated with two-foot bracing reported in the literature to provide preliminary estimates of the effects of lower-extremity muscle activation on knee-thigh-hip injury potential in frontal impacts. The current study addresses a major limitation of these preliminary simulations by using the AnyBody three-dimensional musculoskeletal model to estimate muscle forces produced in 35 muscles in each lower extremity during emergency one-foot braking. To check the predictions of the AnyBody Model, activation levels of twelve major muscles in the hip and lower extremities were measured using surface EMG electrodes on 12 midsize-male subjects performing simulated maximum and 50% of maximum braking in a laboratory seating buck. Comparisons between test results and the predictions of the AnyBody Model when it was used to simulate these same braking tests suggest that the AnyBody model appropriately predicts agonistic muscle activations but under predicts antagonistic muscle activations. Simulations of knee-to-knee-bolster impacts were performed by impacting the knees of the lower-extremity finite element model with and without the muscle forces predicted by the validated AnyBody Model. Results of these simulations confirm previous findings that muscle tension increases knee-impact force by increasing the effective mass of the KTH complex due to tighter coupling of muscle mass to bone. They also indicate that muscle activation preferentially couples mass distal to the hip, thereby accentuating the decrease in femur force from the knee to the hip. However, the reduction in force transmitted from the knee to the hip is offset by the increased force at the knee and by increased compressive forces at the hip due to activation of lower-extremity muscles. As a result, approximately 45% to 60% and 50% to 65% of the force applied to the knee is applied to the hip in the simulations without and with muscle tension, respectively. The simulation results suggest that lower-extremity muscle tension has little effect on the risk of hip injuries, but it increases the bending moments in the femoral shaft, thereby increasing the risk of femoral shaft fractures by 20%-40%. However, these findings may be affected by the inability of the AnyBody Model to appropriately predict antagonistic muscle forces.

Deciphering landscape complexity to predict (non)linear responses to extreme climatic events

USDA-ARS?s Scientific Manuscript database

Extreme events are increasing in frequency and magnitude for many landscapes globally. Ecologically, most of the focus on extreme climatic events has been on effects of either short-term pulses (floods, freezes) or long-term drought. Multi-year increases in precipitation are also occurring with litt...

Forecasting seasonal hydrologic response in major river basins

NASA Astrophysics Data System (ADS)

Bhuiyan, A. M.

2014-05-01

Seasonal precipitation variation due to natural climate variation influences stream flow and the apparent frequency and severity of extreme hydrological conditions such as flood and drought. To study hydrologic response and understand the occurrence of extreme hydrological events, the relevant forcing variables must be identified. This study attempts to assess and quantify the historical occurrence and context of extreme hydrologic flow events and quantify the relation between relevant climate variables. Once identified, the flow data and climate variables are evaluated to identify the primary relationship indicators of hydrologic extreme event occurrence. Existing studies focus on developing basin-scale forecasting techniques based on climate anomalies in El Nino/La Nina episodes linked to global climate. Building on earlier work, the goal of this research is to quantify variations in historical river flows at seasonal temporal-scale, and regional to continental spatial-scale. The work identifies and quantifies runoff variability of major river basins and correlates flow with environmental forcing variables such as El Nino, La Nina, sunspot cycle. These variables are expected to be the primary external natural indicators of inter-annual and inter-seasonal patterns of regional precipitation and river flow. Relations between continental-scale hydrologic flows and external climate variables are evaluated through direct correlations in a seasonal context with environmental phenomenon such as sun spot numbers (SSN), Southern Oscillation Index (SOI), and Pacific Decadal Oscillation (PDO). Methods including stochastic time series analysis and artificial neural networks are developed to represent the seasonal variability evident in the historical records of river flows. River flows are categorized into low, average and high flow levels to evaluate and simulate flow variations under associated climate variable variations. Results demonstrated not any particular method is suited to represent scenarios leading to extreme flow conditions. For selected flow scenarios, the persistence model performance may be comparable to more complex multivariate approaches, and complex methods did not always improve flow estimation. Overall model performance indicates inclusion of river flows and forcing variables on average improve model extreme event forecasting skills. As a means to further refine the flow estimation, an ensemble forecast method is implemented to provide a likelihood-based indication of expected river flow magnitude and variability. Results indicate seasonal flow variations are well-captured in the ensemble range, therefore the ensemble approach can often prove efficient in estimating extreme river flow conditions. The discriminant prediction approach, a probabilistic measure to forecast streamflow, is also adopted to derive model performance. Results show the efficiency of the method in terms of representing uncertainties in the forecasts.

Risk factors, management and primary prevention of thrombotic complications related to the use of central venous catheters.

PubMed

Linnemann, Birgit; Lindhoff-Last, Edelgard

2012-09-01

An adequate vascular access is of importance for the treatment of patients with cancer and complex illnesses in the intensive, perioperative or palliative care setting. Deep vein thrombosis and thrombotic occlusion are the most common complications attributed to central venous catheters in short-term and, especially, in long-term use. In this review we will focus on the risk factors, management and prevention strategies of catheter-related thrombosis and occlusion. Due to the lack of randomised controlled trials, there is still controversy about the optimal treatment of catheter-related thrombotic complications, and therapy has been widely adopted using the evidence concerning lower extremity deep vein thrombosis. Given the increasing use of central venous catheters in patients that require long-term intravenous therapy, the problem of upper extremity deep venous thrombosis can be expected to increase in the future. We provide data for establishing a more uniform strategy for preventing, diagnosing and treating catheter-related thrombotic complications.

Diagnosing the Nature of Land-Atmosphere Coupling During the 2006-7 Dry/Wet Extremes in the U. S. Southern Great Plains

NASA Technical Reports Server (NTRS)

Santanello, Joseph A., Jr.; Peters-Lidard, Christa D.; Kumar, Sujay V.; Dong, Xiquan; Kennedy, Aaron D.

2011-01-01

The degree of coupling between the land surface and PBL in NWP models remains largely undiagnosed due to the complex interactions and feedbacks present across a range of scales. In this study, a framework for diagnosing local land-atmosphere coupling (LoCo) is presented using a coupled mesoscale model with observations during the summers of 2006/7 in the U.S. Southern Great Plains. Specifically, the Weather Research and Forecasting (WRF) model has been coupled to NASA's Land Information System (LIS), which enables a suite of PBL and land surface model (LSM) options along provides a flexible and high-resolution representation and initialization of land surface physics and states. This coupling is one component of a larger project to develop a NASA-Unified WRF (NU-WRF) system. A range of diagnostics exploring the feedbacks between soil moisture and precipitation are examined for the dry/wet extremes, along with the sensitivity of PBL-LSM coupling to perturbations in soil moisture.

PANORAMA: An approach to performance modeling and diagnosis of extreme-scale workflows

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deelman, Ewa; Carothers, Christopher; Mandal, Anirban

Here we report that computational science is well established as the third pillar of scientific discovery and is on par with experimentation and theory. However, as we move closer toward the ability to execute exascale calculations and process the ensuing extreme-scale amounts of data produced by both experiments and computations alike, the complexity of managing the compute and data analysis tasks has grown beyond the capabilities of domain scientists. Therefore, workflow management systems are absolutely necessary to ensure current and future scientific discoveries. A key research question for these workflow management systems concerns the performance optimization of complex calculation andmore » data analysis tasks. The central contribution of this article is a description of the PANORAMA approach for modeling and diagnosing the run-time performance of complex scientific workflows. This approach integrates extreme-scale systems testbed experimentation, structured analytical modeling, and parallel systems simulation into a comprehensive workflow framework called Pegasus for understanding and improving the overall performance of complex scientific workflows.« less

PANORAMA: An approach to performance modeling and diagnosis of extreme-scale workflows

DOE PAGES

Deelman, Ewa; Carothers, Christopher; Mandal, Anirban; ...

2015-07-14

Here we report that computational science is well established as the third pillar of scientific discovery and is on par with experimentation and theory. However, as we move closer toward the ability to execute exascale calculations and process the ensuing extreme-scale amounts of data produced by both experiments and computations alike, the complexity of managing the compute and data analysis tasks has grown beyond the capabilities of domain scientists. Therefore, workflow management systems are absolutely necessary to ensure current and future scientific discoveries. A key research question for these workflow management systems concerns the performance optimization of complex calculation andmore » data analysis tasks. The central contribution of this article is a description of the PANORAMA approach for modeling and diagnosing the run-time performance of complex scientific workflows. This approach integrates extreme-scale systems testbed experimentation, structured analytical modeling, and parallel systems simulation into a comprehensive workflow framework called Pegasus for understanding and improving the overall performance of complex scientific workflows.« less

Flooding experience at Veracruz: not only a natural disaster

NASA Astrophysics Data System (ADS)

Welsh-Rodriguez, C. M.; Nava Bringas, M.; Ochoa Martinez, C.; Local; regional impacts of global change

2013-05-01

The Veracruz state lies on the middle of the Gulf of Mexico in Mexican Republic; has a surface of 72815 Km2 represent almost the 4% of Mexico. Due to the complex topography, the rainfall, runoff and the extreme weather the 33% of Mexican water goes trough Veracruz, and every year the presence of tropical depressions, tropical storms and hurricanes impacts on the habitants of Veracruz (7.5 millions). For Veracruz the Sierra Madre is the natural border on the West and on the East the Gulf of Mexico. It is located from 17°10' to 23°38' (N) and between 93° to 99° (W). We will try to get the find out the primary information source for the floods on 2005 and 20010 and correlate with the laws on environment and civil protection for Veracruz. In 1999 a tropical depression more than 200 000 persons and more than 20 died, in 2005 Stan hurricane affected more than a million persons but no one died. In 2010 the effects of hurricane Karl were similar but a few days after the tropical depression Mathew affected 150 000 persons more and 15 people died. The patterns of people habitat in Veracruz since middle of XX century follows the oil industry develop at south east Mexico, so the risk increased as the population density increased, that's a critical reason to concluded that is not only cause - effect issue on Veracruz. So if the extreme events increase as consequence of the climate variability and climate change the vulnerability on this region will not be address in prevention policies, and the future scenario on adaptation will be a deep complex problem to solve from all perspectives.Reported impactst; Extreme events. Data from Veracruz Government.

The dynamics of heatwave over a coastal megacity

NASA Astrophysics Data System (ADS)

Ramamurthy, P.

2017-12-01

A majority of the current population in the U.S. resides in urban areas and nearly 40% live in urban coastal communities. These cities are disproportionately affected by extreme events such as heatwaves, hurricanes and extreme precipitation. The microclimate of the coastal cities is profoundly influenced by the interaction between the highly convective urban core and the moist sea breeze advection. However, such interactions are poorly characterized due to lack of observations over these complex terrains. Herein we use a comprehensive observational platform and numerical simulations to characterize the impact of heatwaves over New York City. As part of the campaign the urban boundary layer over New York City was continuously monitored during July 2016, a period that witnessed three heatwave events. Surface weather stations and indoor sensors were also used to characterize the urban heat island intensity. Our results reveal that during the month, the urban heat island intensity was nearly twice as compared to the decadal average. During the heatwave episodes urban heat island intensities as high as 10 ˚C were observed. The thermal profiles indicate elevated temperatures in much of the boundary layer between 800-2500 m during the heatwave episodes. The profiles indicate a complex thermal structure and high intra-city variability. Thermal internal boundary layer was observed in neighborhoods populated by tall buildings. The results show that heat released from buildings heating and air conditioning system during extreme heat events can be as high as 18 percent of the overall available energy. Overall the high-pressure system during the heatwave episodes acted as a thermal block and much of the heat generated in the urban surface layer remained within the boundary layer, thereby amplifying the near surface air temperature.

Control and instanton trajectories for random transitions in turbulent flows

NASA Astrophysics Data System (ADS)

Bouchet, Freddy; Laurie, Jason; Zaboronski, Oleg

2011-12-01

Many turbulent systems exhibit random switches between qualitatively different attractors. The transition between these bistable states is often an extremely rare event, that can not be computed through DNS, due to complexity limitations. We present results for the calculation of instanton trajectories (a control problem) between non-equilibrium stationary states (attractors) in the 2D stochastic Navier-Stokes equations. By representing the transition probability between two states using a path integral formulation, we can compute the most probable trajectory (instanton) joining two non-equilibrium stationary states. Technically, this is equivalent to the minimization of an action, which can be related to a fluid mechanics control problem.

Management of pediatric mandibular fracture: a case series.

PubMed

Agarwal, Ravi M; Yeluri, Ramakrishna; Singh, Chanchal; Chaudhry, Kalpna; Munshi, Autar K

2014-09-01

A pediatric mandibular fracture can cause a child severe pain and the parent or caregiver extreme worry. While the pattern of fractures and associated injuries in children is similar to adults, the incidence is low. Due to a number of factors, including the anatomical complexity of the developing mandible in a child, management of such fractures differs from that of adults and can greatly challenge the pediatric dentist. Various treatment modalities of managing mandibular fracture are available, such as closed/open cap splint with circummandibular wiring, arch-bar fixation, and cementation of the cap splint. This article reviews 19 cases in the management of pediatric facial fracture using varied treatment methods.

Lower extremity manifestations of "skin-popping" an illicit drug use technique: A report of two cases.

PubMed

Canales, Michael; Gerhard, John; Younce, Erin

2015-06-01

Presented is a rare case of tibial and fibular osteomyelitis and a case of fibular periositis, both a direct consequence of a peculiar drug use technique. The osseous manifestations secondary to presentation of necrotic wounds with indurated rim and serous drainage with associated cellulitis, both resulting from "skin popping." Due to the complex treatment plan required, the importance of a motivated patient, a strong social support system, a controlled environment, and a multidisciplinary team cannot be overstated. Despite comprehensive efforts, devastating consequences may be unavoidable as individuals plunge downward, victimized by their addiction. 4. Copyright © 2015 Elsevier Ltd. All rights reserved.

Advanced asymmetric synthesis of (1R,2S)-1-amino-2-vinylcyclopropanecarboxylic acid by alkylation/cyclization of newly designed axially chiral Ni(II) complex of glycine Schiff base.

PubMed

Kawashima, Aki; Shu, Shuangjie; Takeda, Ryosuke; Kawamura, Akie; Sato, Tatsunori; Moriwaki, Hiroki; Wang, Jiang; Izawa, Kunisuke; Aceña, José Luis; Soloshonok, Vadim A; Liu, Hong

2016-04-01

Asymmetric synthesis of (1R,2S)-1-amino-2-vinylcyclopropanecarboxylic acid (vinyl-ACCA) is in extremely high demand due to the pharmaceutical importance of this tailor-made, sterically constrained α-amino acid. Here we report the development of an advanced procedure for preparation of the target amino acid via two-step SN2 and SN2' alkylation of novel axially chiral nucleophilic glycine equivalent. Excellent yields and diastereoselectivity coupled with reliable and easy scalability render this method of immediate use for practical synthesis of (1R,2S)-vinyl-ACCA.

The complex hybrid origins of the root knot nematodes revealed through comparative genomics

PubMed Central

Kumar, Sujai; Koutsovoulos, Georgios; Blaxter, Mark L.

2014-01-01

Root knot nematodes (RKN) can infect most of the world’s agricultural crop species and are among the most important of all plant pathogens. As yet however we have little understanding of their origins or the genomic basis of their extreme polyphagy. The most damaging pathogens reproduce by obligatory mitotic parthenogenesis and it has been suggested that these species originated from interspecific hybridizations between unknown parental taxa. We have sequenced the genome of the diploid meiotic parthenogen Meloidogyne floridensis, and use a comparative genomic approach to test the hypothesis that this species was involved in the hybrid origin of the tropical mitotic parthenogen Meloidogyne incognita. Phylogenomic analysis of gene families from M. floridensis, M. incognita and an outgroup species Meloidogyne hapla was carried out to trace the evolutionary history of these species’ genomes, and we demonstrate that M. floridensis was one of the parental species in the hybrid origins of M. incognita. Analysis of the M. floridensis genome itself revealed many gene loci present in divergent copies, as they are in M. incognita, indicating that it too had a hybrid origin. The triploid M. incognita is shown to be a complex double-hybrid between M. floridensis and a third, unidentified, parent. The agriculturally important RKN have very complex origins involving the mixing of several parental genomes by hybridization and their extreme polyphagy and success in agricultural environments may be related to this hybridization, producing transgressive variation on which natural selection can act. It is now clear that studying RKN variation via individual marker loci may fail due to the species’ convoluted origins, and multi-species population genomics is essential to understand the hybrid diversity and adaptive variation of this important species complex. This comparative genomic analysis provides a compelling example of the importance and complexity of hybridization in generating animal species diversity more generally. PMID:24860695

From lepton protoplasm to the genesis of hadrons

NASA Astrophysics Data System (ADS)

Eliseev, S. M.; Kosmachev, O. S.

2016-01-01

Theory of matter under extreme conditions opens a new stage in particle physics. It is necessary here to combine Dirac's elementary particle physics with Prigogine's dynamics of nonequilibrium systems. In the article we discuss the problem of the hierarchy of complexity. What can be considered as the lowest level of the organization of extreme matter on the basis of which the self-organization of the complex form occur?

Evaluation of Intersection Traffic Control Measures through Simulation

NASA Astrophysics Data System (ADS)

Asaithambi, Gowri; Sivanandan, R.

2015-12-01

Modeling traffic flow is stochastic in nature due to randomness in variables such as vehicle arrivals and speeds. Due to this and due to complex vehicular interactions and their manoeuvres, it is extremely difficult to model the traffic flow through analytical methods. To study this type of complex traffic system and vehicle interactions, simulation is considered as an effective tool. Application of homogeneous traffic models to heterogeneous traffic may not be able to capture the complex manoeuvres and interactions in such flows. Hence, a microscopic simulation model for heterogeneous traffic is developed using object oriented concepts. This simulation model acts as a tool for evaluating various control measures at signalized intersections. The present study focuses on the evaluation of Right Turn Lane (RTL) and Channelised Left Turn Lane (CLTL). A sensitivity analysis was performed to evaluate RTL and CLTL by varying the approach volumes, turn proportions and turn lane lengths. RTL is found to be advantageous only up to certain approach volumes and right-turn proportions, beyond which it is counter-productive. CLTL is found to be advantageous for lower approach volumes for all turn proportions, signifying the benefits of CLTL. It is counter-productive for higher approach volume and lower turn proportions. This study pinpoints the break-even points for various scenarios. The developed simulation model can be used as an appropriate intersection lane control tool for enhancing the efficiency of flow at intersections. This model can also be employed for scenario analysis and can be valuable to field traffic engineers in implementing vehicle-type based and lane-based traffic control measures.

Complex Regional Pain Syndrome (CRPS type-1) in an Adolescent Following Extravasation of Dextrose Containing Fluid-an Underdiagnosed Case.

PubMed

Subedi, Asish; Bhattarai, Balkrishna; Biswas, Binay K; Khatiwada, Sindhu

2011-06-01

Due to its complex pathophysiology and wide spectrum of clinical manifestations, the diagnosis of CRPS is often missed in the early stage by primary care physicians. After being treated by a primary care physician for 5 months for chronic cellulitis, a 16-year-old girl was referred to our hospital with features of type-1 CRPS of the right upper extremity. Inability to diagnose early caused prolonged suffering to the girl with all the consequence of CRPS. The patient responded well with marked functional recovery from multimodal therapy. Ability to distinguish CRPS from other pain conditions, referral for specialty care at the appropriate time and full awareness of this condition and its clinical features among various healthcare professionals are essential in reducing patient suffering and stopping its progression towards difficult-to-treat situations.

Effect of ubiquinone Q(10) and antioxidant vitamins on free radical oxidation of phospholipids in biological membranes of rat liver.

PubMed

Tikhaze, A K; Konovalova, G G; Lankin, V Z; Kaminnyi, A I; Kaminnaja, V I; Ruuge, E K; Kukharchuk, V V

2005-08-01

We studied the effects of 30-day peroral treatment with beta-carotene, a complex of antioxidant vitamins (vitamins C and E and provitamin A) and selenium, and solubilized ubiquinone Q(10) on the antioxidant potential in rat liver (ascorbate-dependent free radical oxidation of unsaturated membrane phospholipids). beta-Carotene irrespective of the administration route increased antioxidant potential of the liver by 2-3.5 times. The complex of antioxidant vitamins and selenium increased this parameter by more than 15 times. Antiradical activity in rat liver was extremely high after administration of solubilized ubiquinone Q(10) (increase by more than by 36 times). It can be expected that reduced ubiquinone Q(10) in vivo should produce a more pronounced protective effect due to activity of the system for bioregeneration of this natural antioxidant.

Significance of fibrotic bands in utero--Amniotic band sequence with limb body wall complex: A rare case of fetal autopsy.

PubMed

Devi, P Lekshmi; Cicy, P J; Thambi, Renu; Poothiode, Usha

2015-01-01

Amniotic band sequence (ABS) includes a wide spectrum of abnormalities resulting from entrapment of various fetal parts from a disrupted amnion, ranging from a mere constriction ring affecting a finger to a fatal form called limb body wall complex (LBWC). Reported cases of ABS with LBWC are very few. The spectrum of anomalies depends on which part gets entrapped and at what point of gestation. Hence, the clinical presentation can be extremely variable. Early detection of such cases using sonology is really challenging due to the small size of the fibrotic bands. Here, we present a case of amniotic band syndrome with LBWC in a fetus at 24 weeks of gestation, which was referred for an autopsy. The fetus also showed scoliosis, gastroschisis, lumbosacral meningocele, congenital talipes equinovarus, and cleft palate, thus having features of placenta cranial and placenta abdominal phenotype which is very rare.

Scaling in geology: landforms and earthquakes.

PubMed Central

Turcotte, D L

1995-01-01

Landforms and earthquakes appear to be extremely complex; yet, there is order in the complexity. Both satisfy fractal statistics in a variety of ways. A basic question is whether the fractal behavior is due to scale invariance or is the signature of a broadly applicable class of physical processes. Both landscape evolution and regional seismicity appear to be examples of self-organized critical phenomena. A variety of statistical models have been proposed to model landforms, including diffusion-limited aggregation, self-avoiding percolation, and cellular automata. Many authors have studied the behavior of multiple slider-block models, both in terms of the rupture of a fault to generate an earthquake and in terms of the interactions between faults associated with regional seismicity. The slider-block models exhibit a remarkably rich spectrum of behavior; two slider blocks can exhibit low-order chaotic behavior. Large numbers of slider blocks clearly exhibit self-organized critical behavior. Images Fig. 6 PMID:11607562

Capturing rogue waves by multi-point statistics

NASA Astrophysics Data System (ADS)

Hadjihosseini, A.; Wächter, Matthias; Hoffmann, N. P.; Peinke, J.

2016-01-01

As an example of a complex system with extreme events, we investigate ocean wave states exhibiting rogue waves. We present a statistical method of data analysis based on multi-point statistics which for the first time allows the grasping of extreme rogue wave events in a highly satisfactory statistical manner. The key to the success of the approach is mapping the complexity of multi-point data onto the statistics of hierarchically ordered height increments for different time scales, for which we can show that a stochastic cascade process with Markov properties is governed by a Fokker-Planck equation. Conditional probabilities as well as the Fokker-Planck equation itself can be estimated directly from the available observational data. With this stochastic description surrogate data sets can in turn be generated, which makes it possible to work out arbitrary statistical features of the complex sea state in general, and extreme rogue wave events in particular. The results also open up new perspectives for forecasting the occurrence probability of extreme rogue wave events, and even for forecasting the occurrence of individual rogue waves based on precursory dynamics.

Impact and recovery process of mini flash crashes: An empirical study.

PubMed

Braun, Tobias; Fiegen, Jonas A; Wagner, Daniel C; Krause, Sebastian M; Guhr, Thomas

2018-01-01

In an Ultrafast Extreme Event (or Mini Flash Crash), the price of a traded stock increases or decreases strongly within milliseconds. We present a detailed study of Ultrafast Extreme Events in stock market data. In contrast to popular belief, our analysis suggests that most of the Ultrafast Extreme Events are not necessarily due to feedbacks in High Frequency Trading: In at least 60 percent of the observed Ultrafast Extreme Events, the largest fraction of the price change is due to a single market order. In times of financial crisis, large market orders are more likely which leads to a significant increase of Ultrafast Extreme Events occurrences. Furthermore, we analyze the 100 trades following each Ultrafast Extreme Events. While we observe a tendency of the prices to partially recover, less than 40 percent recover completely. On the other hand we find 25 percent of the Ultrafast Extreme Events to be almost recovered after only one trade which differs from the usually found price impact of market orders.

Impact and recovery process of mini flash crashes: An empirical study

PubMed Central

Wagner, Daniel C.; Krause, Sebastian M.; Guhr, Thomas

2018-01-01

In an Ultrafast Extreme Event (or Mini Flash Crash), the price of a traded stock increases or decreases strongly within milliseconds. We present a detailed study of Ultrafast Extreme Events in stock market data. In contrast to popular belief, our analysis suggests that most of the Ultrafast Extreme Events are not necessarily due to feedbacks in High Frequency Trading: In at least 60 percent of the observed Ultrafast Extreme Events, the largest fraction of the price change is due to a single market order. In times of financial crisis, large market orders are more likely which leads to a significant increase of Ultrafast Extreme Events occurrences. Furthermore, we analyze the 100 trades following each Ultrafast Extreme Events. While we observe a tendency of the prices to partially recover, less than 40 percent recover completely. On the other hand we find 25 percent of the Ultrafast Extreme Events to be almost recovered after only one trade which differs from the usually found price impact of market orders. PMID:29782503

Additional adjoint Monte Carlo studies of the shielding of concrete structures against initial gamma radiation. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beer, M.; Cohen, M.O.

1975-02-01

The adjoint Monte Carlo method previously developed by MAGI has been applied to the calculation of initial radiation dose due to air secondary gamma rays and fission product gamma rays at detector points within buildings for a wide variety of problems. These provide an in-depth survey of structure shielding effects as well as many new benchmark problems for matching by simplified models. Specifically, elevated ring source results were obtained in the following areas: doses at on-and off-centerline detectors in four concrete blockhouse structures; doses at detector positions along the centerline of a high-rise structure without walls; dose mapping at basementmore » detector positions in the high-rise structure; doses at detector points within a complex concrete structure containing exterior windows and walls and interior partitions; modeling of the complex structure by replacing interior partitions by additional material at exterior walls; effects of elevation angle changes; effects on the dose of changes in fission product ambient spectra; and modeling of mutual shielding due to external structures. In addition, point source results yielding dose extremes about the ring source average were obtained. (auth)« less

Exact simulation of max-stable processes.

PubMed

Dombry, Clément; Engelke, Sebastian; Oesting, Marco

2016-06-01

Max-stable processes play an important role as models for spatial extreme events. Their complex structure as the pointwise maximum over an infinite number of random functions makes their simulation difficult. Algorithms based on finite approximations are often inexact and computationally inefficient. We present a new algorithm for exact simulation of a max-stable process at a finite number of locations. It relies on the idea of simulating only the extremal functions, that is, those functions in the construction of a max-stable process that effectively contribute to the pointwise maximum. We further generalize the algorithm by Dieker & Mikosch (2015) for Brown-Resnick processes and use it for exact simulation via the spectral measure. We study the complexity of both algorithms, prove that our new approach via extremal functions is always more efficient, and provide closed-form expressions for their implementation that cover most popular models for max-stable processes and multivariate extreme value distributions. For simulation on dense grids, an adaptive design of the extremal function algorithm is proposed.

Utilization of manual therapy to the lumbar spine in conjunction with traditional conservative care for individuals with bilateral lower extremity complex regional pain syndrome: A case series.

PubMed

Walston, Zachary; Hernandez, Luis; Yake, Dale

2018-06-06

Conservative therapies for complex regional pain syndrome (CRPS) have traditionally focused on exercise and desensitization techniques targeted at the involved extremity. The primary purpose of this case series is to report on the potential benefit of utilizing manual therapy to the lumbar spine in conjunction with traditional conservative care when treating patients with lower extremity CRPS. Two patients with the diagnosis of lower extremity CRPS were treated with manual therapy to the lumbar spine in conjunction with education, exercise, desensitization, and soft tissue techniques for the extremity. Patient 1 received 13 sessions over 6 weeks resulting in a 34-point improvement in oswestry disability index (ODI) and 35-point improvement in lower extremity functional scale (LEFS). Patient 2 received 21 sessions over 12 weeks resulting in a 28-point improvement in ODI and a 41-point improvement in LEFS. Both patients exhibited reductions in pain and clinically meaningful improvements in function. Manual therapies when applied to the lumbar spine in these patients as part of a comprehensive treatment plan resulted in improved spinal mobility, decreased pain, and reduction is distal referred symptoms. Although one cannot infer a cause and effect relationship from a case series, this report identifies meaningful clinical outcomes potentially associated with manual physical therapy to the lumbar spine for two patients with complex regional pain syndrome type 1.

Effects of Extreme Events on Arsenic Cycling in Salt Marshes

NASA Astrophysics Data System (ADS)

Northrup, Kristy; Capooci, Margaret; Seyfferth, Angelia L.

2018-03-01

Extreme events such as storm surges, intense precipitation, and supermoons cause anomalous and large fluctuations in water level in tidal salt marshes, which impacts the sediment biogeochemistry that dictates arsenic (As) cycling. In addition to changes in water level, which impacts soil redox potential, these extreme events may also change salinity due to freshwater inputs from precipitation or saltwater inputs due to surge. It is currently unknown how As mobility in tidal salt marshes will be impacted by extreme events, as fluctuations in salinity and redox potential may act synergistically to mobilize As. To investigate impacts of extreme events on As cycling in tidal salt marshes, we conducted a combined laboratory and field investigation. We monitored pore water and soil samples before, during, and after two extreme events: a supermoon lunar eclipse followed by a storm surge and precipitation induced by Hurricane Joaquin in fall 2015 at the St. Jones Reserve in Dover, Delaware, a representative tidal salt marsh in the Mid-Atlantic United States. We also conducted soil incubations of marsh sediments in batch and in flow-through experiments in which redox potential and/or salinity were manipulated. Field investigations showed that pore water As was inversely proportional to redox potential. During the extreme events, a distinct pulse of As was observed in the pore water with maximum salinity. Combined field and laboratory investigations revealed that this As pulse is likely due to rapid changes in salinity. These results have implications for As mobility in the face of extreme weather variability.

Investigating low flow process controls, through complex modelling, in a UK chalk catchment

NASA Astrophysics Data System (ADS)

Lubega Musuuza, Jude; Wagener, Thorsten; Coxon, Gemma; Freer, Jim; Woods, Ross; Howden, Nicholas

2017-04-01

The typical streamflow response of Chalk catchments is dominated by groundwater contributions due the high degree of groundwater recharge through preferential flow pathways. The groundwater store attenuates the precipitation signal, which causes a delay between the corresponding high and low extremes in the precipitation and the stream flow signals. Streamflow responses can therefore be quite out of phase with the precipitation input to a Chalk catchment. Therefore characterising such catchment systems, including modelling approaches, clearly need to reproduce these percolation and groundwater dominated pathways to capture these dominant flow pathways. The simulation of low flow conditions for chalk catchments in numerical models is especially difficult due to the complex interactions between various processes that may not be adequately represented or resolved in the models. Periods of low stream flows are particularly important due to competing water uses in the summer, including agriculture and water supply. In this study we apply and evaluate the physically-based Pennstate Integrated Hydrologic Model (PIHM) to the River Kennet, a sub-catchment of the Thames Basin, to demonstrate how the simulations of a chalk catchment are improved by a physically-based system representation. We also use an ensemble of simulations to investigate the sensitivity of various hydrologic signatures (relevant to low flows and droughts) to the different parameters in the model, thereby inferring the levels of control exerted by the processes that the parameters represent.

Using pattern analysis methods to do fast detection of manufacturing pattern failures

NASA Astrophysics Data System (ADS)

Zhao, Evan; Wang, Jessie; Sun, Mason; Wang, Jeff; Zhang, Yifan; Sweis, Jason; Lai, Ya-Chieh; Ding, Hua

2016-03-01

At the advanced technology node, logic design has become extremely complex and is getting more challenging as the pattern geometry size decreases. The small sizes of layout patterns are becoming very sensitive to process variations. Meanwhile, the high pressure of yield ramp is always there due to time-to-market competition. The company that achieves patterning maturity earlier than others will have a great advantage and a better chance to realize maximum profit margins. For debugging silicon failures, DFT diagnostics can identify which nets or cells caused the yield loss. But normally, a long time period is needed with many resources to identify which failures are due to one common layout pattern or structure. This paper will present a new yield diagnostic flow, based on preliminary EFA results, to show how pattern analysis can more efficiently detect pattern related systematic defects. Increased visibility on design pattern related failures also allows more precise yield loss estimation.

Validity of Molecular Tagging Velocimetry in a Cavitating Flow for Turbopump Analysis

NASA Astrophysics Data System (ADS)

Kuzmich, Kayla; Bohl, Doug

2012-11-01

This research establishes multi-phase molecular tagging velocimetry (MTV) use and explores its limitations. The flow conditions and geometry in the inducer of an upper stage liquid Oxygen (LOX)/LH2 engine frequently cause cavitation which decreases turbopump performance. Complications arise in performing experiments in liquid hydrogen and oxygen due to high costs, high pressures, extremely low fluid temperatures, the presence of cavitation, and associated safety risks. Due to the complex geometry and hazardous nature of the fluids, a simplified throat geometry with water as a simulant fluid is used. Flow characteristics are measured using MTV, a noninvasive flow diagnostic technique. MTV is found to be an applicable tool in cases of low cavitation. Highly cavitating flows reflect and scatter most of the laser beam disallowing penetration into the cavitation cloud. However, data can be obtained in high cavitation cases near the cloud boundary layer. Distribution A: Public Release, Public Affairs Clearance Number: 12654

[Replantation at lower leg level].

PubMed

Daigeler, A; Fansa, H; Westphal, T; Schneider, W

2003-11-01

Replantation in reconstructive surgery is an established procedure due to microsurgical techniques. It can be routinely performed in unilateral lower leg amputation. In some cases of bilateral amputation, in which orthotopic replantation is not possible due to the complex trauma, heterotopic replantation is a therapeutic option. This avoids prosthetic fitting. We report five cases of orthotopic and two of heterotopic lower limb replantations. Functional outcome concerning sensibility, mobility, pain, and aesthetic result were assessed clinically and using a questionnaire. Functional outcome and patient satisfaction were good. The psychological situation of the patients as well as mobility and stability of the replanted limbs were satisfying. Heterotopically replanted patients found the replanted legs superior to the prostheses. We conclude that, in lower leg amputation, attempts should be made to replant the extremity. In bilateral lower leg amputations, at least one limb should be reconstructed, even if "only" a heterotopic replantation can be performed.

[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.

Surface Complexation Modeling of Eu(III) and U(VI) Interactions with Graphene Oxide.

PubMed

Xie, Yu; Helvenston, Edward M; Shuller-Nickles, Lindsay C; Powell, Brian A

2016-02-16

Graphene oxide (GO) has great potential for actinide removal due to its extremely high sorption capacity, but the mechanism of sorption remains unclear. In this study, the carboxylic functional group and an unexpected sulfonate functional group on GO were characterized as the reactive surface sites and quantified via diffuse layer modeling of the GO acid/base titrations. The presence of sulfonate functional group on GO was confirmed using elemental analysis and X-ray photoelectron spectroscopy. Batch experiments of Eu(III) and U(VI) sorption to GO as the function of pH (1-8) and as the function of analyte concentration (10-100, 000 ppb) at a constant pH ≈ 5 were conducted; the batch sorption results were modeled simultaneously using surface complexation modeling (SCM). The SCM indicated that Eu(III) and U(VI) complexation to carboxylate functional group is the main mechanism for their sorption to GO; their complexation to the sulfonate site occurred at the lower pH range and the complexation of Eu(III) to sulfonate site are more significant than that of U(VI). Eu(III) and U(VI) facilitated GO aggregation was observed with high Eu(III) and U(VI) concentration and may be caused by surface charge neutralization of GO after sorption.

Integrating seasonal optical and thermal infrared spectra to characterize urban impervious surfaces with extreme spectral complexity: a Shanghai case study

NASA Astrophysics Data System (ADS)

Wang, Wei; Yao, Xinfeng; Ji, Minhe

2016-01-01

Despite recent rapid advancement in remote sensing technology, accurate mapping of the urban landscape in China still faces a great challenge due to unusually high spectral complexity in many big cities. Much of this complication comes from severe spectral confusion of impervious surfaces with polluted water bodies and bright bare soils. This paper proposes a two-step land cover decomposition method, which combines optical and thermal spectra from different seasons to cope with the issue of urban spectral complexity. First, a linear spectral mixture analysis was employed to generate fraction images for three preliminary endmembers (high albedo, low albedo, and vegetation). Seasonal change analysis on land surface temperature induced from thermal infrared spectra and coarse component fractions obtained from the first step was then used to reduce the confusion between impervious surfaces and nonimpervious materials. This method was tested with two-date Landsat multispectral data in Shanghai, one of China's megacities. The results showed that the method was capable of consistently estimating impervious surfaces in highly complex urban environments with an accuracy of R2 greater than 0.70 and both root mean square error and mean average error less than 0.20 for all test sites. This strategy seemed very promising for landscape mapping of complex urban areas.

Multiple-reason decision making based on automatic processing.

PubMed

Glöckner, Andreas; Betsch, Tilmann

2008-09-01

It has been repeatedly shown that in decisions under time constraints, individuals predominantly use noncompensatory strategies rather than complex compensatory ones. The authors argue that these findings might be due not to limitations of cognitive capacity but instead to limitations of information search imposed by the commonly used experimental tool Mouselab (J. W. Payne, J. R. Bettman, & E. J. Johnson, 1988). The authors tested this assumption in 3 experiments. In the 1st experiment, information was openly presented, whereas in the 2nd experiment, the standard Mouselab program was used under different time limits. The results indicate that individuals are able to compute weighted additive decision strategies extremely quickly if information search is not restricted by the experimental procedure. In a 3rd experiment, these results were replicated using more complex decision tasks, and the major alternative explanations that individuals use more complex heuristics or that they merely encode the constellation of cues were ruled out. In sum, the findings challenge the fundaments of bounded rationality and highlight the importance of automatic processes in decision making. (c) 2008 APA, all rights reserved.

Service Center for Climate Change Adaptation in Agriculture - an initiative of the University of West Hungary

NASA Astrophysics Data System (ADS)

Matyas, Cs.; Berki, I.; Drüszler, A.; Eredics, A.; Galos, B.; Moricz, N.; Rasztovits, E.

2012-04-01

In whole Central Europe agricultural production is highly vulnerable and sensitive to impacts of projected climatic changes. The low-elevation regions of the Carpathian Basin (most of the territory of Hungary), where precipitation is the minimum factor of production, are especially exposed to climatic extremes, especially to droughts. Rainfed agriculture, animal husbandry on nature-close pastures and nature-close forestry are the most sensitive sectors due to limited possibilities to counterbalance moisture supply constraints. These sectors have to be best prepared to frequency increase of extreme events, disasters and economic losses. So far, there is a lack of information about the middle and long term consequences on regional and local level. Therefore the importance of complex, long term management planning and of land use optimation is increasing. The aim of the initiative is to set up a fine-scale, GIS-based, complex, integrated system for the definition of the most important regional and local challenges and tasks of climate change adaptation and mitigation in agriculture, forestry, animal husbandry and also nature protection. The Service Center for Climate Change Adaptation in Agriculture is planned to provide the following services: § Complex, GIS-supported database, which integrates the basic information about present and projected climates, extremes, hydrology and soil conditions; § Evaluation of existing satellite-based and earth-based monitoring systems; § GIS-supported information about the future trends of climate change impacts on the agroecological potential and sensitivity status on regional and local level (e.g. land cover/use and expectable changes, production, water and carbon cycle, biodiversity and other ecosystem services, potential pests and diseases, tolerance limits etc.) in fine-scale horizontal resolution, based first of all on natural produce, including also social and economic consequences; § Complex decision supporting system on regional and local scale for middle- and long term adaptation and mitigation strategies, providing information on optimum technologies and energy balances. Cooperation with already existing Climate Service Centres and national and international collaboration in monitoring and research are important elements of the activity of the Centre. In the future, the Centre is planned to form part of a national information system on climate change adaptation and mitigation, supported by the Ministry of Development. Keywords: climate change impacts, forestry, rainfed agriculture, animal husbandry

Learning Human Aspects of Collaborative Software Development

ERIC Educational Resources Information Center

Hadar, Irit; Sherman, Sofia; Hazzan, Orit

2008-01-01

Collaboration has become increasingly widespread in the software industry as systems have become larger and more complex, adding human complexity to the technological complexity already involved in developing software systems. To deal with this complexity, human-centric software development methods, such as Extreme Programming and other agile…

Predictability of extremes in non-linear hierarchically organized systems

NASA Astrophysics Data System (ADS)

Kossobokov, V. G.; Soloviev, A.

2011-12-01

Understanding the complexity of non-linear dynamics of hierarchically organized systems progresses to new approaches in assessing hazard and risk of the extreme catastrophic events. In particular, a series of interrelated step-by-step studies of seismic process along with its non-stationary though self-organized behaviors, has led already to reproducible intermediate-term middle-range earthquake forecast/prediction technique that has passed control in forward real-time applications during the last two decades. The observed seismic dynamics prior to and after many mega, great, major, and strong earthquakes demonstrate common features of predictability and diverse behavior in course durable phase transitions in complex hierarchical non-linear system of blocks-and-faults of the Earth lithosphere. The confirmed fractal nature of earthquakes and their distribution in space and time implies that many traditional estimations of seismic hazard (from term-less to short-term ones) are usually based on erroneous assumptions of easy tractable analytical models, which leads to widespread practice of their deceptive application. The consequences of underestimation of seismic hazard propagate non-linearly into inflicted underestimation of risk and, eventually, into unexpected societal losses due to earthquakes and associated phenomena (i.e., collapse of buildings, landslides, tsunamis, liquefaction, etc.). The studies aimed at forecast/prediction of extreme events (interpreted as critical transitions) in geophysical and socio-economical systems include: (i) large earthquakes in geophysical systems of the lithosphere blocks-and-faults, (ii) starts and ends of economic recessions, (iii) episodes of a sharp increase in the unemployment rate, (iv) surge of the homicides in socio-economic systems. These studies are based on a heuristic search of phenomena preceding critical transitions and application of methodologies of pattern recognition of infrequent events. Any study of rare phenomena of highly complex origin, by their nature, implies using problem oriented methods, which design breaks the limits of classical statistical or econometric applications. The unambiguously designed forecast/prediction algorithms of the "yes or no" variety, analyze the observable quantitative integrals and indicators available to a given date, then provides unambiguous answer to the question whether a critical transition should be expected or not in the next time interval. Since the predictability of an originating non-linear dynamical system is limited in principle, the probabilistic component of forecast/prediction algorithms is represented by the empirical probabilities of alarms, on one side, and failures-to-predict, on the other, estimated on control sets achieved in the retro- and prospective experiments. Predicting in advance is the only decisive test of forecast/predictions and the relevant on-going experiments are conducted in the case seismic extremes, recessions, and increases of unemployment rate. The results achieved in real-time testing keep being encouraging and confirm predictability of the extremes.

Study of Environmental Data Complexity using Extreme Learning Machine

NASA Astrophysics Data System (ADS)

Leuenberger, Michael; Kanevski, Mikhail

2017-04-01

The main goals of environmental data science using machine learning algorithm deal, in a broad sense, around the calibration, the prediction and the visualization of hidden relationship between input and output variables. In order to optimize the models and to understand the phenomenon under study, the characterization of the complexity (at different levels) should be taken into account. Therefore, the identification of the linear or non-linear behavior between input and output variables adds valuable information for the knowledge of the phenomenon complexity. The present research highlights and investigates the different issues that can occur when identifying the complexity (linear/non-linear) of environmental data using machine learning algorithm. In particular, the main attention is paid to the description of a self-consistent methodology for the use of Extreme Learning Machines (ELM, Huang et al., 2006), which recently gained a great popularity. By applying two ELM models (with linear and non-linear activation functions) and by comparing their efficiency, quantification of the linearity can be evaluated. The considered approach is accompanied by simulated and real high dimensional and multivariate data case studies. In conclusion, the current challenges and future development in complexity quantification using environmental data mining are discussed. References - Huang, G.-B., Zhu, Q.-Y., Siew, C.-K., 2006. Extreme learning machine: theory and applications. Neurocomputing 70 (1-3), 489-501. - Kanevski, M., Pozdnoukhov, A., Timonin, V., 2009. Machine Learning for Spatial Environmental Data. EPFL Press; Lausanne, Switzerland, p.392. - Leuenberger, M., Kanevski, M., 2015. Extreme Learning Machines for spatial environmental data. Computers and Geosciences 85, 64-73.

Improving high impact weather and climate prediction for societal resilience in Subtropical South America: Proyecto RELAMPAGO-CACTI

NASA Astrophysics Data System (ADS)

Nesbitt, S. W.; Salio, P. V.; Varble, A.; Trapp, R. J.; Roberts, R. R.; Dominguez, F.; Machado, L.; Saulo, C.

2017-12-01

Subtropical South America is host to many types of weather and climate hazards. The convective systems that initiate near and apart from the complex terrain of the Andes and Sierras de Córdoba are by many measures the most intense in the world, producing hazards such as damaging winds, hail, tornadoes, extreme and unusual lightning behavior, and flash and riverine flooding. These systems are modulated by interannual, intraseasonal, and synoptic drivers, however multi-scale models suffer from extreme biases in low level temperature and humidity due to their poor representation of organized convection and representation of convection near complex terrain, which hampers predictive skill of relevant processes across all timescales. To address these cross-cutting issues, we have proposed a large, multi-agency international field campaign called RELAMPAGO-CACTI, which will address key gaps in physical process understanding in the production of convective storms in this region. RELAMPAGO (Remote sensing of Electrification, Lightning, And Mesoscale/microscale Processes with Adaptive Ground Observations), funded by NSF/NOAA/NASA/MinCyT/FAPESP, will be a 24-month hydrological-meteorological field campaign, with an intensive observing period 1 Nov - 15 Dec 2018 in the near the Sierras de Córdoba (SDC), the Andes foothills near Mendoza, and the region near São Borja, Brazil. A complementary funded 7-month DOE field campaign called Clouds, Aerosols, and Complex Terrain Interactions (CACTI), which will focus on detailed observations of cloud and aerosol lifecycle near the SDC while an intensive observing period featuring aircraft observations will match RELAMPAGO's. While collecting the observations will enhance knowledge of the processes acting to modulate extremes in the region, a coordinated modeling effort will aim to evaluate coupled weather, climate, and hydrologic models using RELAMPAGO-CACTI observations. In addition, partnerships with the Servicio Meteorológico Nacional (SMN) of Argentina and Brazil's Centro de Previsão de Tempo e Estudos Climáticos (CPTEC), as well as related international and local societal impacts projects such as the World Meteorological Organization's High-Impact Weather project will enable improved end-to-end impacts predictions in this vulnerable region.

A dependence modelling study of extreme rainfall in Madeira Island

NASA Astrophysics Data System (ADS)

Gouveia-Reis, Délia; Guerreiro Lopes, Luiz; Mendonça, Sandra

2016-08-01

The dependence between variables plays a central role in multivariate extremes. In this paper, spatial dependence of Madeira Island's rainfall data is addressed within an extreme value copula approach through an analysis of maximum annual data. The impact of altitude, slope orientation, distance between rain gauge stations and distance from the stations to the sea are investigated for two different periods of time. The results obtained highlight the influence of the island's complex topography on the spatial distribution of extreme rainfall in Madeira Island.

Chiral reagents in glycosylation and modification of carbohydrates.

PubMed

Wang, Hao-Yuan; Blaszczyk, Stephanie A; Xiao, Guozhi; Tang, Weiping

2018-02-05

Carbohydrates play a significant role in numerous biological events, and the chemical synthesis of carbohydrates is vital for further studies to understand their various biological functions. Due to the structural complexity of carbohydrates, the stereoselective formation of glycosidic linkages and the site-selective modification of hydroxyl groups are very challenging and at the same time extremely important. In recent years, the rapid development of chiral reagents including both chiral auxiliaries and chiral catalysts has significantly improved the stereoselectivity for glycosylation reactions and the site-selectivity for the modification of carbohydrates. These new tools will greatly facilitate the efficient synthesis of oligosaccharides, polysaccharides, and glycoconjugates. In this tutorial review, we will summarize these advances and highlight the most recent examples.

Pen-based computers: Computers without keys

NASA Technical Reports Server (NTRS)

Conklin, Cheryl L.

1994-01-01

The National Space Transportation System (NSTS) is comprised of many diverse and highly complex systems incorporating the latest technologies. Data collection associated with ground processing of the various Space Shuttle system elements is extremely challenging due to the many separate processing locations where data is generated. This presents a significant problem when the timely collection, transfer, collation, and storage of data is required. This paper describes how new technology, referred to as Pen-Based computers, is being used to transform the data collection process at Kennedy Space Center (KSC). Pen-Based computers have streamlined procedures, increased data accuracy, and now provide more complete information than previous methods. The end results is the elimination of Shuttle processing delays associated with data deficiencies.

State of Art of Cancer Pharmacogenomics in Latin American Populations.

PubMed

López-Cortés, Andrés; Guerrero, Santiago; Redal, María Ana; Alvarado, Angel Tito; Quiñones, Luis Abel

2017-05-23

Over the past decades, several studies have shown that tumor-related somatic and germline alterations predicts tumor prognosis, drug response and toxicity. Latin American populations present a vast geno-phenotypic diversity due to the great interethnic and interracial mixing. This genetic flow leads to the appearance of complex characteristics that allow individuals to adapt to endemic environments, such as high altitude or extreme tropical weather. These genetic changes, most of them subtle and unexplored, could establish a mutational profile to develop new pharmacogenomic therapies specific for Latin American populations. In this review, we present the current status of research on somatic and germline alterations in Latin America compared to those found in Caucasian and Asian populations.

Practical Use Of It In Traceability In Food Value Chains

NASA Astrophysics Data System (ADS)

Ratcliff, Jon; Boddington, Michael

Traceability is today considered an essential requirement for the food value chain due to the need to provide consumers with accurate information in the event of food safety recalls, to provide assurance with regard the source and production systems for food products and in certain countries to comply with government legislation. Within an individual business traceability can be quite simple to implement, however, in a global trading market, traceability of the entire supply chain, including logistics is extremely complex. For this reason IT solutions such as TraceTracker have been developed which not only provide electronic solutions for complete traceability but also allow products to be tracked at any point in the supply chain.

The analyses of extreme climate events over China based on CMIP5 historical and future simulations

NASA Astrophysics Data System (ADS)

Yang, S.; Dong, W.; Feng, J.; Chou, J.

2013-12-01

The extreme climate events have a serious influence on human society. Based on observations and 12 simulations from Coupled Model Intercomparison Project Phase 5 (CMIP5), Climatic extremes and their changes over china in history and future scenarios of three Representative Concentration Pathways (RCPs) are analyzed. Because of the background of global warming, in observations, the frost days (FD) and low-temperature threshold days (TN10P) have decreasing trend, and summer days (SU), high-temperature threshold days (TX90P), the heavy precipitation days (R20) and contribution of heavy precipitation days (P95T) show an increasing trend. Most coupled models can basically simulate main characteristics of most extreme indexes. The models reproduce the mean FD and TX90P value best and can give basic trends of the FD, TN10P, SU and TX90P. High correlation coefficients between simulated results and observation are found in FD, SU and P95T. For FD and SU index, most of the models have good ability to capture the spatial differences between the mean state of the 1986-2005 and 1961-1980 periods, but for other indexes, most of models' simulation ability for spatial disparity are not so satisfactory and have to be promoted. Under the high emission scenario of RCP8.5, the century-scale linear changes of Multi-Model Ensembles (MME) for FD, SU, TN10P, TX90P, R20 and P95T are -46.9, 46.0, -27.1, 175.4, 2.9 days and 9.9%, respectively. Due to the complexities of physical process parameterizations and the limitation of forcing data, a large uncertainty still exists in the simulations of climatic extremes. Fig.1 Observed and modeled multi-year average for each index (Dotted line: observation) Table1. Extreme index definition

Changing precipitation extremes and flood risk over the conterminous U.S.

NASA Astrophysics Data System (ADS)

Lettenmaier, D. P.

2017-12-01

On the basis of first principles, precipitation extremes should increase in a warming climate. Effectively, the atmospheric "heat engine" is expected to turn over more rapidly as the climate warms, due to increased water holding capacity of the atmosphere. Most climate models reflect this behavior, and project that precipitation extremes should increase, at roughly the Clausius-Clapyron rate. From a societal standpoint though, changing precipitation extremes in and of themselves aren't necessarily a concern - rather, the question of societal interest is "are and/or will flood extremes change". Flood extremes of course respond to precipitation extremes, but they are affected by a number of other factors, among them being the duration of precipitation relative to catchment size and channel features, storm orientation relative to catchment orientation, soil characteristics, and antecedent hydrologic conditions. Various studies have shown that over both the conterminous U.S. and globally, there have been slight increases in precipitation extremes (i.e., more than would be expected due to chance. On the other hand, evidence for increases in flooding are less pervasive. I review past work in this area, and suggest the nature of studies that might be conducted going forward to better understand the likely signature of changing precipitation extremes on flooding.

Reliability of the mangled extremity severity score in combat-related upper and lower extremity injuries.

PubMed

Ege, Tolga; Unlu, Aytekin; Tas, Huseyin; Bek, Dogan; Turkan, Selim; Cetinkaya, Aytac

2015-01-01

Decision of limb salvage or amputation is generally aided with several trauma scoring systems such as the mangled extremity severity score (MESS). However, the reliability of the injury scores in the settling of open fractures due to explosives and missiles is challenging. Mortality and morbidity of the extremity trauma due to firearms are generally associated with time delay in revascularization, injury mechanism, anatomy of the injured site, associated injuries, age and the environmental circumstance. The purpose of the retrospective study was to evaluate the extent of extremity injuries due to ballistic missiles and to detect the reliability of mangled extremity severity score (MESS) in both upper and lower extremities. Between 2004 and 2014, 139 Gustillo Anderson Type III open fractures of both the upper and lower extremities were enrolled in the study. Data for patient age, fire arm type, transporting time from the field to the hospital (and the method), injury severity scores, MESS scores, fracture types, amputation levels, bone fixation methods and postoperative infections and complications retrieved from the two level-2 trauma center's data base. Sensitivity, specificity, positive and negative predictive values of the MESS were calculated to detect the ability in deciding amputation in the mangled limb. Amputation was performed in 39 extremities and limb salvage attempted in 100 extremities. The mean followup time was 14.6 months (range 6-32 months). In the amputated group, the mean MESS scores for upper and lower extremity were 8.8 (range 6-11) and 9.24 (range 6-11), respectively. In the limb salvage group, the mean MESS scores for upper and lower extremities were 5.29 (range 4-7) and 5.19 (range 3-8), respectively. Sensitivity of MESS in upper and lower extremities were calculated as 80% and 79.4% and positive predictive values detected as 55.55% and 83.3%, respectively. Specificity of MESS score for upper and lower extremities was 84% and 86.6%; negative predictive values were calculated as 95.45% and 90.2%, respectively. MESS is not predictive in combat related extremity injuries especially if between a score of 6-8. Limb ischemia and presence or absence of shock can be used in initial decision-making for amputation.

Reliability of the mangled extremity severity score in combat-related upper and lower extremity injuries

PubMed Central

Ege, Tolga; Unlu, Aytekin; Tas, Huseyin; Bek, Dogan; Turkan, Selim; Cetinkaya, Aytac

2015-01-01

Background: Decision of limb salvage or amputation is generally aided with several trauma scoring systems such as the mangled extremity severity score (MESS). However, the reliability of the injury scores in the settling of open fractures due to explosives and missiles is challenging. Mortality and morbidity of the extremity trauma due to firearms are generally associated with time delay in revascularization, injury mechanism, anatomy of the injured site, associated injuries, age and the environmental circumstance. The purpose of the retrospective study was to evaluate the extent of extremity injuries due to ballistic missiles and to detect the reliability of mangled extremity severity score (MESS) in both upper and lower extremities. Materials and Methods: Between 2004 and 2014, 139 Gustillo Anderson Type III open fractures of both the upper and lower extremities were enrolled in the study. Data for patient age, fire arm type, transporting time from the field to the hospital (and the method), injury severity scores, MESS scores, fracture types, amputation levels, bone fixation methods and postoperative infections and complications retrieved from the two level-2 trauma center's data base. Sensitivity, specificity, positive and negative predictive values of the MESS were calculated to detect the ability in deciding amputation in the mangled limb. Results: Amputation was performed in 39 extremities and limb salvage attempted in 100 extremities. The mean followup time was 14.6 months (range 6–32 months). In the amputated group, the mean MESS scores for upper and lower extremity were 8.8 (range 6–11) and 9.24 (range 6–11), respectively. In the limb salvage group, the mean MESS scores for upper and lower extremities were 5.29 (range 4–7) and 5.19 (range 3–8), respectively. Sensitivity of MESS in upper and lower extremities were calculated as 80% and 79.4% and positive predictive values detected as 55.55% and 83.3%, respectively. Specificity of MESS score for upper and lower extremities was 84% and 86.6%; negative predictive values were calculated as 95.45% and 90.2%, respectively. Conclusion: MESS is not predictive in combat related extremity injuries especially if between a score of 6–8. Limb ischemia and presence or absence of shock can be used in initial decision-making for amputation. PMID:26806974

Causes of Glacier Melt Extremes in the Alps Since 1949

NASA Astrophysics Data System (ADS)

Thibert, E.; Dkengne Sielenou, P.; Vionnet, V.; Eckert, N.; Vincent, C.

2018-01-01

Recent record-breaking glacier melt values are attributable to peculiar extreme events and long-term warming trends that shift averages upward. Analyzing one of the world's longest mass balance series with extreme value statistics, we show that detrending melt anomalies makes it possible to disentangle these effects, leading to a fairer evaluation of the return period of melt extreme values such as 2003, and to characterize them by a more realistic bounded behavior. Using surface energy balance simulations, we show that three independent drivers control melt: global radiation, latent heat, and the amount of snow at the beginning of the melting season. Extremes are governed by large deviations in global radiation combined with sensible heat. Long-term trends are driven by the lengthening of melt duration due to earlier and longer-lasting melting of ice along with melt intensification caused by trends in long-wave irradiance and latent heat due to higher air moisture.

Near-tetraploidy is associated with Richter transformation in chronic lymphocytic leukemia patients receiving ibrutinib.

PubMed

Miller, Cecelia R; Ruppert, Amy S; Heerema, Nyla A; Maddocks, Kami J; Labanowska, Jadwiga; Breidenbach, Heather; Lozanski, Gerard; Zhao, Weiqiang; Gordon, Amber L; Jones, Jeffrey A; Flynn, Joseph M; Jaglowski, Samantha M; Andritsos, Leslie A; Blum, Kristie A; T Awan, Farrukh; Rogers, Kerry A; Grever, Michael R; Johnson, Amy J; Abruzzo, Lynne V; Hertlein, Erin K; Blachly, James S; Woyach, Jennifer A; Byrd, John C

2017-08-22

Ibrutinib is a highly effective targeted therapy for chronic lymphocytic leukemia (CLL). However, ibrutinib must be discontinued in a subset of patients due to progressive CLL or transformation to aggressive lymphoma (Richter transformation). Transformation occurs early in the course of therapy and has an extremely poor prognosis. Thus, identification of prognostic markers associated with transformation is of utmost importance. Near-tetraploidy (4 copies of most chromosomes within a cell) has been reported in various lymphomas, but its incidence and significance in CLL has not been described. Using fluorescence in situ hybridization, we detected near-tetraploidy in 9 of 297 patients with CLL prior to beginning ibrutinib treatment on 1 of 4 clinical trials (3.0%; 95% confidence interval [CI], 1.4%-5.7%). Near-tetraploidy was associated with aggressive disease characteristics: Rai stage 3/4 ( P = .03), deletion 17p ( P = .03), and complex karyotype ( P = .01). Near-tetraploidy was also associated with ibrutinib discontinuation due to Richter transformation ( P < .0001), but not due to progressive CLL ( P = .41). Of the 9 patients with near-tetraploidy, 6 had Richter transformation with diffuse large B-cell lymphoma. In a multivariable model, near-tetraploidy (hazard ratio [HR], 8.66; 95% CI, 3.83-19.59; P < .0001) and complex karyotype (HR, 4.77; 95% CI, 1.42-15.94; P = .01) were independent risk factors for discontinuing ibrutinib due to transformation. Our results suggest that near-tetraploidy is a potential prognostic marker for Richter transformation to assess in patients going on ibrutinib.

A review of droughts on the African continent: a geospatial and long-term perspective

NASA Astrophysics Data System (ADS)

Masih, I.; Maskey, S.; Mussá, F. E. F.; Trambauer, P.

2014-09-01

This paper presents a comprehensive review and analysis of the available literature and information on droughts to build a continental, regional and country level perspective on geospatial and temporal variation of droughts in Africa. The study is based on the review and analysis of droughts occurred during 1900-2013, as well as evidence available from past centuries based on studies on the lake sediment analysis, tree-ring chronologies and written and oral histories and future predictions from the global climate change models. Most of the studies based on instrumental records indicate that droughts have become more frequent, intense and widespread during the last 50 years. The extreme droughts of 1972-1973, 1983-1984 and 1991-1992 were continental in nature and stand unique in the available records. Additionally, many severe and prolonged droughts were recorded in the recent past such as the 1999-2002 drought in northwest Africa, 1970s and 1980s droughts in western Africa (Sahel), 2010-2011 drought in eastern Africa (Horn of Africa) and 2001-2003 drought in southern and southeastern Africa, to name a few. The available (though limited) evidence before the 20th century confirms the occurrence of several extreme and multi-year droughts during each century, with the most prolonged and intense droughts that occurred in Sahel and equatorial eastern Africa. The complex and highly variant nature of many physical mechanisms such as El Niño-Southern Oscillation (ENSO), sea surface temperature (SST) and land-atmosphere feedback adds to the daunting challenge of drought monitoring and forecasting. The future predictions of droughts based on global climate models indicate increased droughts and aridity at the continental scale but large differences exist due to model limitations and complexity of the processes especially for Sahel and northern Africa. However, the available evidence from the past clearly shows that the African continent is likely to face extreme and widespread droughts in future. This evident challenge is likely to aggravate due to slow progress in drought risk management, increased population and demand for water and degradation of land and environment. Thus, there is a clear need for increased and integrated efforts in drought mitigation to reduce the negative impacts of droughts anticipated in the future.

A review of droughts in the African continent: a geospatial and long-term perspective

NASA Astrophysics Data System (ADS)

Masih, I.; Maskey, S.; Mussá, F. E. F.; Trambauer, P.

2014-03-01

This paper presents a comprehensive review and analysis of the available literature and information on droughts to build a continental, regional and country level perspective on geospatial and temporal variation of droughts in Africa. The study is based on the review and analysis of droughts occurred during 1900-2013 as well as evidence available from past centuries based on studies on the lake sediment analysis, tree-ring chronologies and written and oral histories and future predictions from the global climate change models. Most of the studies based on instrumental records indicate that droughts have become more frequent, intense and widespread during the last 50 yr. The extreme droughts of 1972-1973, 1983-1984 and 1991-1992 were continental in nature and stand unique in the available records. Additionally, many severe and prolonged droughts were recorded in the recent past such as the 1999-2002 drought in Northwest Africa, 1970s and 1980s droughts in West Africa (Sahel), 2010-2011 drought in East Africa (Horn of Africa) and 2001-2003 drought in Southern and Southeast Africa, to name a few. The available (though limited) evidence before the 20th century confirms the occurrence of several extreme and multi-year droughts during each century, with the most prolonged and intense droughts that occurred in Sahel and Equatorial East Africa regions. Complex and highly variant nature of many physical mechanisms such as El Niño-Southern Oscillation (ENSO), Sea Surface Temperature (SST) and land-atmosphere feedback adds to the daunting challenge of drought monitoring and forecasting. The future predictions of droughts based on global climate models indicate increased droughts and aridity at the continental scale but large differences exist due to model limitations and complexity of the processes especially for Sahel and North Africa regions. However, the available evidence from the past clearly shows that the African continent is likely to face extreme and widespread droughts in future. This evident challenge is likely to aggravate due to slow progress in drought risk management, increased population and demand for water and degradation of land and environment. Thus, there is a clear need for increased and integrated efforts in drought mitigation to reduce the negative impacts of droughts anticipated in future.

Uncertainty quantification in flood risk assessment

NASA Astrophysics Data System (ADS)

Blöschl, Günter; Hall, Julia; Kiss, Andrea; Parajka, Juraj; Perdigão, Rui A. P.; Rogger, Magdalena; Salinas, José Luis; Viglione, Alberto

2017-04-01

Uncertainty is inherent to flood risk assessments because of the complexity of the human-water system, which is characterised by nonlinearities and interdependencies, because of limited knowledge about system properties and because of cognitive biases in human perception and decision-making. On top of the uncertainty associated with the assessment of the existing risk to extreme events, additional uncertainty arises because of temporal changes in the system due to climate change, modifications of the environment, population growth and the associated increase in assets. Novel risk assessment concepts are needed that take into account all these sources of uncertainty. They should be based on the understanding of how flood extremes are generated and how they change over time. They should also account for the dynamics of risk perception of decision makers and population in the floodplains. In this talk we discuss these novel risk assessment concepts through examples from Flood Frequency Hydrology, Socio-Hydrology and Predictions Under Change. We believe that uncertainty quantification in flood risk assessment should lead to a robust approach of integrated flood risk management aiming at enhancing resilience rather than searching for optimal defense strategies.

Quasiparticle Lifetime Broadening in Resonant X-ray Scattering of NH4NO3.

PubMed

Vinson, John; Jach, Terrence; Müller, Matthias; Unterumsberger, Rainer; Beckhoff, Burkhard

2016-07-15

It has been previously shown that two effects cause dramatic changes in the x-ray absorption and emission spectra from the N K edge of the insulating crystal ammonium nitrate. First, vibrational disorder causes major changes in the absorption spectrum, originating not only from the thermal population of phonons, but, significantly, from zero-point motion as well. Second, the anomalously large broadening ( ~ 4 eV) of the emission originating from nitrate σ states is due to unusually short lifetimes of quasiparticles in an otherwise extremely narrow band. In this work we investigate the coupling of these effects to core and valence excitons that are created as the initial x-ray excitation energy is progressively reduced toward the N edge. Using a GW /Bethe-Salpeter approach, we show the extent to which this anomalous broadening is captured by the GW approximation. The data and calculations demonstrate the importance that the complex self-energies (finite lifetimes) of valence bands have on the interpretation of emission spectra. We produce a scheme to explain why extreme lifetimes should appear in σ states of other similar compounds.

Changes in extreme events and the potential impacts on human health.

PubMed

Bell, Jesse E; Brown, Claudia Langford; Conlon, Kathryn; Herring, Stephanie; Kunkel, Kenneth E; Lawrimore, Jay; Luber, George; Schreck, Carl; Smith, Adam; Uejio, Christopher

2018-04-01

Extreme weather and climate-related events affect human health by causing death, injury, and illness, as well as having large socioeconomic impacts. Climate change has caused changes in extreme event frequency, intensity, and geographic distribution, and will continue to be a driver for change in the future. Some of these events include heat waves, droughts, wildfires, dust storms, flooding rains, coastal flooding, storm surges, and hurricanes. The pathways connecting extreme events to health outcomes and economic losses can be diverse and complex. The difficulty in predicting these relationships comes from the local societal and environmental factors that affect disease burden. More information is needed about the impacts of climate change on public health and economies to effectively plan for and adapt to climate change. This paper describes some of the ways extreme events are changing and provides examples of the potential impacts on human health and infrastructure. It also identifies key research gaps to be addressed to improve the resilience of public health to extreme events in the future. Extreme weather and climate events affect human health by causing death, injury, and illness, as well as having large socioeconomic impacts. Climate change has caused changes in extreme event frequency, intensity, and geographic distribution, and will continue to be a driver for change in the future. Some of these events include heat waves, droughts, wildfires, flooding rains, coastal flooding, surges, and hurricanes. The pathways connecting extreme events to health outcomes and economic losses can be diverse and complex. The difficulty in predicting these relationships comes from the local societal and environmental factors that affect disease burden.

Inter-model variability in hydrological extremes projections for Amazonian sub-basins

NASA Astrophysics Data System (ADS)

Andres Rodriguez, Daniel; Garofolo, Lucas; Lázaro de Siqueira Júnior, José; Samprogna Mohor, Guilherme; Tomasella, Javier

2014-05-01

Irreducible uncertainties due to knowledge's limitations, chaotic nature of climate system and human decision-making process drive uncertainties in Climate Change projections. Such uncertainties affect the impact studies, mainly when associated to extreme events, and difficult the decision-making process aimed at mitigation and adaptation. However, these uncertainties allow the possibility to develop exploratory analyses on system's vulnerability to different sceneries. The use of different climate model's projections allows to aboard uncertainties issues allowing the use of multiple runs to explore a wide range of potential impacts and its implications for potential vulnerabilities. Statistical approaches for analyses of extreme values are usually based on stationarity assumptions. However, nonstationarity is relevant at the time scales considered for extreme value analyses and could have great implications in dynamic complex systems, mainly under climate change transformations. Because this, it is required to consider the nonstationarity in the statistical distribution parameters. We carried out a study of the dispersion in hydrological extremes projections using climate change projections from several climate models to feed the Distributed Hydrological Model of the National Institute for Spatial Research, MHD-INPE, applied in Amazonian sub-basins. This model is a large-scale hydrological model that uses a TopModel approach to solve runoff generation processes at the grid-cell scale. MHD-INPE model was calibrated for 1970-1990 using observed meteorological data and comparing observed and simulated discharges by using several performance coeficients. Hydrological Model integrations were performed for present historical time (1970-1990) and for future period (2010-2100). Because climate models simulate the variability of the climate system in statistical terms rather than reproduce the historical behavior of climate variables, the performances of the model's runs during the historical period, when feed with climate model data, were tested using descriptors of the Flow Duration Curves. The analyses of projected extreme values were carried out considering the nonstationarity of the GEV distribution parameters and compared with extremes events in present time. Results show inter-model variability in a broad dispersion on projected extreme's values. Such dispersion implies different degrees of socio-economic impacts associated to extreme hydrological events. Despite the no existence of one optimum result, this variability allows the analyses of adaptation strategies and its potential vulnerabilities.

Mean and extreme sea level changes in the southwestern Baltic Sea

NASA Astrophysics Data System (ADS)

Schmidt, Jessica; Patzke, Justus; Dangendorf, Sönke; Arns, Arne; Jensen, Jürgen; Fröhle, Peter

2016-04-01

In this contribution an overview over the BMBF project AMSeL_Ostsee (2015-2018) for the assessment of mean and extreme sea level changes over the past 150 years in the southwestern Baltic Sea is presented. We compile several high resolution tide gauge records provided by the Water and Shipping Administration (WSV) along the German Baltic Sea coastline and merge them in internationally available data bases (UHSLC, PSMSL, and data officially available at national authorities). In addition, we make efforts in digitizing historical records to expand the number of available data sets in this complex and vulnerable coastal region. To separate absolute from relative long-term changes in sea level the vertical land motion (VLM) at specific sites is assessed. Possible sources of VLM are independently assessed by using different state-of-the-art approaches, that is: Glacial Isostatic Adjustment (GIA) modelled by viscoelastic Earth models, GPS derived VLM, and the difference between tide gauge and nearby satellite altimetry. The VLM corrected tide gauge records are further assessed for linear and non-linear trends as well as possible acceleration/deceleration patterns by applying advanced time series models such as Singular System Analysis (SSA) combined with a Monte-Carlo-Autoregressive-Padding approach (Wahl et al., 2010). These trend assessments are applied to mean and extreme sea levels independently to prove whether observed changes in extremes are either due to an underlying trend on mean sea levels or changes in storminess. References: Wahl, T., Jensen, J., Frank, T. (2011): On analysing sea level rise in the German Bight since 1844, NHESS, 10, 171-179.

Dynamical properties and extremes of Northern Hemisphere climate fields over the past 60 years

NASA Astrophysics Data System (ADS)

Faranda, Davide; Messori, Gabriele; Alvarez-Castro, M. Carmen; Yiou, Pascal

2017-12-01

Atmospheric dynamics are described by a set of partial differential equations yielding an infinite-dimensional phase space. However, the actual trajectories followed by the system appear to be constrained to a finite-dimensional phase space, i.e. a strange attractor. The dynamical properties of this attractor are difficult to determine due to the complex nature of atmospheric motions. A first step to simplify the problem is to focus on observables which affect - or are linked to phenomena which affect - human welfare and activities, such as sea-level pressure, 2 m temperature, and precipitation frequency. We make use of recent advances in dynamical systems theory to estimate two instantaneous dynamical properties of the above fields for the Northern Hemisphere: local dimension and persistence. We then use these metrics to characterize the seasonality of the different fields and their interplay. We further analyse the large-scale anomaly patterns corresponding to phase-space extremes - namely time steps at which the fields display extremes in their instantaneous dynamical properties. The analysis is based on the NCEP/NCAR reanalysis data, over the period 1948-2013. The results show that (i) despite the high dimensionality of atmospheric dynamics, the Northern Hemisphere sea-level pressure and temperature fields can on average be described by roughly 20 degrees of freedom; (ii) the precipitation field has a higher dimensionality; and (iii) the seasonal forcing modulates the variability of the dynamical indicators and affects the occurrence of phase-space extremes. We further identify a number of robust correlations between the dynamical properties of the different variables.

Defining Extreme Events: A Cross-Disciplinary Review

NASA Astrophysics Data System (ADS)

McPhillips, Lauren E.; Chang, Heejun; Chester, Mikhail V.; Depietri, Yaella; Friedman, Erin; Grimm, Nancy B.; Kominoski, John S.; McPhearson, Timon; Méndez-Lázaro, Pablo; Rosi, Emma J.; Shafiei Shiva, Javad

2018-03-01

Extreme events are of interest worldwide given their potential for substantial impacts on social, ecological, and technical systems. Many climate-related extreme events are increasing in frequency and/or magnitude due to anthropogenic climate change, and there is increased potential for impacts due to the location of urbanization and the expansion of urban centers and infrastructures. Many disciplines are engaged in research and management of these events. However, a lack of coherence exists in what constitutes and defines an extreme event across these fields, which impedes our ability to holistically understand and manage these events. Here, we review 10 years of academic literature and use text analysis to elucidate how six major disciplines—climatology, earth sciences, ecology, engineering, hydrology, and social sciences—define and communicate extreme events. Our results highlight critical disciplinary differences in the language used to communicate extreme events. Additionally, we found a wide range in definitions and thresholds, with more than half of examined papers not providing an explicit definition, and disagreement over whether impacts are included in the definition. We urge distinction between extreme events and their impacts, so that we can better assess when responses to extreme events have actually enhanced resilience. Additionally, we suggest that all researchers and managers of extreme events be more explicit in their definition of such events as well as be more cognizant of how they are communicating extreme events. We believe clearer and more consistent definitions and communication can support transdisciplinary understanding and management of extreme events.

Examining global extreme sea level variations on the coast from in-situ and remote observations

NASA Astrophysics Data System (ADS)

Menendez, Melisa; Benkler, Anna S.

2017-04-01

The estimation of extreme water level values on the coast is a requirement for a wide range of engineering and coastal management applications. In addition, climate variations of extreme sea levels on the coastal area result from a complex interacting of oceanic, atmospheric and terrestrial processes across a wide range of spatial and temporal scales. In this study, variations of extreme sea level return values are investigated from two available sources of information: in-situ tide-gauge records and satellite altimetry data. Long time series of sea level from tide-gauge records are the most valuable observations since they directly measure water level in a specific coastal location. They have however a number of sources of in-homogeneities that may affect the climate description of extremes when this data source is used. Among others, the presence of gaps, historical time in-homogeneities and jumps in the mean sea level signal are factors that can provide uncertainty in the characterization of the extreme sea level behaviour. Moreover, long records from tide-gauges are sparse and there are many coastal areas worldwide without in-situ available information. On the other hand, with the accumulating altimeter records of several satellite missions from the 1990s, approaching 25 recorded years at the time of writing, it is becoming possible the analysis of extreme sea level events from this data source. Aside the well-known issue of altimeter measurements very close to the coast (mainly due to corruption by land, wet troposphere path delay errors and local tide effects on the coastal area), there are other aspects that have to be considered when sea surface height values estimated from satellite are going to be used in a statistical extreme model, such as the use of a multi-mission product to get long observed periods and the selection of the maxima sample, since altimeter observations do not provide values uniform in time and space. Here, we have compared the extreme values of 'still water level' and 'non-tidal-residual' of in-situ records from the GESLA2 dataset (Woodworth et al. 2016) against the novel coastal altimetry datasets (Cipollini et al. 2016). Seasonal patterns, inter-annual variability and long-term trends are analyzed. Then, a time-dependent extreme model (Menendez et al. 2009) is applied to characterize extreme sea level return values and their variability on the coastal area around the world.

Efficient methods and readily customizable libraries for managing complexity of large networks.

PubMed

Dogrusoz, Ugur; Karacelik, Alper; Safarli, Ilkin; Balci, Hasan; Dervishi, Leonard; Siper, Metin Can

2018-01-01

One common problem in visualizing real-life networks, including biological pathways, is the large size of these networks. Often times, users find themselves facing slow, non-scaling operations due to network size, if not a "hairball" network, hindering effective analysis. One extremely useful method for reducing complexity of large networks is the use of hierarchical clustering and nesting, and applying expand-collapse operations on demand during analysis. Another such method is hiding currently unnecessary details, to later gradually reveal on demand. Major challenges when applying complexity reduction operations on large networks include efficiency and maintaining the user's mental map of the drawing. We developed specialized incremental layout methods for preserving a user's mental map while managing complexity of large networks through expand-collapse and hide-show operations. We also developed open-source JavaScript libraries as plug-ins to the web based graph visualization library named Cytsocape.js to implement these methods as complexity management operations. Through efficient specialized algorithms provided by these extensions, one can collapse or hide desired parts of a network, yielding potentially much smaller networks, making them more suitable for interactive visual analysis. This work fills an important gap by making efficient implementations of some already known complexity management techniques freely available to tool developers through a couple of open source, customizable software libraries, and by introducing some heuristics which can be applied upon such complexity management techniques to ensure preserving mental map of users.

Atmospheric Extremes in a Changing Climate: A Strategy for Improved Understanding Driven by International Security Concerns

NASA Astrophysics Data System (ADS)

Davis, A. B.; Kao, C. J.

2001-05-01

The overarching mission of Los Alamos National Laboratory is to use science and technology to reduce nuclear danger. In the complex multipolar reality of the post cold-war era, this core mission is naturally enlarged to include all weapons of mass destruction (nuclear, chemical, and biological) as well as acts of terrorism. Traditionally, LANL and other institutions in the DOE weapons complex pay little attention to the reasons a country or group of individuals chooses the road of proliferation. That is considered a ``soft'' science at best and, at any rate, is left to other government agencies, their non-governmental and their international partners. However, this division-of-labor overlooks an area of challenging science where DOE laboratories such as LANL, in partnership with academia, can offer valuable insight into a sensitive ``trigger'' in the proliferation process. Indeed, a population subjected to catastrophic environmental degradation becomes far more likely to endorse a proliferant regime or spawn terrorist groups simply because it has little more to lose. Once physical health and economic survival is in jeopardy, whole populations and individuals alike become desperate. This situation is more easily exploited politically than remedied through international aid, especially when the region is already volatile. Scenarios of political de-stabilization due to environmental degradation become even more likely when reminded that the planet is gradually warming and, quite possibly, this trend in the mean will drive changes in extreme weather patterns, quite possibly, for the worse in terms of intensity, duration and frequency. Of the long list of natural disasters that threaten populations and infrastructure, most involve the atmosphere, largely because it is the least inert (hence most turbulent) of the geophysical fluids. Furthermore, the dominant nonlinear response in a complex socio-environmental system is generically not to a change in the mean, but to a critical threshold crossing. So extreme atmospheric phenomena are of the essence yet they are poorly understood, even in a steady climate, because they challenge both dynamical modelers and statisticians. The authors will describe a preliminary proposal to harness some of the unique human, computational and observational resources at LANL that could lead to a significant breakthrough in our understanding of extreme weather mechanisms and how they relate to climate and climate change. If implemented, this program could open new relationships between the laboratory and presently unsuspecting client-agencies such as FEMA, CDC, EPA, State Department, and so on.

A statistical mechanics approach to computing rare transitions in multi-stable turbulent geophysical flows

NASA Astrophysics Data System (ADS)

Laurie, J.; Bouchet, F.

2012-04-01

Many turbulent flows undergo sporadic random transitions, after long periods of apparent statistical stationarity. For instance, paths of the Kuroshio [1], the Earth's magnetic field reversal, atmospheric flows [2], MHD experiments [3], 2D turbulence experiments [4,5], 3D flows [6] show this kind of behavior. The understanding of this phenomena is extremely difficult due to the complexity, the large number of degrees of freedom, and the non-equilibrium nature of these turbulent flows. It is however a key issue for many geophysical problems. A straightforward study of these transitions, through a direct numerical simulation of the governing equations, is nearly always impracticable. This is mainly a complexity problem, due to the large number of degrees of freedom involved for genuine turbulent flows, and the extremely long time between two transitions. In this talk, we consider two-dimensional and geostrophic turbulent models, with stochastic forces. We consider regimes where two or more attractors coexist. As an alternative to direct numerical simulation, we propose a non-equilibrium statistical mechanics approach to the computation of this phenomenon. Our strategy is based on large deviation theory [7], derived from a path integral representation of the stochastic process. Among the trajectories connecting two non-equilibrium attractors, we determine the most probable one. Moreover, we also determine the transition rates, and in which cases this most probable trajectory is a typical one. Interestingly, we prove that in the class of models we consider, a mechanism exists for diffusion over sets of connected attractors. For the type of stochastic forces that allows this diffusion, the transition between attractors is not a rare event. It is then very difficult to characterize the flow as bistable. However for another class of stochastic forces, this diffusion mechanism is prevented, and genuine bistability or multi-stability is observed. We discuss how these results are probably connected to the long debated existence of multi-stability in the atmosphere and oceans.

Integration of modern statistical tools for the analysis of climate extremes into the web-GIS “CLIMATE”

NASA Astrophysics Data System (ADS)

Ryazanova, A. A.; Okladnikov, I. G.; Gordov, E. P.

2017-11-01

The frequency of occurrence and magnitude of precipitation and temperature extreme events show positive trends in several geographical regions. These events must be analyzed and studied in order to better understand their impact on the environment, predict their occurrences, and mitigate their effects. For this purpose, we augmented web-GIS called “CLIMATE” to include a dedicated statistical package developed in the R language. The web-GIS “CLIMATE” is a software platform for cloud storage processing and visualization of distributed archives of spatial datasets. It is based on a combined use of web and GIS technologies with reliable procedures for searching, extracting, processing, and visualizing the spatial data archives. The system provides a set of thematic online tools for the complex analysis of current and future climate changes and their effects on the environment. The package includes new powerful methods of time-dependent statistics of extremes, quantile regression and copula approach for the detailed analysis of various climate extreme events. Specifically, the very promising copula approach allows obtaining the structural connections between the extremes and the various environmental characteristics. The new statistical methods integrated into the web-GIS “CLIMATE” can significantly facilitate and accelerate the complex analysis of climate extremes using only a desktop PC connected to the Internet.

Affective temperament and executive functions in emergency medicine professionals.

PubMed

Jaracz, Marcin; Paciorek, Przemysław; Buciński, Adam; Borkowska, Alina

2014-10-01

Recent studies indicate that choice of profession is related to differences in affective temperament, which is probably due to various predispositions needed to efficiently perform particular professions. The aim of the present study was to assess affective temperament and executive functions in a sample of emergency medicine professionals. 75 emergency medicine professionals were enrolled in the study. Affective temperament was assessed by means of TEMPS-A. Executive functions were assessed by means of Trail Making Test and Stroop Color Word Interference Test. Subjects showed significantly higher rates of hyperthymic, compared to depressive, cyclothymic, irritable and anxious temperaments. The principal component analysis revealed that hyperthymic temperament contributes to a different factor, than the remaining ones. Higher rates of depressive, cyclothymic, irritable and anxious temperaments were related to poorer performance in Trail Making Test, whereas hyperthymic temperament had the opposite effect. Due to the size of the sample, results of the present study may have lacked power to show all the relationships between tested variables. Hyperthymic temperament promotes efficient performance of complex tasks under time pressure. Depressive, cyclothymic, irritable and anxious temperaments have the opposite effect. This makes hyperthymic temperament a desirable trait in emergency medicine professionals, performing complex medical tasks under extreme conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

Optimal and fast rotational alignment of volumes with missing data in Fourier space.

PubMed

Shatsky, Maxim; Arbelaez, Pablo; Glaeser, Robert M; Brenner, Steven E

2013-11-01

Electron tomography of intact cells has the potential to reveal the entire cellular content at a resolution corresponding to individual macromolecular complexes. Characterization of macromolecular complexes in tomograms is nevertheless an extremely challenging task due to the high level of noise, and due to the limited tilt angle that results in missing data in Fourier space. By identifying particles of the same type and averaging their 3D volumes, it is possible to obtain a structure at a more useful resolution for biological interpretation. Currently, classification and averaging of sub-tomograms is limited by the speed of computational methods that optimize alignment between two sub-tomographic volumes. The alignment optimization is hampered by the fact that the missing data in Fourier space has to be taken into account during the rotational search. A similar problem appears in single particle electron microscopy where the random conical tilt procedure may require averaging of volumes with a missing cone in Fourier space. We present a fast implementation of a method guaranteed to find an optimal rotational alignment that maximizes the constrained cross-correlation function (cCCF) computed over the actual overlap of data in Fourier space. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

Wound ballistics and blast injuries.

PubMed

Prat, N J; Daban, J-L; Voiglio, E J; Rongieras, F

2017-12-01

Wounds due to gunshot and explosions, while usually observed during battlefield combat, are no longer an exceptional occurrence in civilian practice in France. The principles of wound ballistics are based on the interaction between the projectile and the human body as well as the transfer of energy from the projectile to tissues. The treatment of ballistic wounds relies on several principles: extremity wound debridement and absence of initial closure, complementary medical treatment, routine immobilization, revision surgery and secondary closure. Victims of explosions usually present with a complex clinical picture since injuries are directly or indirectly related to the shock wave (blast) originating from the explosion. These injuries depend on the type of explosive device, the environment and the situation of the victim at the time of the explosion, and are classed as primary, secondary, tertiary or quaternary. Secondary injuries due to flying debris and bomb fragments are generally the predominant presenting symptoms while isolated primary injuries (blast) are rare. The resulting complexity of the clinical picture explains why triage of these victims is particularly difficult. Certain myths, such as inevitable necrosis of the soft tissues that are displaced by the formation of the temporary cavitation by the projectile, or sterilization of the wounds by heat generated by the projectile should be forgotten. Ballistic-protective body armor and helmets are not infallible, even when they are not perforated, and can even be at the origin of injuries, either due to missile impact, or to the blast. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Within-summer variation in out-of-hospital cardiac arrest due to extremely long sunshine duration.

PubMed

Onozuka, Daisuke; Hagihara, Akihito

2017-03-15

Although several studies have reported the impacts of extremely high temperatures on cardiovascular diseases, no studies have examined whether variation in out-of-hospital cardiac arrest (OHCA) due to extremely long sunshine duration changes during the summer. We obtained daily data on all cases of OHCA and weather variations for all 47 prefectures of Japan during the summer (June to September) between 2005 and 2014. A distributed lag non-linear model combined with a quasi-Poisson regression model was used to estimate within-summer variation in OHCA due to extremely long sunshine duration for each prefecture. Then, multivariate random-effects meta-analysis was performed to derive overall effect estimates of sunshine duration at the national level. A total of 166,496 OHCAs of presumed cardiac origin met the inclusion criteria. The minimum morbidity percentile (MMP) was the 0th percentile of sunshine duration at the national level. The overall cumulative relative risk (RR) at the 99th percentile vs. the MMP was 1.15 (95% CI: 1.05-1.27) during the summer. The effect of extremely long sunshine duration on OHCA in early summer was acute and did not persist, whereas an identical effect was observed in late summer, but it was delayed and lasted for several days. During summer periods, excessive sunshine duration could increase the risk of OHCA. Timely preventive measures to reduce the OHCA risk due to extremely long sunshine duration are important in early summer, whereas these measures could include a wider time window of several days to reduce the risk in late summer. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Assessing the effects of Climate Change on Urban Pluvial Flooding to provide a Risk Management Framework

NASA Astrophysics Data System (ADS)

Rianna, G.; Mercogliano, P.

2017-12-01

Urbanization increases the flood risk because of heightened vulnerability, stemming from population concentration and hazard due to soil sealing affecting the largest part of urban settlements and reducing the concentration time of interested basins. Furthermore, current and future hazards are exacerbated by expected increases in extreme rainfall events due to Climate Changes (CC) making inadequate urban drainage infrastructures designed under the assumption of steady conditions. In this work, we present a modeling chain/algorithm to assess potential increase in pluvial flood hazard able to take into account CC forcing. The adopted simulation chain reckon on three main elements: Regional Climate Model, COSMO_CLM, dynamically downscaling GCM CMCC_CM (Scoccimarro et al., 2011) and optimized, at high resolution (about 8km), by Bucchignani et al. (2015) on Italy provide projections about precipitation up to 2100 under two concentration scenarios (RCP4.5 and RCP8.5). Such projections are used in Equidistance Quantile Mapping (EQM) approach, developed by Srivastav et al. (2014) to estimate expected variations in IDF (Intensity-Duration-Frequency) curves calculated through Generalized Extreme Value (GEV) approach on the basis of available rainfall data. To this aim, 1971-2000 observations are used as reference. Finally, a 1-D/2-D coupled urban drainage/flooding model forced by IDF (current and projected) is used to simulate storm-sewer surcharge and surface inundation to establish the variations in urban flooding risk. As test case is considered the city center of Naples (Southern Italy). In this respective, the sewage and urban drainage network is highly complex due to the historical and subsequent transformations of the city. Under such constraints, the reliability of the results maybe deeply conditioned by uncertainties not undermining the illustrative purposes of the work. Briefly, EQM returns a remarkable increase in extreme precipitations; such increase is driven by concentration scenarios (higher for RCP8.5) and investigated time horizon (more significant for 2071-2100 time span). Furthermore, results provided by hydraulic models clearly highlight the inadequacy of the actual drainage system especially under a RCP8.5-driven scenario showing large portions of the city center flooded.

A cognitive information processing framework for distributed sensor networks

NASA Astrophysics Data System (ADS)

Wang, Feiyi; Qi, Hairong

2004-09-01

In this paper, we present a cognitive agent framework (CAF) based on swarm intelligence and self-organization principles, and demonstrate it through collaborative processing for target classification in sensor networks. The framework involves integrated designs to provide both cognitive behavior at the organization level to conquer complexity and reactive behavior at the individual agent level to retain simplicity. The design tackles various problems in the current information processing systems, including overly complex systems, maintenance difficulties, increasing vulnerability to attack, lack of capability to tolerate faults, and inability to identify and cope with low-frequency patterns. An important and distinguishing point of the presented work from classical AI research is that the acquired intelligence does not pertain to distinct individuals but to groups. It also deviates from multi-agent systems (MAS) due to sheer quantity of extremely simple agents we are able to accommodate, to the degree that some loss of coordination messages and behavior of faulty/compromised agents will not affect the collective decision made by the group.

Molecular typing of Burkholderia cepacia complex isolated from patients attending an Italian Cystic Fibrosis Centre.

PubMed

Teri, Antonio; Sottotetti, Samantha; Biffi, Arianna; Girelli, Daniela; D'Accico, Monica; Arghittu, Milena; Colombo, Carla; Corti, Fabiola; Pizzamiglio, Giovanna; Cariani, Lisa

2018-04-01

Bacteria from the Burkholderia cepacia complex (Bcc) are capable of causing severe infections in patients with cystic fibrosis (CF). Bcc infection is often extremely difficult to treat due to its intrinsic resistance to multiple antibiotics. In addition, it seems to speed up the decline of lung function and is considered a contraindication for lung transplantation in CF. This study investigates the species of the Bcc strains recovered from chronically infected CF subjects by means of: isolation, identification methods and complete recA nucleotide sequences of 151 samples. Molecular typing showed that B. cenocepacia III is the dominant strain found in the group of subjects being treated at the Milan CF Centre (Italy) and that the infection is chronically maintained by the same species. Defining species by means of molecular analysis yields important information for the clinician in order to establish the most appropriate therapy and implement correct measures for prevention of transmission among CF subjects.

Modification of the SERS spectrum of cyanide traces due to complex formation between cyanide and silver

NASA Astrophysics Data System (ADS)

Cao Dao, Tran; Kieu, Ngoc Minh; Quynh Ngan Luong, Truc; Cao, Tuan Anh; Hai Nguyen, Ngoc; Le, Van Vu

2018-06-01

It is well known that cyanide is an extremely toxic lethal poison with human death within minutes after exposure to only 300 ppm cyanide. On the other hand, cyanide is released into the environment (mainly through waste water) every day from various human activities. Therefore, rapid, sensitive and cost-effective cyanide trace detection is an urgent need. Surface-enhanced Raman scattering (SERS) is a method that meets these requirements. It should be noted, however, that in this technique SERS substrates, which are usually made of gold or silver, will be leached with aqueous cyanide by the formation of complexes between gold or silver with cyanide. This will cause the SERS spectrum of cyanide to be modified. When determining cyanide concentrations by SERS analysis, this spectral modification should be taken into account. This report presents the SERS spectral modification of aqueous cyanide traces (in ppm and lower concentration range) when the SERS substrates used are flower-like silver micro-structures.

Reaction factoring and bipartite update graphs accelerate the Gillespie Algorithm for large-scale biochemical systems.

PubMed

Indurkhya, Sagar; Beal, Jacob

2010-01-06

ODE simulations of chemical systems perform poorly when some of the species have extremely low concentrations. Stochastic simulation methods, which can handle this case, have been impractical for large systems due to computational complexity. We observe, however, that when modeling complex biological systems: (1) a small number of reactions tend to occur a disproportionately large percentage of the time, and (2) a small number of species tend to participate in a disproportionately large percentage of reactions. We exploit these properties in LOLCAT Method, a new implementation of the Gillespie Algorithm. First, factoring reaction propensities allows many propensities dependent on a single species to be updated in a single operation. Second, representing dependencies between reactions with a bipartite graph of reactions and species requires only storage for reactions, rather than the required for a graph that includes only reactions. Together, these improvements allow our implementation of LOLCAT Method to execute orders of magnitude faster than currently existing Gillespie Algorithm variants when simulating several yeast MAPK cascade models.

Reaction Factoring and Bipartite Update Graphs Accelerate the Gillespie Algorithm for Large-Scale Biochemical Systems

PubMed Central

Indurkhya, Sagar; Beal, Jacob

2010-01-01

ODE simulations of chemical systems perform poorly when some of the species have extremely low concentrations. Stochastic simulation methods, which can handle this case, have been impractical for large systems due to computational complexity. We observe, however, that when modeling complex biological systems: (1) a small number of reactions tend to occur a disproportionately large percentage of the time, and (2) a small number of species tend to participate in a disproportionately large percentage of reactions. We exploit these properties in LOLCAT Method, a new implementation of the Gillespie Algorithm. First, factoring reaction propensities allows many propensities dependent on a single species to be updated in a single operation. Second, representing dependencies between reactions with a bipartite graph of reactions and species requires only storage for reactions, rather than the required for a graph that includes only reactions. Together, these improvements allow our implementation of LOLCAT Method to execute orders of magnitude faster than currently existing Gillespie Algorithm variants when simulating several yeast MAPK cascade models. PMID:20066048

Explosive genetic evidence for explosive human population growth

PubMed Central

Gao, Feng; Keinan, Alon

2016-01-01

The advent of next-generation sequencing technology has allowed the collection of vast amounts of genetic variation data. A recurring discovery from studying larger and larger samples of individuals had been the extreme, previously unexpected, excess of very rare genetic variants, which has been shown to be mostly due to the recent explosive growth of human populations. Here, we review recent literature that inferred recent changes in population size in different human populations and with different methodologies, with many pointing to recent explosive growth, especially in European populations for which more data has been available. We also review the state-of-the-art methods and software for the inference of historical population size changes that lead to these discoveries. Finally, we discuss the implications of recent population growth on personalized genomics, on purifying selection in the non-equilibrium state it entails and, as a consequence, on the genetic architecture underlying complex disease and the performance of mapping methods in discovering rare variants that contribute to complex disease risk. PMID:27710906

Considerations on thermic and mechanic processes that appear when 3D printing using ABS fused deposition modelling technology

NASA Astrophysics Data System (ADS)

Amza, Catalin Gheorghe; Niţoi, Dan Florin

2018-02-01

3D printers are of recent history, but with an extremely rapid evolution both in technology and hardware involved. At present excellent performances are reached in applications such as 3D printing of various Acrylonitrile butadiene styrene (ABS) plastic parts for house building using Fused Deposition Modelling technology. Nevertheless, the thermic and mechanic processes that appear when manufacturing such plastic components are quite complex. This aspect is very important, especially when one wants to optimize the manufacturing of parts with certain geometrical complexity. The Finite Element Analysis/Modelling (FEA/FEM) is among the few methods that can study the thermic transfer processes and shape modifications that can appear due to non-seamar behavior that takes place when the ABS plastic material is cooling down. The current papers present such an analysis when simulating the deposition of several strings of materials. A thermic analysis is made followed by a study of deformations that appear when the structure cools down.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghosh, Subimal; Das, Debasish; Kao, Shih-Chieh

Recent studies disagree on how rainfall extremes over India have changed in space and time over the past half century, as well as on whether the changes observed are due to global warming or regional urbanization. Although a uniform and consistent decrease in moderate rainfall has been reported, a lack of agreement about trends in heavy rainfall may be due in part to differences in the characterization and spatial averaging of extremes. Here we use extreme value theory to examine trends in Indian rainfall over the past half century in the context of long-term, low-frequency variability.We show that when generalizedmore » extreme value theory is applied to annual maximum rainfall over India, no statistically significant spatially uniform trends are observed, in agreement with previous studies using different approaches. Furthermore, our space time regression analysis of the return levels points to increasing spatial variability of rainfall extremes over India. Our findings highlight the need for systematic examination of global versus regional drivers of trends in Indian rainfall extremes, and may help to inform flood hazard preparedness and water resource management in the region.« less

Dialogue-Based Research in Man-Machine Communication

DTIC Science & Technology

1975-11-01

This paper first surveys current knowledge of human communication from a point of view which seeks to find or develop knowledge that will be useful...complexity is explored. Building a useful knowledge of human communication is an extremely complex task. Controlling this complexity and its effects, without

Statistical complexity without explicit reference to underlying probabilities

NASA Astrophysics Data System (ADS)

Pennini, F.; Plastino, A.

2018-06-01

We show that extremely simple systems of a not too large number of particles can be simultaneously thermally stable and complex. To such an end, we extend the statistical complexity's notion to simple configurations of non-interacting particles, without appeal to probabilities, and discuss configurational properties.

Complex Fluids and Hydraulic Fracturing.

PubMed

Barbati, Alexander C; Desroches, Jean; Robisson, Agathe; McKinley, Gareth H

2016-06-07

Nearly 70 years old, hydraulic fracturing is a core technique for stimulating hydrocarbon production in a majority of oil and gas reservoirs. Complex fluids are implemented in nearly every step of the fracturing process, most significantly to generate and sustain fractures and transport and distribute proppant particles during and following fluid injection. An extremely wide range of complex fluids are used: naturally occurring polysaccharide and synthetic polymer solutions, aqueous physical and chemical gels, organic gels, micellar surfactant solutions, emulsions, and foams. These fluids are loaded over a wide range of concentrations with particles of varying sizes and aspect ratios and are subjected to extreme mechanical and environmental conditions. We describe the settings of hydraulic fracturing (framed by geology), fracturing mechanics and physics, and the critical role that non-Newtonian fluid dynamics and complex fluids play in the hydraulic fracturing process.

The Effect of Driver Age On The Incidence And Severity Of Upper Extremity Injuries Due To Second Generation Front Air Bag Deployment

PubMed Central

Marshall, Rafael; Hunting, Katherine; McKay, Mary Pat

2010-01-01

This study used NHTSA NASS/CDS data to examine whether advancing age was associated with a higher incidence and severity of front airbag-related upper extremity injury (UEI). Using a retrospective cohort design we analyzed weighted data from 1998–2007 for. The study population consisted of lap/shoulder belted people over 16 years of age who were driving passenger vehicles with model years 1998–2003 and were involved in a frontal crash where their front airbag deployed. Drivers who were ejected, involved in a vehicle rollover, or accompanied by a passenger sitting directly behind them were omitted. The exposure variable was age and the outcome variables were UEI incidence and severity. Associations were adjusted for gender, seat track position, vehicle type, vehicle weight, intrusion, and delta-v. Logistic regressions were performed using SAS survey procedures to account for the complex survey design. Overall, 42% of drivers sustained an UEI. Advancing age was associated with a higher incidence (p<0. 0001) and severity (p<0. 0001) of UEI. Nineteen percent of drivers sustained an UEI related to the airbag. No significant differences in the incidence or severity of airbag-related UEI were found between young drivers and older driver age groups. The degree of severity due to airbag-related UEI was generally minor. The majority of airbag-related UEI appeared to shift slightly from abrasions to contusions with aging. These results indicate that UEI due to depowered airbag deployment is common but not disproportionately high among older drivers, and injury severity is generally minor across all age groups. PMID:21050604

Potentialities of ensemble strategies for flood forecasting over the Milano urban area

NASA Astrophysics Data System (ADS)

Ravazzani, Giovanni; Amengual, Arnau; Ceppi, Alessandro; Homar, Víctor; Romero, Romu; Lombardi, Gabriele; Mancini, Marco

2016-08-01

Analysis of ensemble forecasting strategies, which can provide a tangible backing for flood early warning procedures and mitigation measures over the Mediterranean region, is one of the fundamental motivations of the international HyMeX programme. Here, we examine two severe hydrometeorological episodes that affected the Milano urban area and for which the complex flood protection system of the city did not completely succeed. Indeed, flood damage have exponentially increased during the last 60 years, due to industrial and urban developments. Thus, the improvement of the Milano flood control system needs a synergism between structural and non-structural approaches. First, we examine how land-use changes due to urban development have altered the hydrological response to intense rainfalls. Second, we test a flood forecasting system which comprises the Flash-flood Event-based Spatially distributed rainfall-runoff Transformation, including Water Balance (FEST-WB) and the Weather Research and Forecasting (WRF) models. Accurate forecasts of deep moist convection and extreme precipitation are difficult to be predicted due to uncertainties arising from the numeric weather prediction (NWP) physical parameterizations and high sensitivity to misrepresentation of the atmospheric state; however, two hydrological ensemble prediction systems (HEPS) have been designed to explicitly cope with uncertainties in the initial and lateral boundary conditions (IC/LBCs) and physical parameterizations of the NWP model. No substantial differences in skill have been found between both ensemble strategies when considering an enhanced diversity of IC/LBCs for the perturbed initial conditions ensemble. Furthermore, no additional benefits have been found by considering more frequent LBCs in a mixed physics ensemble, as ensemble spread seems to be reduced. These findings could help to design the most appropriate ensemble strategies before these hydrometeorological extremes, given the computational cost of running such advanced HEPSs for operational purposes.

Combining local search with co-evolution in a remarkably simple way

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boettcher, S.; Percus, A.

2000-05-01

The authors explore a new general-purpose heuristic for finding high-quality solutions to hard optimization problem. The method, called extremal optimization, is inspired by self-organized criticality, a concept introduced to describe emergent complexity in physical systems. In contrast to genetic algorithms, which operate on an entire gene-pool of possible solutions, extremal optimization successively replaces extremely undesirable elements of a single sub-optimal solution with new, random ones. Large fluctuations, or avalanches, ensue that efficiently explore many local optima. Drawing upon models used to simulate far-from-equilibrium dynamics, extremal optimization complements heuristics inspired by equilibrium statistical physics, such as simulated annealing. With only onemore » adjustable parameter, its performance has proved competitive with more elaborate methods, especially near phase transitions. Phase transitions are found in many combinatorial optimization problems, and have been conjectured to occur in the region of parameter space containing the hardest instances. We demonstrate how extremal optimization can be implemented for a variety of hard optimization problems. We believe that this will be a useful tool in the investigation of phase transitions in combinatorial optimization, thereby helping to elucidate the origin of computational complexity.« less

Recent advances in environmental data mining

NASA Astrophysics Data System (ADS)

Leuenberger, Michael; Kanevski, Mikhail

2016-04-01

Due to the large amount and complexity of data available nowadays in geo- and environmental sciences, we face the need to develop and incorporate more robust and efficient methods for their analysis, modelling and visualization. An important part of these developments deals with an elaboration and application of a contemporary and coherent methodology following the process from data collection to the justification and communication of the results. Recent fundamental progress in machine learning (ML) can considerably contribute to the development of the emerging field - environmental data science. The present research highlights and investigates the different issues that can occur when dealing with environmental data mining using cutting-edge machine learning algorithms. In particular, the main attention is paid to the description of the self-consistent methodology and two efficient algorithms - Random Forest (RF, Breiman, 2001) and Extreme Learning Machines (ELM, Huang et al., 2006), which recently gained a great popularity. Despite the fact that they are based on two different concepts, i.e. decision trees vs artificial neural networks, they both propose promising results for complex, high dimensional and non-linear data modelling. In addition, the study discusses several important issues of data driven modelling, including feature selection and uncertainties. The approach considered is accompanied by simulated and real data case studies from renewable resources assessment and natural hazards tasks. In conclusion, the current challenges and future developments in statistical environmental data learning are discussed. References - Breiman, L., 2001. Random Forests. Machine Learning 45 (1), 5-32. - Huang, G.-B., Zhu, Q.-Y., Siew, C.-K., 2006. Extreme learning machine: theory and applications. Neurocomputing 70 (1-3), 489-501. - Kanevski, M., Pozdnoukhov, A., Timonin, V., 2009. Machine Learning for Spatial Environmental Data. EPFL Press; Lausanne, Switzerland, p.392. - Leuenberger, M., Kanevski, M., 2015. Extreme Learning Machines for spatial environmental data. Computers and Geosciences 85, 64-73.

Multi-Scale Simulations of Past and Future Projections of Hydrology in Lake Tahoe Basin, California-Nevada (Invited)

NASA Astrophysics Data System (ADS)

Niswonger, R. G.; Huntington, J. L.; Dettinger, M. D.; Rajagopal, S.; Gardner, M.; Morton, C. G.; Reeves, D. M.; Pohll, G. M.

2013-12-01

Water resources in the Tahoe basin are susceptible to long-term climate change and extreme events because it is a middle-altitude, snow-dominated basin that experiences large inter-annual climate variations. Lake Tahoe provides critical water supply for its basin and downstream populations, but changes in water supply are obscured by complex climatic and hydrologic gradients across the high relief, geologically complex basin. An integrated surface and groundwater model of the Lake Tahoe basin has been developed using GSFLOW to assess the effects of climate change and extreme events on surface and groundwater resources. Key hydrologic mechanisms are identified with this model that explains recent changes in water resources of the region. Critical vulnerabilities of regional water-supplies and hazards also were explored. Maintaining a balance between (a) accurate representation of spatial features (e.g., geology, streams, and topography) and hydrologic response (i.e., groundwater, stream, lake, and wetland flows and storages), and (b) computational efficiency, is a necessity for the desired model applications. Potential climatic influences on water resources are analyzed here in simulations of long-term water-availability and flood responses to selected 100-year climate-model projections. GSFLOW is also used to simulate a scenario depicting an especially extreme storm event that was constructed from a combination of two historical atmospheric-river storm events as part of the USGS MultiHazards Demonstration Project. Historical simulated groundwater levels, streamflow, wetlands, and lake levels compare well with measured values for a 30-year historical simulation period. Results are consistent for both small and large model grid cell sizes, due to the model's ability to represent water table altitude, streams, and other hydrologic features at the sub-grid scale. Simulated hydrologic responses are affected by climate change, where less groundwater resources will be available during more frequent droughts. Simulated floods for the region indicate issues related to drainage in the developed areas around Lake Tahoe, and necessary dam releases that create downstream flood risks.

Gallium(III) complexes of DOTA and DOTA-monoamide: kinetic and thermodynamic studies.

PubMed

Kubícek, Vojtech; Havlícková, Jana; Kotek, Jan; Tircsó, Gyula; Hermann, Petr; Tóth, Eva; Lukes, Ivan

2010-12-06

Given the practical advantages of the (68)Ga isotope in positron emission tomography applications, gallium complexes are gaining increasing importance in biomedical imaging. However, the strong tendency of Ga(3+) to hydrolyze and the slow formation and very high stability of macrocyclic complexes altogether render Ga(3+) coordination chemistry difficult and explain why stability and kinetic data on Ga(3+) complexes are rather scarce. Here we report solution and solid-state studies of Ga(3+) complexes formed with the macrocyclic ligand 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid, (DOTA)(4-), and its mono(n-butylamide) derivative, (DO3AM(Bu))(3-). Thermodynamic stability constants, log K(GaDOTA) = 26.05 and log K(GaDO3AM(Bu)) = 24.64, were determined by out-of-cell pH-potentiometric titrations. Due to the very slow formation and dissociation of the complexes, equilibration times of up to ∼4 weeks were necessary. The kinetics of complex dissociation were followed by (71)Ga NMR under both acidic and alkaline conditions. The GaDOTA complex is significantly more inert (τ(1/2) ∼12.2 d at pH = 0 and τ(1/2) ∼6.2 h at pH = 10) than the GaDO3AM(Bu) analogue (τ(1/2) ∼2.7 d at pH = 0 and τ(1/2) ∼0.7 h at pH = 10). Nevertheless, the kinetic inertness of both chelates is extremely high and approves the application of Ga(3+) complexes of such DOTA-like ligands in molecular imaging. The solid-state structure of the GaDOTA complex, crystallized from a strongly acidic solution (pH < 1), evidenced a diprotonated form with protons localized on the free carboxylate pendants.

Mirrored continuum and molecular scale simulations of the ignition of gamma phase RDX

NASA Astrophysics Data System (ADS)

Stewart, D. Scott; Chaudhuri, Santanu; Joshi, Kaushik; Lee, Kibaek

2017-01-01

We describe the ignition of an explosive crystal of gamma-phase RDX due to a thermal hot spot with reactive molecular dynamics (RMD), with first-principles trained, reactive force field based molecular potentials that represents an extremely complex reaction network. The RMD simulation is analyzed by sorting molecular product fragments into high and low molecular weight groups, to represent identifiable components that can be interpreted by a continuum model. A continuum model based on a Gibbs formulation has a single temperature and stress state for the mixture. The continuum simulation that mirrors the atomistic simulation allows us to study the atomistic simulation in the familiar physical chemistry framework and provides an essential, continuum/atomistic link.

Microanalysis study on ancient Wiangkalong Pottery

NASA Astrophysics Data System (ADS)

Won-in, K.; Tancharakorn, S.; Dararutana, P.

2017-09-01

Wiangkalong is one of major ceramic production cities in northern of Thailand, once colonized by the ancient Lanna Kingdom (1290 A.D.). Ancient Wiangkalong potteries were produced with shapes and designs as similar as those of the Chinese Yuan and Ming Dynasties. Due to the complex nature of materials and objects, extremely sensitive, spatially resolved, multi-elemental and versatile analytical instruments using non-destructive and non-sampling methods to analyze theirs composition are need. In this work, micro-beam X-ray fluorescence spectroscopy based on synchrotron radiation was firstly used to characterize the elemental composition of the ancient Wiangkalong pottery. The results showed the variations in elemental composition of the body matrix, the glaze and the underglaze painting, such as K, Ca, Ti, V, Cr, Mn and Fe.

State of Art of Cancer Pharmacogenomics in Latin American Populations

PubMed Central

López-Cortés, Andrés; Guerrero, Santiago; Redal, María Ana; Alvarado, Angel Tito; Quiñones, Luis Abel

2017-01-01

Over the past decades, several studies have shown that tumor-related somatic and germline alterations predicts tumor prognosis, drug response and toxicity. Latin American populations present a vast geno-phenotypic diversity due to the great interethnic and interracial mixing. This genetic flow leads to the appearance of complex characteristics that allow individuals to adapt to endemic environments, such as high altitude or extreme tropical weather. These genetic changes, most of them subtle and unexplored, could establish a mutational profile to develop new pharmacogenomic therapies specific for Latin American populations. In this review, we present the current status of research on somatic and germline alterations in Latin America compared to those found in Caucasian and Asian populations. PMID:28545225

Plastic Surgery Challenges in War Wounded I: Flap-Based Extremity Reconstruction

PubMed Central

Sabino, Jennifer M.; Slater, Julia; Valerio, Ian L.

2016-01-01

Scope and Significance: Reconstruction of traumatic injuries requiring tissue transfer begins with aggressive resuscitation and stabilization. Systematic advances in acute casualty care at the point of injury have improved survival and allowed for increasingly complex treatment before definitive reconstruction at tertiary medical facilities outside the combat zone. As a result, the complexity of the limb salvage algorithm has increased over 14 years of combat activities in Iraq and Afghanistan. Problem: Severe poly-extremity trauma in combat casualties has led to a large number of extremity salvage cases. Advanced reconstructive techniques coupled with regenerative medicine applications have played a critical role in the restoration, recovery, and rehabilitation of functional limb salvage. Translational Relevance: The past 14 years of war trauma have increased our understanding of tissue transfer for extremity reconstruction in the treatment of combat casualties. Injury patterns, flap choice, and reconstruction timing are critical variables to consider for optimal outcomes. Clinical Relevance: Subacute reconstruction with specifically chosen flap tissue and donor site location based on individual injuries result in successful tissue transfer, even in critically injured patients. These considerations can be combined with regenerative therapies to optimize massive wound coverage and limb salvage form and function in previously active patients. Summary: Traditional soft tissue reconstruction is integral in the treatment of war extremity trauma. Pedicle and free flaps are a critically important part of the reconstructive ladder for salvaging extreme extremity injuries that are seen as a result of the current practice of war. PMID:27679751

A Unique Sample of Extreme-BCG Clusters at 0.2 < z < 0.5

NASA Astrophysics Data System (ADS)

Garmire, Gordon

2017-09-01

The recently-discovered Phoenix cluster harbors the most extreme BCG in the known universe. Despite the cluster's high mass and X-ray luminosity, it was consistently identified by surveys as an isolated AGN, due to the bright central point source and the compact cool core. Armed with hindsight, we have undertaken an all-sky survey based on archival X-ray, OIR, and radio data to identify other similarly-extreme systems that were likewise missed. A pilot study demonstrated that this strategy works, leading to the discovery of a new, massive cluster at z 0.2 which was missed by previous X-ray surveys due to the presence of a bright central QSO. We propose here to observe 6 new clusters from our complete northern-sky survey, which harbor some of the most extreme central galaxies known.

Regional trends in short-duration precipitation extremes: a flexible multivariate monotone quantile regression approach

NASA Astrophysics Data System (ADS)

Cannon, Alex

2017-04-01

Estimating historical trends in short-duration rainfall extremes at regional and local scales is challenging due to low signal-to-noise ratios and the limited availability of homogenized observational data. In addition to being of scientific interest, trends in rainfall extremes are of practical importance, as their presence calls into question the stationarity assumptions that underpin traditional engineering and infrastructure design practice. Even with these fundamental challenges, increasingly complex questions are being asked about time series of extremes. For instance, users may not only want to know whether or not rainfall extremes have changed over time, they may also want information on the modulation of trends by large-scale climate modes or on the nonstationarity of trends (e.g., identifying hiatus periods or periods of accelerating positive trends). Efforts have thus been devoted to the development and application of more robust and powerful statistical estimators for regional and local scale trends. While a standard nonparametric method like the regional Mann-Kendall test, which tests for the presence of monotonic trends (i.e., strictly non-decreasing or non-increasing changes), makes fewer assumptions than parametric methods and pools information from stations within a region, it is not designed to visualize detected trends, include information from covariates, or answer questions about the rate of change in trends. As a remedy, monotone quantile regression (MQR) has been developed as a nonparametric alternative that can be used to estimate a common monotonic trend in extremes at multiple stations. Quantile regression makes efficient use of data by directly estimating conditional quantiles based on information from all rainfall data in a region, i.e., without having to precompute the sample quantiles. The MQR method is also flexible and can be used to visualize and analyze the nonlinearity of the detected trend. However, it is fundamentally a univariate technique, and cannot incorporate information from additional covariates, for example ENSO state or physiographic controls on extreme rainfall within a region. Here, the univariate MQR model is extended to allow the use of multiple covariates. Multivariate monotone quantile regression (MMQR) is based on a single hidden-layer feedforward network with the quantile regression error function and partial monotonicity constraints. The MMQR model is demonstrated via Monte Carlo simulations and the estimation and visualization of regional trends in moderate rainfall extremes based on homogenized sub-daily precipitation data at stations in Canada.

Complex Regional Pain Syndrome

MedlinePlus

Complex regional pain syndrome (CRPS) is a chronic pain condition. It causes intense pain, usually in the arms, hands, legs, or feet. ... in skin temperature, color, or texture Intense burning pain Extreme skin sensitivity Swelling and stiffness in affected ...

Does high diurnal variability in a reef flat from Ofu, American Samoa confer resistance to ocean acidification?

NASA Astrophysics Data System (ADS)

Koweek, D.; Samuel, L.; Mucciarone, D. A.; Woodson, C. B.; Monismith, S. G.; Dunbar, R. B.

2012-12-01

Forecasts for coral reefs under various ocean acidification scenarios are becoming increasingly complex due to significant inter-site variability in biogeochemistry, ecology, and physical oceanography. The reef flats of Ofu, American Samoa are a potential end-member of this vulnerability spectrum due to extremely high diurnal variability in their biogeochemistry. Here we present coupled biogeochemical and physical oceanographic measurements from a shallow reef flat on Ofu in November 2011. We observed diurnal temperature ranges of up to 7°C, along with diurnal pH and dissolved oxygen ranges of 0.6 units, and 160 percent of saturation, respectively. Carbon system measurements were less extreme. Alkalinity varied between 2240-2360 μmol/kg and total dissolved inorganic carbon (TDIC) ranged between 1850-2100 μmol/kg during the diurnal cycle. These observations suggest diurnal ranges of ~240ppm CO2 and 1.5 units of ΩAr. The larger diurnal range in TDIC relative to alkalinity suggests a reef environment dominated by photosynthesis. From these observations, we explore the balance between the dominant biogeochemical processes of production and calcification on the reef flat in more detail, along with its implication for conferring resistance to ocean acidification. We use calcification rate estimates to provide insight to patterns of day and night growth and/or dissolution on the reef. Finally, we present evidence of tidal modulation of the biogeochemical signals and discuss the role of localized physical circulation in helping to determine a reef's vulnerability to ocean acidification.

Tailoring the physical properties of Ni-based single-phase equiatomic alloys by modifying the chemical complexity

DOE PAGES

Jin, Ke; Sales, Brian C.; Stocks, George Malcolm; ...

2016-02-01

We discovered that equiatomic alloys (e.g. high entropy alloys) have recently attracted considerable interest due to their exceptional properties, which might be closely related to their extreme disorder induced by the chemical complexity. To understand the effects of chemical complexity on their fundamental physical properties, a family of (eight) Ni-based, face-center-cubic (FCC), equiatomic alloys, extending from elemental Ni to quinary high entropy alloys, has been synthesized, and their electrical, thermal, and magnetic properties are systematically investigated in the range of 4–300 K by combining experiments with ab initio Korring-Kohn-Rostoker coherent-potential-approximation (KKR-CPA) calculations. The scattering of electrons is significantly increased duemore » to the chemical (especially magnetic) disorder. It has weak correlation with the number of elements but strongly depends on the type of elements. Thermal conductivities of the alloys are largely lower than pure metals, primarily because the high electrical resistivity suppresses the electronic thermal conductivity. Moreover, the temperature dependence of the electrical and thermal transport properties is further discussed, and the magnetization of five alloys containing three or more elements is measured in magnetic fields up to 4 T.« less

Patterning highly ordered arrays of complex nanofeatures through EUV directed polarity switching of non chemically amplified photoresist

PubMed Central

Ghosh, Subrata; Satyanarayana, V. S. V.; Pramanick, Bulti; Sharma, Satinder K.; Pradeep, Chullikkattil P.; Morales-Reyes, Israel; Batina, Nikola; Gonsalves, Kenneth E.

2016-01-01

Given the importance of complex nanofeatures in the filed of micro-/nanoelectronics particularly in the area of high-density magnetic recording, photonic crystals, information storage, micro-lens arrays, tissue engineering and catalysis, the present work demonstrates the development of new methodology for patterning complex nanofeatures using a recently developed non-chemically amplified photoresist (n-CARs) poly(4-(methacryloyloxy)phenyl)dimethylsulfoniumtriflate) (polyMAPDST) with the help of extreme ultraviolet lithography (EUVL) as patterning tool. The photosensitivity of polyMAPDST is mainly due to the presence of radiation sensitive trifluoromethanesulfonate unit (triflate group) which undergoes photodegradation upon exposure with EUV photons, and thus brings in polarity change in the polymer structure. Integration of such radiation sensitive unit into polymer network avoids the need of chemical amplification which is otherwise needed for polarity switching in the case of chemically amplified photoresists (CARs). Indeed, we successfully patterned highly ordered wide-raging dense nanofeatures that include nanodots, nanowaves, nanoboats, star-elbow etc. All these developed nanopatterns have been well characterized by FESEM and AFM techniques. Finally, the potential of polyMAPDST has been established by successful transfer of patterns into silicon substrate through adaptation of compatible etch recipes. PMID:26975782

Novel spin transition between S = 5/2 and S = 3/2 in highly saddled iron(III) porphyrin complexes at extremely low temperatures.

PubMed

Ohgo, Yoshiki; Chiba, Yuya; Hashizume, Daisuke; Uekusa, Hidehiro; Ozeki, Tomoji; Nakamura, Mikio

2006-05-14

A novel spin transition between S = 5/2 and S = 3/2 has been observed for the first time in five-coordinate, highly saddled iron(III) porphyrinates by EPR and SQUID measurements at extremely low temperatures.

EFFECTS OF ULTRAVIOLET RADIATION ON THE MODERATE HALOPHILE HALOMONAS ELONGATA AND THE EXTREME HALOPHILE HALOBACTERIUM SALINARUM

EPA Science Inventory

Both the moderately halophilic bacterium, Halomonas elongata, and the extremely halophilic archaea, Halobacterium salinarum, can be found in hypersaline environments (e.g., salterns). On complex media, H. elongata grows over a salt range of 0.05-5.2 M, whereas, H. salinarum multi...

Self-amplified Amazon forest loss due to vegetation-atmosphere feedbacks.

PubMed

Zemp, Delphine Clara; Schleussner, Carl-Friedrich; Barbosa, Henrique M J; Hirota, Marina; Montade, Vincent; Sampaio, Gilvan; Staal, Arie; Wang-Erlandsson, Lan; Rammig, Anja

2017-03-13

Reduced rainfall increases the risk of forest dieback, while in return forest loss might intensify regional droughts. The consequences of this vegetation-atmosphere feedback for the stability of the Amazon forest are still unclear. Here we show that the risk of self-amplified Amazon forest loss increases nonlinearly with dry-season intensification. We apply a novel complex-network approach, in which Amazon forest patches are linked by observation-based atmospheric water fluxes. Our results suggest that the risk of self-amplified forest loss is reduced with increasing heterogeneity in the response of forest patches to reduced rainfall. Under dry-season Amazonian rainfall reductions, comparable to Last Glacial Maximum conditions, additional forest loss due to self-amplified effects occurs in 10-13% of the Amazon basin. Although our findings do not indicate that the projected rainfall changes for the end of the twenty-first century will lead to complete Amazon dieback, they suggest that frequent extreme drought events have the potential to destabilize large parts of the Amazon forest.

Self-amplified Amazon forest loss due to vegetation-atmosphere feedbacks

NASA Astrophysics Data System (ADS)

Zemp, Delphine Clara; Schleussner, Carl-Friedrich; Barbosa, Henrique M. J.; Hirota, Marina; Montade, Vincent; Sampaio, Gilvan; Staal, Arie; Wang-Erlandsson, Lan; Rammig, Anja

2017-03-01

Reduced rainfall increases the risk of forest dieback, while in return forest loss might intensify regional droughts. The consequences of this vegetation-atmosphere feedback for the stability of the Amazon forest are still unclear. Here we show that the risk of self-amplified Amazon forest loss increases nonlinearly with dry-season intensification. We apply a novel complex-network approach, in which Amazon forest patches are linked by observation-based atmospheric water fluxes. Our results suggest that the risk of self-amplified forest loss is reduced with increasing heterogeneity in the response of forest patches to reduced rainfall. Under dry-season Amazonian rainfall reductions, comparable to Last Glacial Maximum conditions, additional forest loss due to self-amplified effects occurs in 10-13% of the Amazon basin. Although our findings do not indicate that the projected rainfall changes for the end of the twenty-first century will lead to complete Amazon dieback, they suggest that frequent extreme drought events have the potential to destabilize large parts of the Amazon forest.

Degradation Mechanisms of an Advanced Jet Engine Service-Retired TBC Component

NASA Astrophysics Data System (ADS)

Wu, Rudder T.; Osawa, Makoto; Yokokawa, Tadaharu; Kawagishi, Kyoko; Harada, Hiroshi

Current use of TBCs is subjected to premature spallation failure mainly due to the formation of thermally grown oxides (TGOs). Although extensive research has been carried out to gain better understanding of the thermo - mechanical and -chemical characteristics of TBCs, laboratory-scale studies and simulation tests are often carried out in conditions significantly differed from the complex and extreme environment typically of a modern gas-turbine engine, thus, failed to truly model service conditions. In particular, the difference in oxygen partial pressure and the effects of contaminants present in the engine compartment have often been neglected. In this respect, an investigation is carried out to study the in-service degradation of an EB-PVD TBC coated nozzle-guide vane. Several modes of degradation were observed due to three factors: 1) presence of residual stresses induced by the thermal-expansion mismatches, 2) evolution of bond coat microstructure and subsequent formation of oxide spinels, 3) deposition of CMAS on the surface of TBC.

Overview of Propellant Delivery Systems at the NASA John C. Stennis Space Center

NASA Technical Reports Server (NTRS)

Haselmaier, L. Haynes; Field, Robert E.; Ryan, Harry M.; Dickey, Jonathan C.

2006-01-01

A wide range of rocket propulsion test work occurs at he NASA John C. Stennis Space Center (SSC) including full-scale engine test activities at test facilities A-1, A-2, B-1 and B-2 as well as combustion device research and development activities at the E-Complex (E-1, E-2. E-3 and E-4) test facilities. One of the greatest challenges associated with operating a test facility is maintaining the health of the primary propellant system and test-critical support systems. The challenge emerges due to the fact that the operating conditions of the various system components are extreme (e.g., low temperatures, high pressures) and due to the fact that many of the components and systems are unique. The purpose of this paper is to briefly describe the experience and modeling techniques that are used to operate the unique test facilities at NASA SSC that continue to support successful propulsion testing.

Self-amplified Amazon forest loss due to vegetation-atmosphere feedbacks

PubMed Central

Zemp, Delphine Clara; Schleussner, Carl-Friedrich; Barbosa, Henrique M. J.; Hirota, Marina; Montade, Vincent; Sampaio, Gilvan; Staal, Arie; Wang-Erlandsson, Lan; Rammig, Anja

2017-01-01

Reduced rainfall increases the risk of forest dieback, while in return forest loss might intensify regional droughts. The consequences of this vegetation–atmosphere feedback for the stability of the Amazon forest are still unclear. Here we show that the risk of self-amplified Amazon forest loss increases nonlinearly with dry-season intensification. We apply a novel complex-network approach, in which Amazon forest patches are linked by observation-based atmospheric water fluxes. Our results suggest that the risk of self-amplified forest loss is reduced with increasing heterogeneity in the response of forest patches to reduced rainfall. Under dry-season Amazonian rainfall reductions, comparable to Last Glacial Maximum conditions, additional forest loss due to self-amplified effects occurs in 10–13% of the Amazon basin. Although our findings do not indicate that the projected rainfall changes for the end of the twenty-first century will lead to complete Amazon dieback, they suggest that frequent extreme drought events have the potential to destabilize large parts of the Amazon forest. PMID:28287104

The Extreme Climate Index: a novel and multi-hazard index for extreme weather events.

NASA Astrophysics Data System (ADS)

Cucchi, Marco; Petitta, Marcello; Calmanti, Sandro

2017-04-01

In this presentation we introduce the Extreme Climate Index (ECI): an objective, multi-hazard index capable of tracking changes in the frequency or magnitude of extreme weather events in African countries, thus indicating that a shift to a new climate regime is underway in a particular area. This index has been developed in the context of XCF (eXtreme Climate Facilities) project lead by ARC (African Risk Capacity, specialised agency of the African Union), and will be used in the payouts triggering mechanism of an insurance programme against risks related to the increase of frequency and magnitude of extreme weather events due to climate regimes' changes. The main hazards covered by ECI will be extreme dry, wet and heat events, with the possibility of adding region-specific risk events such as tropical cyclones for the most vulnerable areas. It will be based on data coming from consistent, sufficiently long, high quality historical records and will be standardized across broad geographical regions, so that extreme events occurring under different climatic regimes in Africa can be comparable. The first step to construct such an index is to define single hazard indicators. In this first study we focused on extreme dry/wet and heat events, using for their description respectively the well-known SPI (Standardized Precipitation Index) and an index developed by us, called SHI (Standardized Heat-waves Index). The second step consists in the development of a computational strategy to combine these, and possibly other indices, so that the ECI can describe, by means of a single indicator, different types of climatic extremes. According to the methodology proposed in this paper, the ECI is defined by two statistical components: the ECI intensity, which indicates whether an event is extreme or not; the angular component, which represent the contribution of each hazard to the overall intensity of the index. The ECI can thus be used to identify "extremes" after defining a suitable threshold above which the events can be held as extremes. In this presentation, after describing the methodology we used for the construction of the ECI, we present results obtained on different African regions, using NCEP Reanalysis dataset for air temperature at sig995 level and CHIRP dataset for precipitations. Particular attention will be devoted to 2015/2016 Malawi drought, which received some media attention due to the failure of the risk assessment model used to trigger due payouts: it will be shown how, on the contrary, combination of hydrological and temperature data used in ECI succeed in evaluating the extremeness of this event.

Towards a unified study of extreme events using universality concepts and transdisciplinary analysis methods

NASA Astrophysics Data System (ADS)

Balasis, George; Donner, Reik V.; Donges, Jonathan F.; Radebach, Alexander; Eftaxias, Konstantinos; Kurths, Jürgen

2013-04-01

The dynamics of many complex systems is characterized by the same universal principles. In particular, systems which are otherwise quite different in nature show striking similarities in their behavior near tipping points (bifurcations, phase transitions, sudden regime shifts) and associated extreme events. Such critical phenomena are frequently found in diverse fields such as climate, seismology, or financial markets. Notably, the observed similarities include a high degree of organization, persistent behavior, and accelerated energy release, which are common to (among others) phenomena related to geomagnetic variability of the terrestrial magnetosphere (intense magnetic storms), seismic activity (electromagnetic emissions prior to earthquakes), solar-terrestrial physics (solar flares), neurophysiology (epileptic seizures), and socioeconomic systems (stock market crashes). It is an open question whether the spatial and temporal complexity associated with extreme events arises from the system's structural organization (geometry) or from the chaotic behavior inherent to the nonlinear equations governing the dynamics of these phenomena. On the one hand, the presence of scaling laws associated with earthquakes and geomagnetic disturbances suggests understanding these events as generalized phase transitions similar to nucleation and critical phenomena in thermal and magnetic systems. On the other hand, because of the structural organization of the systems (e.g., as complex networks) the associated spatial geometry and/or topology of interactions plays a fundamental role in the emergence of extreme events. Here, a few aspects of the interplay between geometry and dynamics (critical phase transitions) that could result in the emergence of extreme events, which is an open problem, will be discussed.

Thermodynamic properties of rhodium at high temperature and pressure by using mean field potential approach

NASA Astrophysics Data System (ADS)

Kumar, Priyank; Bhatt, Nisarg K.; Vyas, Pulastya R.; Gohel, Vinod B.

2016-10-01

The thermophysical properties of rhodium are studied up to melting temperature by incorporating anharmonic effects due to lattice ions and thermally excited electrons. In order to account anharmonic effects due to lattice vibrations, we have employed mean field potential (MFP) approach and for thermally excited electrons Mermin functional. The local form of the pseudopotential with only one effective adjustable parameter rc is used to construct MFP and hence vibrational free energy due to ions - Fion. We have studied equation of state at 300 K and further, to access the applicability of present conjunction scheme, we have also estimated shock-Hugoniot and temperature along principle Hugoniot. We have carried out the study of temperature variation of several thermophysical properties like thermal expansion (βP), enthalpy (EH), specific heats at constant pressure and volume (CP and CV), specific heats due to lattice ions and thermally excited electrons ( and , isothermal and adiabatic bulk moduli (BT and Bs) and thermodynamic Gruneisen parameter (γth) in order to examine the inclusion of anharmonic effects in the present study. The computed results are compared with available experimental results measured by using different methods and previously obtained theoretical results using different theoretical philosophy. Our computed results are in good agreement with experimental findings and for some physical quantities better or comparable with other theoretical results. We conclude that local form of the pseudopotential used accounts s-p-d hybridization properly and found to be transferable at extreme environment without changing the values of the parameter. Thus, even the behavior of transition metals having complexity in electronic structure can be well understood with local pseudopotential without any modification in the potential at extreme environment. Looking to the success of present scheme (MFP + pseudopotential) we would like to extend it further for the study of liquid state properties as well as thermophysical properties of d and f block metals.

Changes in the extremes of the climate simulated by CCC GCM2 under CO{sub 2} doubling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zwiers, F.W.; Kharin, V.V.

Changes due to CO{sub 2} doubling in the extremes of the surface climate as simulated by the second-generation circulation model of the Canadian Centre for Climate Modelling and Analysis are studied in two 20-yr equilibrium simulations. Extreme values of screen temperature, precipitation, and near-surface wind in the control climate are compared to those estimated from 17 yr of the NCEP-NCAR reanalysis data and from some Canadian station data. The extremes of screen temperature are reasonably well reproduced in the control climate. Their changes under CO{sub 2} doubling can be connected with other physical changes such as surface albedo changes duemore » to the reduction of snow and sea ice cover as well as a decrease of soil moisture in the warmer world. The signal in the extremes of daily precipitation and near-surface wind speed due to CO{sub 2} doubling is less obvious. The precipitation extremes increase almost everywhere over the globe. The strongest change, over northwest India, is related to the intensification of the summer monsoon in this region in the warmer world. The modest reduction of wind extremes in the Tropics and middle latitudes is consistent with the reduction of the meridional temperature gradient in the 2{times}CO{sub 2} climate. The larger wind extremes occur in the areas where sea ice has retreated.« less

Mining the LIPG Allelic Spectrum Reveals the Contribution of Rare and Common Regulatory Variants to HDL Cholesterol

PubMed Central

Raghavan, Avanthi; Neeli, Hemanth; Jin, Weijun; Badellino, Karen O.; Demissie, Serkalem; Manning, Alisa K.; DerOhannessian, Stephanie L.; Wolfe, Megan L.; Cupples, L. Adrienne; Li, Mingyao; Kathiresan, Sekar; Rader, Daniel J.

2011-01-01

Genome-wide association studies (GWAS) have successfully identified loci associated with quantitative traits, such as blood lipids. Deep resequencing studies are being utilized to catalogue the allelic spectrum at GWAS loci. The goal of these studies is to identify causative variants and missing heritability, including heritability due to low frequency and rare alleles with large phenotypic impact. Whereas rare variant efforts have primarily focused on nonsynonymous coding variants, we hypothesized that noncoding variants in these loci are also functionally important. Using the HDL-C gene LIPG as an example, we explored the effect of regulatory variants identified through resequencing of subjects at HDL-C extremes on gene expression, protein levels, and phenotype. Resequencing a portion of the LIPG promoter and 5′ UTR in human subjects with extreme HDL-C, we identified several rare variants in individuals from both extremes. Luciferase reporter assays were used to measure the effect of these rare variants on LIPG expression. Variants conferring opposing effects on gene expression were enriched in opposite extremes of the phenotypic distribution. Minor alleles of a common regulatory haplotype and noncoding GWAS SNPs were associated with reduced plasma levels of the LIPG gene product endothelial lipase (EL), consistent with its role in HDL-C catabolism. Additionally, we found that a common nonfunctional coding variant associated with HDL-C (rs2000813) is in linkage disequilibrium with a 5′ UTR variant (rs34474737) that decreases LIPG promoter activity. We attribute the gene regulatory role of rs34474737 to the observed association of the coding variant with plasma EL levels and HDL-C. Taken together, the findings show that both rare and common noncoding regulatory variants are important contributors to the allelic spectrum in complex trait loci. PMID:22174694

Climate extremes promote fatal co-infections during canine distemper epidemics in African lions.

PubMed

Munson, Linda; Terio, Karen A; Kock, Richard; Mlengeya, Titus; Roelke, Melody E; Dubovi, Edward; Summers, Brian; Sinclair, Anthony R E; Packer, Craig

2008-06-25

Extreme climatic conditions may alter historic host-pathogen relationships and synchronize the temporal and spatial convergence of multiple infectious agents, triggering epidemics with far greater mortality than those due to single pathogens. Here we present the first data to clearly illustrate how climate extremes can promote a complex interplay between epidemic and endemic pathogens that are normally tolerated in isolation, but with co-infection, result in catastrophic mortality. A 1994 canine distemper virus (CDV) epidemic in Serengeti lions (Panthera leo) coincided with the death of a third of the population, and a second high-mortality CDV epidemic struck the nearby Ngorongoro Crater lion population in 2001. The extent of adult mortalities was unusual for CDV and prompted an investigation into contributing factors. Serological analyses indicated that at least five "silent" CDV epidemics swept through the same two lion populations between 1976 and 2006 without clinical signs or measurable mortality, indicating that CDV was not necessarily fatal. Clinical and pathology findings suggested that hemoparsitism was a major contributing factor during fatal epidemics. Using quantitative real-time PCR, we measured the magnitude of hemoparasite infections in these populations over 22 years and demonstrated significantly higher levels of Babesia during the 1994 and 2001 epidemics. Babesia levels correlated with mortalities and extent of CDV exposure within prides. The common event preceding the two high mortality CDV outbreaks was extreme drought conditions with wide-spread herbivore die-offs, most notably of Cape buffalo (Syncerus caffer). As a consequence of high tick numbers after the resumption of rains and heavy tick infestations of starving buffalo, the lions were infected by unusually high numbers of Babesia, infections that were magnified by the immunosuppressive effects of coincident CDV, leading to unprecedented mortality. Such mass mortality events may become increasingly common if climate extremes disrupt historic stable relationships between co-existing pathogens and their susceptible hosts.

Climate Extremes Promote Fatal Co-Infections during Canine Distemper Epidemics in African Lions

PubMed Central

Munson, Linda; Terio, Karen A.; Kock, Richard; Mlengeya, Titus; Roelke, Melody E.; Dubovi, Edward; Summers, Brian; Sinclair, Anthony R. E.; Packer, Craig

2008-01-01

Extreme climatic conditions may alter historic host-pathogen relationships and synchronize the temporal and spatial convergence of multiple infectious agents, triggering epidemics with far greater mortality than those due to single pathogens. Here we present the first data to clearly illustrate how climate extremes can promote a complex interplay between epidemic and endemic pathogens that are normally tolerated in isolation, but with co-infection, result in catastrophic mortality. A 1994 canine distemper virus (CDV) epidemic in Serengeti lions (Panthera leo) coincided with the death of a third of the population, and a second high-mortality CDV epidemic struck the nearby Ngorongoro Crater lion population in 2001. The extent of adult mortalities was unusual for CDV and prompted an investigation into contributing factors. Serological analyses indicated that at least five “silent” CDV epidemics swept through the same two lion populations between 1976 and 2006 without clinical signs or measurable mortality, indicating that CDV was not necessarily fatal. Clinical and pathology findings suggested that hemoparsitism was a major contributing factor during fatal epidemics. Using quantitative real-time PCR, we measured the magnitude of hemoparasite infections in these populations over 22 years and demonstrated significantly higher levels of Babesia during the 1994 and 2001 epidemics. Babesia levels correlated with mortalities and extent of CDV exposure within prides. The common event preceding the two high mortality CDV outbreaks was extreme drought conditions with wide-spread herbivore die-offs, most notably of Cape buffalo (Syncerus caffer). As a consequence of high tick numbers after the resumption of rains and heavy tick infestations of starving buffalo, the lions were infected by unusually high numbers of Babesia, infections that were magnified by the immunosuppressive effects of coincident CDV, leading to unprecedented mortality. Such mass mortality events may become increasingly common if climate extremes disrupt historic stable relationships between co-existing pathogens and their susceptible hosts. PMID:18575601

Forensic hydro-meteorological analysis of an extreme flash flood: The 2016-05-29 event in Braunsbach, SW Germany.

PubMed

Bronstert, Axel; Agarwal, Ankit; Boessenkool, Berry; Crisologo, Irene; Fischer, Madlen; Heistermann, Maik; Köhn-Reich, Lisei; López-Tarazón, José Andrés; Moran, Thomas; Ozturk, Ugur; Reinhardt-Imjela, Christian; Wendi, Dadiyorto

2018-07-15

The flash-flood in Braunsbach in the north-eastern part of Baden-Wuerttemberg/Germany was a particularly strong and concise event which took place during the floods in southern Germany at the end of May/early June 2016. This article presents a detailed analysis of the hydro-meteorological forcing and the hydrological consequences of this event. A specific approach, the "forensic hydrological analysis" was followed in order to include and combine retrospectively a variety of data from different disciplines. Such an approach investigates the origins, mechanisms and course of such natural events if possible in a "near real time" mode, in order to follow the most recent traces of the event. The results show that it was a very rare rainfall event with extreme intensities which, in combination with catchment properties, led to extreme runoff plus severe geomorphological hazards, i.e. great debris flows, which together resulted in immense damage in this small rural town Braunsbach. It was definitely a record-breaking event and greatly exceeded existing design guidelines for extreme flood discharge for this region, i.e. by a factor of about 10. Being such a rare or even unique event, it is not reliably feasible to put it into a crisp probabilistic context. However, one can conclude that a return period clearly above 100years can be assigned for all event components: rainfall, peak discharge and sediment transport. Due to the complex and interacting processes, no single flood cause or reason for the very high damage can be identified, since only the interplay and the cascading characteristics of those led to such an event. The roles of different human activities on the origin and/or intensification of such an extreme event are finally discussed. Copyright © 2018. Published by Elsevier B.V.

Hyperspectral remote sensing and long term monitoring reveal watershed-estuary ecosystem interactions

NASA Astrophysics Data System (ADS)

Hestir, E. L.; Schoellhamer, D. H.; Santos, M. J.; Greenberg, J. A.; Morgan-King, T.; Khanna, S.; Ustin, S.

2016-02-01

Estuarine ecosystems and their biogeochemical processes are extremely vulnerable to climate and environmental changes, and are threatened by sea level rise and upstream activities such as land use/land cover and hydrological changes. Despite the recognized threat to estuaries, most aspects of how change will affect estuaries are not well understood due to the poorly resolved understanding of the complex physical, chemical and biological processes and their interactions in estuarine systems. Remote sensing technologies such as high spectral resolution optical systems enable measurements of key environmental parameters needed to establish baseline conditions and improve modeling efforts. The San Francisco Bay-Delta is a highly modified estuary system in a state of ecological crisis due to the numerous threats to its sustainability. In this study, we used a combination of hyperspectral remote sensing and long-term in situ monitoring records to investigate how water clarity has been responding to extreme climatic events, anthropogenic watershed disturbances, and submerged aquatic vegetation (SAV) invasions. From the long-term turbidity monitoring record, we found that water clarity underwent significant increasing step changes associated with sediment depletion and El Nino-extreme run-off events. Hyperspectral remote sensing data revealed that invasive submerged aquatic pant species have facultative C3 and C4-like photosynthetic pathways that give them a competitive advantage under the changing water clarity conditions of the Bay-Delta system. We postulate that this adaptation facilitated the rapid expansion of SAV following the significant step changes in increasing water clarity caused by watershed disturbances and the 1982-1983 El Nino events. Using SAV maps from hyperspectral remote sensing, we estimate that SAV-water clarity feedbacks were responsible for 20-70% of the increasing water clarity trend in the Bay-Delta. Ongoing and future developments in airborne and global mapping hyperspectral satellite missions will enable full canopy-to-benthos characterization of estuarine ecosystems. When coupled with synoptic watershed measurements, these will improve understanding of watershed-estuary interactions for improved sustainable management.

Effect of Environment-Based Coursework on the Nature of Attitudes toward the Endangered Species Act.

ERIC Educational Resources Information Center

Bright, Alan D.; Tarrant, Michael A.

2002-01-01

Examines college students' attitudes and complexity of thinking about the Endangered Species Act (ESA) and the effects of environment-based coursework on their attitudes and thinking. Investigates attitudes in terms of their direction, extremity, ambivalence, and importance and measures complexity of thinking as integrative complexity. (Contains…

USACE Extreme Sea levels

DTIC Science & Technology

2014-03-14

with expected changes due to climate change. (tropicals and extra-tropicals) Ivan provided some good information on work being done on tropical...Pattiaratchi, C., Jensen, J., 2013. Estimating extreme water level probabilities: a comparison of the direct methods and recommendations for best practise ...sites: site-by-site analyses. Proudman Oceanographic Laboratory , Internal Document, No. 65, 229pp. Dixon, M.J., Tawn, J.A. (1995) Extreme sea-levels

Dismounted Complex Blast Injury.

PubMed

Andersen, Romney C; Fleming, Mark; Forsberg, Jonathan A; Gordon, Wade T; Nanos, George P; Charlton, Michael T; Ficke, James R

2012-01-01

The severe Dismounted Complex Blast Injury (DCBI) is characterized by high-energy injuries to the bilateral lower extremities (usually proximal transfemoral amputations) and/or upper extremity (usually involving the non-dominant side), in addition to open pelvic injuries, genitourinary, and abdominal trauma. Initial resuscitation and multidisciplinary surgical management appear to be the keys to survival. Definitive treatment follows general principals of open wound management and includes decontamination through aggressive and frequent debridement, hemorrhage control, viable tissue preservation, and appropriate timing of wound closure. These devastating injuries are associated with paradoxically favorable survival rates, but associated injuries and higher amputation levels lead to more difficult reconstructive challenges.

Associations between extreme precipitation and acute gastro-intestinal illness due to cryptosporidiosis and giardiasis in an urban Canadian drinking water system (1997-2009).

PubMed

Chhetri, Bimal K; Takaro, Tim K; Balshaw, Robert; Otterstatter, Michael; Mak, Sunny; Lem, Marcus; Zubel, Marc; Lysyshyn, Mark; Clarkson, Len; Edwards, Joanne; Fleury, Manon D; Henderson, Sarah B; Galanis, Eleni

2017-10-01

Drinking water related infections are expected to increase in the future due to climate change. Understanding the current links between these infections and environmental factors is vital to understand and reduce the future burden of illness. We investigated the relationship between weekly reported cryptosporidiosis and giardiasis (n = 7,422), extreme precipitation (>90th percentile), drinking water turbidity, and preceding dry periods in a drinking water system located in greater Vancouver, British Columbia, Canada (1997-2009) using distributed lag non-linear Poisson regression models adjusted for seasonality, secular trend, and the effect of holidays on reporting. We found a significant increase in cryptosporidiosis and giardiasis 4-6 weeks after extreme precipitation. The effect was greater following a dry period. Similarly, extreme precipitation led to significantly increased turbidity only after prolonged dry periods. Our results suggest that the risk of cryptosporidiosis and giardiasis increases with extreme precipitation, and that the effects are more pronounced after a prolonged dry period. Given that extreme precipitation events are expected to increase with climate change, it is important to further understand the risks from these events, develop planning tools, and build resilience to these future risks.

Impacts of Extreme Events on Human Health. Chapter 4

NASA Technical Reports Server (NTRS)

Bell, Jesse E.; Herring, Stephanie C.; Jantarasami, Lesley; Adrianopoli, Carl; Benedict, Kaitlin; Conlon, Kathryn; Escobar, Vanessa; Hess, Jeremy; Luvall, Jeffrey; Garcia-Pando, Carlos Perez;

Fast mask writers: technology options and considerations

NASA Astrophysics Data System (ADS)

Litt, Lloyd C.; Groves, Timothy; Hughes, Greg

2011-04-01

The semiconductor industry is under constant pressure to reduce production costs even as the complexity of technology increases. Lithography represents the most expensive process due to its high capital equipment costs and the implementation of low-k1 lithographic processes, which have added to the complexity of making masks because of the greater use of optical proximity correction, pixelated masks, and double or triple patterning. Each of these mask technologies allows the production of semiconductors at future nodes while extending the utility of current immersion tools. Low-k1 patterning complexity combined with increased data due to smaller feature sizes is driving extremely long mask write times. While a majority of the industry is willing to accept times of up to 24 hours, evidence suggests that the write times for many masks at the 22 nm node and beyond will be significantly longer. It has been estimated that funding on the order of 50M to 90M for non-recurring engineering (NRE) costs will be required to develop a multiple beam mask writer system, yet the business case to recover this kind of investment is not strong. Moreover, funding such a development poses a high risk for an individual supplier. The structure of the mask fabrication marketplace separates the mask writer equipment customer (the mask supplier) from the final customer (wafer manufacturer) that will be most effected by the increase in mask cost that will result if a high speed mask writer is not available. Since no individual company will likely risk entering this market, some type of industry-wide funding model will be needed.

Modeling the fracture of ice sheets on parallel computers.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waisman, Haim; Bell, Robin; Keyes, David

2010-03-01

The objective of this project is to investigate the complex fracture of ice and understand its role within larger ice sheet simulations and global climate change. At the present time, ice fracture is not explicitly considered within ice sheet models due in part to large computational costs associated with the accurate modeling of this complex phenomena. However, fracture not only plays an extremely important role in regional behavior but also influences ice dynamics over much larger zones in ways that are currently not well understood. Dramatic illustrations of fracture-induced phenomena most notably include the recent collapse of ice shelves inmore » Antarctica (e.g. partial collapse of the Wilkins shelf in March of 2008 and the diminishing extent of the Larsen B shelf from 1998 to 2002). Other fracture examples include ice calving (fracture of icebergs) which is presently approximated in simplistic ways within ice sheet models, and the draining of supraglacial lakes through a complex network of cracks, a so called ice sheet plumbing system, that is believed to cause accelerated ice sheet flows due essentially to lubrication of the contact surface with the ground. These dramatic changes are emblematic of the ongoing change in the Earth's polar regions and highlight the important role of fracturing ice. To model ice fracture, a simulation capability will be designed centered around extended finite elements and solved by specialized multigrid methods on parallel computers. In addition, appropriate dynamic load balancing techniques will be employed to ensure an approximate equal amount of work for each processor.« less

Chicago, IL Adapts to Improve Extreme Heat Preparedness

EPA Pesticide Factsheets

Recognizing that heat waves are expected to increase in Chicago due to climate change,–supported by the Chicago Climate Impacts Report, the city adopted a comprehensive set of actions to reduce deaths from extreme heat events.

The Braunsbach Flashflood of May 29, 2016: A forensic analysis of the meteorological origin and the hydrological development an extreme hydro-meteorological event

NASA Astrophysics Data System (ADS)

Bronstert, Axel; Ankit, Agarwal; Berry, Boessenkool; Madlen, Fischer; Maik, Heistermann; Lisei, Köhn-Reich; Thomas, Moran; Dadiyorto, Wendi

2017-04-01

The flash-flood at 29th May 2016 in the vicinity of the village of Braunsbach in Southwestern Germany, State of Baden-Wuerttemberg, has been a particularly concise event of the floods occurring in southern Germany at the end of May / early June 2016. This extreme event was triggered by a convective high intensity rain storm, causing extreme discharge rates and subsequent debris flow in the local creek. This led to severe flooding of the village with immense damages. Besides its extreme nature, the event is characterized by very local and short term scales, i.e. the catchment of the creek covers an area of only six km2 and the whole event lasted only two hours. This contribution presents a retrospective analysis with regard to meteorology and hydrology to obtain a quantitative assessment of the governing processes and their development. We term this a "forensic analysis" because due to the very local and sudden feature of this flashflood event, the processes cannot be directly measured during the event and/or at the site. Instead, they need to be reconstructed and estimated after the event from a variety of rather different information sources and "soft" data. Using these types of post event observations and analysis, we aim at obtaining a rather comprehensive picture of the event and its consequences. Regarding rainfall, both station data from the surroundings of the catchment and radar data from the German Weather Service were analyzed, including the analysis of different errors types and dynamic features of the convective system. The flood hydrograph, including the maximum discharge rate during the event, was estimated by three different approaches, which were compared to obtain an idea of the associated uncertainty. The overall results of this forensic analysis show that it was a very rare rainfall event with extreme rainfall intensities, e.g. return period exceeding 100 years. Catalyzed by catchment properties, this lead to extreme runoff, severe soil erosion, and subsequent debris flow processes. Due to the complex and interacting processes, the hazard must not be attributed to a single cause, since only the interplay of the different processes and catchment conditions can lead to such an event. The people in the region say that such an event "has never happened before". However, from some first geomorphological analysis we got some indications that such events, including debris flow, might have happened before during previous times (time scale of millennia). Therefore, it would be more appropriate to state that "nobody can remember of such an event".

Hydrometeorological extremes at the Veselí nad Moravou estate (Czech Republic) in the period 1794-1850 derived from documentary evidence of the economic character

NASA Astrophysics Data System (ADS)

Chromá, Kateřina

2010-05-01

Hydrometeorological extremes influenced always human activities (agriculture, forestry, water management) and caused losses of human lives and great material damage. Systematic meteorological and hydrological observations in the Czech Lands (recent Czech Republic) started generally in the latter half of the 19th century. In order to create long-term series of hydrometeorological extremes, it is necessary to search for other sources of information for their study before 1850. Such direct and indirect information about hydrometeorological extremes is included in documentary evidence (e.g. chronicles, memoirs, diaries, early visual weather observations, newspapers, economic sources etc.). Documentary evidence of economic character belongs to the most important sources, especially documents related to taxation records. Damage to agricultural crops on the fields or damage to hay on meadows due to the hydrological and meteorological phenomena has been a good reason for the abatement of tax duty. Based on the official correspondence of the estate of Veselí nad Moravou (southern Moravia), archival information about taxation from the Moravian Land Archives in Brno was excerpted. Based on it, 46 hydrometeorological extremes which occurred between the years 1794 and 1850 were selected and further analysed. Because of fields and meadows of the above estate were located along the Morava River, reports of damage due to floods were the most frequent, followed by damage due to torrential rains and hailstorms.

Bayesian estimation of extreme flood quantiles using a rainfall-runoff model and a stochastic daily rainfall generator

NASA Astrophysics Data System (ADS)

Costa, Veber; Fernandes, Wilson

2017-11-01

Extreme flood estimation has been a key research topic in hydrological sciences. Reliable estimates of such events are necessary as structures for flood conveyance are continuously evolving in size and complexity and, as a result, their failure-associated hazards become more and more pronounced. Due to this fact, several estimation techniques intended to improve flood frequency analysis and reducing uncertainty in extreme quantile estimation have been addressed in the literature in the last decades. In this paper, we develop a Bayesian framework for the indirect estimation of extreme flood quantiles from rainfall-runoff models. In the proposed approach, an ensemble of long daily rainfall series is simulated with a stochastic generator, which models extreme rainfall amounts with an upper-bounded distribution function, namely, the 4-parameter lognormal model. The rationale behind the generation model is that physical limits for rainfall amounts, and consequently for floods, exist and, by imposing an appropriate upper bound for the probabilistic model, more plausible estimates can be obtained for those rainfall quantiles with very low exceedance probabilities. Daily rainfall time series are converted into streamflows by routing each realization of the synthetic ensemble through a conceptual hydrologic model, the Rio Grande rainfall-runoff model. Calibration of parameters is performed through a nonlinear regression model, by means of the specification of a statistical model for the residuals that is able to accommodate autocorrelation, heteroscedasticity and nonnormality. By combining the outlined steps in a Bayesian structure of analysis, one is able to properly summarize the resulting uncertainty and estimating more accurate credible intervals for a set of flood quantiles of interest. The method for extreme flood indirect estimation was applied to the American river catchment, at the Folsom dam, in the state of California, USA. Results show that most floods, including exceptionally large non-systematic events, were reasonably estimated with the proposed approach. In addition, by accounting for uncertainties in each modeling step, one is able to obtain a better understanding of the influential factors in large flood formation dynamics.

Strategy for introduction of rainwater management facility considering rainfall event applied on new apartment complex

NASA Astrophysics Data System (ADS)

KIM, H.; Lee, D. K.; Yoo, S.

2014-12-01

As regional torrential rains become frequent due to climate change, urban flooding happens very often. That is why it is necessary to prepare for integrated measures against a wide range of rainfall. This study proposes introduction of effective rainwater management facilities to maximize the rainwater runoff reductions and recover natural water circulation for unpredictable extreme rainfall in apartment complex scale. The study site is new apartment complex in Hanam located in east of Seoul, Korea. It has an area of 7.28ha and is analysed using the EPA-SWMM and STORM model. First, it is analyzed that green infrastructure(GI) had efficiency of flood reduction at the various rainfall events and soil characteristics, and then the most effective value of variables are derived. In case of rainfall event, Last 10 years data of 15 minutes were used for analysis. A comparison between A(686mm rainfall during 22days) and B(661mm/4days) knew that soil infiltration of A is 17.08% and B is 5.48% of the rainfall. Reduction of runoff after introduction of the GI of A is 24.76% and B is 6.56%. These results mean that GI is effective to small rainfall intensity, and artificial rainwater retarding reservoir is needed at extreme rainfall. Second, set of target year is conducted for the recovery of hydrological cycle at the predevelopment. And an amount of infiltration, evaporation, surface runoff of the target year and now is analysed on the basis of land coverage, and an arrangement of LID facilities. Third, rainwater management scenarios are established and simulated by the SWMM-LID. Rainwater management facilities include GI(green roof, porous pavement, vegetative swale, ecological pond, and raingarden), and artificial rainwater. Design scenarios are categorized five type: 1)no GI, 2)conventional GI design(current design), 3)intensive GI design, 4)GI design+rainwater retarding reservoir 5)maximized rainwater retarding reservoir. Intensive GI design is to have attribute value to obtain the maximum efficiency for each GI facility with in-depth experts interviews. Climate change scenario is also used to set the capacity of the rainwater management facilities considering the extreme precipitation. These all scenarios are not only simulated for calculating the hydrological balance but analysed the cost for each scenarios effect.

Challenges of Representing Sub-Grid Physics in an Adaptive Mesh Refinement Atmospheric Model

NASA Astrophysics Data System (ADS)

O'Brien, T. A.; Johansen, H.; Johnson, J. N.; Rosa, D.; Benedict, J. J.; Keen, N. D.; Collins, W.; Goodfriend, E.

2015-12-01

Some of the greatest potential impacts from future climate change are tied to extreme atmospheric phenomena that are inherently multiscale, including tropical cyclones and atmospheric rivers. Extremes are challenging to simulate in conventional climate models due to existing models' coarse resolutions relative to the native length-scales of these phenomena. Studying the weather systems of interest requires an atmospheric model with sufficient local resolution, and sufficient performance for long-duration climate-change simulations. To this end, we have developed a new global climate code with adaptive spatial and temporal resolution. The dynamics are formulated using a block-structured conservative finite volume approach suitable for moist non-hydrostatic atmospheric dynamics. By using both space- and time-adaptive mesh refinement, the solver focuses computational resources only where greater accuracy is needed to resolve critical phenomena. We explore different methods for parameterizing sub-grid physics, such as microphysics, macrophysics, turbulence, and radiative transfer. In particular, we contrast the simplified physics representation of Reed and Jablonowski (2012) with the more complex physics representation used in the System for Atmospheric Modeling of Khairoutdinov and Randall (2003). We also explore the use of a novel macrophysics parameterization that is designed to be explicitly scale-aware.

Quasiparticle lifetime broadening in resonant x-ray scattering of NH4NO3

NASA Astrophysics Data System (ADS)

Vinson, John; Jach, Terrence; Müller, Matthias; Unterumsberger, Rainer; Beckhoff, Burkhard

2016-07-01

It has been previously shown that two effects cause dramatic changes in the x-ray absorption and emission spectra from the N K edge of the insulating crystal ammonium nitrate. First, vibrational disorder causes major changes in the absorption spectrum, originating not only from the thermal population of phonons, but, significantly, from zero-point motion as well. Second, the anomalously large broadening (˜4 eV) of the emission originating from nitrate σ states is due to the unusually short lifetimes of quasiparticles in an otherwise extremely narrow band. In this work, we investigate the coupling of these effects to core and valence excitons that are created as the initial x-ray excitation energy is progressively reduced toward the N edge. Using a G W /Bethe-Salpeter approach, we show the extent to which this anomalous broadening is captured by the G W approximation. The data and calculations demonstrate the importance that the complex self-energies (finite lifetimes) of the valence bands have on the interpretation of emission spectra. We produce a scheme to explain why extreme lifetimes should appear in σ states of other similar compounds.

Knowledge management performance methodology regarding manufacturing organizations

NASA Astrophysics Data System (ADS)

Istrate, C.; Herghiligiu, I. V.

2016-08-01

The current business situation is extremely complicated. Business must adapt to the changes in order (a) to survive on the increasingly dynamic markets, (b) to meet customers’ new request for complex, customized and innovative products. In modern manufacturing organizations it can be seen a substantial improvement regarding the management of knowledge. This occurs due to the fact that organizations realized that knowledge and an efficient management of knowledge generates the highest value. Even it could be said that the manufacturing organizations were and are the biggest beneficiary of KM science. Knowledge management performance (KMP) evaluation in manufacturing organizations can be considered as extremely important because without measuring it, they are unable to properly assess (a) what goals, targets and activities must have continuity, (b) what must be improved and (c) what must be completed. Therefore a proper KM will generate multiple competitive advantages for organizations. This paper presents a developed methodological framework regarding the KMP importance regarding manufacturing organizations. This methodological framework was developed using as research methods: bibliographical research and a panel of specialists. The purpose of this paper is to improve the evaluation process of KMP and to provide a viable tool for manufacturing organizations managers.

Simulating transitional hydrodynamics of the cerebrospinal fluid at extreme scale

NASA Astrophysics Data System (ADS)

Jain, Kartik; Roller, Sabine; Mardal, Kent-Andre

Chiari malformation type I is a disorder characterized by the herniation of cerebellar tonsils into the spinal canal through the foramen magnum resulting in obstruction to cerebrospinal fluid (CSF) outflow. The flow of pulsating bidirectional CSF is of acutely complex nature due to the anatomy of the conduit containing it - the subarachnoid space. We report lattice Boltzmann method based direct numerical simulations on patient specific cases with spatial resolution of 24 μm amounting meshes of up to 2 billion cells conducted on 50000 cores of the Hazelhen supercomputer in Stuttgart. The goal is to characterize intricate dynamics of the CSF at resolutions that are of the order of Kolmogorov microscales. Results unfold velocity fluctuations up to ~ 10 KHz , turbulent kinetic energy ~ 2 times of the mean flow energy in Chiari patients whereas the flow remains laminar in a control subject. The fluctuations confine near the cranio-vertebral junction and are commensurate with the extremeness of pathology and the extent of herniation. The results advocate that the manifestation of pathological conditions like Chiari malformation may lead to transitional hydrodynamics of the CSF, and a prudent calibration of numerical approach is necessary to avoid overlook of such phenomena.

Core stability: implications for dance injuries.

PubMed

Rickman, Ashley M; Ambegaonkar, Jatin P; Cortes, Nelson

2012-09-01

Dancers experience a high incidence of injury due to the extreme physical demands of dancing. The majority of dance injuries are chronic in nature and occur in the lower extremities and low back. Researchers have indicated decreased core stability (CS) as a risk factor for these injuries. Although decreased CS is suggested to negatively affect lower extremity joint motion and lumbar control during activity, this relationship has not been extensively discussed in previous dance literature. Understanding the relationship between CS and injury risk is important to help reduce dance injury incidence and improve performance. The purposes of this review were to discuss: 1. the core and components of CS, 2. the relationship between CS and injury, 3. CS assessment techniques, and 4. future dance CS research areas. CS is the integration of passive (non-contractile), active (contractile), and neural structures to minimize the effects of external forces and maintain stability. CS is maintained by a combination of muscle power, strength, endurance, and sensory-motor control of the lumbopelvic-hip complex. CS assessments include measuring muscle strength and power using maximal voluntary isometric and isokinetic contractions and measuring endurance using the Biering-Sorensen, plank, and lateral plank tests. Measuring sensory-motor control requires specialized equipment (e.g., balance platforms). Overall, limited research has comprehensively examined all components of CS together and their relationships to injury. Rather, previous researchers have separately examined core power, strength, endurance, or sensory-motor control. Future researchers should explore the multifactorial role of CS in reducing injury risk and enhancing performance in dancers.

Hazards posed by distal ash transport and sedimentation from extreme volcanic eruptions

NASA Astrophysics Data System (ADS)

Sahagian, D. L.; Proussevitch, A. A.; White, C. M.; Klewicki, J.

2016-12-01

Volcanic ash injected into the upper troposphere and lower stratosphere poses a significant hazard to aviation and human security as a result of extreme, explosive eruptions. These have occurred in the recent geologic past, and are expected to occur again, now that modern society and its infrastructure is far more vulnerable than ever before. Atmospheric transport, dispersion, and sedimentation of Ash particles is controlled by fundamentally different processes than control other particles normally transported in the atmosphere due to their complex internal and external morphology. It is thus necessary to elucidate the fundamental processes of particle-fluid interactions in the upper troposphere and lower stratosphere, where most air traffic resides, and thereby enhance the capability of volcanic ash transport models to predict the ash concentration in distal regions that pose aviation and other hazards. Current Volcanic Ash Transport and Dispersion (VATD) models use simplistic stokes settling velocities for larger ash particles, and treat smaller ash particles (that are a large part of the hazard) merely as passive tracers. By incorporating the dynamics of fine ash particle-atmosphere interactions into existing VATD models provides the foundation for a much more accurate assessment framework applied to the hazard posed by specific future extreme eruptions, and thus dramatically reduce both the risk to air traffic and the cost of airport and flight closures, in addition to human health, water quality, agricultural, infrastructure hazards, as well as ice cap albedo and short term climate impacts.

Changes in Extreme Events and the Potential Impacts on National Security

NASA Astrophysics Data System (ADS)

Bell, J.

2017-12-01

Extreme weather and climate events affect human health by causing death, injury, and illness, as well as having large socio-economic impacts. Climate change has caused changes in extreme event frequency, intensity and geographic distribution, and will continue to be a driver for changes in the future. Some of the extreme events that have already changed are heat waves, droughts, wildfires, flooding rains, coastal flooding, storm surge, and hurricanes. The pathways connecting extreme events to health outcomes and economic losses can be diverse and complex. The difficulty in predicting these relationships comes from the local intricacies of societal and environmental factors that influences the level of exposure. The goal of this presentation is to discuss the national security implications of changes in extreme weather events and demonstrate how changes in extremes can lead to a host cascading issues. To illustrate this point, this presentation will provide examples of the various pathways that extreme events can increase disease burden and cause economic stress.

Towards a full representation of tropical cyclones in a global reanalysis of extreme sea levels

NASA Astrophysics Data System (ADS)

Muis, S.; Verlaan, M.; Lin, N.; Winsemius, H.; Vatvani, D.; Ward, P.; Aerts, J.

2016-12-01

Tropical cyclones (TCs), including hurricanes and typhoons, are characterised by high wind speeds and low pressure, and cause dangerous storm surges in coastal areas. Recent disasters like the flooding of New Orleans in 2005 due to Hurricane Katrina and of New York in 2012 due to Hurricane Sandy exemplify the significant TC risk in the United States. In this contribution, we present a new framework to model TC storm surges and probabilities at the Atlantic basin- and, ultimately, global scales. This works builds on the work of Muis et al. (2016), which presented the first dynamically-derived reanalysis dataset of storm surges that covers the entire world's coastline (GTSR dataset). Surge levels for the period 1979-2014 were simulated by forcing the Global Surge and Tide Model (GTSM) with wind speed and atmospheric pressure from the ERA-Interim reanalysis. There is generally a good agreement between simulated and observed sea level extremes in extra-tropical regions; however for areas prone to TCs there is a severe underestimation of extremes. For example, the maximum surge levels during Hurricane Katrina in New Orleans exceeded 8 m, whilst the GTSM surge levels in that area do not exceed 2-3 m. Hence, due to the coarse grid resolution, the strong intensities of TCs are not fully captured in ERA-Interim. Furthermore, the length of ERA-Interim data set, like other reanalysis datasets, is too short to estimate the probabilities of extreme TC events in a reliable way. For accurate risk assessments it is essential to improve the representation of TCs in these global reanalysis of extreme sea levels. First, we need a higher resolution of meteorological forcing, which can be modelled with input from the observed best track data. Second, we need to statistically extend the observed record to many thousands of years. We will present the first results of these steps for the east coast of the United States. We will validate the GTSM model forced with best track data using recent extreme events like Katrina and Sandy. We will investigate how the statistics of the extreme sea level will change due to improved representation of TCs.

The influence of species, density, and diversity of macroalgal aggregations on microphytobenthic settlement.

PubMed

Umanzor, Schery; Ladah, Lydia; Zertuche-González, José A

2017-10-01

Intertidal macroalgae can modulate their biophysical environment by ameliorating physical conditions and creating habitats. Exploring how seaweed aggregations made up of different species at different densities modify the local environment may help explain how associated organisms respond to the attenuation of extreme physical conditions. Using Silvetia compressa, Chondracanthus canaliculatus, and Pyropia perforata, we constructed monocultures representing the leathery, corticated and foliose functional forms as well as a mixed tri-culture assemblage including the former three, at four densities. Treatment quadrats were installed in the intertidal where we measured irradiance, temperature, particle retention, and water motion underneath the canopies. Additionally, we examined the abundance and richness of the understory microphytobenthos with settlement slides. We found that the density and species composition of the assemblages modulated the amelioration of extreme physical conditions, with macroalgal aggregations of greater structural complexity due to their form and density showing greater physical factor attenuation. However, increasing the number of species within a patch did not directly result in increased complexity and therefore, did not necessarily cause greater amelioration of the environment. Microphytobenthic composition was also affected by species composition and density, with higher abundances under S. compressa and C. canaliculatus canopies at high and mid densities. These results support the idea that the environmental modifications driven by these macroalgae have a significant effect on the dynamics of the intertidal environment by promoting distinct temporal and spatial patchiness in the microphytobenthos, with potentially significant effects on the overall productivity of these ecosystems. © 2017 Phycological Society of America.

Diurnal and nocturnal skin temperature regulation in chronic complex regional pain syndrome.

PubMed

Schilder, Johanna C M; Niehof, Sjoerd P; Marinus, Johan; van Hilten, Jacobus J

2015-03-01

Skin temperature changes due to vasomotor disturbances are important features of complex regional pain syndrome (CRPS). Because this phenomenon has only been studied under controlled conditions, information on daily circadian variability is lacking. Also, studies in chronic CRPS patients with abnormal posturing, in which coldness of the affected extremity is more common, do not exist. We examined the response to external heating as well as circadian temperature changes over several days in the affected legs of 14 chronic CRPS patients with abnormal posturing and 17 controls. Skin temperatures were recorded hourly for 14 days using wireless sensors. Although the patients' affected extremities were significantly colder before external heating, the vasodilatory response was similar in the 2 groups. Additionally, median skin temperature differences between both legs and their variability was larger in patients than in controls during the day, but not during the night. These findings indicate that the mechanisms underlying impaired skin circulation in CRPS during daytime are reversible under certain circumstances. The large variation in skin temperature differences during the day questions the validity of using a single measurement in the diagnosis of CRPS, and our results indicate that only temperature differences >1.0 °C should be considered to reflect vasomotor disturbances. This article shows that chronic CRPS patients have a normal vasodilatory response to external heating and that skin temperature differences between the affected and unaffected lower limbs, which were highly variable during daytime, disappeared during sleep. This indicates that part of the vasomotor regulation in these patients is still functional. Copyright © 2015 American Pain Society. Published by Elsevier Inc. All rights reserved.

Genetic and life-history consequences of extreme climate events

PubMed Central

Mangel, Marc; Jesensek, Dusan; Garza, John Carlos; Crivelli, Alain J.

2017-01-01

Climate change is predicted to increase the frequency and intensity of extreme climate events. Tests on empirical data of theory-based predictions on the consequences of extreme climate events are thus necessary to understand the adaptive potential of species and the overarching risks associated with all aspects of climate change. We tested predictions on the genetic and life-history consequences of extreme climate events in two populations of marble trout Salmo marmoratus that have experienced severe demographic bottlenecks due to flash floods. We combined long-term field and genotyping data with pedigree reconstruction in a theory-based framework. Our results show that after flash floods, reproduction occurred at a younger age in one population. In both populations, we found the highest reproductive variance in the first cohort born after the floods due to a combination of fewer parents and higher early survival of offspring. A small number of parents allowed for demographic recovery after the floods, but the genetic bottleneck further reduced genetic diversity in both populations. Our results also elucidate some of the mechanisms responsible for a greater prevalence of faster life histories after the extreme event. PMID:28148745

Extreme Facial Expressions Classification Based on Reality Parameters

NASA Astrophysics Data System (ADS)

Rahim, Mohd Shafry Mohd; Rad, Abdolvahab Ehsani; Rehman, Amjad; Altameem, Ayman

2014-09-01

Extreme expressions are really type of emotional expressions that are basically stimulated through the strong emotion. An example of those extreme expression is satisfied through tears. So to be able to provide these types of features; additional elements like fluid mechanism (particle system) plus some of physics techniques like (SPH) are introduced. The fusion of facile animation with SPH exhibits promising results. Accordingly, proposed fluid technique using facial animation is the real tenor for this research to get the complex expression, like laugh, smile, cry (tears emergence) or the sadness until cry strongly, as an extreme expression classification that's happens on the human face in some cases.

Evaluation of Potential Climate Change Impacts on Particle Movement in Open Channel Flow

NASA Astrophysics Data System (ADS)

Lin, E.; Tsai, C.

2014-12-01

It is important to develop a forecast model to predict the trajectory of sediment particles when extreme flow events occur. In extreme flow environments, the stochastic jump diffusion particle tracking model (SJD-PTM) can be used to model the movement of sediment particles in response to extreme events. This proposed SJD-PTM can be separated into three main parts — a drift motion, a turbulence term and a jump term due to random occurrences of extreme flow events. The study is intended to modify the jump term, which models the abrupt changes of particle position in the extreme flow environments. The frequency of extreme flow occurrences might change due to many uncertain factors such as climate change. The study attempts to use the concept of the logistic regression and the parameter of odds ratio, namely the trend magnitude to investigate the frequency change of extreme flow event occurrences and its impact on sediment particle movement. With the SJD-PTM, the ensemble mean and variance of particle trajectory can be quantified via simulations. The results show that by taking the effect of the trend magnitude into consideration, the particle position and its uncertainty may undergo a significant increase. Such findings will have many important implications to the environmental and hydraulic engineering design and planning. For instance, when the frequency of the occurrence of flow events with higher extremity increases, particles can travel further and faster downstream. It is observed that flow events with higher extremity can induce a higher degree of entrainment and particle resuspension, and consequently more significant bed and bank erosion.

An observational and modeling study of the August 2017 Florida climate extreme event.

NASA Astrophysics Data System (ADS)

Konduru, R.; Singh, V.; Routray, A.

2017-12-01

A special report on the climate extremes by the Intergovernmental Panel on Climate Change (IPCC) elucidates that the sole cause of disasters is due to the exposure and vulnerability of the human and natural system to the climate extremes. The cause of such a climate extreme could be anthropogenic or non-anthropogenic. Therefore, it is challenging to discern the critical factor of influence for a particular climate extreme. Such kind of perceptive study with reasonable confidence on climate extreme events is possible only if there exist any past case studies. A similar rarest climate extreme problem encountered in the case of Houston floods and extreme rainfall over Florida in August 2017. A continuum of hurricanes like Harvey and Irma targeted the Florida region and caused catastrophe. Due to the rarity of August 2017 Florida climate extreme event, it requires the in-depth study on this case. To understand the multi-faceted nature of the event, a study on the development of the Harvey hurricane and its progression and dynamics is significant. Current article focus on the observational and modeling study on the Harvey hurricane. A global model named as NCUM (The global UK Met office Unified Model (UM) operational at National Center for Medium Range Weather Forecasting, India, was utilized to simulate the Harvey hurricane. The simulated rainfall and wind fields were compared with the observational datasets like Tropical Rainfall Measuring Mission rainfall datasets and Era-Interim wind fields. The National Centre for Environmental Prediction (NCEP) automated tracking system was utilized to track the Harvey hurricane, and the tracks were analyzed statistically for different forecasts concerning the Harvey hurricane track of Joint Typhon Warning Centre. Further, the current study will be continued to investigate the atmospheric processes involved in the August 2017 Florida climate extreme event.

Lagrangian Statistics and Intermittency in Gulf of Mexico.

PubMed

Lin, Liru; Zhuang, Wei; Huang, Yongxiang

2017-12-12

Due to the nonlinear interaction between different flow patterns, for instance, ocean current, meso-scale eddies, waves, etc, the movement of ocean is extremely complex, where a multiscale statistics is then relevant. In this work, a high time-resolution velocity with a time step 15 minutes obtained by the Lagrangian drifter deployed in the Gulf of Mexico (GoM) from July 2012 to October 2012 is considered. The measured Lagrangian velocity correlation function shows a strong daily cycle due to the diurnal tidal cycle. The estimated Fourier power spectrum E(f) implies a dual-power-law behavior which is separated by the daily cycle. The corresponding scaling exponents are close to -1.75 and -2.75 respectively for the time scale larger (resp. 0.1 ≤ f ≤ 0.4 day -1 ) and smaller (resp. 2 ≤ f ≤ 8 day -1 ) than 1 day. A Hilbert-based approach is then applied to this data set to identify the possible multifractal property of the cascade process. The results show an intermittent dynamics for the time scale larger than 1 day, while a less intermittent dynamics for the time scale smaller than 1 day. It is speculated that the energy is partially injected via the diurnal tidal movement and then transferred to larger and small scales through a complex cascade process, which needs more studies in the near future.

The attitudes of neonatal nurses towards extremely preterm infants.

PubMed

Gallagher, Katie; Marlow, Neil; Edgley, Alison; Porock, Davina

2012-08-01

The paper is a report of a study of the attitudes of neonatal nurses towards extremely preterm infants. Alongside advancing survival at extremely preterm gestational ages, ethical debates concerning the provision of invasive care have proliferated in light of the high morbidity. Despite nurses being the healthcare professionals who work closest with the infant and their family, their potential influence is usually ignored when determining how parents come to decisions about future care for their extremely premature infant. A Q methodology was employed to explore the attitudes of neonatal nurses towards caring for extremely preterm infants. Data were collected between 2007 and 2008 and analysed using PQMethod and Card Content Analysis. Thirty-six nurses from six neonatal units in the United Kingdom participated. Although there was consensus around the professional role of the nurse, when faced with the complexities of neonatal nursing three distinguishing factors emerged: the importance of parental choice in decision-making, the belief that technology should be used to assess response to treatment, and the belief that healthcare professionals should undertake difficult decisions. Neonatal nurses report unexpected difficulties in upholding their professionally defined role through highly complex and ever varied decision-making processes. Recognition of individual attitudes to the care of extremely preterm infants and the role of the family in the face of difficult decisions should facilitate more open communication between the nurse and the parents and improve the experience of both the nurse and the family during these emotional situations. © 2011 Blackwell Publishing Ltd.

Quantifying the role of climate variability on extreme total water level impacts: An application of a full simulation model to Ocean Beach, California

NASA Astrophysics Data System (ADS)

Serafin, K.; Ruggiero, P.; Stockdon, H. F.; Barnard, P.; Long, J.

2014-12-01

Many coastal communities worldwide are vulnerable to flooding and erosion driven by extreme total water levels (TWL), potentially dangerous events produced by the combination of large waves, high tides, and high non-tidal residuals. The West coast of the United States provides an especially challenging environment to model these processes due to its complex geological setting combined with uncertain forecasts for sea level rise (SLR), changes in storminess, and possible changes in the frequency of major El Niños. Our research therefore aims to develop an appropriate methodology to assess present-day and future storm-induced coastal hazards along the entire U.S. West coast, filling this information gap. We present the application of this framework in a pilot study at Ocean Beach, California, a National Park site within the Golden Gate National Recreation Area where existing event-scale coastal change data can be used for model calibration and verification. We use a probabilistic, full simulation TWL model (TWL-FSM; Serafin and Ruggiero, in press) that captures the seasonal and interannual climatic variability in extremes using functions of regional climate indices, such as the Multivariate ENSO index (MEI), to represent atmospheric patterns related to the El Niño-Southern Oscillation (ENSO). In order to characterize the effect of climate variability on TWL components, we refine the TWL-FSM by splitting non-tidal residuals into low (monthly mean sea level anomalies) and high frequency (storm surge) components. We also develop synthetic climate indices using Markov sequences to reproduce the autocorrelated nature of ENSO behavior. With the refined TWL-FSM, we simulate each TWL component, resulting in synthetic TWL records providing robust estimates of extreme return level events (e.g., the 100-yr event) and the ability to examine the relative contribution of each TWL component to these extreme events. Extreme return levels are then used to drive storm impact models to examine the probability of coastal change (Stockdon et al., 2013) and thus, the vulnerability to storm-induced coastal hazards that Ocean Beach faces. Future climate variability is easily incorporated into this framework, allowing us to quantify how an evolving climate will alter future extreme TWLs and their related coastal impacts.

SOI N-Channel Field Effect Transistors, CHT-NMOS80, for Extreme Temperatures

NASA Technical Reports Server (NTRS)

Patterson, Richard L.; Hammoud, Almad

2009-01-01

Extreme temperatures, both hot and cold, are anticipated in many of NASA space exploration missions as well as in terrestrial applications. One can seldom find electronics that are capable of operation under both regimes. Even for operation under one (hot or cold) temperature extreme, some thermal controls need to be introduced to provide appropriate ambient temperatures so that spacecraft on-board or field on-site electronic systems work properly. The inclusion of these controls, which comprise of heating elements and radiators along with their associated structures, adds to the complexity in the design of the system, increases cost and weight, and affects overall reliability. Thus, it would be highly desirable and very beneficial to eliminate these thermal measures in order to simplify system's design, improve efficiency, reduce development and launch costs, and improve reliability. These requirements can only be met through the development of electronic parts that are designed for proper and efficient operation under extreme temperature conditions. Silicon-on-insulator (SOI) based devices are finding more use in harsh environments due to the benefits that their inherent design offers in terms of reduced leakage currents, less power consumption, faster switching speeds, good radiation tolerance, and extreme temperature operability. Little is known, however, about their performance at cryogenic temperatures and under wide thermal swings. The objective of this work was to evaluate the performance of a new commercial-off-the-shelf (COTS) SOI parts over an extended temperature range and to determine the effects of thermal cycling on their performance. The results will establish a baseline on the suitability of such devices for use in space exploration missions under extreme temperatures, and will aid mission planners and circuit designers in the proper selection of electronic parts and circuits. The electronic part investigated in this work comprised of a CHT-NMOS80 high temperature N-channel MOSFET (metal-oxide semiconductor field-effect transistor) device that was manufactured by CISSOID. This high voltage, medium-power transistor is fabricated using SOI processes and is designed for extreme wide temperature applications such as geothermal well logging, aerospace and avionics, and automotive industry. It has a high DC current capability and is specified for operation in the temperature range of -55 C to +225 C

Hydroxypropyl cyclic β-(1 → 2)-D-glucans and epichlorohydrin β-cyclodextrin dimers as effective carbohydrate-solubilizers for polycyclic aromatic hydrocarbons.

PubMed

Choi, Jae Min; Jeong, Daham; Piao, Jinglan; Kim, Kyoungtea; Nguyen, Andrew Bao Loc; Kwon, Nak-Jung; Lee, Mi-Kyung; Lee, Im Soon; Yu, Jae-Hyuk; Jung, Seunho

2015-01-12

The removal of polycyclic aromatic hydrocarbons by soil washing using water is extremely difficult due to their intrinsic hydrophobic nature. In this study, the effective aqueous solubility enhancements of seven polycyclic aromatic hydrocarbons by chemically modified hydroxypropyl rhizobial cyclic β-(1 → 2)-D-glucans and epichlorohydrin β-cyclodextrin dimer have been investigated for the first time. In the presence of hydroxypropyl cyclic β-(1 → 2)-D-glucans, the solubility of benzo[a]pyrene is increased up to 38 fold of its native solubility. The solubility of pyrene and phenanthrene dramatically increased up to 160 and 359. Coronene, chrysene, perylene, and fluoranthene also show an increase of 11, 23, 23, and 97 fold, respectively, of enhanced solubility by complexation with synthetic epichlorohydrin β-cyclodextrin dimer. The physicochemical properties of the complex are characterized by Fourier-transform infrared spectra and differential scanning calorimetry. Utilizing a scanning electron microscopy, the morphological structures of native benzo[a]pyrene, pyrene, phenanthrene, coronene, chrysene, perylene, fluoranthene and their complex with novel carbohydrate-solubilizers are studied. These results elucidate that polycyclic aromatic hydrocarbons are able to form an efficient complex with hydroxypropyl cyclic β-(1 → 2)-D-glucans and β-cyclodextrin dimer, suggesting the potential usage of chemically modified novel carbohydrate-solubilizers. Copyright © 2014 Elsevier Ltd. All rights reserved.

Design loads and uncertainties for the transverse strength of ships

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pittaluga, A.

1995-12-31

Rational design of ship structures is becoming a reality, and a reliability based approach for the longitudinal strength assessment of ship hulls is close to implementation. Transverse strength of ships is a step behind, mainly due to the complexity of the collapse modes associated with transverse strength. Nevertheless, some investigations are being made and the importance of an acceptable stochastic model for the environmental demand on the transverse structures is widely recognized. In the paper, the problem of the determination of the sea loads on a transverse section of a ship is discussed. The problem of extrapolating the calculated results,more » which are relevant to the submerged portion of the hull, to areas which are only occasionally wet in extreme conditions is also addressed.« less

Impacts of Climate Change on Inequities in Child Health.

PubMed

Bennett, Charmian M; Friel, Sharon

2014-12-03

This paper addresses an often overlooked aspect of climate change impacts on child health: the amplification of existing child health inequities by climate change. Although the effects of climate change on child health will likely be negative, the distribution of these impacts across populations will be uneven. The burden of climate change-related ill-health will fall heavily on the world's poorest and socially-disadvantaged children, who already have poor survival rates and low life expectancies due to issues including poverty, endemic disease, undernutrition, inadequate living conditions and socio-economic disadvantage. Climate change will exacerbate these existing inequities to disproportionately affect disadvantaged children. We discuss heat stress, extreme weather events, vector-borne diseases and undernutrition as exemplars of the complex interactions between climate change and inequities in child health.

CVB: the Constrained Vapor Bubble Capillary Experiment on the International Space Station MARANGONI FLOW REGION

NASA Technical Reports Server (NTRS)

Wayner, Peter C., Jr.; Kundan, Akshay; Plawsky, Joel

2014-01-01

The Constrained Vapor Bubble (CVB) is a wickless, grooved heat pipe and we report on a full- scale fluids experiment flown on the International Space Station (ISS). The CVB system consists of a relatively simple setup a quartz cuvette with sharp corners partially filled with either pentane or an ideal mixture of pentane and isohexane as the working fluids. Along with temperature and pressure measurements, the two-dimensional thickness profile of the menisci formed at the corners of the quartz cuvette was determined using the Light Microscopy Module (LMM). Even with the large, millimeter dimensions of the CVB, interfacial forces dominate in these exceedingly small Bond Number systems. The experiments were carried out at various power inputs. Although conceptually simple, the transport processes were found to be very complex with many different regions. At the heated end of the CVB, due to a high temperature gradient, we observed Marangoni flow at some power inputs. This region from the heated end to the central drop region is defined as a Marangoni dominated region. We present a simple analysis based on interfacial phenomena using only measurements from the ISS experiments that lead to a predictive equation for the thickness of the film near the heated end of the CVB. The average pressure gradient for flow in the film is assumed due to the measured capillary pressure at the two ends of the liquid film and that the pressure stress gradient due to cohesion self adjusts to a constant value over a distance L. The boundary conditions are the no slip condition at the wall interface and an interfacial shear stress at the liquid- vapor interface due to the Marangoni stress, which is due to the high temperature gradient. Although the heated end is extremely complex, since it includes three- dimensional variations in radiation, conduction, evaporation, condensation, fluid flow and interfacial forces, we find that using the above simplifying assumptions, a simple successful model can be developed.

The role of activity complexes in the distribution of solar magnetic fields.

NASA Astrophysics Data System (ADS)

García de La Rosa, J. I.; Reyes, R. C.

Using published data on the large-scale distribution of solar activity, the authors conclude that the longlived coronal holes are formed and maintained by the unbalanced magnetic flux which developes at both extremes of the complexes of activity.

Application of complex discrete wavelet transform in classification of Doppler signals using complex-valued artificial neural network.

PubMed

Ceylan, Murat; Ceylan, Rahime; Ozbay, Yüksel; Kara, Sadik

2008-09-01

In biomedical signal classification, due to the huge amount of data, to compress the biomedical waveform data is vital. This paper presents two different structures formed using feature extraction algorithms to decrease size of feature set in training and test data. The proposed structures, named as wavelet transform-complex-valued artificial neural network (WT-CVANN) and complex wavelet transform-complex-valued artificial neural network (CWT-CVANN), use real and complex discrete wavelet transform for feature extraction. The aim of using wavelet transform is to compress data and to reduce training time of network without decreasing accuracy rate. In this study, the presented structures were applied to the problem of classification in carotid arterial Doppler ultrasound signals. Carotid arterial Doppler ultrasound signals were acquired from left carotid arteries of 38 patients and 40 healthy volunteers. The patient group included 22 males and 16 females with an established diagnosis of the early phase of atherosclerosis through coronary or aortofemoropopliteal (lower extremity) angiographies (mean age, 59 years; range, 48-72 years). Healthy volunteers were young non-smokers who seem to not bear any risk of atherosclerosis, including 28 males and 12 females (mean age, 23 years; range, 19-27 years). Sensitivity, specificity and average detection rate were calculated for comparison, after training and test phases of all structures finished. These parameters have demonstrated that training times of CVANN and real-valued artificial neural network (RVANN) were reduced using feature extraction algorithms without decreasing accuracy rate in accordance to our aim.

New Developments of Computational Fluid Dynamics and Their Applications to Practical Engineering Problems

NASA Astrophysics Data System (ADS)

Chen, Hudong

2001-06-01

There have been considerable advances in Lattice Boltzmann (LB) based methods in the last decade. By now, the fundamental concept of using the approach as an alternative tool for computational fluid dynamics (CFD) has been substantially appreciated and validated in mainstream scientific research and in industrial engineering communities. Lattice Boltzmann based methods possess several major advantages: a) less numerical dissipation due to the linear Lagrange type advection operator in the Boltzmann equation; b) local dynamic interactions suitable for highly parallel processing; c) physical handling of boundary conditions for complicated geometries and accurate control of fluxes; d) microscopically consistent modeling of thermodynamics and of interface properties in complex multiphase flows. It provides a great opportunity to apply the method to practical engineering problems encountered in a wide range of industries from automotive, aerospace to chemical, biomedical, petroleum, nuclear, and others. One of the key challenges is to extend the applicability of this alternative approach to regimes of highly turbulent flows commonly encountered in practical engineering situations involving high Reynolds numbers. Over the past ten years, significant efforts have been made on this front at Exa Corporation in developing a lattice Boltzmann based commercial CFD software, PowerFLOW. It has become a useful computational tool for the simulation of turbulent aerodynamics in practical engineering problems involving extremely complex geometries and flow situations, such as in new automotive vehicle designs world wide. In this talk, we present an overall LB based algorithm concept along with certain key extensions in order to accurately handle turbulent flows involving extremely complex geometries. To demonstrate the accuracy of turbulent flow simulations, we provide a set of validation results for some well known academic benchmarks. These include straight channels, backward-facing steps, flows over a curved hill and typical NACA airfoils at various angles of attack including prediction of stall angle. We further provide numerous engineering cases, ranging from external aerodynamics around various car bodies to internal flows involved in various industrial devices. We conclude with a discussion of certain future extensions for complex fluids.

Complicated Lower Extremity Wound Caused by Immune Thrombocytopenic Purpura Leading to Hypercoagulable State: A Team Approach for Limb Salvage

PubMed Central

Simman, Richard; Haluschak, John; Jackson, Sarah

2010-01-01

This article describes a complicated lower extremity wound due to hypercoagulable state caused by immune thrombocytopenic purpura. A team approach was important to limb salvage. A literature review is included. PMID:24527141

Early motor learning changes in upper-limb dynamics and shoulder complex loading during handrim wheelchair propulsion.

PubMed

Vegter, Riemer J K; Hartog, Johanneke; de Groot, Sonja; Lamoth, Claudine J; Bekker, Michel J; van der Scheer, Jan W; van der Woude, Lucas H V; Veeger, Dirkjan H E J

2015-03-10

To propel in an energy-efficient manner, handrim wheelchair users must learn to control the bimanually applied forces onto the rims, preserving both speed and direction of locomotion. Previous studies have found an increase in mechanical efficiency due to motor learning associated with changes in propulsion technique, but it is unclear in what way the propulsion technique impacts the load on the shoulder complex. The purpose of this study was to evaluate mechanical efficiency, propulsion technique and load on the shoulder complex during the initial stage of motor learning. 15 naive able-bodied participants received 12-minutes uninstructed wheelchair practice on a motor driven treadmill, consisting of three 4-minute blocks separated by two minutes rest. Practice was performed at a fixed belt speed (v = 1.1 m/s) and constant low-intensity power output (0.2 W/kg). Energy consumption, kinematics and kinetics of propulsion technique were continuously measured. The Delft Shoulder Model was used to calculate net joint moments, muscle activity and glenohumeral reaction force. With practice mechanical efficiency increased and propulsion technique changed, reflected by a reduced push frequency and increased work per push, performed over a larger contact angle, with more tangentially applied force and reduced power losses before and after each push. Contrary to our expectations, the above mentioned propulsion technique changes were found together with an increased load on the shoulder complex reflected by higher net moments, a higher total muscle power and higher peak and mean glenohumeral reaction forces. It appears that the early stages of motor learning in handrim wheelchair propulsion are indeed associated with improved technique and efficiency due to optimization of the kinematics and dynamics of the upper extremity. This process goes at the cost of an increased muscular effort and mechanical loading of the shoulder complex. This seems to be associated with an unchanged stable function of the trunk and could be due to the early learning phase where participants still have to learn to effectively use the full movement amplitude available within the wheelchair-user combination. Apparently whole body energy efficiency has priority over mechanical loading in the early stages of learning to propel a handrim wheelchair.

Game theory and extremal optimization for community detection in complex dynamic networks.

PubMed

Lung, Rodica Ioana; Chira, Camelia; Andreica, Anca

2014-01-01

The detection of evolving communities in dynamic complex networks is a challenging problem that recently received attention from the research community. Dynamics clearly add another complexity dimension to the difficult task of community detection. Methods should be able to detect changes in the network structure and produce a set of community structures corresponding to different timestamps and reflecting the evolution in time of network data. We propose a novel approach based on game theory elements and extremal optimization to address dynamic communities detection. Thus, the problem is formulated as a mathematical game in which nodes take the role of players that seek to choose a community that maximizes their profit viewed as a fitness function. Numerical results obtained for both synthetic and real-world networks illustrate the competitive performance of this game theoretical approach.

[Complex heterogeneity phenotypes and genotypes of glutaric aciduria type 1].

PubMed

Wang, Qiao; Yang, Yan-Ling

2016-05-01

Glutaric aciduria type 1 is a rare autosomal recessive disorder. GCDH gene mutations cause glutaryl-CoA dehydrogenase deficiency and accumulation of glutaric acid and 3-hydroxyglutaric acid, resulting in damage of striatum and other brain nucleus and neurodegeneration. Patients with glutaric aciduria type 1 present with complex heterogeneous phenotypes and genotypes. The symptoms are extremely variable. The ages of the clinical onset of the patients range from the fetus period to adulthood. The patients with mild glutaric aciduria type 1 are almost asymptomatic before onset, however, severe glutaric aciduria type 1 may cause death or disability due to acute encephalopathy. Acute metabolic crisis in patients with underlying glutaric aciduria type 1 is often triggered by febrile illnesses, trauma, hunger, high-protein foods and vaccination during a vulnerable period of brain development in infancy or early childhood. The early-onset patients usually have a poor prognosis. Urinary organic acids analysis, blood acylcarnitines analysis and GCDH study are important for the diagnosis of this disorder. Neonatal screening is essential for the early diagnosis and the improvement of prognosis.

Mesenchymal Stem Cells as Therapeutics Agents: Quality and Environmental Regulatory Aspects

PubMed Central

Sabata, Roger; Verges, Josep; Zugaza, José L.; Ruiz, Adolfina; Clares, Beatriz

2016-01-01

Mesenchymal stem cells (MSCs) are one of the main stem cells that have been used for advanced therapies and regenerative medicine. To carry out the translational clinical application of MSCs, their manufacturing and administration in human must be controlled; therefore they should be considered as medicine: stem cell-based medicinal products (SCMPs). The development of MSCs as SCMPs represents complicated therapeutics due to their extreme complex nature and rigorous regulatory oversights. The manufacturing process of MSCs needs to be addressed in clean environments in compliance with requirements of Good Manufacturing Practice (GMP). Facilities should maintain these GMP conditions according to international and national medicinal regulatory frameworks that introduce a number of specifications in order to produce MSCs as safe SCMPs. One of these important and complex requirements is the environmental monitoring. Although a number of environmental requirements are clearly defined, some others are provided as recommendations. In this review we aim to outline the current issues with regard to international guidelines which impact environmental monitoring in cleanrooms and clean areas for the manufacturing of MSCs. PMID:27999600

As-built data capture of complex piping using photogrammetry technology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morray, J.P.; Ziu, C.G.

1995-11-01

Plant owners face an increasingly difficult and expensive task of updating drawings, both regarding the plant logic and physical layout. Through the use of photogrammetry technology, H-H spectrum has created a complete operating plant data capture service, with the result that the task of recording accurate plant configurations has become assured and economical. The technology has proven to be extremely valuable for the capture of complex piping configurations, as well as entire plant facilities, and yields accuracy within 1/4 inch. The method uses photographs and workstation technology to quickly document and compute the plant layout, with all components, regardless ofmore » size, included in the resulting model. The system has the capability to compute actual 3-D coordinates of any point based on previous triangulations, allowing for an immediate assessment of accuracy. This ensures a consistent level of accuracy, which is impossible to achieve in a manual approach. Due to the speed of the process, the approach is very important in hazardous/difficult environments such as nuclear power facilities or offshore platforms.« less

Underestimating extreme events in power-law behavior due to machine-dependent cutoffs

NASA Astrophysics Data System (ADS)

Radicchi, Filippo

2014-11-01

Power-law distributions are typical macroscopic features occurring in almost all complex systems observable in nature. As a result, researchers in quantitative analyses must often generate random synthetic variates obeying power-law distributions. The task is usually performed through standard methods that map uniform random variates into the desired probability space. Whereas all these algorithms are theoretically solid, in this paper we show that they are subject to severe machine-dependent limitations. As a result, two dramatic consequences arise: (i) the sampling in the tail of the distribution is not random but deterministic; (ii) the moments of the sample distribution, which are theoretically expected to diverge as functions of the sample sizes, converge instead to finite values. We provide quantitative indications for the range of distribution parameters that can be safely handled by standard libraries used in computational analyses. Whereas our findings indicate possible reinterpretations of numerical results obtained through flawed sampling methodologies, they also pave the way for the search for a concrete solution to this central issue shared by all quantitative sciences dealing with complexity.

Statistical robustness of machine-learning estimates for characterizing a groundwater-surface water system, Southland, New Zealand

NASA Astrophysics Data System (ADS)

Friedel, M. J.; Daughney, C.

2016-12-01

The development of a successful surface-groundwater management strategy depends on the quality of data provided for analysis. This study evaluates the statistical robustness when using a modified self-organizing map (MSOM) technique to estimate missing values for three hypersurface models: synoptic groundwater-surface water hydrochemistry, time-series of groundwater-surface water hydrochemistry, and mixed-survey (combination of groundwater-surface water hydrochemistry and lithologies) hydrostratigraphic unit data. These models of increasing complexity are developed and validated based on observations from the Southland region of New Zealand. In each case, the estimation method is sufficiently robust to cope with groundwater-surface water hydrochemistry vagaries due to sample size and extreme data insufficiency, even when >80% of the data are missing. The estimation of surface water hydrochemistry time series values enabled the evaluation of seasonal variation, and the imputation of lithologies facilitated the evaluation of hydrostratigraphic controls on groundwater-surface water interaction. The robust statistical results for groundwater-surface water models of increasing data complexity provide justification to apply the MSOM technique in other regions of New Zealand and abroad.

Neutral and anionic duality of 1,2,4-triazole α-amino acid scaffold in 1D coordination polymers

NASA Astrophysics Data System (ADS)

Naik, Anil D.; Dîrtu, Marinela M.; Garcia, Yann

2012-03-01

A tiny supramolecular synthon, 4H-1,2,4-triazol-4-yl acetic acid (HGlytrz) which is bifunctional by design having an electronic asymmetry and conformational flexibility has been introduced to synthesize iron(II) complexes. Having 1,2,4-triazole or carboxylic extremities on the same framework HGlytrz could display dual functionality by acting as a neutral as well as anionic ligand based on the possibility of deprotonation of carboxylic group. Four new iron(II) HGlytrz complexes with ClO4- ( 1), NO3- ( 2), BF4- ( 3) and CF3SO3- ( 4) anions were prepared. Formulation of their composition which is complicated due to ligand deprotonation is discussed. Unlike its ester protected counterpart ethyl-4H-1,2,4-triazol-4-yl-acetate ( αGlytrz) which show hysteretic room temperature spin crossover, 1- 4 remain in the high-spin state as revealed by 57Mössbauer spectroscopy. Prospects of such 1D coordination polymers with dangling unbounded carboxylic entities in the realm of self-assembled monolayer (SAM) are discussed.

AgroClimate: Simulating and Monitoring the Risk of Extreme Weather Events from a Crop Phenology Perspective

NASA Astrophysics Data System (ADS)

Fraisse, C.; Pequeno, D.; Staub, C. G.; Perry, C.

2016-12-01

Climate variability, particularly the occurrence of extreme weather conditions such as dry spells and heat stress during sensitive crop developmental phases can substantially increase the prospect of reduced crop yields. Yield losses or crop failure risk due to stressful weather conditions vary mainly due to stress severity and exposure time and duration. The magnitude of stress effects is also crop specific, differing in terms of thresholds and adaptation to environmental conditions. To help producers in the Southeast USA mitigate and monitor the risk of crop losses due to extreme weather events we developed a web-based tool that evaluates the risk of extreme weather events during the season taking into account the crop development stages. Producers can enter their plans for the upcoming season in a given field (e.g. crop, variety, planting date, acreage etc.), select or not a specific El Nino Southern Oscillation (ENSO) phase, and will be presented with the probabilities (ranging from 0 -100%) of extreme weather events occurring during sensitive phases of the growing season for the selected conditions. The DSSAT models CERES-Maize, CROPGRO-Soybean, CROPGRO-Cotton, and N-Wheat phenology models have been translated from FORTRAN to a standalone versions in R language. These models have been tested in collaboration with Extension faculty and producers during the 2016 season and their usefulness for risk mitigation and monitoring evaluated. A companion AgroClimate app was also developed to help producers track and monitor phenology development during the cropping season.

Revisiting the Quantum Brain Hypothesis: Toward Quantum (Neuro)biology?

PubMed Central

Jedlicka, Peter

2017-01-01

The nervous system is a non-linear dynamical complex system with many feedback loops. A conventional wisdom is that in the brain the quantum fluctuations are self-averaging and thus functionally negligible. However, this intuition might be misleading in the case of non-linear complex systems. Because of an extreme sensitivity to initial conditions, in complex systems the microscopic fluctuations may be amplified and thereby affect the system’s behavior. In this way quantum dynamics might influence neuronal computations. Accumulating evidence in non-neuronal systems indicates that biological evolution is able to exploit quantum stochasticity. The recent rise of quantum biology as an emerging field at the border between quantum physics and the life sciences suggests that quantum events could play a non-trivial role also in neuronal cells. Direct experimental evidence for this is still missing but future research should address the possibility that quantum events contribute to an extremely high complexity, variability and computational power of neuronal dynamics. PMID:29163041

Variable complexity online sequential extreme learning machine, with applications to streamflow prediction

NASA Astrophysics Data System (ADS)

Lima, Aranildo R.; Hsieh, William W.; Cannon, Alex J.

2017-12-01

In situations where new data arrive continually, online learning algorithms are computationally much less costly than batch learning ones in maintaining the model up-to-date. The extreme learning machine (ELM), a single hidden layer artificial neural network with random weights in the hidden layer, is solved by linear least squares, and has an online learning version, the online sequential ELM (OSELM). As more data become available during online learning, information on the longer time scale becomes available, so ideally the model complexity should be allowed to change, but the number of hidden nodes (HN) remains fixed in OSELM. A variable complexity VC-OSELM algorithm is proposed to dynamically add or remove HN in the OSELM, allowing the model complexity to vary automatically as online learning proceeds. The performance of VC-OSELM was compared with OSELM in daily streamflow predictions at two hydrological stations in British Columbia, Canada, with VC-OSELM significantly outperforming OSELM in mean absolute error, root mean squared error and Nash-Sutcliffe efficiency at both stations.

Winds, Mountains, and Wildland Fire: Improved Understanding of Coupled Atmosphere-Topography-Fire Interactions Through Large-Eddy Simulation

NASA Astrophysics Data System (ADS)

Munoz-Esparza, D.; Sauer, J.; Linn, R.

2015-12-01

Anomalous and unexpected fire behavior in complex terrain continues to result in substantial loss of property and extremely dangerous conditions for firefighting field personnel. We briefly discuss proposed hypotheses of fire interactions with atmospheric flows over complex terrain that can lead to poorly-understood and potentially catastrophic scenarios. Then, our recent results of numerical investigations via large-eddy simulation of coupled atmosphere-topography-fire phenomenology with the Los Alamos National Laboratory, HiGrad-Firetec model are presented as an example of the potential for increased understanding of these complex processes. This investigation focuses on the influence of downslope surface wind enhancement through stably stratified flow over an isolated hill, and the resulting dramatic changes in fire behavior including spread rate, and intensity. Implications with respect to counter-intuitive fire behavior and extreme fire events are discussed. This work demonstrates a tremendous opportunity to immediately create safer and more effective policy for field personnel through improved predictability of atmospheric conditions over complex terrain

Revisiting the Quantum Brain Hypothesis: Toward Quantum (Neuro)biology?

PubMed

Jedlicka, Peter

2017-01-01

The nervous system is a non-linear dynamical complex system with many feedback loops. A conventional wisdom is that in the brain the quantum fluctuations are self-averaging and thus functionally negligible. However, this intuition might be misleading in the case of non-linear complex systems. Because of an extreme sensitivity to initial conditions, in complex systems the microscopic fluctuations may be amplified and thereby affect the system's behavior. In this way quantum dynamics might influence neuronal computations. Accumulating evidence in non-neuronal systems indicates that biological evolution is able to exploit quantum stochasticity. The recent rise of quantum biology as an emerging field at the border between quantum physics and the life sciences suggests that quantum events could play a non-trivial role also in neuronal cells. Direct experimental evidence for this is still missing but future research should address the possibility that quantum events contribute to an extremely high complexity, variability and computational power of neuronal dynamics.

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.

Poverty, Disease, and the Ecology of Complex Systems

PubMed Central

Pluciński, Mateusz M.; Murray, Megan B.; Farmer, Paul E.; Barrett, Christopher B.; Keenan, Donald C.

2014-01-01

Understanding why some human populations remain persistently poor remains a significant challenge for both the social and natural sciences. The extremely poor are generally reliant on their immediate natural resource base for subsistence and suffer high rates of mortality due to parasitic and infectious diseases. Economists have developed a range of models to explain persistent poverty, often characterized as poverty traps, but these rarely account for complex biophysical processes. In this Essay, we argue that by coupling insights from ecology and economics, we can begin to model and understand the complex dynamics that underlie the generation and maintenance of poverty traps, which can then be used to inform analyses and possible intervention policies. To illustrate the utility of this approach, we present a simple coupled model of infectious diseases and economic growth, where poverty traps emerge from nonlinear relationships determined by the number of pathogens in the system. These nonlinearities are comparable to those often incorporated into poverty trap models in the economics literature, but, importantly, here the mechanism is anchored in core ecological principles. Coupled models of this sort could be usefully developed in many economically important biophysical systems—such as agriculture, fisheries, nutrition, and land use change—to serve as foundations for deeper explorations of how fundamental ecological processes influence structural poverty and economic development. PMID:24690902

Poverty, disease, and the ecology of complex systems.

PubMed

Ngonghala, Calistus N; Pluciński, Mateusz M; Murray, Megan B; Farmer, Paul E; Barrett, Christopher B; Keenan, Donald C; Bonds, Matthew H

2014-04-01

Understanding why some human populations remain persistently poor remains a significant challenge for both the social and natural sciences. The extremely poor are generally reliant on their immediate natural resource base for subsistence and suffer high rates of mortality due to parasitic and infectious diseases. Economists have developed a range of models to explain persistent poverty, often characterized as poverty traps, but these rarely account for complex biophysical processes. In this Essay, we argue that by coupling insights from ecology and economics, we can begin to model and understand the complex dynamics that underlie the generation and maintenance of poverty traps, which can then be used to inform analyses and possible intervention policies. To illustrate the utility of this approach, we present a simple coupled model of infectious diseases and economic growth, where poverty traps emerge from nonlinear relationships determined by the number of pathogens in the system. These nonlinearities are comparable to those often incorporated into poverty trap models in the economics literature, but, importantly, here the mechanism is anchored in core ecological principles. Coupled models of this sort could be usefully developed in many economically important biophysical systems--such as agriculture, fisheries, nutrition, and land use change--to serve as foundations for deeper explorations of how fundamental ecological processes influence structural poverty and economic development.

Microbial communities and their predicted metabolic functions in a desiccating acid salt lake.

PubMed

Zaikova, Elena; Benison, Kathleen C; Mormile, Melanie R; Johnson, Sarah Stewart

2018-05-01

The waters of Lake Magic in Western Australia are among the most geochemically extreme on Earth. This ephemeral saline lake is characterized by pH as low as 1.6 salinity as high as 32% total dissolved solids, and unusually complex geochemistry, including extremely high concentrations of aluminum, silica, and iron. We examined the microbial composition and putative function in this extreme acid brine environment by analyzing lake water, groundwater, and sediment samples collected during the austral summer near peak evapoconcentration. Our results reveal that the lake water metagenome, surprisingly, was comprised of mostly eukaryote sequences, particularly fungi and to a lesser extent, green algae. Groundwater and sediment samples were dominated by acidophilic Firmicutes, with eukaryotic community members only detected at low abundances. The lake water bacterial community was less diverse than that in groundwater and sediment, and was overwhelmingly represented by a single OTU affiliated with Salinisphaera. Pathways associated with halotolerance were found in the metagenomes, as were genes associated with biosynthesis of protective carotenoids. During periods of complete desiccation of the lake, we hypothesize that dormancy and entrapment in fluid inclusions in halite crystals may increase long-term survival, leading to the resilience of complex eukaryotes in this extreme environment.

Genetic and life-history consequences of extreme climate events.

PubMed

Vincenzi, Simone; Mangel, Marc; Jesensek, Dusan; Garza, John Carlos; Crivelli, Alain J

2017-02-08

Climate change is predicted to increase the frequency and intensity of extreme climate events. Tests on empirical data of theory-based predictions on the consequences of extreme climate events are thus necessary to understand the adaptive potential of species and the overarching risks associated with all aspects of climate change. We tested predictions on the genetic and life-history consequences of extreme climate events in two populations of marble trout Salmo marmoratus that have experienced severe demographic bottlenecks due to flash floods. We combined long-term field and genotyping data with pedigree reconstruction in a theory-based framework. Our results show that after flash floods, reproduction occurred at a younger age in one population. In both populations, we found the highest reproductive variance in the first cohort born after the floods due to a combination of fewer parents and higher early survival of offspring. A small number of parents allowed for demographic recovery after the floods, but the genetic bottleneck further reduced genetic diversity in both populations. Our results also elucidate some of the mechanisms responsible for a greater prevalence of faster life histories after the extreme event. © 2017 The Author(s).

Growth condition dependency is the major cause of non-responsiveness upon genetic perturbation

PubMed Central

Amini, Saman; Holstege, Frank C. P.

2017-01-01

Investigating the role and interplay between individual proteins in biological processes is often performed by assessing the functional consequences of gene inactivation or removal. Depending on the sensitivity of the assay used for determining phenotype, between 66% (growth) and 53% (gene expression) of Saccharomyces cerevisiae gene deletion strains show no defect when analyzed under a single condition. Although it is well known that this non-responsive behavior is caused by different types of redundancy mechanisms or by growth condition/cell type dependency, it is not known what the relative contribution of these different causes is. Understanding the underlying causes of and their relative contribution to non-responsive behavior upon genetic perturbation is extremely important for designing efficient strategies aimed at elucidating gene function and unraveling complex cellular systems. Here, we provide a systematic classification of the underlying causes of and their relative contribution to non-responsive behavior upon gene deletion. The overall contribution of redundancy to non-responsive behavior is estimated at 29%, of which approximately 17% is due to homology-based redundancy and 12% is due to pathway-based redundancy. The major determinant of non-responsiveness is condition dependency (71%). For approximately 14% of protein complexes, just-in-time assembly can be put forward as a potential mechanistic explanation for how proteins can be regulated in a condition dependent manner. Taken together, the results underscore the large contribution of growth condition requirement to non-responsive behavior, which needs to be taken into account for strategies aimed at determining gene function. The classification provided here, can also be further harnessed in systematic analyses of complex cellular systems. PMID:28257504

Clinical and pathophysiological evidence supporting the safety of extremely low LDL levels-The zero-LDL hypothesis.

PubMed

Masana, Luis; Girona, Josefa; Ibarretxe, Daiana; Rodríguez-Calvo, Ricardo; Rosales, Roser; Vallvé, Joan-Carles; Rodríguez-Borjabad, Cèlia; Guardiola, Montserrat; Rodríguez, Marina; Guaita-Esteruelas, Sandra; Oliva, Iris; Martínez-Micaelo, Neus; Heras, Mercedes; Ferré, Raimon; Ribalta, Josep; Plana, Núria

While the impact of very low concentrations of low-density lipoprotein cholesterol (LDL-C) on cardiovascular prevention is very reassuring, it is intriguing to know what effect these extremely low LDL-C concentrations have on lipid homoeostasis. The evidence supporting the safety of extremely low LDL levels comes from genetic studies and clinical drug trials. Individuals with lifelong low LDL levels due to mutations in genes associated with increased LDL-LDL receptor (LDLR) activity reveal no safety issues. Patients achieving extremely low LDL levels in the IMPROVE-IT and FOURIER, and the PROFICIO and ODYSSEY programs seem not to have an increased prevalence of adverse effects. The main concern regarding extremely low LDL-C plasma concentrations is the adequacy of the supply of cholesterol, and other molecules, to peripheral tissues. However, LDL proteomic and kinetic studies reaffirm that LDL is the final product of endogenous lipoprotein metabolism. Four of 5 LDL particles are cleared through the LDL-LDLR pathway in the liver. Given that mammalian cells have no enzymatic systems to degrade cholesterol, the LDL-LDLR pathway is the main mechanism for removal of cholesterol from the body. Our focus, therefore, is to review, from a physiological perspective, why such extremely low LDL-C concentrations do not appear to be detrimental. We suggest that extremely low LDL-C levels due to increased LDLR activity may be a surrogate of adequate LDL-LDLR pathway function. Copyright © 2018 National Lipid Association. Published by Elsevier Inc. All rights reserved.

Quantifying population exposure to airborne particulate matter during extreme events in California due to climate change

NASA Astrophysics Data System (ADS)

Mahmud, A.; Hixson, M.; Kleeman, M. J.

2012-08-01

The effect of climate change on population-weighted concentrations of particulate matter (PM) during extreme pollution events was studied using the Parallel Climate Model (PCM), the Weather Research and Forecasting (WRF) model and the UCD/CIT 3-D photochemical air quality model. A "business as usual" (B06.44) global emissions scenario was dynamically downscaled for the entire state of California between the years 2000-2006 and 2047-2053. Air quality simulations were carried out for 1008 days in each of the present-day and future climate conditions using year-2000 emissions. Population-weighted concentrations of PM0.1, PM2.5, and PM10 total mass, components species, and primary source contributions were calculated for California and three air basins: the Sacramento Valley air basin (SV), the San Joaquin Valley air basin (SJV) and the South Coast Air Basin (SoCAB). Results over annual-average periods were contrasted with extreme events. The current study found that the change in annual-average population-weighted PM2.5 mass concentrations due to climate change between 2000 vs. 2050 within any major sub-region in California was not statistically significant. However, climate change did alter the annual-average composition of the airborne particles in the SoCAB, with notable reductions of elemental carbon (EC; -3%) and organic carbon (OC; -3%) due to increased annual-average wind speeds that diluted primary concentrations from gasoline combustion (-3%) and food cooking (-4%). In contrast, climate change caused significant increases in population-weighted PM2.5 mass concentrations in central California during extreme events. The maximum 24-h average PM2.5 concentration experienced by an average person during a ten-yr period in the SJV increased by 21% due to enhanced production of secondary particulate matter (manifested as NH4NO3). In general, climate change caused increased stagnation during future extreme pollution events, leading to higher exposure to diesel engines particles (+32%) and wood combustion particles (+14%) when averaging across the population of the entire state. Enhanced stagnation also isolated populations from distant sources such as shipping (-61%) during extreme events. The combination of these factors altered the statewide population-averaged composition of particles during extreme events, with EC increasing by 23 %, nitrate increasing by 58%, and sulfate decreasing by 46%.

Modeling extreme sea levels due to tropical and extra-tropical cyclones at the global-scale

NASA Astrophysics Data System (ADS)

Muis, S.; Lin, N.; Verlaan, M.; Winsemius, H.; Ward, P.; Aerts, J.

2017-12-01

Extreme sea levels, a combination of storm surges and astronomical tides, can cause catastrophic floods. Due to their intense wind speeds and low pressure, tropical cyclones (TCs) typically cause higher storm surges than extra-tropical cyclones (ETCs), but ETCs may still contribute significantly to the overall flood risk. In this contribution, we show a novel approach to model extreme sea levels due to both tropical and extra-tropical cyclones at the global-scale. Using a global hydrodynamic model we have developed the Global Tide and Surge Reanalysis (GTSR) dataset (Muis et al., 2016), which provides daily maximum timeseries of storm tide from 1979 to 2014. GTSR is based on wind and pressure fields from the ERA-Interim climate reanalysis (Dee at al., 2011). A severe limitation of the GTSR dataset is the underrepresentation of TCs. This is due to the relatively coarse grid resolution of ERA-Interim, which means that the strong intensities of TCs are not fully included. Furthermore, the length of ERA-Interim is too short to estimate the probabilities of extreme TCs in a reliable way. We will discuss potential ways to address this limitation, and demonstrate how to improve the global GTSR framework. We will apply the improved framework to the east coast of the United States. First, we improve our meteorological forcing by applying a parametric hurricane model (Holland 1980), and we improve the tide and surge reanalysis dataset (Muis et al., 2016) by explicitly modeling the historical TCs in the Extended Best Track dataset (Demuth et al., 2006). Second, we improve our sampling by statistically extending the observed TC record to many thousands of years (Emanuel et al., 2006). The improved framework allows for the mapping of probabilities of extreme sea levels, including extremes TC events, for the east coast of the United States. ReferencesDee et al (2011). The ERA-Interim reanalysis: configuration and performance of the data assimilation system. Q. J. R. Meteorol. Soc. 137, 553-97. Emanuel et al (2006). A Statistical Deterministic Approach to Hurricane Risk Assessment/ Bull. Am. Meteorol. Soc. 87, 299-314. Holland (1980). An analytic model of the wind and pressure profiles in hurricanes. Mon. Weather Rev. 108, 1212-1218. Muis et al (2016). A global reanalysis of storm surge and extreme sea levels. Nat. Commun. 7, 1-11

Photodissociation spectroscopy of the dysprosium monochloride molecular ion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dunning, Alexander, E-mail: alexander.dunning@gmail.com; Schowalter, Steven J.; Puri, Prateek

2015-09-28

We have performed a combined experimental and theoretical study of the photodissociation cross section of the molecular ion DyCl{sup +}. The photodissociation cross section for the photon energy range 35 500 cm{sup −1} to 47 500 cm{sup −1} is measured using an integrated ion trap and time-of-flight mass spectrometer; we observe a broad, asymmetric profile that is peaked near 43 000 cm{sup −1}. The theoretical cross section is determined from electronic potentials and transition dipole moments calculated using the relativistic configuration-interaction valence-bond and coupled-cluster methods. The electronic structure of DyCl{sup +} is extremely complex due to the presence of multiple open electronic shells,more » including the 4f{sup 10} configuration. The molecule has nine attractive potentials with ionically bonded electrons and 99 repulsive potentials dissociating to a ground state Dy{sup +} ion and Cl atom. We explain the lack of symmetry in the cross section as due to multiple contributions from one-electron-dominated transitions between the vibrational ground state and several resolved repulsive excited states.« less

Charge carrier trapping and acoustic phonon modes in single CdTe nanowires.

PubMed

Lo, Shun Shang; Major, Todd A; Petchsang, Nattasamon; Huang, Libai; Kuno, Masaru K; Hartland, Gregory V

2012-06-26

Semiconductor nanostructures produced by wet chemical synthesis are extremely heterogeneous, which makes single particle techniques a useful way to interrogate their properties. In this paper the ultrafast dynamics of single CdTe nanowires are studied by transient absorption microscopy. The wires have lengths of several micrometers and lateral dimensions on the order of 30 nm. The transient absorption traces show very fast decays, which are assigned to charge carrier trapping into surface defects. The time constants vary for different wires due to differences in the energetics and/or density of surface trap sites. Measurements performed at the band edge compared to the near-IR give slightly different time constants, implying that the dynamics for electron and hole trapping are different. The rate of charge carrier trapping was observed to slow down at high carrier densities, which was attributed to trap-state filling. Modulations due to the fundamental and first overtone of the acoustic breathing mode were also observed in the transient absorption traces. The quality factors for these modes were similar to those measured for metal nanostructures, and indicate a complex interaction with the environment.

Catalogue of Diptera of Colombia: an introduction.

PubMed

Wolff, Marta; Nihei, Silvio S; Carvalho, Claudio J B De

2016-06-14

Colombia has an imposing natural wealth due to its topography has many unique characteristics as a consequence of having Caribbean and Pacific shores, as well as sharing part of the Amazon basin and northern Andes mountains. Thus, many natural and biological features are due to the convergence of three biogeographical regions: Pacific, Andes and Amazonia. The Andean uplift created a complex mosaic of mountains and isolated valleys, including eleven biogeographical provinces (Morrone 2006). The Andes dominate the Colombian topography and cross the country south to north. There are three mountain ranges (Western, Central, and Eastern) with a maximum elevation of 5,775 m, and an average elevation of 2,000 m. The Magdalena and Cauca River valleys separate these ranges, that along with the Putumayo and Caquetá Rivers, the Catatumbo watershed, the Darién, Pique Hill, the Orinoquia Region (with its savannas), the Amazon region (with tropical rainforests), and some lower mountain ranges (Macarena and Chiribiquete), have generated the conditions for very high levels of endemism. This variety of conditions has resulted in an extremely diverse plant and animal biota, and in which 48% of the nation remains unexplored.

Message Passing and Shared Address Space Parallelism on an SMP Cluster

NASA Technical Reports Server (NTRS)

Shan, Hongzhang; Singh, Jaswinder P.; Oliker, Leonid; Biswas, Rupak; Biegel, Bryan (Technical Monitor)

2002-01-01

Currently, message passing (MP) and shared address space (SAS) are the two leading parallel programming paradigms. MP has been standardized with MPI, and is the more common and mature approach; however, code development can be extremely difficult, especially for irregularly structured computations. SAS offers substantial ease of programming, but may suffer from performance limitations due to poor spatial locality and high protocol overhead. In this paper, we compare the performance of and the programming effort required for six applications under both programming models on a 32-processor PC-SMP cluster, a platform that is becoming increasingly attractive for high-end scientific computing. Our application suite consists of codes that typically do not exhibit scalable performance under shared-memory programming due to their high communication-to-computation ratios and/or complex communication patterns. Results indicate that SAS can achieve about half the parallel efficiency of MPI for most of our applications, while being competitive for the others. A hybrid MPI+SAS strategy shows only a small performance advantage over pure MPI in some cases. Finally, improved implementations of two MPI collective operations on PC-SMP clusters are presented.

Stress fracture of ulna due to excessive push-ups.

PubMed

Meena, Sanjay; Rastogi, Devarshi; Solanki, Bipin; Chowdhury, Buddhadev

2014-01-01

Stress fractures are most common in the weight-bearing bones of the lower extremities and spine, but are rarely found in non-weight-bearing bones of the body. Stress fracture of the ulna is extremely rare. We report a case of complete stress fracture of ulna caused due to excessive push ups in a young athlete. Conservative management was successful in healing of fracture and returning this patient back to his previous activity level. Physician should have high index of suspicion, whenever they encounter a young athlete complaining of forearm pain.

Characteristics of occurrence of heavy rainfall events over Odisha during summer monsoon season

NASA Astrophysics Data System (ADS)

Swain, Madhusmita; Pattanayak, Sujata; Mohanty, U. C.

2018-06-01

During summer monsoon season heavy to very heavy rainfall events have been occurring over most part of India, routinely result in flooding over Indian Monsoon Region (IMR). It is worthwhile to mention that as per Geological Survey of India, Odisha is one of the most flood prone regions of India. The present study analyses the occurrence of very light (0-2.4 mm/day), light (2.5 - 15.5 mm/day), moderate (15.6 - 64.4 mm/day), heavy (64.5 - 115.4 mm/day), very heavy (115.5 - 204.4 mm/day) and extreme (≥ 204.5 mm/day) rainy days over Odisha during summer monsoon season for a period of 113 years (1901 - 2013) and a detailed study has been done for heavy-to-extreme rainy days. For this purpose, India Meteorological Department (IMD) gridded (0.25° × 0.25° lat/lon) rainfall data and the European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-Interim) (0.125° × 0.125° lat/lon) datasets are used. The analysis reveals that the frequency of very light, light and moderate rainy days persists with almost constant trend, but the heavy, very heavy and extreme rainy days exhibit an increasing trend during the study period. It may be noted that more than 60% of heavy-to-extreme rainy days are observed in the month of July and August. Furthermore, during the recent period (1980-2013), there are a total of 150 extreme rainy days are observed over Odisha, out of which 47% are associated with monsoon depressions (MDs) and cyclonic storms, 41% are with lows, 2% are due to the presence of middle and upper tropospheric cyclonic circulations, 1% is due to monsoon trough and other 9% of extreme rainy days does not follow any of these synoptic conditions. Since a large (nearly half) percentage of extreme rainy days over Odisha is due to the presence of MDs, a detailed examination of MDs is illustrated in this study. Analysis reveals that there are a total of 91 MDs formed over the Bay of Bengal (BoB) during 1980 - 2013, and out of which 56 (61.5% of total MD) MDs crossed Odisha. Further spatial analysis of extreme rainfall days exhibits that the maximum frequency of extreme rainy days is present over the south west region of Odisha.

Complexity-aware simple modeling.

PubMed

Gómez-Schiavon, Mariana; El-Samad, Hana

2018-02-26

Mathematical models continue to be essential for deepening our understanding of biology. On one extreme, simple or small-scale models help delineate general biological principles. However, the parsimony of detail in these models as well as their assumption of modularity and insulation make them inaccurate for describing quantitative features. On the other extreme, large-scale and detailed models can quantitatively recapitulate a phenotype of interest, but have to rely on many unknown parameters, making them often difficult to parse mechanistically and to use for extracting general principles. We discuss some examples of a new approach-complexity-aware simple modeling-that can bridge the gap between the small-scale and large-scale approaches. Copyright © 2018 Elsevier Ltd. All rights reserved.

Progress on high-performance rapid prototype aluminum mirrors

NASA Astrophysics Data System (ADS)

Woodard, Kenneth S.; Myrick, Bruce H.

2017-05-01

Near net shape parts can be produced using some very old processes (investment casting) and the relatively new direct metal laser sintering (DMLS) process. These processes have significant advantages for complex blank lightweighting and costs but are not inherently suited for producing high performance mirrors. The DMLS process can provide extremely complex lightweight structures but the high residual stresses left in the material results in unstable mirror figure retention. Although not to the extreme intricacy of DMLS, investment casting can also provide complex lightweight structures at considerably lower costs than DMLS and even conventional wrought mirror blanks but the less than 100% density for casting (and also DMLS) limits finishing quality. This paper will cover the progress that has been made to make both the DMLS and investment casting processes into viable near net shape blank options for high performance aluminum mirrors. Finish and figure results will be presented to show performance commensurate with existing conventional processes.

Difficult Decisions Made Easier

NASA Technical Reports Server (NTRS)

2006-01-01

NASA missions are extremely complex and prone to sudden, catastrophic failure if equipment falters or if an unforeseen event occurs. For these reasons, NASA trains to expect the unexpected. It tests its equipment and systems in extreme conditions, and it develops risk-analysis tests to foresee any possible problems. The Space Agency recently worked with an industry partner to develop reliability analysis software capable of modeling complex, highly dynamic systems, taking into account variations in input parameters and the evolution of the system over the course of a mission. The goal of this research was multifold. It included performance and risk analyses of complex, multiphase missions, like the insertion of the Mars Reconnaissance Orbiter; reliability analyses of systems with redundant and/or repairable components; optimization analyses of system configurations with respect to cost and reliability; and sensitivity analyses to identify optimal areas for uncertainty reduction or performance enhancement.

Guidelines to Support Professional Copyright Practice

ERIC Educational Resources Information Center

Dryden, Jean

2012-01-01

Copyright is extremely complex, and it is difficult to convey its complexities in a clear and concise form. Through decades of experience, archivists developed informal best practices for dealing with copyright in the analog world; however the application of copyright in the digital environment is evolving in response to rapidly changing…

Explicit Computations of Instantons and Large Deviations in Beta-Plane Turbulence

NASA Astrophysics Data System (ADS)

Laurie, J.; Bouchet, F.; Zaboronski, O.

2012-12-01

We use a path integral formalism and instanton theory in order to make explicit analytical predictions about large deviations and rare events in beta-plane turbulence. The path integral formalism is a concise way to get large deviation results in dynamical systems forced by random noise. In the most simple cases, it leads to the same results as the Freidlin-Wentzell theory, but it has a wider range of applicability. This approach is however usually extremely limited, due to the complexity of the theoretical problems. As a consequence it provides explicit results in a fairly limited number of models, often extremely simple ones with only a few degrees of freedom. Few exception exist outside the realm of equilibrium statistical physics. We will show that the barotropic model of beta-plane turbulence is one of these non-equilibrium exceptions. We describe sets of explicit solutions to the instanton equation, and precise derivations of the action functional (or large deviation rate function). The reason why such exact computations are possible is related to the existence of hidden symmetries and conservation laws for the instanton dynamics. We outline several applications of this apporach. For instance, we compute explicitly the very low probability to observe flows with an energy much larger or smaller than the typical one. Moreover, we consider regimes for which the system has multiple attractors (corresponding to different numbers of alternating jets), and discuss the computation of transition probabilities between two such attractors. These extremely rare events are of the utmost importance as the dynamics undergo qualitative macroscopic changes during such transitions.

Under-reported dosimetry errors due to interplay effects during VMAT dose delivery in extreme hypofractionated stereotactic radiotherapy.

PubMed

Gauer, Tobias; Sothmann, Thilo; Blanck, Oliver; Petersen, Cordula; Werner, René

2018-06-01

Radiotherapy of extracranial metastases changed from normofractioned 3D CRT to extreme hypofractionated stereotactic treatment using VMAT beam techniques. Random interaction between tumour motion and dynamically changing beam parameters might result in underdosage of the CTV even for an appropriately dimensioned ITV (interplay effect). This study presents a clinical scenario of extreme hypofractionated stereotactic treatment and analyses the impact of interplay effects on CTV dose coverage. For a thoracic/abdominal phantom with an integrated high-resolution detector array placed on a 4D motion platform, dual-arc treatment plans with homogenous target coverage were created using a common VMAT technique and delivered in a single fraction. CTV underdosage through interplay effects was investigated by comparing dose measurements with and without tumour motion during plan delivery. Our study agrees with previous works that pointed out insignificant interplay effects on target coverage for very regular tumour motion patterns like simple sinusoidal motion. However, we identified and illustrated scenarios that are likely to result in a clinically relevant CTV underdosage. For tumour motion with abnormal variability, target coverage quantified by the CTV area receiving more than 98% of the prescribed dose decreased to 78% compared to 100% at static dose measurement. This study is further proof of considerable influence of interplay effects on VMAT dose delivery in stereotactic radiotherapy. For selected conditions of an exemplary scenario, interplay effects and related motion-induced target underdosage primarily occurred in tumour motion pattern with increased motion variability and VMAT plan delivery using complex MLC dose modulation.

Modeling of thermomechanical changes of extreme-ultraviolet mask and their dependence on absorber variation

NASA Astrophysics Data System (ADS)

Ban, Chung-Hyun; Park, Eun-Sang; Park, Jae-Hun; Oh, Hye-Keun

2018-06-01

Thermal and structural deformation of extreme-ultraviolet lithography (EUVL) masks during the exposure process may become important issues as these masks are subject to rigorous image placement and flatness requirements. The reflective masks used for EUVL absorb energy during exposure, and the temperature of the masks rises as a result. This can cause thermomechanical deformation that can reduce the pattern quality. The use of very thick low-thermal-expansion substrate materials (LTEMs) may reduce energy absorption, but they do not completely eliminate mask deformation. Therefore, it is necessary to predict and optimize the effects of energy transferred from the extreme-ultraviolet (EUV) light source and the resultant patterns of structured EUV masks with complex multilayers. Our study shows that heat accumulates in the masks as exposure progresses. It has been found that a higher absorber ratio (pattern density) applied to the patterning of EUV masks exacerbates the problem, especially in masks with more complex patterns.

A Large-Scale Multi-Hop Localization Algorithm Based on Regularized Extreme Learning for Wireless Networks.

PubMed

Zheng, Wei; Yan, Xiaoyong; Zhao, Wei; Qian, Chengshan

2017-12-20

A novel large-scale multi-hop localization algorithm based on regularized extreme learning is proposed in this paper. The large-scale multi-hop localization problem is formulated as a learning problem. Unlike other similar localization algorithms, the proposed algorithm overcomes the shortcoming of the traditional algorithms which are only applicable to an isotropic network, therefore has a strong adaptability to the complex deployment environment. The proposed algorithm is composed of three stages: data acquisition, modeling and location estimation. In data acquisition stage, the training information between nodes of the given network is collected. In modeling stage, the model among the hop-counts and the physical distances between nodes is constructed using regularized extreme learning. In location estimation stage, each node finds its specific location in a distributed manner. Theoretical analysis and several experiments show that the proposed algorithm can adapt to the different topological environments with low computational cost. Furthermore, high accuracy can be achieved by this method without setting complex parameters.

Applying complex networks to evaluate precipitation patterns over South America

NASA Astrophysics Data System (ADS)

Ciemer, Catrin; Boers, Niklas; Barbosa, Henrique; Kurths, Jürgen; Rammig, Anja

2016-04-01

The climate of South America exhibits pronounced differences between the wet- and the dry-season, which are accompanied by specific synoptic events like changes in the location of the South American Low Level Jet (SALLJ) and the establishment of the South American Convergence Zone (SACZ). The onset of these events can be related to the presence of typical large-scale precipitation patterns over South America, as previous studies have shown[1,2]. The application of complex network methods to precipitation data recently received increased scientific attention for the special case of extreme events, as it is possible with such methods to analyze the spatiotemporal correlation structure as well as possible teleconnections of these events[3,4]. In these approaches the correlation between precipitation datasets is calculated by means of Event Synchronization which restricts their applicability to extreme precipitation events. In this work, we propose a method which is able to consider not only extreme precipitation but complete time series. A direct application of standard similarity measures in order to correlate precipitation time series is impossible due to their intricate statistical properties as the large amount of zeros. Therefore, we introduced and evaluated a suitable modification of Pearson's correlation coefficient to construct spatial correlation networks of precipitation. By analyzing the characteristics of spatial correlation networks constructed on the basis of this new measure, we are able to determine coherent areas of similar precipitation patterns, spot teleconnections of correlated areas, and detect central regions for precipitation correlation. By analyzing the change of the network over the year[5], we are also able to determine local and global changes in precipitation correlation patterns. Additionally, global network characteristics as the network connectivity yield indications for beginning and end of wet- and dry season. In order to identify large-scale synoptic events like the SACZ and SALLJ onset, detecting the changes of correlation over time between certain regions is of significant relevance. [1] Nieto-Ferreira et al. Quarterly Journal of the Royal Meteorological Society (2011) [2] Vera et al. Bulletin of the American Meteorological Society (2006) [3] Quiroga et al. Physical review E (2002) [4] Boers et al. nature communications (2014) [5] Radebach et al. Physical review E (2013)

High resolution modeling of a small urban catchment

NASA Astrophysics Data System (ADS)

Skouri-Plakali, Ilektra; Ichiba, Abdellah; Gires, Auguste; Tchiguirinskaia, Ioulia; Schertzer, Daniel

2016-04-01

Flooding is one of the most complex issues that urban environments have to deal with. In France, flooding remains the first natural risk with 72% of decrees state of natural disaster issued between October 1982 and mid-November 2014. Flooding is a result of meteorological extremes that are usually aggravated by the hydrological behavior of urban catchments and human factors. The continuing urbanization process is indeed changing the whole urban water cycle by limiting the infiltration and promoting runoff. Urban environments are very complex systems due to their extreme variability, the interference between human activities and natural processes but also the effect of the ongoing urbanization process that changes the landscape and hardly influences their hydrologic behavior. Moreover, many recent works highlight the need to simulate all urban water processes at their specific temporal and spatial scales. However, considering urban catchments heterogeneity still challenging for urban hydrology, even after advances noticed in term of high-resolution data collection and computational resources. This issue is more to be related to the architecture of urban models being used and how far these models are ready to take into account the extreme variability of urban catchments. In this work, high spatio-temporal resolution modeling is performed for a small and well-equipped urban catchment. The aim of this work is to identify urban modeling needs in terms of spatial and temporal resolution especially for a very small urban area (3.7 ha urban catchment located in the Perreux-sur-Marne city at the southeast of Paris) MultiHydro model was selected to carry out this work, it is a physical based and fully distributed model that interacts four existing modules each of them representing a portion of the water cycle in urban environments. MultiHydro was implemented at 10m, 5m and 2m resolution. Simulations were performed at different spatio-temporal resolutions and analyzed with respect to real flow measurements. First Results coming out show improvements obtained in terms of the model performance at high spatio-temporal resolution.

Meningococcus Disease Photos

MedlinePlus

... of hands and lower extremities due to meningococcemia http://www.vaccineinformation.org/photos/menicdc001.jpg Courtesy Centers ... female with gangrene of feet due to meningococcemia http://www.vaccineinformation.org/photos/menicdc002.jpg Courtesy Centers ...

Changes in extremes due to half a degree warming in observations and models

NASA Astrophysics Data System (ADS)

Fischer, E. M.; Schleussner, C. F.; Pfleiderer, P.

2017-12-01

Assessing the climate impacts of half-a-degree warming increments is high on the post-Paris science agenda. Discriminating those effects is particularly challenging for climate extremes such as heavy precipitation and heat extremes for which model uncertainties are generally large, and for which internal variability is so important that it can easily offset or strongly amplify the forced local changes induced by half a degree warming. Despite these challenges we provide evidence for large-scale changes in the intensity and frequency of climate extremes due to half a degree warming. We first assess the difference in extreme climate indicators in observational data for the 1960s and 1970s versus the recent past, two periods differ by half a degree. We identify distinct differences for the global and continental-scale occurrence of heat and heavy precipitation extremes. We show that those observed changes in heavy precipitation and heat extremes broadly agree with simulated historical differences and are informative for the projected differences between 1.5 and 2°C warming despite different radiative forcings. We therefore argue that evidence from the observational record can inform the debate about discernible climate impacts in the light of model uncertainty by providing a conservative estimate of the implications of 0.5°C warming. A limitation of using the observational record arises from potential non-linearities in the response of climate extremes to a certain level of warming. We test for potential non-linearities in the response of heat and heavy precipitation extremes in a large ensemble of transient climate simulations. We further quantify differences between a time-window approach in a coupled model large ensemble vs. time-slice experiments using prescribed SST experiments performed in the context of the HAPPI-MIP project. Thereby we provide different lines of evidence that half a degree warming leads to substantial changes in the expected occurrence of heat and heavy precipitation extremes.

Extreme seismicity and disaster risks: Hazard versus vulnerability (Invited)

NASA Astrophysics Data System (ADS)

Ismail-Zadeh, A.

2013-12-01

Although the extreme nature of earthquakes has been known for millennia due to the resultant devastation from many of them, the vulnerability of our civilization to extreme seismic events is still growing. It is partly because of the increase in the number of high-risk objects and clustering of populations and infrastructure in the areas prone to seismic hazards. Today an earthquake may affect several hundreds thousand lives and cause significant damage up to hundred billion dollars; it can trigger an ecological catastrophe if occurs in close vicinity to a nuclear power plant. Two types of extreme natural events can be distinguished: (i) large magnitude low probability events, and (ii) the events leading to disasters. Although the first-type events may affect earthquake-prone countries directly or indirectly (as tsunamis, landslides etc.), the second-type events occur mainly in economically less-developed countries where the vulnerability is high and the resilience is low. Although earthquake hazards cannot be reduced, vulnerability to extreme events can be diminished by monitoring human systems and by relevant laws preventing an increase in vulnerability. Significant new knowledge should be gained on extreme seismicity through observations, monitoring, analysis, modeling, comprehensive hazard assessment, prediction, and interpretations to assist in disaster risk analysis. The advanced disaster risk communication skill should be developed to link scientists, emergency management authorities, and the public. Natural, social, economic, and political reasons leading to disasters due to earthquakes will be discussed.

Extreme ultraviolet and X-ray spectroheliograph for OSO-H

NASA Technical Reports Server (NTRS)

Sterk, A. A.; Kieser, F.; Peck, S.; Knox, E.

1972-01-01

A complex scientific instrument was designed, fabricated, tested, and calibrated for launch onboard OSO-H. This instrument consisted of four spectroheliographs and an X-ray polarimeter. The instrument is designed to study solar radiation at selected wavelengths in the X-ray and the extreme ultraviolet ranges, make observations at the H-alpha wavelength, and measure the degree of polarization of X-ray emissions.

Upper Extremity Injuries in Tennis Players: Diagnosis, Treatment, and Management

PubMed Central

Chung, Kevin C.; Lark, Meghan E.

2016-01-01

Synopsis Upper extremity tennis injuries are most commonly characterized as overuse injuries to the wrist, elbow and shoulder. The complex anatomy of these structures and their interaction with biomechanical properties of tennis strokes contributes to the diagnostic challenges. A thorough understanding of tennis kinetics, in combination with the current literature surrounding diagnostic and treatment methods, will improve clinical decision-making. PMID:27886833

Acidic Ribosomal Proteins from the Extreme ’Halobacterium cutirubrum’,

DTIC Science & Technology

the extreme halophilic bacterium, Halobacterium cutirubrum. The identification of the protein moieties involved in these and other interactions in...the halophile ribosome requires a rapid and reproducible screening method for the separation, enumeration and identification of these acidic...polypeptides in the complex ribosomal protein mixtures. In this paper the authors present the results of analyses of the halophile ribosomal proteins using a

Life in extreme environments: how will humans perform on Mars?

NASA Technical Reports Server (NTRS)

Newman, D. J.

2000-01-01

This review of astronaut extravehicular activity (EVA) and the details of American and Soviet/Russian spacesuit design focuses on design recommendations to enhance astronaut safety and effectiveness. Innovative spacesuit design is essential, given the challenges of future exploration-class missions in which astronauts will be called upon to perform increasingly complex and physically demanding tasks in the extreme environments of microgravity and partial gravity.

Beating the curse of dimension with accurate statistics for the Fokker-Planck equation in complex turbulent systems.

PubMed

Chen, Nan; Majda, Andrew J

2017-12-05

Solving the Fokker-Planck equation for high-dimensional complex dynamical systems is an important issue. Recently, the authors developed efficient statistically accurate algorithms for solving the Fokker-Planck equations associated with high-dimensional nonlinear turbulent dynamical systems with conditional Gaussian structures, which contain many strong non-Gaussian features such as intermittency and fat-tailed probability density functions (PDFs). The algorithms involve a hybrid strategy with a small number of samples [Formula: see text], where a conditional Gaussian mixture in a high-dimensional subspace via an extremely efficient parametric method is combined with a judicious Gaussian kernel density estimation in the remaining low-dimensional subspace. In this article, two effective strategies are developed and incorporated into these algorithms. The first strategy involves a judicious block decomposition of the conditional covariance matrix such that the evolutions of different blocks have no interactions, which allows an extremely efficient parallel computation due to the small size of each individual block. The second strategy exploits statistical symmetry for a further reduction of [Formula: see text] The resulting algorithms can efficiently solve the Fokker-Planck equation with strongly non-Gaussian PDFs in much higher dimensions even with orders in the millions and thus beat the curse of dimension. The algorithms are applied to a [Formula: see text]-dimensional stochastic coupled FitzHugh-Nagumo model for excitable media. An accurate recovery of both the transient and equilibrium non-Gaussian PDFs requires only [Formula: see text] samples! In addition, the block decomposition facilitates the algorithms to efficiently capture the distinct non-Gaussian features at different locations in a [Formula: see text]-dimensional two-layer inhomogeneous Lorenz 96 model, using only [Formula: see text] samples. Copyright © 2017 the Author(s). Published by PNAS.

Extreme infrared variables from UKIDSS - II. An end-of-survey catalogue of eruptive YSOs and unusual stars

NASA Astrophysics Data System (ADS)

Lucas, P. W.; Smith, L. C.; Contreras Peña, C.; Froebrich, D.; Drew, J. E.; Kumar, M. S. N.; Borissova, J.; Minniti, D.; Kurtev, R.; Monguió, M.

2017-12-01

We present a catalogue of 618 high-amplitude infrared variable stars (1 < ΔK < 5 mag) detected by the two widely separated epochs of 2.2 μm data in the UKIDSS Galactic plane survey, from searches covering ∼1470 deg2. Most were discovered by a search of all fields at 30 < l < 230°. Sources include new dusty Mira variables, three new cataclysmic variable candidates, a blazar and a peculiar source that may be an interacting binary system. However, ∼60 per cent are young stellar obbjects (YSOs), based on spatial association with star-forming regions at distances ranging from 300 pc to over 10 kpc. This confirms our initial result in Contreras Peña et al. (Paper I) that YSOs dominate the high-amplitude infrared variable sky in the Galactic disc. It is also supported by recently published VISTA Variables in the Via Lactea (VVV) results at 295 < l < 350°. The spectral energy distributions of the YSOs indicate class I or flat-spectrum systems in most cases, as in the VVV sample. A large number of variable YSOs are associated with the Cygnus X complex and other groups are associated with the North America/Pelican nebula, the Gemini OB1 molecular cloud, the Rosette complex, the Cone nebula, the W51 star-forming region and the S86 and S236 H II regions. Most of the YSO variability is likely due to variable/episodic accretion on time-scales of years, albeit usually less extreme than classical FUors and EXors. Luminosities at the 2010 Wide-field Infrared Survey Explorer epoch range from ∼0.1 to 103 L⊙ but only rarely exceed 102.5 L⊙.

Online sparse Gaussian process based human motion intent learning for an electrically actuated lower extremity exoskeleton.

PubMed

Long, Yi; Du, Zhi-Jiang; Chen, Chao-Feng; Dong, Wei; Wang, Wei-Dong

2017-07-01

The most important step for lower extremity exoskeleton is to infer human motion intent (HMI), which contributes to achieve human exoskeleton collaboration. Since the user is in the control loop, the relationship between human robot interaction (HRI) information and HMI is nonlinear and complicated, which is difficult to be modeled by using mathematical approaches. The nonlinear approximation can be learned by using machine learning approaches. Gaussian Process (GP) regression is suitable for high-dimensional and small-sample nonlinear regression problems. GP regression is restrictive for large data sets due to its computation complexity. In this paper, an online sparse GP algorithm is constructed to learn the HMI. The original training dataset is collected when the user wears the exoskeleton system with friction compensation to perform unconstrained movement as far as possible. The dataset has two kinds of data, i.e., (1) physical HRI, which is collected by torque sensors placed at the interaction cuffs for the active joints, i.e., knee joints; (2) joint angular position, which is measured by optical position sensors. To reduce the computation complexity of GP, grey relational analysis (GRA) is utilized to specify the original dataset and provide the final training dataset. Those hyper-parameters are optimized offline by maximizing marginal likelihood and will be applied into online GP regression algorithm. The HMI, i.e., angular position of human joints, will be regarded as the reference trajectory for the mechanical legs. To verify the effectiveness of the proposed algorithm, experiments are performed on a subject at a natural speed. The experimental results show the HMI can be obtained in real time, which can be extended and employed in the similar exoskeleton systems.

Controlling Emergent Ferromagnetism at Complex Oxide Interfaces

NASA Astrophysics Data System (ADS)

Grutter, Alexander

The emergence of complex magnetic ground states at ABO3 perovskite heterostructure interfaces is among the most promising routes towards highly tunable nanoscale materials for spintronic device applications. Despite recent progress, isolating and controlling the underlying mechanisms behind these emergent properties remains a highly challenging materials physics problems. In particular, generating and tuning ferromagnetism localized at the interface of two non-ferromagnetic materials is of fundamental and technological interest. An ideal model system in which to study such effects is the CaRuO3/CaMnO3 interface, where the constituent materials are paramagnetic and antiferromagnetic in the bulk, respectively. Due to small fractional charge transfer to the CaMnO3 (0.07 e-/Mn) from the CaRuO3, the interfacial Mn ions are in a canted antiferromagnetic state. The delicate balance between antiferromagnetic superexchange and ferromagnetic double exchange results in a magnetic ground state which is extremely sensitive to perturbations. We exploit this sensitivity to achieve control of the magnetic interface, tipping the balance between ferromagnetic and antiferromagnetic interactions through octahedral connectivity modification. Such connectivity effects are typically tightly confined to interfaces, but by targeting a purely interfacial emergent magnetic system, we achieve drastic alterations to the magnetic ground state. These results demonstrate the extreme sensitivity of the magnetic state to the magnitude of the charge transfer, suggesting the potential for direct electric field control. We achieve such electric field control through direct back gating of a CaRuO3/CaMnO3 bilayer. Thus, the CaRuO3/CaMnO3 system provides new insight into how charge transfer, interfacial symmetry, and electric fields may be used to control ferromagnetism at the atomic scale.

Long-lasting injection of solar energetic electrons into the heliosphere

NASA Astrophysics Data System (ADS)

Dresing, N.; Gómez-Herrero, R.; Heber, B.; Klassen, A.; Temmer, M.; Veronig, A.

2018-05-01

Context. The main sources of solar energetic particle (SEP) events are solar flares and shocks driven by coronal mass ejections (CMEs). While it is generally accepted that energetic protons can be accelerated by shocks, whether or not these shocks can also efficiently accelerate solar energetic electrons is still debated. In this study we present observations of the extremely widespread SEP event of 26 Dec 2013 To the knowledge of the authors, this is the widest longitudinal SEP distribution ever observed together with unusually long-lasting energetic electron anisotropies at all observer positions. Further striking features of the event are long-lasting SEP intensity increases, two distinct SEP components with the second component mainly consisting of high-energy particles, a complex associated coronal activity including a pronounced signature of a shock in radio type-II observations, and the interaction of two CMEs early in the event. Aims: The observations require a prolonged injection scenario not only for protons but also for electrons. We therefore analyze the data comprehensively to characterize the possible role of the shock for the electron event. Methods: Remote-sensing observations of the complex solar activity are combined with in situ measurements of the particle event. We also apply a graduated cylindrical shell (GCS) model to the coronagraph observations of the two associated CMEs to analyze their interaction. Results: We find that the shock alone is likely not responsible for this extremely wide SEP event. Therefore we propose a scenario of trapped energetic particles inside the CME-CME interaction region which undergo further acceleration due to the shock propagating through this region, stochastic acceleration, or ongoing reconnection processes inside the interaction region. The origin of the second component of the SEP event is likely caused by a sudden opening of the particle trap.

Retrieval of the complex refractive index of aerosol droplets from optical tweezers measurements.

PubMed

Miles, Rachael E H; Walker, Jim S; Burnham, Daniel R; Reid, Jonathan P

2012-03-07

The cavity enhanced Raman scattering spectrum recorded from an aerosol droplet provides a unique fingerprint of droplet radius and refractive index, assuming that the droplet is homogeneous in composition. Aerosol optical tweezers are used in this study to capture a single droplet and a Raman fingerprint is recorded using the trapping laser as the source for the Raman excitation. We report here the retrieval of the real part of the refractive index with an uncertainty of ± 0.0012 (better than ± 0.11%), simultaneously measuring the size of the micrometre sized liquid droplet with a precision of better than 1 nm (< ± 0.05% error). In addition, the equilibrium size of the droplet is shown to depend on the laser irradiance due to optical absorption, which elevates the droplet temperature above that of the ambient gas phase. Modulation of the illuminating laser power leads to a modulation in droplet size as the temperature elevation is altered. By measuring induced size changes of <1 nm, we show that the imaginary part of the refractive index can be retrieved even when less than 10 × 10(-9) with an accuracy of better than ± 0.5 × 10(-9). The combination of these measurements allows the complex refractive index of a droplet to be retrieved with high accuracy, with the possibility of making extremely sensitive optical absorption measurements on aerosol samples and the testing of frequently used mixing rules for treating aerosol optical properties. More generally, this method provides an extremely sensitive approach for measuring refractive indices, particularly under solute supersaturation conditions that cannot be accessed by simple bulk-phase measurements.

Settlement-Size Scaling among Prehistoric Hunter-Gatherer Settlement Systems in the New World

PubMed Central

Haas, W. Randall; Klink, Cynthia J.; Maggard, Greg J.; Aldenderfer, Mark S.

2015-01-01

Settlement size predicts extreme variation in the rates and magnitudes of many social and ecological processes in human societies. Yet, the factors that drive human settlement-size variation remain poorly understood. Size variation among economically integrated settlements tends to be heavy tailed such that the smallest settlements are extremely common and the largest settlements extremely large and rare. The upper tail of this size distribution is often formalized mathematically as a power-law function. Explanations for this scaling structure in human settlement systems tend to emphasize complex socioeconomic processes including agriculture, manufacturing, and warfare—behaviors that tend to differentially nucleate and disperse populations hierarchically among settlements. But, the degree to which heavy-tailed settlement-size variation requires such complex behaviors remains unclear. By examining the settlement patterns of eight prehistoric New World hunter-gatherer settlement systems spanning three distinct environmental contexts, this analysis explores the degree to which heavy-tailed settlement-size scaling depends on the aforementioned socioeconomic complexities. Surprisingly, the analysis finds that power-law models offer plausible and parsimonious statistical descriptions of prehistoric hunter-gatherer settlement-size variation. This finding reveals that incipient forms of hierarchical settlement structure may have preceded socioeconomic complexity in human societies and points to a need for additional research to explicate how mobile foragers came to exhibit settlement patterns that are more commonly associated with hierarchical organization. We propose that hunter-gatherer mobility with preferential attachment to previously occupied locations may account for the observed structure in site-size variation. PMID:26536241

The Influence of Coral Reef Benthic Condition on Associated Fish Assemblages

PubMed Central

Chong-Seng, Karen M.; Mannering, Thomas D.; Pratchett, Morgan S.; Bellwood, David R.; Graham, Nicholas A. J.

2012-01-01

Accumulative disturbances can erode a coral reef’s resilience, often leading to replacement of scleractinian corals by macroalgae or other non-coral organisms. These degraded reef systems have been mostly described based on changes in the composition of the reef benthos, and there is little understanding of how such changes are influenced by, and in turn influence, other components of the reef ecosystem. This study investigated the spatial variation in benthic communities on fringing reefs around the inner Seychelles islands. Specifically, relationships between benthic composition and the underlying substrata, as well as the associated fish assemblages were assessed. High variability in benthic composition was found among reefs, with a gradient from high coral cover (up to 58%) and high structural complexity to high macroalgae cover (up to 95%) and low structural complexity at the extremes. This gradient was associated with declining species richness of fishes, reduced diversity of fish functional groups, and lower abundance of corallivorous fishes. There were no reciprocal increases in herbivorous fish abundances, and relationships with other fish functional groups and total fish abundance were weak. Reefs grouping at the extremes of complex coral habitats or low-complexity macroalgal habitats displayed markedly different fish communities, with only two species of benthic invertebrate feeding fishes in greater abundance in the macroalgal habitat. These results have negative implications for the continuation of many coral reef ecosystem processes and services if more reefs shift to extreme degraded conditions dominated by macroalgae. PMID:22870294

The influence of coral reef benthic condition on associated fish assemblages.

PubMed

Chong-Seng, Karen M; Mannering, Thomas D; Pratchett, Morgan S; Bellwood, David R; Graham, Nicholas A J

2012-01-01

Accumulative disturbances can erode a coral reef's resilience, often leading to replacement of scleractinian corals by macroalgae or other non-coral organisms. These degraded reef systems have been mostly described based on changes in the composition of the reef benthos, and there is little understanding of how such changes are influenced by, and in turn influence, other components of the reef ecosystem. This study investigated the spatial variation in benthic communities on fringing reefs around the inner Seychelles islands. Specifically, relationships between benthic composition and the underlying substrata, as well as the associated fish assemblages were assessed. High variability in benthic composition was found among reefs, with a gradient from high coral cover (up to 58%) and high structural complexity to high macroalgae cover (up to 95%) and low structural complexity at the extremes. This gradient was associated with declining species richness of fishes, reduced diversity of fish functional groups, and lower abundance of corallivorous fishes. There were no reciprocal increases in herbivorous fish abundances, and relationships with other fish functional groups and total fish abundance were weak. Reefs grouping at the extremes of complex coral habitats or low-complexity macroalgal habitats displayed markedly different fish communities, with only two species of benthic invertebrate feeding fishes in greater abundance in the macroalgal habitat. These results have negative implications for the continuation of many coral reef ecosystem processes and services if more reefs shift to extreme degraded conditions dominated by macroalgae.

Hypothermia.

PubMed

Turk, Elisabeth E

2010-06-01

Hypothermia refers to a situation where there is a drop in body core temperature below 35 degrees C. It is a potentially fatal condition. In forensic medicine and pathology, cases of hypothermia often pose a special challenge to experts because of their complex nature, and the often absent or nonspecific nature of morphological findings. The scene of the incident may raise suspicions of a crime initially, due to phenomena such as terminal burrowing behavior and paradoxical undressing. An element of hypothermia often contributes to the cause of death in drug- and alcohol-related fatalities, in the homeless, in immersion deaths, in accidents and in cases of abuse or neglect, making the condition extremely relevant to forensic medical specialists. The aim of this review is to give an overview of the pathophysiological aspects of hypothermia and to illustrate different aspects relevant to forensic medical casework.

Molecular Pathogenesis and Diagnostic, Prognostic and Predictive Molecular Markers in Sarcoma.

PubMed

Mariño-Enríquez, Adrián; Bovée, Judith V M G

2016-09-01

Sarcomas are infrequent mesenchymal neoplasms characterized by notable morphological and molecular heterogeneity. Molecular studies in sarcoma provide refinements to morphologic classification, and contribute diagnostic information (frequently), prognostic stratification (rarely) and predict therapeutic response (occasionally). Herein, we summarize the major molecular mechanisms underlying sarcoma pathogenesis and present clinically useful diagnostic, prognostic and predictive molecular markers for sarcoma. Five major molecular alterations are discussed, illustrated with representative sarcoma types, including 1. the presence of chimeric transcription factors, in vascular tumors; 2. abnormal kinase signaling, in gastrointestinal stromal tumor; 3. epigenetic deregulation, in chondrosarcoma, chondroblastoma, and other tumors; 4. deregulated cell survival and proliferation, due to focal copy number alterations, in dedifferentiated liposarcoma; 5. extreme genomic instability, in conventional osteosarcoma as a representative example of sarcomas with highly complex karyotype. Copyright © 2016 Elsevier Inc. All rights reserved.

The costs and benefits of bone marrow transplantation.

PubMed

Beard, M E; Inder, A B; Allen, J R; Hart, D N; Heaton, D C; Spearing, R L

1991-07-24

The average direct costs of performing a bone marrow transplant (BMT), including the subsequent year, was found to be NZ$27,074 for 43 consecutive transplants. In 29 BMTs a full two year period of follow up was available and a quality of life analysis was carried out on these patients. It was calculated that 59 quality adjusted life years (QALYs) had been gained by the BMT procedure at the time of analysis. By combining these two analyses the cost of each QALY gained by BMT is NZ$13,272. The relatively low cost of BMT is partly due to the extremely low annual costs in second and subsequent years post BMT. In our patients this cost amounted to $195 per year. The costs and benefits of BMT compare very favourably with other complex medical procedures.

Simulation of air pollution due to marine engines

NASA Astrophysics Data System (ADS)

Stan, L. C.

2017-08-01

This paperwork tried to simulate the combustion inside the marine engines using the newest computer methods and technologies with the result of a diverse and rich palette of solutions, extremely useful for the study and prediction of complex phenomena of the fuel combustion. The paperwork is contributing to the theoretical systematization of the area of interest bringing into attention a thoroughly inventory of the thermodynamic description of the phenomena which take place in the combustion process into the marine diesel engines; to the in depth multidimensional combustion models description along with the interdisciplinary phenomenology taking place in the combustion models; to the FEA (Finite Elements Method) modelling for the combustion chemistry in the nonpremixed mixtures approach considered too; the CFD (Computational Fluid Dynamics) model was issued for the combustion area and a rich palette of results interesting for any researcher of the process.

Wind flow in an urban environment.

PubMed

Dutt, A J

1991-10-01

The wind environment at ground leven in built-up areas is influenced by the extremely complex interaction amongst incident wind, mean vertical velocity gradient, turbulence and the shapes, sizes and layouts of building. Random layout of buildings could generate zones of overspeed and vortices in the connecting passage way between buildings, terraces, opensided shelters, courtyards, which could potentially cause unpleasantness, hazard from resuspended particulates, and airborne rain penetration into the buildings. The paper presents the results of two case studies comprising field measurements made within the Kent Ridge Campus, National University of Singapore, using DANTEC 54N10 Multichannel Flow Analyser and Probes. Results are presented in terms of non-dimensional windspeed coefficients. It is concluded that there is significant increase in windspeed due to channel and venturi effects. This information provides useful guidelines for building plans and layouts to the architects and engineers.

Biologically-Inspired Control for a Planetary Exploration Tensegrity Robot

NASA Technical Reports Server (NTRS)

Leroy, Marc

2017-01-01

Tensegrity structures are becoming increasingly popular as mechanical structures for robots. Their inherent compliance makes them extremely robust to environmental disturbances, and their design allows them to have a high strength-to-weight ratio whilst being lightweight compared to traditional robots. For these reasons they would be of interest to the aerospace industry, particularly for planetary exploration. However, being such compliant structures thanks to their network of elastic elements also means that their control is not an easy task. Relying solely on traditional control strategies to generate efficient locomotion would surely be near impossible due to the complex oscillatory motions and nonlinear interactions of its members. The goal of this project was to use bio-inspired control techniques to generate locomotion for a tensegrity icosahedron, namely the SUPERball project of the Intelligent Robotics Group of NASA Ames Research Center.

Numerical models of cell death in RF ablation with monopolar and bipolar probes

NASA Astrophysics Data System (ADS)

Bright, Benjamin M.; Pearce, John A.

2013-02-01

Radio frequency (RF) is used clinically to treat unresectible tumors. Finite element modeling has proven useful in treatment planning and applicator design. Typically isotherms in the middle 50s °C have been used as the parameter of assessment in these models. We compare and contrast isotherms for multiple known Arrhenius thermal damage predictors including collagen denaturation, vascular disruption, liver coagulation and cell death. Models for RITA probe geometries are included in the study. Comparison to isotherms is sensible when the activation time is held constant, but varies considerably when heating times vary. The purpose of this paper is to demonstrate the importance of looking at specific processes and keeping track of the methods used to derive the Arrhenius coefficients in order to study the extremely complex cell death processes due to thermal therapies.

Assessment, prevention and management of skin tears.

PubMed

Benbow, Maureen

2017-04-28

Skin tears are common in older people. They are acute wounds that are at high risk of becoming complex, chronic wounds due to the interplay between the physiological changes in the skin and trauma from the external environment. Skin tears have been reported to have prevalence rates equal to, or greater than, those for pressure ulcers. A comprehensive risk assessment should include assessment of the individual's general health (chronic/critical disease, polypharmacy and cognitive, sensory and nutritional status); mobility (history of falls, impaired mobility, dependent activities of daily living, and mechanical trauma); and skin (extremes of age, fragile skin and previous skin tears). A recognised classification system should be used to identify and document skin tears and guide treatment decisions in line with local wound management protocols. Nurses and carers are in a prime position to prevent, assess and manage skin tears.

Spatiotemporal variability of extreme temperature frequency and amplitude in China

NASA Astrophysics Data System (ADS)

Zhang, Yuanjie; Gao, Zhiqiu; Pan, Zaitao; Li, Dan; Huang, Xinhui

2017-03-01

Temperature extremes in China are examined based on daily maximum and minimum temperatures from station observations and multiple global climate models. The magnitude and frequency of extremes are expressed in terms of return values and periods, respectively, estimated by the fitted Generalized Extreme Value (GEV) distribution of annual extreme temperatures. The observations suggest that changes in temperature extremes considerably exceed changes in the respective climatological means during the past five decades, with greater amplitude of increases in cold extremes than in warm extremes. The frequency of warm (cold) extremes increases (decreases) over most areas, with an increasingly faster rate as the extremity level rises. Changes in warm extremes are more dependent on the varying shape of GEV distribution than the location shift, whereas changes in cold extremes are more closely associated with the location shift. The models simulate the overall pattern of temperature extremes during 1961-1981 reasonably well in China, but they show a smaller asymmetry between changes in warm and cold extremes primarily due to their underestimation of increases in cold extremes especially over southern China. Projections from a high emission scenario show the multi-model median change in warm and cold extremes by 2040 relative to 1971 will be 2.6 °C and 2.8 °C, respectively, with the strongest changes in cold extremes shifting southward. By 2040, warm extremes at the 1971 20-year return values would occur about every three years, while the 1971 cold extremes would occur once in > 500 years.

[Extreme (complicated, ultra-high) refractive errors: terminological misconceptions!?

PubMed

Avetisov, S E

2018-01-01

The article reviews development mechanisms of different refractive errors accompanied by marked defocus of light rays reaching the retina. Terminology used for such ametropias includes terms extreme, ultra-high and complicated. Justification of their usage for primary ametropias, whose symptom complex is based on changes in axial eye length, is an ongoing discussion. To comply with thesaurus definitions of 'diagnosis' and 'pathogenesis', to characterize refractive and anatomical-functional disorders in patients with primary ametropias it is proposed to use the terms 'hyperaxial and hypoaxial syndromes' with elaboration of specific symptoms instead of such expressions as extreme (ultra-high) myopia and hypermetropia.

Tying Variability in Summertime North American Extreme Weather Regimes to the Boreal Summer Intraseasonal Oscillation

NASA Astrophysics Data System (ADS)

Jenney, A. M.; Randall, D. A.

2017-12-01

Tropical intraseasonal oscillations are known to be a source of extratropical variability. We show that subseasonal variability in observed North American epidemiologically significant regional extreme weather regimes is teleconnected to the boreal summer intraseasonal oscillation (BSISO)—a complex tropical weather system that is active during the northern summer and has a 30-50 day timescale. The dynamics of the teleconnection are examined. We also find that interannual variability of the tropical mean-state can modulate the teleconnection. Our results suggest that the BSISO may enable subseasonal to seasonal predictions of North American summertime weather extremes.

Complex life cycles in a pond food web: effects of life stage structure and parasites on network properties, trophic positions and the fit of a probabilistic niche model.

PubMed

Preston, Daniel L; Jacobs, Abigail Z; Orlofske, Sarah A; Johnson, Pieter T J

2014-03-01

Most food webs use taxonomic or trophic species as building blocks, thereby collapsing variability in feeding linkages that occurs during the growth and development of individuals. This issue is particularly relevant to integrating parasites into food webs because parasites often undergo extreme ontogenetic niche shifts. Here, we used three versions of a freshwater pond food web with varying levels of node resolution (from taxonomic species to life stages) to examine how complex life cycles and parasites alter web properties, the perceived trophic position of organisms, and the fit of a probabilistic niche model. Consistent with prior studies, parasites increased most measures of web complexity in the taxonomic species web; however, when nodes were disaggregated into life stages, the effects of parasites on several network properties (e.g., connectance and nestedness) were reversed, due in part to the lower trophic generality of parasite life stages relative to free-living life stages. Disaggregation also reduced the trophic level of organisms with either complex or direct life cycles and was particularly useful when including predation on parasites, which can inflate trophic positions when life stages are collapsed. Contrary to predictions, disaggregation decreased network intervality and did not enhance the fit of a probabilistic niche model to the food webs with parasites. Although the most useful level of biological organization in food webs will vary with the questions of interest, our results suggest that disaggregating species-level nodes may refine our perception of how parasites and other complex life cycle organisms influence ecological networks.

Influence of extreme weather disasters on global crop production.

PubMed

Lesk, Corey; Rowhani, Pedram; Ramankutty, Navin

2016-01-07

In recent years, several extreme weather disasters have partially or completely damaged regional crop production. While detailed regional accounts of the effects of extreme weather disasters exist, the global scale effects of droughts, floods and extreme temperature on crop production are yet to be quantified. Here we estimate for the first time, to our knowledge, national cereal production losses across the globe resulting from reported extreme weather disasters during 1964-2007. We show that droughts and extreme heat significantly reduced national cereal production by 9-10%, whereas our analysis could not identify an effect from floods and extreme cold in the national data. Analysing the underlying processes, we find that production losses due to droughts were associated with a reduction in both harvested area and yields, whereas extreme heat mainly decreased cereal yields. Furthermore, the results highlight ~7% greater production damage from more recent droughts and 8-11% more damage in developed countries than in developing ones. Our findings may help to guide agricultural priorities in international disaster risk reduction and adaptation efforts.

Fundamentals of Cryogenics

NASA Technical Reports Server (NTRS)

Johnson, Wesley; Tomsik, Thomas; Moder, Jeff

2014-01-01

Analysis of the extreme conditions that are encountered in cryogenic systems requires the most effort out of analysts and engineers. Due to the costs and complexity associated with the extremely cold temperatures involved, testing is sometimes minimized and extra analysis is often relied upon. This short course is designed as an introduction to cryogenic engineering and analysis, and it is intended to introduce the basic concepts related to cryogenic analysis and testing as well as help the analyst understand the impacts of various requests on a test facility. Discussion will revolve around operational functions often found in cryogenic systems, hardware for both tests and facilities, and what design or modelling tools are available for performing the analysis. Emphasis will be placed on what scenarios to use what hardware or the analysis tools to get the desired results. The class will provide a review of first principles, engineering practices, and those relations directly applicable to this subject including such topics as cryogenic fluids, thermodynamics and heat transfer, material properties at low temperature, insulation, cryogenic equipment, instrumentation, refrigeration, testing of cryogenic systems, cryogenics safety and typical thermal and fluid analysis used by the engineer. The class will provide references for further learning on various topics in cryogenics for those who want to dive deeper into the subject or have encountered specific problems.

Social Cooperation and Disharmony in Communities Mediated through Common Pool Resource Exploitation

NASA Astrophysics Data System (ADS)

Sugiarto, H. S.; Lansing, J. S.; Chung, N. N.; Lai, C. H.; Cheong, S. A.; Chew, L. Y.

2017-05-01

It was theorized that when a society exploits a shared resource, the system can undergo extreme phase transition from full cooperation in abiding by a social agreement, to full defection from it. This was shown to happen in an integrated society with complex social relationships. However, real-world agents tend to segregate into communities whose interactions contain features of the associated community structure. We found that such social segregation softens the abrupt extreme transition through the emergence of multiple intermediate phases composed of communities of cooperators and defectors. Phase transitions thus now occur through these intermediate phases which avert the instantaneous collapse of social cooperation within a society. While this is beneficial to society, it nonetheless costs society in two ways. First, the return to full cooperation from full defection at the phase transition is no longer immediate. Community linkages have rendered greater societal inertia such that the switch back is now typically stepwise rather than a single change. Second, there is a drastic increase in social disharmony within the society due to the greater tension in the relationship between segregated communities of defectors and cooperators. Intriguingly, these results on multiple phases with its associated phenomenon of social disharmony are found to characterize the level of cooperation within a society of Balinese farmers who exploit water for rice production.

A methodological approach to a realistic evaluation of skin absorbed doses during manipulation of radioactive sources by means of GAMOS Monte Carlo simulations

NASA Astrophysics Data System (ADS)

Italiano, Antonio; Amato, Ernesto; Auditore, Lucrezia; Baldari, Sergio

2018-05-01

The accurate evaluation of the radiation burden associated with radiation absorbed doses to the skin of the extremities during the manipulation of radioactive sources is a critical issue in operational radiological protection, deserving the most accurate calculation approaches available. Monte Carlo simulation of the radiation transport and interaction is the gold standard for the calculation of dose distributions in complex geometries and in presence of extended spectra of multi-radiation sources. We propose the use of Monte Carlo simulations in GAMOS, in order to accurately estimate the dose to the extremities during manipulation of radioactive sources. We report the results of these simulations for 90Y, 131I, 18F and 111In nuclides in water solutions enclosed in glass or plastic receptacles, such as vials or syringes. Skin equivalent doses at 70 μm of depth and dose-depth profiles are reported for different configurations, highlighting the importance of adopting a realistic geometrical configuration in order to get accurate dosimetric estimations. Due to the easiness of implementation of GAMOS simulations, case-specific geometries and nuclides can be adopted and results can be obtained in less than about ten minutes of computation time with a common workstation.

Sympathetic blocks for the treatment of complex regional pain syndrome: A case series.

PubMed

Gungor, Semih; Aiyer, Rohit; Baykoca, Buse

2018-05-01

To present the successful treatment of complex regional pain syndrome type -1 utilizing sympathetic blocks. Severe pain interfering with activities of daily living and temporary disability secondary to complex regional pain syndrome. Complex regional pain syndrome type-1 with involvement of lower extremity (2 patients), and upper extremity (1 patient). We report the management of 3 patients with diagnosis of complex regional pain syndrome type-1 by early institution of sympathetic blocks for diagnostic and therapeutic purposes. All 3 patients were able to tolerate physical therapy only after adequate pain relief had been achieved with institution of sympathetic blocks. All 3 patients responded very favorably to sympathetic blocks with dramatic reversal of pathology. All patients reported almost complete resolution of pain, symptoms, and signs within 6 months duration after diagnosis of complex regional pain syndrome. All 3 patients were able to wean their pain medications and achieve normal activities of daily living without any significant limitations. All patients were able to return to full-time employment. Treatment options are limited and there is lack of high quality research regarding the efficacy of sympathetic blocks in the treatment of complex regional pain syndrome. As presented in this case series, sympathetic blocks maybe very effective in the treatment of complex regional pain syndrome in a subset of patients. Thus, early institution of sympathetic blocks should be considered in complex regional pain syndrome prior to physical therapy and consideration of more invasive pain management interventions.

Climate Resiliency Planning: Making Extreme Event Science Useful for Managers and Planners in Northern Nevada

NASA Astrophysics Data System (ADS)

McCarthy, M.; Kenneston, A.; Wall, T. U.; Brown, T. J.; Redmond, K. T.

2014-12-01

Effective climate resiliency planning at the regional level requires extensive interactive dialogue among climate scientists, emergency managers, public health officials, urban planners, social scientists, and policy makers. Engaging federal, tribal, state, local governments and private sector business and infrastructure owners/operators in defining, assessing and characterizing the impacts of extreme events allows communities to understand how different events "break the system" forcing local communities to seek support and resources from state/federal governments and/or the private sector and what actions can be taken proactively to mitigate consequences and accelerate recovery. The Washoe County Regional Resiliency Study was prepared in response to potential climate variability related impacts specific to the Northern Nevada Region. The last several decades have seen dramatic growth in the region, coupled with increased resource demands that have forced local governments to consider how those impacts will affect the region and may, in turn, impact the region's ability to provide essential services. The Western Regional Climate Center of the Desert Research Institute provided a synthesis of climate studies with predictions regarding plausible changes in the local climate of Northern California and Nevada for the next 50 years. In general, these predictions indicate that the region's climate is undergoing a gradual shift, which will primarily affect the frequency, amount, and form of precipitation in the Sierra Nevada and Great Basin. Changes in water availability and other extreme events may have serious and long lasting effects in the Northern Nevada Region, and create a variety of social, environmental and economic concerns. A range of extreme events were considered including Adverse Air Quality, Droughts, Floods, Heat Waves, High Wind, Structure Fires, Wildland Fires, and Major Winter Storms. Due to the complexity of our climate systems, and the difficulty in specifying how severe the climate effects may be or how those impacts compound existing hazards in the system, the Resiliency Study focused on identifying a variety of 'no regrets' policy options that can help the local communities anticipate, respond and recover faster and more efficiently to climate extremes.

Nerve transfers for restoration of upper extremity motor function in a child with upper extremity motor deficits due to transverse myelitis: case report.

PubMed

Dorsi, Michael J; Belzberg, Allan J

2012-01-01

Transverse myelitis (TM) may result in permanent neurologic dysfunction. Nerve transfers have been developed to restore function after peripheral nerve injury. Here, we present a case report of a child with permanent right upper extremity weakness due to TM that underwent nerve transfers. The following procedures were performed: double fascicle transfer from median nerve and ulnar nerve to the brachialis and biceps branches of the musculocutaneous nerve, spinal accessory to suprascapular nerve, and medial cord to axillary nerve end-to-side neurorraphy. At 22 months, the patient demonstrated excellent recovery of elbow flexion with minimal improvement in shoulder abduction. We propose that the treatment of permanent deficits from TM represents a novel indication for nerve transfers in a subset of patients. Copyright © 2011 Wiley Periodicals, Inc.

Knotty: Efficient and Accurate Prediction of Complex RNA Pseudoknot Structures.

PubMed

Jabbari, Hosna; Wark, Ian; Montemagno, Carlo; Will, Sebastian

2018-06-01

The computational prediction of RNA secondary structure by free energy minimization has become an important tool in RNA research. However in practice, energy minimization is mostly limited to pseudoknot-free structures or rather simple pseudoknots, not covering many biologically important structures such as kissing hairpins. Algorithms capable of predicting sufficiently complex pseudoknots (for sequences of length n) used to have extreme complexities, e.g. Pknots (Rivas and Eddy, 1999) has O(n6) time and O(n4) space complexity. The algorithm CCJ (Chen et al., 2009) dramatically improves the asymptotic run time for predicting complex pseudoknots (handling almost all relevant pseudoknots, while being slightly less general than Pknots), but this came at the cost of large constant factors in space and time, which strongly limited its practical application (∼200 bases already require 256GB space). We present a CCJ-type algorithm, Knotty, that handles the same comprehensive pseudoknot class of structures as CCJ with improved space complexity of Θ(n3 + Z)-due to the applied technique of sparsification, the number of "candidates", Z, appears to grow significantly slower than n4 on our benchmark set (which include pseudoknotted RNAs up to 400 nucleotides). In terms of run time over this benchmark, Knotty clearly outperforms Pknots and the original CCJ implementation, CCJ 1.0; Knotty's space consumption fundamentally improves over CCJ 1.0, being on a par with the space-economic Pknots. By comparing to CCJ 2.0, our unsparsified Knotty variant, we demonstrate the isolated effect of sparsification. Moreover, Knotty employs the state-of-the-art energy model of "HotKnots DP09", which results in superior prediction accuracy over Pknots. Our software is available at https://github.com/HosnaJabbari/Knotty. will@tbi.unvie.ac.at. Supplementary data are available at Bioinformatics online.

Adaptor Protein Complex 4 Deficiency Causes Severe Autosomal-Recessive Intellectual Disability, Progressive Spastic Paraplegia, Shy Character, and Short Stature

PubMed Central

Abou Jamra, Rami; Philippe, Orianne; Raas-Rothschild, Annick; Eck, Sebastian H.; Graf, Elisabeth; Buchert, Rebecca; Borck, Guntram; Ekici, Arif; Brockschmidt, Felix F.; Nöthen, Markus M.; Munnich, Arnold; Strom, Tim M.; Reis, Andre; Colleaux, Laurence

2011-01-01

Intellectual disability inherited in an autosomal-recessive fashion represents an important fraction of severe cognitive-dysfunction disorders. Yet, the extreme heterogeneity of these conditions markedly hampers gene identification. Here, we report on eight affected individuals who were from three consanguineous families and presented with severe intellectual disability, absent speech, shy character, stereotypic laughter, muscular hypotonia that progressed to spastic paraplegia, microcephaly, foot deformity, decreased muscle mass of the lower limbs, inability to walk, and growth retardation. Using a combination of autozygosity mapping and either Sanger sequencing of candidate genes or next-generation exome sequencing, we identified one mutation in each of three genes encoding adaptor protein complex 4 (AP4) subunits: a nonsense mutation in AP4S1 (NM_007077.3: c.124C>T, p.Arg42∗), a frameshift mutation in AP4B1 (NM_006594.2: c.487_488insTAT, p.Glu163_Ser739delinsVal), and a splice mutation in AP4E1 (NM_007347.3: c.542+1_542+4delGTAA, r.421_542del, p.Glu181Glyfs∗20). Adaptor protein complexes (AP1-4) are ubiquitously expressed, evolutionarily conserved heterotetrameric complexes that mediate different types of vesicle formation and the selection of cargo molecules for inclusion into these vesicles. Interestingly, two mutations affecting AP4M1 and AP4E1 have recently been found to cause cerebral palsy associated with severe intellectual disability. Combined with previous observations, these results support the hypothesis that AP4-complex-mediated trafficking plays a crucial role in brain development and functioning and demonstrate the existence of a clinically recognizable syndrome due to deficiency of the AP4 complex. PMID:21620353

Complex extreme learning machine applications in terahertz pulsed signals feature sets.

PubMed

Yin, X-X; Hadjiloucas, S; Zhang, Y

2014-11-01

This paper presents a novel approach to the automatic classification of very large data sets composed of terahertz pulse transient signals, highlighting their potential use in biochemical, biomedical, pharmaceutical and security applications. Two different types of THz spectra are considered in the classification process. Firstly a binary classification study of poly-A and poly-C ribonucleic acid samples is performed. This is then contrasted with a difficult multi-class classification problem of spectra from six different powder samples that although have fairly indistinguishable features in the optical spectrum, they also possess a few discernable spectral features in the terahertz part of the spectrum. Classification is performed using a complex-valued extreme learning machine algorithm that takes into account features in both the amplitude as well as the phase of the recorded spectra. Classification speed and accuracy are contrasted with that achieved using a support vector machine classifier. The study systematically compares the classifier performance achieved after adopting different Gaussian kernels when separating amplitude and phase signatures. The two signatures are presented as feature vectors for both training and testing purposes. The study confirms the utility of complex-valued extreme learning machine algorithms for classification of the very large data sets generated with current terahertz imaging spectrometers. The classifier can take into consideration heterogeneous layers within an object as would be required within a tomographic setting and is sufficiently robust to detect patterns hidden inside noisy terahertz data sets. The proposed study opens up the opportunity for the establishment of complex-valued extreme learning machine algorithms as new chemometric tools that will assist the wider proliferation of terahertz sensing technology for chemical sensing, quality control, security screening and clinic diagnosis. Furthermore, the proposed algorithm should also be very useful in other applications requiring the classification of very large datasets. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Outcomes and Disability After Massive Proximal Upper Extremity Reconstruction in a Resource-Limited Setting.

PubMed

Giladi, Aviram M; Shanmugakrishnan, R Raja; Venkatramani, Hari; Raja Sekaran, S; Chung, Kevin C; Sabapathy, S Raja

2017-06-01

At Ganga Hospital in Coimbatore, India, a unique approach is applied to treat massive upper limb injuries. However, long-term outcomes of complex reconstruction performed in the resource-limited setting are not known. This hinders understanding of outcomes and disability from these injuries and prevents systematically addressing care delivery around upper extremity trauma in the developing world. This project aims to analyze the details of the unique Ganga Hospital reconstruction experience and use patient-reported outcome measures for the first time in this patient population to evaluate post-injury recovery and disability . Forty-six patients were evaluated 6 months or more after massive proximal upper extremity reconstruction at Ganga Hospital. Patients completed functional tests, Jebsen-Taylor test (JTT), and patient-reported outcomes (PROs)-Michigan Hand Questionnaire (MHQ), Disability of Arm, Shoulder, and Hand questionnaire (DASH), and Short-Form 36 (SF-36). Correlations between metrics were assessed with Pearson's correlation coefficients. Linear regression modeling evaluated associations between severity, reconstruction, and outcomes. MHQ and DASH results correlated with functional test performance, JTT performance, and SF-36 scores (Pearson's coefficients all ≥0.33, p ≤ 0.05). In this cohort, mean MHQ score was 79 ± 15 and mean DASH score was 13 ± 15, which are not significantly different than scores for long-term outcomes after other complex upper extremity procedures. The following factors predicted PROs and functional performance after reconstruction: extent of soft tissue reconstruction, multi-segmental ulna fractures, median nerve injury, and ability for patients to return to work and maintain their job after injury. Complex proximal upper extremity salvage can be performed in the resource-limited setting with excellent long-term functional and patient-reported outcomes. PRO questionnaires are useful for reporting outcomes that correlate to functional and sensory testing and may be used to assess post-traumatic disability.

Advantages of paramagnetic CEST complexes having slow-to-intermediate water exchange properties as responsive MRI agents

PubMed Central

Soesbe, Todd C.; Wu, Yunkou; Sherry, A. Dean

2012-01-01

Paramagnetic saturation transfer chemical exchange (PARACEST) complexes are exogenous contrast agents that have great potential to further extend the functional and molecular imaging capabilities of magnetic resonance. Due to the presence of a central paramagnetic lanthanide ion (Ln3+ ≠ La3+, Gd3+, Lu3+) within the chelate, the resonance frequencies of protons and water molecules bound to the PARACEST agent are shifted far away from the bulk water frequency. This large chemical shift combined with an extreme sensitivity to the chemical exchange rate make PARACEST agents ideally suited for reporting significant biological metrics such as temperature, pH, and the presence of metabolites. Also, the ability to turn PARACEST agents “off” and “on” using a frequency selective saturation pulse gives them a distinct advantage over Gd3+-based contrast agents. A current challenge for PARACEST research is translating the promising in vitro results into in vivo systems. This short review article first describes the basic theory behind PARACEST contrast agents, their benefits over other contrast agents, and their applications to magnetic resonance imaging. It then describes some of the recent PARACEST research results. Specifically, pH measurements using water molecule exchange rate modulation, T2-exchange contrast due to water molecule exchange, the use of ultra-short echo times (TE<10 μs) to overcome T2-exchange line-broadening, and the potential application of T2-exchange as a new contrast mechanism for magnetic resonance imaging. PMID:23055299

Extreme Weather Events and Climate Change Attribution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thomas, Katherine

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 climatemore » 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.« less

On the nonlinearity of spatial scales in extreme weather attribution statements

NASA Astrophysics Data System (ADS)

Angélil, Oliver; Stone, Daíthí; Perkins-Kirkpatrick, Sarah; Alexander, Lisa V.; Wehner, Michael; Shiogama, Hideo; Wolski, Piotr; Ciavarella, Andrew; Christidis, Nikolaos

2018-04-01

In the context of ongoing climate change, extreme weather events are drawing increasing attention from the public and news media. A question often asked is how the likelihood of extremes might have changed by anthropogenic greenhouse-gas emissions. Answers to the question are strongly influenced by the model used, duration, spatial extent, and geographic location of the event—some of these factors often overlooked. Using output from four global climate models, we provide attribution statements characterised by a change in probability of occurrence due to anthropogenic greenhouse-gas emissions, for rainfall and temperature extremes occurring at seven discretised spatial scales and three temporal scales. An understanding of the sensitivity of attribution statements to a range of spatial and temporal scales of extremes allows for the scaling of attribution statements, rendering them relevant to other extremes having similar but non-identical characteristics. This is a procedure simple enough to approximate timely estimates of the anthropogenic contribution to the event probability. Furthermore, since real extremes do not have well-defined physical borders, scaling can help quantify uncertainty around attribution results due to uncertainty around the event definition. Results suggest that the sensitivity of attribution statements to spatial scale is similar across models and that the sensitivity of attribution statements to the model used is often greater than the sensitivity to a doubling or halving of the spatial scale of the event. The use of a range of spatial scales allows us to identify a nonlinear relationship between the spatial scale of the event studied and the attribution statement.

On the nonlinearity of spatial scales in extreme weather attribution statements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Angélil, Oliver; Stone, Daíthí; Perkins-Kirkpatrick, Sarah

In the context of continuing climate change, extreme weather events are drawing increasing attention from the public and news media. A question often asked is how the likelihood of extremes might have changed by anthropogenic greenhouse-gas emissions. Answers to the question are strongly influenced by the model used, duration, spatial extent, and geographic location of the event—some of these factors often overlooked. Using output from four global climate models, we provide attribution statements characterised by a change in probability of occurrence due to anthropogenic greenhouse-gas emissions, for rainfall and temperature extremes occurring at seven discretised spatial scales and three temporalmore » scales. An understanding of the sensitivity of attribution statements to a range of spatial and temporal scales of extremes allows for the scaling of attribution statements, rendering them relevant to other extremes having similar but non-identical characteristics. This is a procedure simple enough to approximate timely estimates of the anthropogenic contribution to the event probability. Furthermore, since real extremes do not have well-defined physical borders, scaling can help quantify uncertainty around attribution results due to uncertainty around the event definition. Results suggest that the sensitivity of attribution statements to spatial scale is similar across models and that the sensitivity of attribution statements to the model used is often greater than the sensitivity to a doubling or halving of the spatial scale of the event. The use of a range of spatial scales allows us to identify a nonlinear relationship between the spatial scale of the event studied and the attribution statement.« less

On the nonlinearity of spatial scales in extreme weather attribution statements

DOE PAGES

Angélil, Oliver; Stone, Daíthí; Perkins-Kirkpatrick, Sarah; ...

2017-06-17

In the context of continuing climate change, extreme weather events are drawing increasing attention from the public and news media. A question often asked is how the likelihood of extremes might have changed by anthropogenic greenhouse-gas emissions. Answers to the question are strongly influenced by the model used, duration, spatial extent, and geographic location of the event—some of these factors often overlooked. Using output from four global climate models, we provide attribution statements characterised by a change in probability of occurrence due to anthropogenic greenhouse-gas emissions, for rainfall and temperature extremes occurring at seven discretised spatial scales and three temporalmore » scales. An understanding of the sensitivity of attribution statements to a range of spatial and temporal scales of extremes allows for the scaling of attribution statements, rendering them relevant to other extremes having similar but non-identical characteristics. This is a procedure simple enough to approximate timely estimates of the anthropogenic contribution to the event probability. Furthermore, since real extremes do not have well-defined physical borders, scaling can help quantify uncertainty around attribution results due to uncertainty around the event definition. Results suggest that the sensitivity of attribution statements to spatial scale is similar across models and that the sensitivity of attribution statements to the model used is often greater than the sensitivity to a doubling or halving of the spatial scale of the event. The use of a range of spatial scales allows us to identify a nonlinear relationship between the spatial scale of the event studied and the attribution statement.« less

Vascular anomalies and the growth of limbs: a review.

PubMed

Enjolras, Odile; Chapot, René; Merland, Jean Jacques

2004-11-01

Growth of the limb in a child can be impaired, with the coexistence of a vascular malformation. In these vascular bone syndromes, altered growth is manifest as overgrowth or hypotrophy. The vascular malformation is usually complex and gets progressively worse with time. The two types of vascular anomalies in limbs, fast-flow and slow-flow, can be associated with limb length discrepancies. The fast-flow vascular malformations together with arteriovenous fistulae are part of Parkes Weber syndrome, characterized by congenital red cutaneous staining, hypertrophy in girth and increasing of limb length, lymphedema, increasing skin alterations due to a distal vascular steal, and pain, all of which develop during childhood. Treatment is generally conservative. An affected lower extremity can be complicated by pelvic tilting and scoliosis because leg length discrepancy may reach 10 cm. To avoid such a course, stapling epiphysiodesis of the knee cartilages is often performed, but this orthopedic procedure may augment the worsening of the arterial venous malformation in the limb. Therefore, less aggressive orthopedic management is preferable. Slow-flow vascular anomalies associated with limb growth alteration include (1) a diffuse capillary malformation (port-wine stain) with congenital hypertrophy of the involved extremity which is non-progressive; (2) purely venous malformations invading skin, muscles and joints, with pain, functional impairment, a chronic localized intravascular coagulopathy requiring distinctive management, and usually a slight undergrowth of the affected extremity and progressing amyotrophy; (3) the triad of a port-wine stain, anomalous veins and overgrowth of the limb, often known as Klippel-Trenaunay syndrome, which requires orthopedic management to decide the optimal timing for epiphysiodesis (i.e. when leg length discrepancy is >2.5 cm). Varicose veins are sometimes surgically removed after ultrasonographic and Doppler evaluation has confirmed a normal deep venous system. Capillary malformations can be effectively treated with pulsed dye laser, but results are usually poor in distal extremities.

[Free latissimus dorsi flap transfer for reconstruction of soft tissue defects of the lower extremity].

PubMed

Knobloch, K; Herold, C; Vogt, P M

2012-04-01

Sustainable and durable soft tissue coverage at the lower extremity following trauma, tumor resections, sequelae of radiation therapy or osteomyelitis using free latissimus dorsi muscle transfer is provided by a free latissimus dorsi muscle flap. Soft tissue defects at the lower extremity following trauma, tumor resections, and sequelae of radiation therapy or osteomyelitis. Thoracotomy with incision of the latissimus dorsi muscle; a relative contraindication in wheelchair drivers as well as in overhead athletes due to potential diminished strength and shoulder proprioception following latissimus dorsi muscle transplantation. Under general anesthesia the patient is positioned laterally, and a substantial and meticulous debridement of the defect is performed, as is the identification and preparation of the target vessel, which is preferentially the posterior tibial artery at the calf, or more proximally the popliteal or femoral artery from the medial side as well as concomitant veins/the great saphenous vein. A tailored latissimus dorsi musculocutaneous flap is harvested with subsequent microsurgical anastomosis to the target vessel with preferential end-to-side anastomosis of the artery and end-to-end anastomosis of one or two veins. A 24-h intermediate care unit, clinical flap monitoring for at least 5-7 days, dangling of the flap using an elastic bandage for an initial 3  times  5 min starting on POD 7, compression stockings for at least 6 months subsequently. From 2001-2007 75 free latissimus dorsi flaps were performed (53 ± 17 years) for soft tissue coverage at the lower extremity. In 58% the target vessel was the posterior tibial artery, in 11% the femoral artery, in 8% the anterior tibial artery and in 8% the popliteal artery. In 15% an arteriovenous (AV) loop was applied. Overall free flap survival was 95%. We encountered four total flap losses, exclusively in complex reconstructions with AV-loop situations.

An innovative early warning system for floods and operational risks in harbours

NASA Astrophysics Data System (ADS)

Smets, Steven; Bolle, Annelies; Mollaert, Justine; Buitrago, Saul; Gruwez, Vincent

2016-04-01

Early Warning Systems (EWS) are nowadays becoming fairly standard in river flood forecasting or in large scale hydrometeorological predictions. For complex coastal morphodynamic problems or in the vicinity of complex coastal structures, such as harbours, EWS are much less used because they are both technically and computationally still very challenging. To advance beyond the state-of-the-art, the EU FP7 project Risc-KIT (www.risc-kit.eu) is developing prototype EWS which address specifically these topics. This paper describes the prototype EWS which IMDC has developed for the case study site of the harbour of Zeebrugge. The harbour of Zeebrugge is the largest industrial seaport on the coast of Belgium, extending more than 3 km into the sea. Two long breakwaters provide shelter for the inner quays and docks for regular conditions and frequent storms. Extreme storms surges and waves can however still enter the harbour and create risks for the harbour operations and infrastructure. The prediction of the effects of storm surges and waves inside harbours are typically very complex and challenging, due to the need of different types of numerical models for representing all different physical processes. In general, waves inside harbours are a combination of locally wind generated waves and offshore wave penetration at the port entrance. During extreme conditions, the waves could overtop the quays and breakwaters and flood the port facilities. Outside a prediction environment, the conditions inside the harbour could be assessed by superimposing processes. The assessment can be carried out by using a combination of a spectral wave model (i.e. SWAN) for the wind generated waves and a Boussinesq type wave model (i.e. Mike 21 BW) for the wave penetration from offshore. Finally, a 2D hydrodynamic model (i.e. TELEMAC) can be used to simulate the overland flooding inside the port facilities. To reproduce these processes in an EWS environment, an additional challenge is to cope with the limitations of the calculation engines. This is especially true with the Boussinesq model. A model train is proposed that integrates processed based modelling, for wind generated waves, with an intelligent simplification of the Boussinesq model for the wave penetration effects. These wave conditions together with the extreme water levels (including storm surge) can then be used to simulate the overtopping/overflow behaviour for the quays. Finally, the hydrodynamic model TELEMAC is run for the inundation forecast inside the port facilities. The complete model train was integrated into the Deltares Delft FEWS software to showcase the potential for real time operations.

Stabilization of erodible slopes with geofibers and nontraditional liquid additives.

DOT National Transportation Integrated Search

2013-05-01

Instability of erodible slopes due to extreme climate events and of permafrost slopes due degradation and thawing is a significant : engineering problem for northern transportation infrastructure. Engineers continually look for mitigation alternative...

Fund Accounting Is Dead: Let This Complex System Rest in Peace.

ERIC Educational Resources Information Center

Coville, Joanne

1995-01-01

It is argued that colleges and universities have created extremely complex and convoluted accounting/reporting systems using fund accounting. Recent changes in accounting standards should be seen as an opportunity to streamline many of the processes that have been designed to support funds, allowing introduction of other approaches. (MSE)

Interrupting Extremism by Creating Educative Turbulence

ERIC Educational Resources Information Center

Davies, Lynn

2014-01-01

This article begins from the premise that it is important to explore how people unlearn, as well as learn, specifically in terms of extremist or violent attitudes. It shows the implications of two aspects of complexity theory--turbulence and self-organisation--for educational practice and the fostering of a complex adaptive school, which can aid…

Hillslope threshold response to rainfall: (2) development and use of a macroscale model

Treesearch

Chris B. Graham; Jeffrey J. McDonnell

2010-01-01

Hillslope hydrological response to precipitation is extremely complex and poorly modeled. One possible approach for reducing the complexity of hillslope response and its mathematical parameterization is to look for macroscale hydrological behavior. Hillslope threshold response to storm precipitation is one such macroscale behavior observed at field sites across the...

The Individual Consistency of Acquiescence and Extreme Response Style in Self-Report Questionnaires

ERIC Educational Resources Information Center

Weijters, Bert; Geuens, Maggie; Schillewaert, Niels

2010-01-01

The severity of bias in respondents' self-reports due to acquiescence response style (ARS) and extreme response style (ERS) depends strongly on how consistent these response styles are over the course of a questionnaire. In the literature, different alternative hypotheses on response style (in)consistency circulate. Therefore, nine alternative…

[Paget-Schroetter síndrome associated with hyperhomocsyteinemia].

PubMed

González, C I; Cires, M; Rubio, T; Jiménez, F; Sarasíbar, E; Gaztelu, M T; González, V

2007-01-01

Venous thromboembolic disease (VTED) in the upper extremities is an infrequent entity, although its incidence has increased in relation to the use of central venous catheters. Its etiology can be primary (idiopathic, spontaneous, due to effort or traumatic) or secondary (related to tumours, central venous catheters, etc.). We present a case of primary venous thrombosis of the upper right extremity, also called the Paget-Schroetter syndrome. This clinical picture is usually associated with intensive and/or repetitive exercise or effort of the affected extremity, anatomical alterations in the zone, or it can be the first manifestation of a previously unknown thrombophilic state, as in the case that concerns us. The clinical picture usually consists of pain in the affected extremity, frequently accompanied by edema and collateral circulation. Echography-Doppler frequently presents false negatives, and it is recommendable to carry out CAT, due to its greater specificity and for evaluating the neighbouring structures, although flebography continues to be the cardinal test for diagnosing this picture. There is no unanimity of opinion concerning treatment, and it is recommendable that this should be individualised in accordance with the characteristics of each case.

Computational Failure Modeling of Lower Extremities

DTIC Science & Technology

2012-01-01

bone fracture, ligament tear, and muscle rupture . While these injuries may seem well-defined through medical imaging, the process of injury and the...to vehicles from improvised explosives cause severe injuries to the lower extremities, in- cluding bone fracture, ligament tear, and muscle rupture ...modeling offers a powerful tool to explore the insult-to-injury process with high-resolution. When studying a complex dynamic process such as this, it is

Upper Extremity Injuries in Tennis Players: Diagnosis, Treatment, and Management.

PubMed

Chung, Kevin C; Lark, Meghan E

2017-02-01

Upper extremity tennis injuries are most commonly characterized as overuse injuries to the wrist, elbow, and shoulder. The complex anatomy of these structures and their interaction with biomechanical properties of tennis strokes contributes to the diagnostic challenges. A thorough understanding of tennis kinetics, in combination with the current literature surrounding diagnostic and treatment methods, will improve clinical decision-making. Copyright © 2016 Elsevier Inc. All rights reserved.

Prevention of Infections Associated with Combat-Related Extremity Injuries

DTIC Science & Technology

2011-08-01

benefit over NPWT alone in a complex ortho- pedic injury goat model using P. aureuginosa. Instillation of an antiseptic, hypochlorous acid solution...antispectic has not been widely assessed clinically, and data discouraged hypochlorous acid (Dakin’s) solution use during World War I.247 The use of NPWT with...Abstract: During combat operations , extremities continue to be the most common sites of injury with associated high rates of infectious complications

Management of complex regional pain syndrome type I in upper extremity-evaluation of continuous stellate ganglion block and continuous infraclavicular brachial plexus block: a pilot study.

PubMed

Toshniwal, Gokul; Sunder, Rani; Thomas, Ronald; Dureja, G P

2012-01-01

Interventional pain management techniques play an important role in the multidisciplinary approach to management of complex regional pain syndrome (CRPS). In this preliminary study we compared the efficacy of continuous stellate ganglion (CSG) block with that of continuous infraclavicular brachial plexus (CIBP) block in management of CRPS type I of upper extremity. Thirty-three patients with CRPS type I of upper extremity were randomly assigned to either CSG or CIBP group. Patients were treated for 1 week with continuous infusion of 0.125% bupivacaine at 2and 5mL/h, respectively. Catheter was removed at 1 week and patients were followed up for 4 weeks. The outcome was evaluated in terms of neuropathic pain scale score (NPSS), edema scores (Grades 0-2), and range of motion (ROM) of all upper extremity joints (Grades 0-2). CIBP group showed statistically significant improvement in NPSS compared with CSG group during the first 12 hours after the procedures (P value <0.05). After 12 hours, the NPSS was comparable between the groups. At 4 weeks, both groups showed clinically significant improvement in edema score and ROM of all upper extremity joints when compared with the baseline. This preliminary study suggests that CIBP block and CSG block may be feasible and effective interventional techniques for the management of CRPS type I of upper extremities. Hence, we recommend a larger well-randomized, well-controlled, clinical trial to confirm our findings and determine if any significant difference exists between the groups in terms of long-term pain relief and functional restoration. Wiley Periodicals, Inc.

Impacts of Climate Change On The Occurrence of Extreme Events: The Mice Project

NASA Astrophysics Data System (ADS)

Palutikof, J. P.; Mice Team

It is widely accepted that climate change due to global warming will have substan- tial impacts on the natural environment, and on human activities. Furthermore, it is increasingly recognized that changes in the severity and frequency of extreme events, such as windstorm and flood, are likely to be more important than changes in the average climate. The EU-funded project MICE (Modelling the Impacts of Climate Extremes) commenced in January 2002. It seeks to identify the likely changes in the occurrence of extremes of rainfall, temperature and windstorm due to global warm- ing, using information from climate models as a basis, and to study the impacts of these changes in selected European environments. The objectives are: a) to evaluate, by comparison with gridded and station observations, the ability of climate models to successfully reproduce the occurrence of extremes at the required spatial and temporal scales. b) to analyse model output with respect to future changes in the occurrence of extremes. Statistical analyses will determine changes in (i) the return periods of ex- tremes, (ii) the joint probability of extremes (combinations of damaging events such as windstorm followed by heavy rain), (iii) the sequential behaviour of extremes (whether events are well-separated or clustered) and (iv) the spatial patterns of extreme event occurrence across Europe. The range of uncertainty in model predictions will be ex- plored by analysing changes in model experiments with different spatial resolutions and forcing scenarios. c) to determine the impacts of the predicted changes in extremes occurrence on selected activity sectors: agriculture (Mediterranean drought), commer- cial forestry and natural forest ecosystems (windstorm and flood in northern Europe, fire in the Mediterranean), energy use (temperature extremes), tourism (heat stress and Mediterranean beach holidays, changes in the snow pack and winter sports ) and civil protection/insurance (windstorm and flood). Impacts will be evaluated through a combination of techniques ranging from quantitative analyses through to expert judge- ment. Throughout the project, a continuing dialogue with stakeholders and end-users will be maintained.

Redo mitral surgery using the Estech endoclamp.

PubMed

Van Nooten, G; Van Belleghem, Y; Van Overbeke, H; Caes, F; François, K; De Pauw, M; De Rijcke, F; Poelaert, J

2001-01-01

Redo-CABG surgery remains extremely hazardous in the presence of open bypass grafts. In our patients with mitral valve pathology with open and well-functioning bypass grafts, we explored alternative approaches in order to avoid damage to the grafts by extensive dissection and direct clamping of the ascending aorta. The "Estech procedure," which uses the Estech remote access perfusion (RAP) endoclamp catheter (Estech Inc., Danville, CA), was selected for these patients. From January 1998 to January 2000, 10 patients underwent an Estech procedure for redo mitral surgery. All patients had previous cardiac operations such as coronary artery bypass grafting (CABG) and/or mitral valve procedures. The Estech procedure consisted of an anterior left thoracotomy and peripheral cannulation at femoral site using the Estech endovascular balloon technique. The series was comprised of seven mitral valve replacements, two valve reconstructions, and one closure of a paravalvular leak. One procedure had to be converted to a standard re-sternotomy due to extreme arteriosclerosis of the descending aorta with plaque dislocation at the time of catheter insertion. However, no damage was inflicted to the open bypass grafts. The follow-up period ranged from six to 30 months and was 100% complete. We encountered one hospital death in our group, which was due to a late post-operative intestinal infarction and multiple organ failure (MOF), and was not procedure related. As expected, morbidity was high in this compromised cohort, but no late death has occurred prior to submission of this article. All survivors progressed to an acceptable NYHA functional class. The excellent results in this complex patient group inspired us to use the Estech procedure as a standard approach for redo mitral surgery.

Extreme storms, sea level rise, and coastal change: implications for infrastructure reliability in the Gulf of Mexico

NASA Astrophysics Data System (ADS)

Anarde, K.; Kameshwar, S.; Irza, N.; Lorenzo-Trueba, J.; Nittrouer, J. A.; Padgett, J.; Bedient, P. B.

2016-12-01

Predicting coastal infrastructure reliability during hurricane events is important for risk-based design and disaster planning, such as delineating viable emergency response routes. Previous research has focused on either infrastructure vulnerability to coastal flooding or the impact of changing sea level and landforms on surge dynamics. Here we investigate the combined impact of sea level, morphology, and coastal flooding on the reliability of highway bridges - the only access points between barrier islands and mainland communities - during future extreme storms. We forward model coastal flooding for static projections of geomorphic change using ADCIRC+SWAN. First-order parameters that are adjusted include sea level and elevation. These are varied for each storm simulation to evaluate relative impact on the reliability of bridges surrounding Freeport, TX. Simulated storms include both synthetic and historical events, which are classified by intensity using the storm's integrated kinetic energy, a metric for surge generation potential. Reliability is estimated through probability of failure - given wave and surge loads - and time inundated. Findings include that: 1) bridge reliability scales inversely with surge height, and 2) sea level rise reduces bridge reliability due to a monotonic increase in surge height. The impact of a shifting landscape on bridge reliability is more complex: barrier island rollback can increase or decrease inundation times for storms of different intensity due to changes in wind-setup and back-barrier bay interactions. Initial storm surge readily inundates the coastal landscape during large intensity storms, however the draining of inland bays following storm passage is significantly impeded by the barrier. From a coastal engineering standpoint, we determine that to protect critical infrastructure, efforts now implemented that nourish low-lying barriers may be enhanced by also armoring back-bay coastlines and elevating bridge approach ramps.

MDcons: Intermolecular contact maps as a tool to analyze the interface of protein complexes from molecular dynamics trajectories

PubMed Central

2014-01-01

Background Molecular Dynamics (MD) simulations of protein complexes suffer from the lack of specific tools in the analysis step. Analyses of MD trajectories of protein complexes indeed generally rely on classical measures, such as the RMSD, RMSF and gyration radius, conceived and developed for single macromolecules. As a matter of fact, instead, researchers engaged in simulating the dynamics of a protein complex are mainly interested in characterizing the conservation/variation of its biological interface. Results On these bases, herein we propose a novel approach to the analysis of MD trajectories or other conformational ensembles of protein complexes, MDcons, which uses the conservation of inter-residue contacts at the interface as a measure of the similarity between different snapshots. A "consensus contact map" is also provided, where the conservation of the different contacts is drawn in a grey scale. Finally, the interface area of the complex is monitored during the simulations. To show its utility, we used this novel approach to study two protein-protein complexes with interfaces of comparable size and both dominated by hydrophilic interactions, but having binding affinities at the extremes of the experimental range. MDcons is demonstrated to be extremely useful to analyse the MD trajectories of the investigated complexes, adding important insight into the dynamic behavior of their biological interface. Conclusions MDcons specifically allows the user to highlight and characterize the dynamics of the interface in protein complexes and can thus be used as a complementary tool for the analysis of MD simulations of both experimental and predicted structures of protein complexes. PMID:25077693

MDcons: Intermolecular contact maps as a tool to analyze the interface of protein complexes from molecular dynamics trajectories.

PubMed

Abdel-Azeim, Safwat; Chermak, Edrisse; Vangone, Anna; Oliva, Romina; Cavallo, Luigi

2014-01-01

Molecular Dynamics (MD) simulations of protein complexes suffer from the lack of specific tools in the analysis step. Analyses of MD trajectories of protein complexes indeed generally rely on classical measures, such as the RMSD, RMSF and gyration radius, conceived and developed for single macromolecules. As a matter of fact, instead, researchers engaged in simulating the dynamics of a protein complex are mainly interested in characterizing the conservation/variation of its biological interface. On these bases, herein we propose a novel approach to the analysis of MD trajectories or other conformational ensembles of protein complexes, MDcons, which uses the conservation of inter-residue contacts at the interface as a measure of the similarity between different snapshots. A "consensus contact map" is also provided, where the conservation of the different contacts is drawn in a grey scale. Finally, the interface area of the complex is monitored during the simulations. To show its utility, we used this novel approach to study two protein-protein complexes with interfaces of comparable size and both dominated by hydrophilic interactions, but having binding affinities at the extremes of the experimental range. MDcons is demonstrated to be extremely useful to analyse the MD trajectories of the investigated complexes, adding important insight into the dynamic behavior of their biological interface. MDcons specifically allows the user to highlight and characterize the dynamics of the interface in protein complexes and can thus be used as a complementary tool for the analysis of MD simulations of both experimental and predicted structures of protein complexes.

Critical illness polyneuropathy: a case report.

PubMed

Celik, Canan; Ucan, Halil; Alemdaroglu, Ebru; Oktay, Fugen

2011-01-01

Critical illness polyneuropathy (CIP) is defined as a common complication of critically ilness patients who were admitted to the intensive care unit due to sepsis, multiple trauma and/or multi-organ failure. We aimed to present a patient who was diagnosed as CIP. He was admitted to our outpatient clinic due to weakness and pain in his lower extremities. He had been followed in an intensive care unit due to suicid five months ago. There were symmetrically and predominantly muscle weakness, sensory impairment, absence of deep tendon reflexes in his lower extremities. Electrophysiological evaluation demonstrated motor and sensory axonal distal polyneuropathy predominantly in lower extremities. At follow up, he had high fever, and elevated acute phase responses. Therefore source of infection was investigated and was suspected to a diagnosis of infective endocarditis. He was discharged to be hospitalized in cardiology clinic. With this case, we think that physiatrists should take into consideration a diagnosis of critical illness polyneuropathy in patients with symmetric motor weakness. In CIP, muscle weakness, sensory loss, neuropathic pain, and autonomic problems lengthened the rehabilitation period. Due to a diagnosis of infective endocarditis in our case, we point out that source of infection should be carefully investigated if there is acute phase responses in CIP patients even if during rehabilitation period.

Bunched black (and grouped grey) swans: Dissipative and non-dissipative models of correlated extreme fluctuations in complex geosystems

NASA Astrophysics Data System (ADS)

Watkins, N. W.

2013-01-01

I review the hierarchy of approaches to complex systems, focusing particularly on stochastic equations. I discuss how the main models advocated by the late Benoit Mandelbrot fit into this classification, and how they continue to contribute to cross-disciplinary approaches to the increasingly important problems of correlated extreme events and unresolved scales. The ideas have broad importance, with applications ranging across science areas as diverse as the heavy tailed distributions of intense rainfall in hydrology, after which Mandelbrot named the "Noah effect"; the problem of correlated runs of dry summers in climate, after which the "Joseph effect" was named; and the intermittent, bursty, volatility seen in finance and fluid turbulence.

Extreme Water Levels in Bangladesh: Past Trends, Future Projections and their Impact on Mortality

NASA Astrophysics Data System (ADS)

Thiele-Eich, I.; Burkart, K.; Hopson, T. M.; Simmer, C.

2014-12-01

Climate change is expected to have an impact on meteorological and therefore hydrological extremes, thereby possibly altering the vulnerability of exposed populations. Our study focuses on Bangladesh, which is particularly vulnerable to changes in extremes due to both the large population at risk, as well as geographical characteristics such as the low-rising slope of the country through which the outflow of the combined catchments of the Ganges, Brahmaputra and Meghna rivers (GBM, ~1.75 million km2) is channeled.Time series of daily discharge and water level data for the past 100 years were analyzed with respect to trends in frequency, magnitude and duration, focusing on rare but particularly high-risk events using extreme-value theory. Mortality data is available for a five-year period (2003-2007), with a distributed lag non-linear model used to examine possible connections between extreme water levels and mortality. Then, using output from the Community Climate System Model CCSM4, projections were made regarding future flooding due to changes in precipitation intensity and frequency, while also accounting for the backwater effect of sea-level rise. For this, the upper catchment precipitation as well as monthly mean thermosteric sea-level rise at the river mouth outflow were taken from the four CCSM4 1° 20th Century ensemble members as well as from six CCSM4 1° ensemble members for the RCP scenarios RCP 2.6, 4.5, 6.0 and 8.5.Results show that while e.g. the mean water level did not significantly rise during the past 100 years, a change in extreme water levels can be detected. In addition, annual minimum water levels have decreased, which is of particular importance as there is a significant connection to an increase in mortality for low water levels. While mortality does not seem to increase significantly due to extreme floods, our results indicate that return levels projected for the future shift progressively, with the effect being strongest for RCP 8.5. Further measures to strengthen the resilience of the exposed population are therefore required to ensure that climate change effects do not overwhelm the population's coping capacities.

Biological Extreme Events - Past, Present, and Future

NASA Astrophysics Data System (ADS)

Gutschick, V. P.

2010-12-01

Biological extreme events span wide ranges temporally and spatially and in type - population dieoffs, extinctions, ecological reorganizations, changes in biogeochemical fluxes, and more. Driving variables consist in meteorology, tectonics, orbital changes, anthropogenic changes (land-use change, species introductions, reactive N injection into the biosphere), and evolution (esp. of diseases). However, the mapping of extremes in the drivers onto biological extremes as organismal responses is complex, as laid out originally in the theoretical framework of Gutschick and BassiriRad (New Phytologist [2003] 100:21-42). Responses are nonlinear and dependent on (mostly unknown and) complex temporal sequences - often of multiple environmental variables. The responses are species- and genotype specific. I review extreme events over from past to present over wide temporal scales, while noting that they are not wholly informative of responses to the current and near-future drivers for at least two reasons: 1) the current combination of numerous environmental extremes - changes in CO2, temperature, precipitation, reactive N, land fragmentation, O3, etc. -is unprecedented in scope, and 2) adaptive genetic variation for organismal responses is constrained by poorly-characterized genetic structures (in organisms and populations) and by loss of genetic variation by genetic drift over long periods. We may expect radical reorganizations of ecosystem and biogeochemical functions. These changes include many ecosystem services in flood control, crop pollination and insect/disease control, C-water-mineral cycling, and more, as well as direct effects on human health. Predictions of such changes will necessarily be very weak in the critical next few decades, given the great deal of observation, experimentation, and theory construction that will be necessary, on both organisms and drivers. To make the research efforts most effective will require extensive, insightful planning, beginning immediately. Massive dieoff of conifers in the US Southwest, an extreme event driven by a remarkably uncommon co-occurrence of high temperature, drought, and long active season for insects

Translations on USSR Science and Technology, Biomedical and Behavioral Sciences, Number 15

DTIC Science & Technology

1977-11-16

processed. By applying systems theory to synthesis of complex man-machine systems we form ergatic organisms which not only have external and internal...without exception (and this is extremely important to emphasize) as a complex , integral formation, which through various traditions has acquired a...and outputs of the whole, which has a complex internal organization and structure, which we can no longer ignore in our analysis. Thus analysis and

Water-Borne Diseases and Extreme Weather Events in Cambodia: Review of Impacts and Implications of Climate Change

PubMed Central

Davies, Grace I.; McIver, Lachlan; Kim, Yoonhee; Hashizume, Masahiro; Iddings, Steven; Chan, Vibol

2014-01-01

Cambodia is prone to extreme weather events, especially floods, droughts and typhoons. Climate change is predicted to increase the frequency and intensity of such events. The Cambodian population is highly vulnerable to the impacts of these events due to poverty; malnutrition; agricultural dependence; settlements in flood-prone areas, and public health, governance and technological limitations. Yet little is known about the health impacts of extreme weather events in Cambodia. Given the extremely low adaptive capacity of the population, this is a crucial knowledge gap. A literature review of the health impacts of floods, droughts and typhoons in Cambodia was conducted, with regional and global information reviewed where Cambodia-specific literature was lacking. Water-borne diseases are of particular concern in Cambodia, in the face of extreme weather events and climate change, due to, inter alia, a high pre-existing burden of diseases such as diarrhoeal illness and a lack of improved sanitation infrastructure in rural areas. A time-series analysis under quasi-Poisson distribution was used to evaluate the association between floods and diarrhoeal disease incidence in Cambodian children between 2001 and 2012 in 16 Cambodian provinces. Floods were significantly associated with increased diarrhoeal disease in two provinces, while the analysis conducted suggested a possible protective effect from toilets and piped water. Addressing the specific, local pre-existing vulnerabilities is vital to promoting population health resilience and strengthening adaptive capacity to extreme weather events and climate change in Cambodia. PMID:25546280

Water-borne diseases and extreme weather events in Cambodia: review of impacts and implications of climate change.

PubMed

Davies, Grace I; McIver, Lachlan; Kim, Yoonhee; Hashizume, Masahiro; Iddings, Steven; Chan, Vibol

2014-12-23

Cambodia is prone to extreme weather events, especially floods, droughts and typhoons. Climate change is predicted to increase the frequency and intensity of such events. The Cambodian population is highly vulnerable to the impacts of these events due to poverty; malnutrition; agricultural dependence; settlements in flood-prone areas, and public health, governance and technological limitations. Yet little is known about the health impacts of extreme weather events in Cambodia. Given the extremely low adaptive capacity of the population, this is a crucial knowledge gap. A literature review of the health impacts of floods, droughts and typhoons in Cambodia was conducted, with regional and global information reviewed where Cambodia-specific literature was lacking. Water-borne diseases are of particular concern in Cambodia, in the face of extreme weather events and climate change, due to, inter alia, a high pre-existing burden of diseases such as diarrhoeal illness and a lack of improved sanitation infrastructure in rural areas. A time-series analysis under quasi-Poisson distribution was used to evaluate the association between floods and diarrhoeal disease incidence in Cambodian children between 2001 and 2012 in 16 Cambodian provinces. Floods were significantly associated with increased diarrhoeal disease in two provinces, while the analysis conducted suggested a possible protective effect from toilets and piped water. Addressing the specific, local pre-existing vulnerabilities is vital to promoting population health resilience and strengthening adaptive capacity to extreme weather events and climate change in Cambodia.

Alignment of a multilayer-coated imaging system using extreme ultraviolet Foucault and Ronchi interferometric testing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ray-Chaudhuri, A.K.; Ng, W.; Cerrina, F.

1995-11-01

Multilayer-coated imaging systems for extreme ultraviolet (EUV) lithography at 13 nm represent a significant challenge for alignment and characterization. The standard practice of utilizing visible light interferometry fundamentally provides an incomplete picture since this technique fails to account for phase effects induced by the multilayer coating. Thus the development of optical techniques at the functional EUV wavelength is required. We present the development of two EUV optical tests based on Foucault and Ronchi techniques. These relatively simple techniques are extremely sensitive due to the factor of 50 reduction in wavelength. Both techniques were utilized to align a Mo--Si multilayer-coated Schwarzschildmore » camera. By varying the illumination wavelength, phase shift effects due to the interplay of multilayer coating and incident angle were uniquely detected. {copyright} {ital 1995} {ital American} {ital Vacuum} {ital Society}« less

More tornadoes in the most extreme U.S. tornado outbreaks

NASA Astrophysics Data System (ADS)

Tippett, Michael K.; Lepore, Chiara; Cohen, Joel E.

2016-12-01

Tornadoes and severe thunderstorms kill people and damage property every year. Estimated U.S. insured losses due to severe thunderstorms in the first half of 2016 were $8.5 billion (US). The largest U.S. effects of tornadoes result from tornado outbreaks, which are sequences of tornadoes that occur in close succession. Here, using extreme value analysis, we find that the frequency of U.S. outbreaks with many tornadoes is increasing and that it is increasing faster for more extreme outbreaks. We model this behavior by extreme value distributions with parameters that are linear functions of time or of some indicators of multidecadal climatic variability. Extreme meteorological environments associated with severe thunderstorms show consistent upward trends, but the trends do not resemble those currently expected to result from global warming.

The analysis of dependence between extreme rainfall and storm surge in the coastal zone

NASA Astrophysics Data System (ADS)

Zheng, F.; Westra, S.

2012-12-01

Flooding in coastal catchments can be caused by runoff generated by an extreme rainfall event, elevated sea levels due to an extreme storm surge event, or the combination of both processes occurring simultaneously or in close succession. Dependence in extreme rainfall and storm surge arises because common meteorological forcings often drive both variables; for example, cyclonic systems may produce extreme rainfall, strong onshore winds and an inverse barometric effect simultaneously, which the former factor influencing catchment discharge and the latter two factors influencing storm surge. Nevertheless there is also the possibility that only one of the variables is extreme at any given time, so that the dependence between rainfall and storm surge is not perfect. Quantification of the strength of dependence between these processes is critical in evaluating the magnitude of flood risk in the coastal zone. This may become more important in the future as the majority of the coastal areas are threatened by the sea level rise due to the climate change. This research uses the most comprehensive record of rainfall and storm surge along the coastline of Australia collected to-date to investigate the strength of dependence between the extreme rainfall and storm surge along the Australia coastline. A bivariate logistic threshold-excess model was employed to this end to carry out the dependence analysis. The strength of the estimated dependence is then evaluated as a function of several factors including: the distance between the tidal gauge and the rain gauge; the lag between the extreme precipitation event and extreme surge event; and the duration of the maximum storm burst. The results show that the dependence between the extreme rainfall and storm surge along the Australia coastline is statistically significant, although some locations clearly exhibit stronger dependence than others. We hypothesize that this is due to a combination of large-scale meteorological effects as well as local scale bathymetry. Additionally, significant dependence can be observed over spatial distances of up to several hundred kilometers, implying that meso-scale meteorological forcings may play an important role in driving the dependence. This is also consistent with the result which shows that significant dependence often remaining for lags of up to one or two days between extremal rainfall and storm surge events. The influence of storm burst duration can also be observed, with rainfall extremes lasting more than several hours typically being more closely associated with storm surge compared with sub-hourly rainfall extremes. These results will have profound implications for how flood risk is evaluated along the coastal zone in Australia, with the strength of dependence varying depending on: (1) the dominant meteorological conditions; (2) the local estuary configuration, influencing the strength of the surge; and (3) the catchment attributes, influencing the duration of the storm burst that will deliver the peak flood events. Although a strong random component remains, we show that the probability of an extreme storm surge during an extreme rainfall event (or vice versa) can be up to ten times greater than under the situation under which there is no dependence, suggesting that failure to account for these interactions can result in a substantial underestimation of flood risk.

Extremes and bursts in complex multi-scale plasmas

NASA Astrophysics Data System (ADS)

Watkins, N. W.; Chapman, S. C.; Hnat, B.

2012-04-01

Quantifying the spectrum of sizes and durations of large and/or long-lived fluctuations in complex, multi-scale, space plasmas is a topic of both theoretical and practical importance. The predictions of inherently multi-scale physical theories such as MHD turbulence have given one direct stimulus for its investigation. There are also space weather implications to an improved ability to assess the likelihood of an extreme fluctuation of a given size. Our intuition as scientists tends to be formed on the familiar Gaussian "normal" distribution, which has a very low likelihood of extreme fluctuations. Perhaps surprisingly, there is both theoretical and observational evidence that favours non-Gaussian, heavier-tailed, probability distributions for some space physics datasets. Additionally there is evidence for the existence of long-ranged memory between the values of fluctuations. In this talk I will show how such properties can be captured in a preliminary way by a self-similar, fractal model. I will show how such a fractal model can be used to make predictions for experimental accessible quantities like the size and duration of a buurst (a sequence of values that exceed a given threshold), or the survival probability of a burst [c.f. preliminary results in Watkins et al, PRE, 2009]. In real-world time series scaling behaviour need not be "mild" enough to be captured by a single self-similarity exponent H, but might instead require a "wild" multifractal spectrum of scaling exponents [e.g. Rypdal and Rypdal, JGR, 2011; Moloney and Davidsen, JGR, 2011] to give a complete description. I will discuss preliminary work on extending the burst approach into the multifractal domain [see also Watkins et al, chapter in press for AGU Chapman Conference on Complexity and Extreme Events in the Geosciences, Hyderabad].

Physician decision-making in the management of work related upper extremity injuries.

PubMed

Szekeres, Mike; Macdermid, Joy C; Katchky, Adam; Grewal, Ruby

2018-05-22

Physicians working in a tertiary care injured worker clinic are faced with clinical decision-making that must balance the needs of patients and society in managing complex clinical problems that are complicated by the work-workplace context. The purpose of this study is to describe and characterize the decision-making process of upper extremity specialized surgeons when managing injured workers within a specialized worker's compensation clinic. Surgeons were interviewed in a semi-structured manner. Following each interview, the surgeon was also observed in a clinic visit during a new patient assessment, allowing observation of the interactional patterns between surgeon and patient, and comparison of the process described in the interview to what actually occurred during clinic visits. The primary central theme emerging from the surgeon interviews and the clinical observation was the focus on the importance of comprehensive assessment to make the first critical decision: an accurate diagnosis. Two subthemes were also found. The first of these involved the decision whether to proceed to management strategies or to continue with further investigation if the correct diagnosis is uncertain. Once the central theme of diagnosis was achieved, a second subtheme was highlighted; selecting appropriate management options, given the complexities of managing the injured worker, the workplace, and the compensation board. This study illustrates that upper extremity surgeons rely on their training and experience with upper extremity conditions to follow a sequential but iterative decision-making process to provide a more definitive diagnosis and treatment plan for workers with injuries that are often complex. The surgeons are challenged by the context which takes them out of their familiar zone of typical clinical practice to deal with the interactions between the injury, worker, work, workplace and insurer.

Daily temperature and precipitation extremes in the Baltic Sea region derived from the BaltAn65+ reanalysis

NASA Astrophysics Data System (ADS)

Toll, Velle; Post, Piia

2018-04-01

Daily 2-m temperature and precipitation extremes in the Baltic Sea region for the time period of 1965-2005 is studied based on data from the BaltAn65 + high resolution atmospheric reanalysis. Moreover, the ability of regional reanalysis to capture extremes is analysed by comparing the reanalysis data to gridded observations. The shortcomings in the simulation of the minimum temperatures over the northern part of the region and in the simulation of the extreme precipitation over the Scandinavian mountains in the BaltAn65+ reanalysis data are detected and analysed. Temporal trends in the temperature and precipitation extremes in the Baltic Sea region, with the largest increases in temperature and precipitation in winter, are detected based on both gridded observations and the BaltAn65+ reanalysis data. However, the reanalysis is not able to capture all of the regional trends in the extremes in the observations due to the shortcomings in the simulation of the extremes.

Characterization of molecular defects in xeroderma pigmentosum group F in relation to its clinically mild symptoms.

PubMed

Matsumura, Y; Nishigori, C; Yagi, T; Imamura, S; Takebe, H

1998-06-01

Xeroderma pigmentosum (XP) complementation group F was first reported in Japan and most XP-F patients reported to date are Japanese. The clinical features of XP-F patients are rather mild, including late onset of skin cancer. Recently a cDNA that corrects the repair deficiency of cultured XP-F cells was isolated. The XPF protein forms a tight complex with ERCC1 and this complex functions as a structure-specific endonuclease responsible for the 5' incision during DNA excision repair. Here we have identified XPF mRNA mutations and examined levels of the mRNA and protein expression in seven primary cell strains from Japanese XP-F patients. The XP-F cell strains were classified into three types in terms of the effect of the mutation on the predicted protein; (i) XPF proteins with amino acid substitutions; (ii) amino acid substituted and truncated XPF proteins; and (iii) truncated XPF protein only. A normal level of expression of XPF mRNA was observed in XP-F cells but XPF protein was extremely low. These results indicate that the detected mutations lead to unstable XPF protein, resulting in a decrease in formation of the ERCC1-XPF endonuclease complex. Slow excision repair of UV-induced DNA damage due to low residual endonuclease activity provides a plausible explanation for the typical mild phenotype of XP-F patients.

Identifying Changes of Complex Flood Dynamics with Recurrence Analysis

NASA Astrophysics Data System (ADS)

Wendi, D.; Merz, B.; Marwan, N.

2016-12-01

Temporal changes in flood hazard system are known to be difficult to detect and attribute due to multiple drivers that include complex processes that are non-stationary and highly variable. These drivers, such as human-induced climate change, natural climate variability, implementation of flood defense, river training, or land use change, could impact variably on space-time scales and influence or mask each other. Flood time series may show complex behavior that vary at a range of time scales and may cluster in time. Moreover hydrological time series (i.e. discharge) are often subject to measurement errors, such as rating curve error especially in the case of extremes where observation are actually derived through extrapolation. This study focuses on the application of recurrence based data analysis techniques (recurrence plot) for understanding and quantifying spatio-temporal changes in flood hazard in Germany. The recurrence plot is known as an effective tool to visualize the dynamics of phase space trajectories i.e. constructed from a time series by using an embedding dimension and a time delay, and it is known to be effective in analyzing non-stationary and non-linear time series. Sensitivity of the common measurement errors and noise on recurrence analysis will also be analyzed and evaluated against conventional methods. The emphasis will be on the identification of characteristic recurrence properties that could associate typical dynamic to certain flood events.

Near-infrared roll-off-free electroluminescence from highly stable diketopyrrolopyrrole light emitting diodes

PubMed Central

Sassi, Mauro; Buccheri, Nunzio; Rooney, Myles; Botta, Chiara; Bruni, Francesco; Giovanella, Umberto; Brovelli, Sergio; Beverina, Luca

2016-01-01

Organic light emitting diodes (OLEDs) operating in the near-infrared spectral region are gaining growing relevance for emerging photonic technologies, such as lab-on-chip platforms for medical diagnostics, flexible self-medicated pads for photodynamic therapy, night vision and plastic-based telecommunications. The achievement of efficient near-infrared electroluminescence from solution-processed OLEDs is, however, an open challenge due to the low photoluminescence efficiency of most narrow-energy-gap organic emitters. Diketopyrrolopyrrole-boron complexes are promising candidates to overcome this limitation as they feature extremely high photoluminescence quantum yield in the near-infrared region and high chemical stability. Here, by incorporating suitably functionalized diketopyrrolopyrrole derivatives emitting at ~760 nm in an active matrix of poly(9,9-dioctylfluorene-alt-benzothiadiazole) and without using complex light out-coupling or encapsulation strategies, we obtain all-solution-processed NIR-OLEDs with external quantum efficiency as high as 0.5%. Importantly, our test-bed devices show no efficiency roll-off even for high current densities and high operational stability, retaining over 50% of the initial radiant emittance for over 50 hours of continuous operation at 10 mA/cm2, which emphasizes the great applicative potential of the proposed strategy. PMID:27677240

Enhancing glycan isomer separations with metal ions and positive and negative polarity ion mobility spectrometry-mass spectrometry analyses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Xueyun; Zhang, Xing; Schocker, Nathaniel S.

Glycomics has become an increasingly important field of research since glycans play critical roles in biology processes ranging from molecular recognition and signaling to cellular communication. Glycans often conjugate with other biomolecules such as proteins and lipids, and alter their properties and functions, so understanding the effect glycans have on cellular systems is essential. However the analysis of glycans is extremely difficult due to their complexity and structural diversity (i.e., the number and identity of monomer units, and configuration of their glycosidic linkages and connectivities). In this work, we coupled ion mobility spectrometry with mass spectrometry (IMS-MS) to characterize glycanmore » standards and biologically important isomers of synthetic αGal-containing O-glycans including glycotopes of the protozoan parasite Trypanosoma cruzi, which is the causative agent of Chagas disease. IMS-MS results showed significant differences for the glycan structural isomers when analyzed in positive and negative polarity and complexed with different metal cations. These results suggest specific metal ions or ion polarities could be used to target and baseline separate glycan isomers of interest with IMS-MS.« less

Effects of behavioral response and vaccination policy on epidemic spreading--an approach based on evolutionary-game dynamics.

PubMed

Zhang, Hai-Feng; Wu, Zhi-Xi; Tang, Ming; Lai, Ying-Cheng

2014-07-11

How effective are governmental incentives to achieve widespread vaccination coverage so as to prevent epidemic outbreak? The answer largely depends on the complex interplay among the type of incentive, individual behavioral responses, and the intrinsic epidemic dynamics. By incorporating evolutionary games into epidemic dynamics, we investigate the effects of two types of incentives strategies: partial-subsidy policy in which certain fraction of the cost of vaccination is offset, and free-subsidy policy in which donees are randomly selected and vaccinated at no cost. Through mean-field analysis and computations, we find that, under the partial-subsidy policy, the vaccination coverage depends monotonically on the sensitivity of individuals to payoff difference, but the dependence is non-monotonous for the free-subsidy policy. Due to the role models of the donees for relatively irrational individuals and the unchanged strategies of the donees for rational individuals, the free-subsidy policy can in general lead to higher vaccination coverage. Our findings indicate that any disease-control policy should be exercised with extreme care: its success depends on the complex interplay among the intrinsic mathematical rules of epidemic spreading, governmental policies, and behavioral responses of individuals.

Fluorescence Fluctuation Approaches to the Study of Adhesion and Signaling

PubMed Central

Bachir, Alexia I.; Kubow, Kristopher E.; Horwitz, Alan R.

2013-01-01

Cell–matrix adhesions are large, multimolecular complexes through which cells sense and respond to their environment. They also mediate migration by serving as traction points and signaling centers and allow the cell to modify the surroucnding tissue. Due to their fundamental role in cell behavior, adhesions are germane to nearly all major human health pathologies. However, adhesions are extremely complex and dynamic structures that include over 100 known interacting proteins and operate over multiple space (nm–µm) and time (ms–min) regimes. Fluorescence fluctuation techniques are well suited for studying adhesions. These methods are sensitive over a large spatiotemporal range and provide a wealth of information including molecular transport dynamics, interactions, and stoichiometry from a single time series. Earlier chapters in this volume have provided the theoretical background, instrumentation, and analysis algorithms for these techniques. In this chapter, we discuss their implementation in living cells to study adhesions in migrating cells. Although each technique and application has its own unique instrumentation and analysis requirements, we provide general guidelines for sample preparation, selection of imaging instrumentation, and optimization of data acquisition and analysis parameters. Finally, we review several recent studies that implement these techniques in the study of adhesions. PMID:23280111

Empirical Bayes Estimation of Semi-parametric Hierarchical Mixture Models for Unbiased Characterization of Polygenic Disease Architectures

PubMed Central

Nishino, Jo; Kochi, Yuta; Shigemizu, Daichi; Kato, Mamoru; Ikari, Katsunori; Ochi, Hidenori; Noma, Hisashi; Matsui, Kota; Morizono, Takashi; Boroevich, Keith A.; Tsunoda, Tatsuhiko; Matsui, Shigeyuki

2018-01-01

Genome-wide association studies (GWAS) suggest that the genetic architecture of complex diseases consists of unexpectedly numerous variants with small effect sizes. However, the polygenic architectures of many diseases have not been well characterized due to lack of simple and fast methods for unbiased estimation of the underlying proportion of disease-associated variants and their effect-size distribution. Applying empirical Bayes estimation of semi-parametric hierarchical mixture models to GWAS summary statistics, we confirmed that schizophrenia was extremely polygenic [~40% of independent genome-wide SNPs are risk variants, most within odds ratio (OR = 1.03)], whereas rheumatoid arthritis was less polygenic (~4 to 8% risk variants, significant portion reaching OR = 1.05 to 1.1). For rheumatoid arthritis, stratified estimations revealed that expression quantitative loci in blood explained large genetic variance, and low- and high-frequency derived alleles were prone to be risk and protective, respectively, suggesting a predominance of deleterious-risk and advantageous-protective mutations. Despite genetic correlation, effect-size distributions for schizophrenia and bipolar disorder differed across allele frequency. These analyses distinguished disease polygenic architectures and provided clues for etiological differences in complex diseases. PMID:29740473

For wind turbines in complex terrain, the devil is in the detail

NASA Astrophysics Data System (ADS)

Lange, Julia; Mann, Jakob; Berg, Jacob; Parvu, Dan; Kilpatrick, Ryan; Costache, Adrian; Chowdhury, Jubayer; Siddiqui, Kamran; Hangan, Horia

2017-09-01

The cost of energy produced by onshore wind turbines is among the lowest available; however, onshore wind turbines are often positioned in a complex terrain, where the wind resources and wind conditions are quite uncertain due to the surrounding topography and/or vegetation. In this study, we use a scale model in a three-dimensional wind-testing chamber to show how minor changes in the terrain can result in significant differences in the flow at turbine height. These differences affect not only the power performance but also the life-time and maintenance costs of wind turbines, and hence, the economy and feasibility of wind turbine projects. We find that the mean wind, wind shear and turbulence level are extremely sensitive to the exact details of the terrain: a small modification of the edge of our scale model, results in a reduction of the estimated annual energy production by at least 50% and an increase in the turbulence level by a factor of five in the worst-case scenario with the most unfavorable wind direction. Wind farm developers should be aware that near escarpments destructive flows can occur and their extent is uncertain thus warranting on-site field measurements.

Mining temporal data sets: hypoplastic left heart syndrome case study

NASA Astrophysics Data System (ADS)

Kusiak, Andrew; Caldarone, Christopher A.; Kelleher, Michael D.; Lamb, Fred S.; Persoon, Thomas J.; Gan, Yuan; Burns, Alex

2003-03-01

Hypoplastic left heart syndrome (HLHS) affects infants and is uniformly fatal without surgery. Post-surgery mortality rates are highly variable and dependent on postoperative management. The high mortality after the first stage surgery usually occurs within the first few days after procedure. Typically, the deaths are attributed to the unstable balance between the pulmonary and systemic circulations. An experienced team of physicians, nurses, and therapists is required to successfully manage the infant. However, even the most experienced teams report significant mortality due to the extremely complex relationships among physiologic parameters in a given patient. A data acquisition system was developed for the simultaneous collection of 73 physiologic, laboratory, and nurse-assessed variables. Data records were created at intervals of 30 seconds. An expert-validated wellness score was computed for each data record. A training data set consisting of over 5000 data records from multiple patients was collected. Preliminary results demonstratd that the knowledge discovery approach was over 94.57% accurate in predicting the "wellness score" of an infant. The discovered knowledge can improve care of complex patients by development of an intelligent simulator that can be used to support decisions.

Effects of behavioral response and vaccination policy on epidemic spreading - an approach based on evolutionary-game dynamics

NASA Astrophysics Data System (ADS)

Zhang, Hai-Feng; Wu, Zhi-Xi; Tang, Ming; Lai, Ying-Cheng

2014-07-01

How effective are governmental incentives to achieve widespread vaccination coverage so as to prevent epidemic outbreak? The answer largely depends on the complex interplay among the type of incentive, individual behavioral responses, and the intrinsic epidemic dynamics. By incorporating evolutionary games into epidemic dynamics, we investigate the effects of two types of incentives strategies: partial-subsidy policy in which certain fraction of the cost of vaccination is offset, and free-subsidy policy in which donees are randomly selected and vaccinated at no cost. Through mean-field analysis and computations, we find that, under the partial-subsidy policy, the vaccination coverage depends monotonically on the sensitivity of individuals to payoff difference, but the dependence is non-monotonous for the free-subsidy policy. Due to the role models of the donees for relatively irrational individuals and the unchanged strategies of the donees for rational individuals, the free-subsidy policy can in general lead to higher vaccination coverage. Our findings indicate that any disease-control policy should be exercised with extreme care: its success depends on the complex interplay among the intrinsic mathematical rules of epidemic spreading, governmental policies, and behavioral responses of individuals.

The Coast Artillery Journal. Volume 57, Number 6, December 1922

DTIC Science & Technology

1922-12-01

theorems ; Chapter III, to application; Chapters IV, V and VI, to infinitesimals and differentials, trigonometric functions, and logarithms and...taneously." There are chapters on complex numbers with simple and direct discussion of the roots of unity; on elementary theorems on the roots of an...through the centuries from the time of Pythagoras , an interest shared on the one extreme by nearly every noted mathematician and on the other extreme by

Principles of Tendon Reconstruction Following Complex Trauma of the Upper Limb

PubMed Central

Chattopadhyay, Arhana; McGoldrick, Rory; Umansky, Elise; Chang, James

2015-01-01

Reconstruction of tendons following complex trauma to the upper limb presents unique clinical and research challenges. In this article, the authors review the principles guiding preoperative assessment, surgical reconstruction, and postoperative rehabilitation and management of the upper extremity. Tissue engineering approaches to address tissue shortages for tendon reconstruction are also discussed. PMID:25685101

Emerging themes in the ecology and management of North American forests

Treesearch

Terry L. Sharik; William Adair; Fred A. Baker; Michael Battaglia; Emily J. Comfort; Anthony W. D' Amato; Craig Delong; R. Justin DeRose; Mark J. Ducey; Mark Harmon; Louise Levy; Jesse A. Logan; Joseph O' Brien; Brian J. Palik; Scott D. Roberts; Paul C. Rogers; Douglas J. Shinneman; Thomas Spies; Sarah L. Taylor; Christopher Woodall; Andrew Youngblood

2010-01-01

Forests are extremely complex systems that respond to an overwhelming number of biological and environmental factors, which can act singularly and in concert with each other, as exemplified by Puettmann et al. [1]. The complexity of forest systems presents an enormous challenge for forest researchers who try to deepen their understanding of the structure and function...

Extreme precipitation forecasting in the Chilean Andean region with complex topography using the Weather Research and Forecasting (WRF) model

NASA Astrophysics Data System (ADS)

Gironás, J.; Yáñez Morroni, G.; Caneo, M.; Delgado, R.

2017-12-01

The Weather Research and Forecasting (WRF) model is broadly used for weather forecasting, hindcasting and researching due to its good performance. However, the atmospheric conditions for simulating are not always optimal when it includes complex topographies: affecting WRF mathematical stability and convergence, therefore, its performance. As Chile is a country strongly characterized by a complex topography and high gradients of elevation, WRF is ineffective resolving Chilean mountainous terrain and foothills. The need to own an effective weather forecasting tool relies on that Chile's main cities are located in these regions. Furthermore, the most intense rainfall events take place here, commonly caused by the presence of cutoff lows. This work analyzes a microphysics scheme ensemble to enhance initial forecasts made by the Chilean Weather Agency (DMC). These forecasts were made over the Santiago piedmont, in Quebrada de Ramón watershed, located upstream an urban area highly populated. In this region a non-existing planning increases the potential damage of a flash flood. An initial testing was made over different vertical levels resolution (39 and 50 levels), and subsequently testing with land use and surface models, and finally with the initial and boundary condition data (GFS/FNL). Our task made emphasis in analyzing microphysics and lead time (3 to 5 days before the storm peak) in the computational simulations over three extreme rainfall events between 2015 and 2017. WRF shortcoming are also related to the complex configuration of the synoptic events, even when the steep topography difficult the rainfall event peak amount, and to a lesser degree, the exact rainfall event beginning prediction. No evident trend was found in the lead time, but as expected, better results in rainfall and zero isotherm height are obtained with smaller anticipation. We found that WRF do predict properly the N-hours with the biggest amount of rainfall (5 hours corresponding to Quebrada de Ramón's time of concentration) and the temperatures during the event. This is a fundamental input to a hydrological model that could forecast flash floods. Finally, WSM-6Class microphysics was chosen as the one with best performance, but a geostatistical approach to countervail WRF forecasts' shortcomings over Andean piedmont is required.

Resection and reconstruction of pelvic and extremity soft tissue sarcomas with major vascular involvement: Current concepts

PubMed Central

McGoldrick, Niall P; Butler, Joseph S; Lavelle, Maire; Sheehan, Stephen; Dudeney, Sean; O'Toole, Gary C

2016-01-01

Soft tissue sarcoma accounts for approximately 1% of all cancers diagnosed annually in the United States. When these rare malignant mesodermal tumours arise in the pelvis and extremities, they may potentially encase or invade large calibre vascular structures. This presents a major challenge in terms of safe excision while also leaving acceptable surgical margins. In recent times, the trend has been towards limb salvage with vascular reconstruction in preference to amputation. Newer orthopaedic and vascular reconstructive techniques including both synthetic and autogenous graft reconstruction have made complex limb-salvage surgery feasible. Despite this, limb-salvage surgery with concomitant vascular reconstruction remains associated with higher rates of post-operative complications including infection and amputation. In this review we describe the initial presentation and investigation of patients presenting with soft tissue sarcomas in the pelvis and extremities, which involve vascular structures. We further discuss the key surgical reconstructive principles and techniques available for the management of these complex tumours, drawn from our institution’s experience as a national tertiary referral sarcoma service. PMID:27190757

Resection and reconstruction of pelvic and extremity soft tissue sarcomas with major vascular involvement: Current concepts.

PubMed

McGoldrick, Niall P; Butler, Joseph S; Lavelle, Maire; Sheehan, Stephen; Dudeney, Sean; O'Toole, Gary C

2016-05-18

Soft tissue sarcoma accounts for approximately 1% of all cancers diagnosed annually in the United States. When these rare malignant mesodermal tumours arise in the pelvis and extremities, they may potentially encase or invade large calibre vascular structures. This presents a major challenge in terms of safe excision while also leaving acceptable surgical margins. In recent times, the trend has been towards limb salvage with vascular reconstruction in preference to amputation. Newer orthopaedic and vascular reconstructive techniques including both synthetic and autogenous graft reconstruction have made complex limb-salvage surgery feasible. Despite this, limb-salvage surgery with concomitant vascular reconstruction remains associated with higher rates of post-operative complications including infection and amputation. In this review we describe the initial presentation and investigation of patients presenting with soft tissue sarcomas in the pelvis and extremities, which involve vascular structures. We further discuss the key surgical reconstructive principles and techniques available for the management of these complex tumours, drawn from our institution's experience as a national tertiary referral sarcoma service.

Systematic review of the effectiveness of mirror therapy in upper extremity function.

PubMed

Ezendam, Daniëlle; Bongers, Raoul M; Jannink, Michiel J A

2009-01-01

This review gives an overview of the current state of research regarding the effectiveness of mirror therapy in upper extremity function. A systematic literature search was performed to identify studies concerning mirror therapy in upper extremity. The included journal articles were reviewed according to a structured diagram and the methodological quality was assessed. Fifteen studies were identified and reviewed. Five different patient categories were studied: two studies focussed on mirror therapy after an amputation of the upper limb, five studies focussed on mirror therapy after stroke, five studies focussed on mirror therapy with complex regional pain syndrome type 1 (CRPS1) patients, one study on mirror therapy with complex regional pain syndrome type 2 (CRPS2) and two studies focussed on mirror therapy after hand surgery other than amputation. Most of the evidence for mirror therapy is from studies with weak methodological quality. The present review showed a trend that mirror therapy is effective in upper limb treatment of stroke patients and patients with CRPS, whereas the effectiveness in other patient groups has yet to be determined.

Extremity fractures associated with ATVs and dirt bikes: a 10-year national epidemiologic study.

PubMed

Lombardo, D J; Jelsema, T; Gambone, A; Weisman, M; Petersen-Fitts, G; Whaley, J D; Sabesan, V J

2017-08-01

Morbidity and mortality of all-terrain vehicles and dirt bikes have been studied, as well as the association of helmet use and head injury. The purpose of this study is to compare and contrast the patterns of extremity fractures associated with ATVs and dirt bikes. We believe there will be unique and potentially preventable injury patterns associated with dirt bikes and three-wheeled ATVs due to the poor stability of these vehicles. Descriptive epidemiology study. The National Electronic Injury Surveillance System (NEISS) was used to acquire data for extremity fractures related to ATV (three wheels, four wheels, and number of wheels undefined) and dirt bike use from 2007 to 2012. Nationwide estimation of injury incidence was determined using NEISS weight calculations. The database yielded an estimate of 229,362 extremity fractures from 2007 to 2012. The incidence rates of extremity fractures associated with ATV and dirt bike use were 3.87 and 6.85 per 1000 participant-years. The largest proportion of all fractures occurred in the shoulder (27.2%), followed by the wrist and lower leg (13.8 and 12.4%, respectively). There were no differences in the distribution of the location of fractures among four-wheeled or unspecified ATVs. However, three-wheeled ATVs and dirt bikes had much larger proportion of lower leg, foot, and ankle fractures compared to the other vehicle types. While upper extremity fractures were the most commonly observed in this database, three-wheeled ATVs and dirt bikes showed increased proportions of lower extremity fractures. Several organizations have previously advocated for better regulation of the sale and use of these specific vehicles due to increased risks. These findings help illustrate some of the specific risks associated with these commonly used vehicles.

Community detection in complex networks using deep auto-encoded extreme learning machine

NASA Astrophysics Data System (ADS)

Wang, Feifan; Zhang, Baihai; Chai, Senchun; Xia, Yuanqing

2018-06-01

Community detection has long been a fascinating topic in complex networks since the community structure usually unveils valuable information of interest. The prevalence and evolution of deep learning and neural networks have been pushing forward the advancement in various research fields and also provide us numerous useful and off the shelf techniques. In this paper, we put the cascaded stacked autoencoders and the unsupervised extreme learning machine (ELM) together in a two-level embedding process and propose a novel community detection algorithm. Extensive comparison experiments in circumstances of both synthetic and real-world networks manifest the advantages of the proposed algorithm. On one hand, it outperforms the k-means clustering in terms of the accuracy and stability thus benefiting from the determinate dimensions of the ELM block and the integration of sparsity restrictions. On the other hand, it endures smaller complexity than the spectral clustering method on account of the shrinkage in time spent on the eigenvalue decomposition procedure.

Artificial Intelligence (AI), Operations Research (OR), and Decision Support Systems (DSS): A conceptual framework

NASA Technical Reports Server (NTRS)

Parnell, Gregory S.; Rowell, William F.; Valusek, John R.

1987-01-01

In recent years there has been increasing interest in applying the computer based problem solving techniques of Artificial Intelligence (AI), Operations Research (OR), and Decision Support Systems (DSS) to analyze extremely complex problems. A conceptual framework is developed for successfully integrating these three techniques. First, the fields of AI, OR, and DSS are defined and the relationships among the three fields are explored. Next, a comprehensive adaptive design methodology for AI and OR modeling within the context of a DSS is described. These observations are made: (1) the solution of extremely complex knowledge problems with ill-defined, changing requirements can benefit greatly from the use of the adaptive design process, (2) the field of DSS provides the focus on the decision making process essential for tailoring solutions to these complex problems, (3) the characteristics of AI, OR, and DSS tools appears to be converging rapidly, and (4) there is a growing need for an interdisciplinary AI/OR/DSS education.

Assessment of Wind Turbine Component Loads Under Yaw-Offset Conditions

DOE PAGES

Damiani, Rick R.; Dana, Scott; Annoni, Jennifer; ...

2018-04-13

Renewed interest in yaw control for wind turbine and power plants for wake redirection and load mitigation demands a clear understanding of the effects of running with skewed inflow. In this paper, we investigate the physics of yawed operations, building up the complexity from a simplified analytical treatment to more complex aeroelastic simulations. Results in terms of damage equivalent loads (DELs) and extreme loads under operating, misaligned conditions are compared to data collected from an instrumented, utility-scale wind turbine. The analysis shows that multiple factors are responsible for the DELs of the various components, and that airfoil aerodynamics, elastic characteristicsmore » of the rotor, and turbulence intensities are the primary drivers. Both fatigue and extreme loads are observed to have relatively complex trends with yaw offsets, which can change depending on the wind-speed regime. As a result, good agreement is found between predicted and measured trends for both fatigue and ultimate loads.« less

Assessment of Wind Turbine Component Loads Under Yaw-Offset Conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Damiani, Rick R.; Dana, Scott; Annoni, Jennifer

Renewed interest in yaw control for wind turbine and power plants for wake redirection and load mitigation demands a clear understanding of the effects of running with skewed inflow. In this paper, we investigate the physics of yawed operations, building up the complexity from a simplified analytical treatment to more complex aeroelastic simulations. Results in terms of damage equivalent loads (DELs) and extreme loads under operating, misaligned conditions are compared to data collected from an instrumented, utility-scale wind turbine. The analysis shows that multiple factors are responsible for the DELs of the various components, and that airfoil aerodynamics, elastic characteristicsmore » of the rotor, and turbulence intensities are the primary drivers. Both fatigue and extreme loads are observed to have relatively complex trends with yaw offsets, which can change depending on the wind-speed regime. As a result, good agreement is found between predicted and measured trends for both fatigue and ultimate loads.« less

Charge Transfer Dissociation of Complex Oligosaccharides: Comparison with Collision-Induced Dissociation and Extreme Ultraviolet Dissociative Photoionization

NASA Astrophysics Data System (ADS)

Ropartz, David; Li, Pengfei; Fanuel, Mathieu; Giuliani, Alexandre; Rogniaux, Hélène; Jackson, Glen P.

2016-10-01

The structural characterization of oligosaccharides still challenges the field of analytical chemistry. Tandem mass spectrometry offers many advantages toward this aim, although the generic fragmentation method (low-energy collision-induced dissociation) shows clear limitations and is often insufficient to retrieve some essential structural information on these molecules. In this work, we present the first application of helium charge transfer dissociation (He-CTD) to characterize the structure of complex oligosaccharides. We compare this method with low-energy collision-induced dissociation and extreme-ultraviolet dissociative photoionization (XUV-DPI), which was shown previously to ensure the successful characterization of complex glycans. Similarly to what could be obtained by XUV-DPI, He-CTD provides a complete description of the investigated structures by producing many informative cross-ring fragments and no ambiguous fragmentation. Unlike XUV-DPI, which is performed at a synchrotron source, He-CTD has the undeniable advantage of being implementable in a conventional benchtop ion trap in a conventional laboratory setting.

A computational model of the human hand 93-ERI-053

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hollerbach, K.; Axelrod, T.

1996-03-01

The objectives of the Computational Hand Modeling project were to prove the feasibility of the Laboratory`s NIKE3D finite element code to orthopaedic problems. Because of the great complexity of anatomical structures and the nonlinearity of their behavior, we have focused on a subset of joints of the hand and lower extremity and have developed algorithms to model their behavior. The algorithms developed here solve fundamental problems in computational biomechanics and can be expanded to describe any other joints of the human body. This kind of computational modeling has never successfully been attempted before, due in part to a lack ofmore » biomaterials data and a lack of computational resources. With the computational resources available at the National Laboratories and the collaborative relationships we have established with experimental and other modeling laboratories, we have been in a position to pursue our innovative approach to biomechanical and orthopedic modeling.« less

Reactivity and reactions to regulatory transparency in medicine, psychotherapy and counselling.

PubMed

McGivern, Gerry; Fischer, Michael D

2012-02-01

We explore how doctors, psychotherapists and counsellors in the U.K. react to regulatory transparency, drawing on qualitative research involving 51 semi-structured interviews conducted during 2008-10. We use the concept of 'reactivity mechanisms' (Espeland & Sauder, 2007) to explain how regulatory transparency disrupts practices through simplifying and decontextualizing them, altering practitioners' reflexivity, leading to defensive forms of practice. We make an empirical contribution by exploring the impact of transparency on doctors compared with psychotherapists and counsellors, who represent an extreme case due to their uniquely complex practice, which is particularly affected by this form of regulation. We make a contribution to knowledge by developing a model of reactivity mechanisms, which explains how clinical professionals make sense of media and professional narratives about regulation in ways that produce emotional reactions and, in turn, defensive reactivity to transparency. Copyright © 2011 Elsevier Ltd. All rights reserved.

A technique for computation of noise temperature due to a beam waveguide shroud

NASA Technical Reports Server (NTRS)

Veruttipong, W.; Franco, M. M.

1993-01-01

Direct analytical computation of the noise temperature of real beam waveguide (BWG) systems, including all mirrors and the surrounding shroud, is an extremely complex problem and virtually impossible to achieve. Yet the DSN antennas are required to be ultra low-noise in order to be effective, and a reasonably accurate prediction is essential. This article presents a relatively simple technique to compute a real BWG system noise temperature by combining analytical techniques with data from experimental tests. Specific expressions and parameters for X-band (8.45-GHz) BWG noise computation are obtained for DSS 13 and DSS 24, now under construction. These expressions are also valid for various conditions of the BWG feed systems, including horn sizes and positions, and mirror sizes, curvatures, and positions. Parameters for S- and Ka-bands (2.3 and 32.0 GHz) have not been determined; however, those can be obtained following the same procedure as for X-band.

Nanomaterial-based electrochemical sensors for arsenic - A review.

PubMed

Kempahanumakkagari, Sureshkumar; Deep, Akash; Kim, Ki-Hyun; Kumar Kailasa, Suresh; Yoon, Hye-On

2017-09-15

The existence of arsenic in the environment poses severe global health threats. Considering its toxicity, the sensing of arsenic is extremely important. Due to the complexity of environmental and biological samples, many of the available detection methods for arsenic have serious limitations on selectivity and sensitivity. To improve sensitivity and selectivity and to circumvent interferences, different electrode systems have been developed based on surface modification with nanomaterials including carbonaceous nanomaterials, metallic nanoparticles (MNPs), metal nanotubes (MNTs), and even enzymes. Despite the progress made in electrochemical sensing of arsenic, some issues still need to be addressed to realize cost effective, portable, and flow-injection type sensor systems. The present review provides an in-depth evaluation of the nanoparticle-modified electrode (NME) based methods for the electrochemical sensing of arsenic. NME based sensing systems are projected to become an important option for monitoring hazardous pollutants in both environmental and biological media. Copyright © 2017 Elsevier B.V. All rights reserved.

Advances in Decoding Breast Cancer Brain Metastasis

PubMed Central

Zhang, Chenyu; Yu, Dihua

2016-01-01

The past decade has witnessed impressive advances in cancer treatment ushered in by targeted and immunotherapies. However, with significantly prolonged survival, upon recurrence, more patients become inflicted by brain metastasis, which is mostly refractory to all currently available therapeutic regimens. Historically, brain metastasis is an understudied area in cancer research, partly due to the dearth of appropriate experimental models that closely simulate the special biological features of metastasis in the unique brain environment; and to the sophistication of techniques required to perform in-depth studies of the extremely complex and challenging brain metastasis. Yet, with increasing clinical demand for more effective treatment options, brain metastasis research has rapidly advanced in recent years. The present review spotlights the recent major progresses in basic and translational studies of brain metastasis with focuses on new animal models, novel imaging technologies, omics “big data” resources, and some new and exciting biological insights on brain metastasis. PMID:27873078

A study of photon propagation in free-space based on hybrid radiosity-radiance theorem.

PubMed

Chen, Xueli; Gao, Xinbo; Qu, Xiaochao; Liang, Jimin; Wang, Lin; Yang, Da'an; Garofalakis, Anikitos; Ripoll, Jorge; Tian, Jie

2009-08-31

Noncontact optical imaging has attracted increasing attention in recent years due to its significant advantages on detection sensitivity, spatial resolution, image quality and system simplicity compared with contact measurement. However, photon transport simulation in free-space is still an extremely challenging topic for the complexity of the optical system. For this purpose, this paper proposes an analytical model for photon propagation in free-space based on hybrid radiosity-radiance theorem (HRRT). It combines Lambert's cosine law and the radiance theorem to handle the influence of the complicated lens and to simplify the photon transport process in the optical system. The performance of the proposed model is evaluated and validated with numerical simulations and physical experiments. Qualitative comparison results of flux distribution at the detector are presented. In particular, error analysis demonstrates the feasibility and potential of the proposed model for simulating photon propagation in free-space.

Ruggedizing vibration sensitive components of electro-optical module using wideband dynamic absorber

NASA Astrophysics Data System (ADS)

Veprik, Alexander; Openhaim, Yaki; Babitsky, Vladimir; Tuito, Avi

2018-05-01

In the modern design approach, the cold portion of Integrated Dewar-Detector-Cooler-Assembly (substrate, infrared focal plane array, cold shield and cold filter) is directly mounted upon the distal end of a cold finger of a cryogenic cooler with no mechanical contact with the warm Dewar shroud. This concept allows for essential reduction of parasitic (conductive) heat load. The penalty, however, is that resulting tip-mass cantilever is lightly damped and, therefore, prone to vibrational extremes typical of the modern battlefield. Without sufficient ruggedizing, vibration induced structural resonances may affect image quality and even may cause mechanical failures due to material fatigue. Use of additional front supports or thickening the cold finger walls results in increased parasitic conductive heat load, power consumption and mechanical complexity. The authors explore the concept of wideband dynamic absorber in application to ruggedizing the Integrated Dewar-Detector-Cooler Assembly.

Data Transfer Advisor with Transport Profiling Optimization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rao, Nageswara S.; Liu, Qiang; Yun, Daqing

The network infrastructures have been rapidly upgraded in many high-performance networks (HPNs). However, such infrastructure investment has not led to corresponding performance improvement in big data transfer, especially at the application layer, largely due to the complexity of optimizing transport control on end hosts. We design and implement ProbData, a PRofiling Optimization Based DAta Transfer Advisor, to help users determine the most effective data transfer method with the most appropriate control parameter values to achieve the best data transfer performance. ProbData employs a profiling optimization based approach to exploit the optimal operational zone of various data transfer methods in supportmore » of big data transfer in extreme scale scientific applications. We present a theoretical framework of the optimized profiling approach employed in ProbData as wellas its detailed design and implementation. The advising procedure and performance benefits of ProbData are illustrated and evaluated by proof-of-concept experiments in real-life networks.« less

Patellofemoral anatomy and biomechanics: current concepts

PubMed Central

ZAFFAGNINI, STEFANO; DEJOUR, DAVID; GRASSI, ALBERTO; BONANZINGA, TOMMASO; MUCCIOLI, GIULIO MARIA MARCHEGGIANI; COLLE, FRANCESCA; RAGGI, FEDERICO; BENZI, ANDREA; MARCACCI, MAURILIO

2013-01-01

The patellofemoral joint, due to its particular bone anatomy and the numerous capsuloligamentous structures and muscles that act dynamically on the patella, is considered one of the most complex joints in the human body from the biomechanical point of view. The medial patellofemoral ligament (MPFL) has been demonstrated to contribute 60% of the force that opposes lateral displacement of the patella, and MPFL injury results in an approximately 50% reduction in the force needed to dislocate the patella laterally with the knee extended. For this reason, recent years have seen a growing interest in the study of this important anatomical structure, whose aponeurotic nature has thus been demonstrated. The MPFL acts as a restraint during motion, playing an active role under conditions of laterally applied stress, but an only marginal role during natural knee flexion. However, it remains extremely difficult to clearly define the anatomy of the MPFL and its relationships with other anatomical structures. PMID:25606512

Premixed autoignition in compressible turbulence

NASA Astrophysics Data System (ADS)

Konduri, Aditya; Kolla, Hemanth; Krisman, Alexander; Chen, Jacqueline

2016-11-01

Prediction of chemical ignition delay in an autoignition process is critical in combustion systems like compression ignition engines and gas turbines. Often, ignition delay times measured in simple homogeneous experiments or homogeneous calculations are not representative of actual autoignition processes in complex turbulent flows. This is due the presence of turbulent mixing which results in fluctuations in thermodynamic properties as well as chemical composition. In the present study the effect of fluctuations of thermodynamic variables on the ignition delay is quantified with direct numerical simulations of compressible isotropic turbulence. A premixed syngas-air mixture is used to remove the effects of inhomogeneity in the chemical composition. Preliminary results show a significant spatial variation in the ignition delay time. We analyze the topology of autoignition kernels and identify the influence of extreme events resulting from compressibility and intermittency. The dependence of ignition delay time on Reynolds and turbulent Mach numbers is also quantified. Supported by Basic Energy Sciences, Dept of Energy, United States.

Aerodynamic study of a stall regulated horizontal-axis wind turbine

NASA Astrophysics Data System (ADS)

Constantinescu, S. G.; Crunteanu, D. E.; Niculescu, M. L.

2013-10-01

The wind energy is deemed as one of the most durable energetic variants of the future because the wind resources are immense. Furthermore, one predicts that the small wind turbines will play a vital role in the urban environment. Unfortunately, the complexity and the price of pitch regulated small horizontal-axis wind turbines represent ones of the main obstacles to widespread the use in populated zones. Moreover, the energetic efficiency of small stall regulated wind turbines has to be high even at low and medium wind velocities because, usually the cities are not windy places. During the running stall regulated wind turbines, due to the extremely broad range of the wind velocity, the angle of attack can reach high values and some regions of the blade will show stall and post-stall behavior. This paper deals with stall and post-stall regimes because they can induce significant vibrations, fatigue and even the wind turbine failure.

In Situ Methods, Infrastructures, and Applications on High Performance Computing Platforms, a State-of-the-art (STAR) Report

DOE PAGES

Bethel, EW; Bauer, A; Abbasi, H; ...

2016-06-10

The considerable interest in the high performance computing (HPC) community regarding analyzing and visualization data without first writing to disk, i.e., in situ processing, is due to several factors. First is an I/O cost savings, where data is analyzed /visualized while being generated, without first storing to a filesystem. Second is the potential for increased accuracy, where fine temporal sampling of transient analysis might expose some complex behavior missed in coarse temporal sampling. Third is the ability to use all available resources, CPU’s and accelerators, in the computation of analysis products. This STAR paper brings together researchers, developers and practitionersmore » using in situ methods in extreme-scale HPC with the goal to present existing methods, infrastructures, and a range of computational science and engineering applications using in situ analysis and visualization.« less

Overview of Engineering Design and Analysis at the NASA John C. Stennis Space Center

NASA Technical Reports Server (NTRS)

Ryan, Harry; Congiardo, Jared; Junell, Justin; Kirkpatrick, Richard

2007-01-01

A wide range of rocket propulsion test work occurs at the NASA John C. Stennis Space Center (SSC) including full-scale engine test activities at test facilities A-1, A-2, B-1 and B-2 as well as combustion device research and development activities at the E-Complex (E-1, E-2, E-3 and E-4) test facilities. The propulsion test engineer at NASA SSC faces many challenges associated with designing and operating a test facility due to the extreme operating conditions (e.g., cryogenic temperatures, high pressures) of the various system components and the uniqueness of many of the components and systems. The purpose of this paper is to briefly describe the NASA SSC Engineering Science Directorate s design and analysis processes, experience, and modeling techniques that are used to design and support the operation of unique rocket propulsion test facilities.

Demographic, genetic and phenotypic characteristics of centenarians in Italy: Focus on gender differences.

PubMed

Montesanto, Alberto; De Rango, Francesco; Pirazzini, Chiara; Guidarelli, Giulia; Domma, Filippo; Franceschi, Claudio; Passarino, Giuseppe

2017-07-01

An impressive and coherent series of epidemiological data from different populations (New England Americans, Mormons, Ashkenazi Jewish, Icelandic, Okinawan Japanese, Italians) suggests that long-lived subjects able to reach the extreme limits of human life, such as centenarians and supercentenarians, represent an extraordinary and informative model to identify the mechanisms responsible for healthy aging and human longevity. In most studies, genetic, demographic and phenotypic characteristics of longevity are discussed separately. However, longevity is a very complex trait due to the complicated interactions of numerous genetic and environmental factors. It is therefore necessary to analyse centenarians with a multidimensional approach, trying to consider different aspects simultaneously. In this review we will focus on Italian centenarians, who have been extensively studied for many years with different approaches, in order to show their peculiarities and the emerging data from the studies carried out on this exceptional population. Copyright © 2017 Elsevier B.V. All rights reserved.

Experimental demonstration of two-dimensional hybrid waveguide-integrated plasmonic crystals on silicon-on-insulator platform

NASA Astrophysics Data System (ADS)

Ren, Guanghui; Yudistira, Didit; Nguyen, Thach G.; Khodasevych, Iryna; Schoenhardt, Steffen; Berean, Kyle J.; Hamm, Joachim M.; Hess, Ortwin; Mitchell, Arnan

2017-07-01

Nanoscale plasmonic structures can offer unique functionality due to extreme sub-wavelength optical confinement, but the realization of complex plasmonic circuits is hampered by high propagation losses. Hybrid approaches can potentially overcome this limitation, but only few practical approaches based on either single or few element arrays of nanoantennas on dielectric nanowire have been experimentally demonstrated. In this paper, we demonstrate a two dimensional hybrid photonic plasmonic crystal interfaced with a standard silicon photonic platform. Off resonance, we observe low loss propagation through our structure, while on resonance we observe strong propagation suppression and intense concentration of light into a dense lattice of nanoscale hot-spots on the surface providing clear evidence of a hybrid photonic plasmonic crystal bandgap. This fully integrated approach is compatible with established silicon-on-insulator (SOI) fabrication techniques and constitutes a significant step toward harnessing plasmonic functionality within SOI photonic circuits.

A study of leeside flow field heat transfer on Shuttle Orbiter configuration

NASA Technical Reports Server (NTRS)

Baranowski, L. C.; Kipp, H. W.

1984-01-01

A coupled inviscid and viscous theoretical solution of the flow about the entire configuration is the desirable and comprehensive approach to defining thermal environments about the space shuttle orbiter. Simplified methods for predicting entry heating on leeside surfaces of the orbiter are considered. Wind tunnel heat transfer and oil flow data at Mach 6 and 10 and Reynolds numbers ranging from 500,000 to 73 million were used to develop correlations for the wing upper surface and the top surface of the fuselage. These correlations were extrapolated to flight Reynolds number and compared with heating data obtained during the shuttle STS-2 reentry. Efforts directed toward the wing leeside surface resulted in an approach which generally agreed with the flight data. Heating predictions for the upper fuselage were less successful due to the extreme complexity of local flow interactions and the associated heating environment.

RX J1856.5-3754: A Strange Star with Solid Quark Surface?

NASA Technical Reports Server (NTRS)

Zhang, Xiaoling; Xu, Renxin; Zhang, Shuangnan

2003-01-01

The featureless spectra of isolated 'neutron stars' may indicate that they are actually bare strange stars but a definitive conclusion on the nature of the compact objects cannot be reached until accurate and theoretically calculated spectra of the bare quark surface are known. However due to the complex nonlinearity of quantum chromodynamics it is almost impossible to present a definitive and accurate calculation of the density-dominated quark-gluon plasma from the first principles. Nevertheless it was suggested that cold quark matter with extremely high baryon density could be in a solid state. Within the realms of this possibility we have fitted the 500ks Chandra LETG/HRC data for the brightest isolated neutron star RX 51856.5-3754 with a phenomenological spectral model and found that electric conductivity of quark matter on the stellar surface is about 1.5 x 10(exp 16)/s.

Targeting HSP70-induced thermotolerance for design of thermal sensitizers.

PubMed

Calderwood, S K; Asea, A

2002-01-01

Thermal therapy has been shown to be an extremely powerful anti-cancer agent and a potent radiation sensitizer. However, the full potential of thermal therapy is hindered by a number of considerations including highly conserved heat resistance pathways in tumour cells and inhomogeneous heating of deep-seated tumours due to energy deposition and perfusion issues. This report reviews recent progress in the development of hyperthermia sensitizing drugs designed to specifically amplify the effects of hyperthermia. Such agents might be particularly useful in situations where heating is not adequate for the full biological effect or is not homogeneously delivered to tumours. The particular pathway concentrated on is thermotolerance, a complex, inducible cellular response that leads to heat resistance. This paper will concentrate on the molecular pathways of thermotolerance induction for designing inhibitors of heat resistance/thermal sensitizers, which may allow the full potential of thermal therapy to be utilized.

Highly Effective Ferroelectric Materials and Technologies for Their Processing

NASA Astrophysics Data System (ADS)

Reznichenko, L. A.; Verbenko, I. A.; Andryushina, I. N.; Andryushin, K. P.; Pavelko, A. A.; Pavlenko, A. A.; Shilkina, L. A.; Dudkina, S. I.; Sudykov, H. A.; Abubakarov, A. G.; Talanov, M. V.; Gershenovich, V. V.; Miller, A. I.; Alyoshin, V. A.

The basis of most commonly ferroelectric ceramic materials (FECMs) used in the modern industry is solid solutions of complex lead oxides. It should be noted that due to significant toxicity of lead compounds there has been an intensive search for alternative materials in recent years. Such efforts resulted from the introduction of a new legislative base aiming at environmental protection [Directive 2002/95/EC of the European Parliament and Council by 27 January 2003 on the restriction of the use of certain hazardous substances in electronic equipment]. In the Research Institute of Physics of SFedU much work has been done for about 30 years to investigate and develop of the environmentally friendly FECMs on the basis of alkali niobate metals. Nowadays such materials are finding more applications in the defense industry rather than other industries. Therefore it is extremely important to promote the production of lead low-cost materials and develop new FECMs.

Lunar Surface Charging during Solar Energetic Particle Events

NASA Astrophysics Data System (ADS)

Halekas, Jasper S.; Delory, G. T.; Mewaldt, R. A.; Lin, R. P.; Fillingim, M. O.; Brain, D. A.; Lee, C. O.; Stubbs, T. J.; Farrell, W. M.; Hudson, M. K.

2006-09-01

The surface of the Moon, not protected by any substantial atmosphere, is directly exposed to the impact of both solar UV and solar wind plasma and energetic particles. This creates a complex lunar electrostatic environment, with the surface typically charging slightly positive in sunlight, and negative in shadow. Observations from the Apollo era and theoretical considerations strongly suggest that surface charging leads to dust electrification and transport, posing a potentially significant hazard for exploration. The most significant charging effects should occur when the Moon is exposed to high-temperature plasmas like those encountered in the terrestrial plasmasheet or in solar storms. We now present evidence for kilovolt-scale negative charging of the shadowed lunar surface during solar energetic particle (SEP) events, utilizing data from the Lunar Prospector Electron Reflectometer (LP ER). We find that SEP events are associated with the most extreme lunar surface charging observed during the LP mission - rivaled only by previously reported charging during traversals of the terrestrial plasmasheet. The largest charging event observed by LP is a 4 kV negative surface potential (as compared to typical values of V) during a SEP event in May 1998. We characterize lunar surface charging during several SEP events, and compare to energetic particle measurements from ACE, Wind, and SOHO in order to determine the relationship between SEP events and extreme lunar surface charging. Space weather events are already considered by NASA to be a significant hazard to lunar exploration, due to high-energy ionizing radiation. Our observations demonstrate that plasma interactions with the lunar surface during SEP events, causing extreme surface charging and potentially significant dust electrification and transport, represent an additional hazard associated with space weather.

Coupled hydro-meteorological modelling on a HPC platform for high-resolution extreme weather impact study

NASA Astrophysics Data System (ADS)

Zhu, Dehua; Echendu, Shirley; Xuan, Yunqing; Webster, Mike; Cluckie, Ian

2016-11-01

Impact-focused studies of extreme weather require coupling of accurate simulations of weather and climate systems and impact-measuring hydrological models which themselves demand larger computer resources. In this paper, we present a preliminary analysis of a high-performance computing (HPC)-based hydrological modelling approach, which is aimed at utilizing and maximizing HPC power resources, to support the study on extreme weather impact due to climate change. Here, four case studies are presented through implementation on the HPC Wales platform of the UK mesoscale meteorological Unified Model (UM) with high-resolution simulation suite UKV, alongside a Linux-based hydrological model, Hydrological Predictions for the Environment (HYPE). The results of this study suggest that the coupled hydro-meteorological model was still able to capture the major flood peaks, compared with the conventional gauge- or radar-driving forecast, but with the added value of much extended forecast lead time. The high-resolution rainfall estimation produced by the UKV performs similarly to that of radar rainfall products in the first 2-3 days of tested flood events, but the uncertainties particularly increased as the forecast horizon goes beyond 3 days. This study takes a step forward to identify how the online mode approach can be used, where both numerical weather prediction and the hydrological model are executed, either simultaneously or on the same hardware infrastructures, so that more effective interaction and communication can be achieved and maintained between the models. But the concluding comments are that running the entire system on a reasonably powerful HPC platform does not yet allow for real-time simulations, even without the most complex and demanding data simulation part.

High-fidelity numerical modeling of the Upper Mississippi River under extreme flood condition

NASA Astrophysics Data System (ADS)

Khosronejad, Ali; Le, Trung; DeWall, Petra; Bartelt, Nicole; Woldeamlak, Solomon; Yang, Xiaolei; Sotiropoulos, Fotis

2016-12-01

We present data-driven numerical simulations of extreme flooding in a large-scale river coupling coherent-structure resolving hydrodynamics with bed morphodynamics under live-bed conditions. The study area is a ∼ 3.2 km long and ∼ 300 m wide reach of the Upper Mississippi River, near Minneapolis MN, which contains several natural islands and man-made hydraulic structures. We employ the large-eddy simulation (LES) and bed-morphodynamic modules of the Virtual Flow Simulator (VFS-Rivers) model, a recently developed in-house code, to investigate the flow and bed evolution of the river during a 100-year flood event. The coupling of the two modules is carried out via a fluid-structure interaction approach using a nested domain approach to enhance the resolution of bridge scour predictions. We integrate data from airborne Light Detection and Ranging (LiDAR), sub-aqueous sonar apparatus on-board a boat and in-situ laser scanners to construct a digital elevation model of the river bathymetry and surrounding flood plain, including islands and bridge piers. A field campaign under base-flow condition is also carried out to collect mean flow measurements via Acoustic Doppler Current Profiler (ADCP) to validate the hydrodynamic module of the VFS-Rivers model. Our simulation results for the bed evolution of the river under the 100-year flood reveal complex sediment transport dynamics near the bridge piers consisting of both scour and refilling events due to the continuous passage of sand dunes. We find that the scour depth near the bridge piers can reach to a maximum of ∼ 9 m. The data-driven simulation strategy we present in this work exemplifies a practical simulation-based-engineering-approach to investigate the resilience of infrastructures to extreme flood events in intricate field-scale riverine systems.

Description of extreme-wave deposits on the northern coast of Bonaire, Netherlands Antilles

USGS Publications Warehouse

Watt, Steven G.; Jaffe, Bruce E.; Morton, Robert A.; Richmond, Bruce M.; Gelfencaum, Guy

2010-01-01

To develop a better understanding of the origins of extreme-wave deposits and to help assess the potential risk of future overwash events, a field mapping survey was conducted in November 2006 on the northern coast of Bonaire, Netherlands Antilles. Deposits were mapped and analyzed to help develop a systematic sedimentological approach to distinguish the type of extreme-wave event (tsunamis or storms) or combination of events that formed and modified the deposits over time. Extreme-wave deposits on the northern coast of Bonaire between Boka Onima and Boka Olivia have formed sand sheets, poly-modal ridge complexes, and boulder fields on a Pleistocene limestone platform 3?8 meters above sea level. The deposits exhibit characteristics that are consistent with both large storm and tsunami processes that often overlap one another. Sand sheets occur as low-relief features underlying and incorporated with boulder field deposits. The seaward edge of ridge complexes are deposited up to 70 m from the shoreline and can extend over 200 m inland. Over 600 clasts were measured in fields and range in size from coarse gravel to fine block, weigh up to 165 metric tons, and are placed over 280 m from the shoreline. Our analyses indicate that the deposits may have been produced by a combination of hurricane and tsunami events spanning 10s to 1000s of years. Comparing the different deposit morphologies between study sites highlights the importance of shoreline orientation to the distribution of extreme-wave deposits onshore. However, further investigation is required to fully understand the processes that have produced and modified these deposits over time.

Tambora and the mackerel year: phenology and fisheries during an extreme climate event

USGS Publications Warehouse

Alexander, Karen E.; Leavenworth, William B.; Hall, Carolyn; Mattocks, Steven; Bittner, Steven M.; Klein, Emily; Staudinger, Michelle D.; Bryan, Alexander; Rosset, Julianne; Willis, Theodore V.; Carr, Benjamin H.; Jordaan, Adrian

2017-01-01

Global warming has increased the frequency of extreme climate events, yet responses of biological and human communities are poorly understood, particularly for aquatic ecosystems and fisheries. Retrospective analysis of known outcomes may provide insights into the nature of adaptations and trajectory of subsequent conditions. We consider the 1815 eruption of the Indonesian volcano Tambora and its impact on Gulf of Maine (GoM) coastal and riparian fisheries in 1816. Applying complex adaptive systems theory with historical methods, we analyzed fish export data and contemporary climate records to disclose human and piscine responses to Tambora’s extreme weather at different spatial and temporal scales while also considering sociopolitical influences. Results identified a tipping point in GoM fisheries induced by concatenating social and biological responses to extreme weather. Abnormal daily temperatures selectively affected targeted fish species—alewives, shad, herring, and mackerel—according to their migration and spawning phenologies and temperature tolerances. First to arrive, alewives suffered the worst. Crop failure and incipient famine intensified fishing pressure, especially in heavily settled regions where dams already compromised watersheds. Insufficient alewife runs led fishers to target mackerel, the next species appearing in abundance along the coast; thus, 1816 became the “mackerel year.” Critically, the shift from riparian to marine fisheries persisted and expanded after temperatures moderated and alewives recovered. We conclude that contingent human adaptations to extraordinary weather permanently altered this complex system. Understanding how adaptive responses to extreme events can trigger unintended consequences may advance long-term planning for resilience in an uncertain future.

Tambora and the mackerel year: Phenology and fisheries during an extreme climate event

PubMed Central

Alexander, Karen E.; Leavenworth, William B.; Willis, Theodore V.; Hall, Carolyn; Mattocks, Steven; Bittner, Steven M.; Klein, Emily; Staudinger, Michelle; Bryan, Alexander; Rosset, Julianne; Carr, Benjamin H.; Jordaan, Adrian

2017-01-01

Global warming has increased the frequency of extreme climate events, yet responses of biological and human communities are poorly understood, particularly for aquatic ecosystems and fisheries. Retrospective analysis of known outcomes may provide insights into the nature of adaptations and trajectory of subsequent conditions. We consider the 1815 eruption of the Indonesian volcano Tambora and its impact on Gulf of Maine (GoM) coastal and riparian fisheries in 1816. Applying complex adaptive systems theory with historical methods, we analyzed fish export data and contemporary climate records to disclose human and piscine responses to Tambora’s extreme weather at different spatial and temporal scales while also considering sociopolitical influences. Results identified a tipping point in GoM fisheries induced by concatenating social and biological responses to extreme weather. Abnormal daily temperatures selectively affected targeted fish species—alewives, shad, herring, and mackerel—according to their migration and spawning phenologies and temperature tolerances. First to arrive, alewives suffered the worst. Crop failure and incipient famine intensified fishing pressure, especially in heavily settled regions where dams already compromised watersheds. Insufficient alewife runs led fishers to target mackerel, the next species appearing in abundance along the coast; thus, 1816 became the “mackerel year.” Critically, the shift from riparian to marine fisheries persisted and expanded after temperatures moderated and alewives recovered. We conclude that contingent human adaptations to extraordinary weather permanently altered this complex system. Understanding how adaptive responses to extreme events can trigger unintended consequences may advance long-term planning for resilience in an uncertain future. PMID:28116356

Abstraction and model evaluation in category learning.

PubMed

Vanpaemel, Wolf; Storms, Gert

2010-05-01

Thirty previously published data sets, from seminal category learning tasks, are reanalyzed using the varying abstraction model (VAM). Unlike a prototype-versus-exemplar analysis, which focuses on extreme levels of abstraction only, a VAM analysis also considers the possibility of partial abstraction. Whereas most data sets support no abstraction when only the extreme possibilities are considered, we show that evidence for abstraction can be provided using the broader view on abstraction provided by the VAM. The present results generalize earlier demonstrations of partial abstraction (Vanpaemel & Storms, 2008), in which only a small number of data sets was analyzed. Following the dominant modus operandi in category learning research, Vanpaemel and Storms evaluated the models on their best fit, a practice known to ignore the complexity of the models under consideration. In the present study, in contrast, model evaluation not only relies on the maximal likelihood, but also on the marginal likelihood, which is sensitive to model complexity. Finally, using a large recovery study, it is demonstrated that, across the 30 data sets, complexity differences between the models in the VAM family are small. This indicates that a (computationally challenging) complexity-sensitive model evaluation method is uncalled for, and that the use of a (computationally straightforward) complexity-insensitive model evaluation method is justified.

Freight economic vulnerabilities due to flooding events.

DOT National Transportation Integrated Search

2016-12-01

Extreme weather events, and flooding in particular, have been occurring more often and with increased severity over the past decade, and there is reason to expect this trend will continue in the future due to a changing climate. Flooding events can u...

Topographic relationships for design rainfalls over Australia

NASA Astrophysics Data System (ADS)

Johnson, F.; Hutchinson, M. F.; The, C.; Beesley, C.; Green, J.

2016-02-01

Design rainfall statistics are the primary inputs used to assess flood risk across river catchments. These statistics normally take the form of Intensity-Duration-Frequency (IDF) curves that are derived from extreme value probability distributions fitted to observed daily, and sub-daily, rainfall data. The design rainfall relationships are often required for catchments where there are limited rainfall records, particularly catchments in remote areas with high topographic relief and hence some form of interpolation is required to provide estimates in these areas. This paper assesses the topographic dependence of rainfall extremes by using elevation-dependent thin plate smoothing splines to interpolate the mean annual maximum rainfall, for periods from one to seven days, across Australia. The analyses confirm the important impact of topography in explaining the spatial patterns of these extreme rainfall statistics. Continent-wide residual and cross validation statistics are used to demonstrate the 100-fold impact of elevation in relation to horizontal coordinates in explaining the spatial patterns, consistent with previous rainfall scaling studies and observational evidence. The impact of the complexity of the fitted spline surfaces, as defined by the number of knots, and the impact of applying variance stabilising transformations to the data, were also assessed. It was found that a relatively large number of 3570 knots, suitably chosen from 8619 gauge locations, was required to minimise the summary error statistics. Square root and log data transformations were found to deliver marginally superior continent-wide cross validation statistics, in comparison to applying no data transformation, but detailed assessments of residuals in complex high rainfall regions with high topographic relief showed that no data transformation gave superior performance in these regions. These results are consistent with the understanding that in areas with modest topographic relief, as for most of the Australian continent, extreme rainfall is closely aligned with elevation, but in areas with high topographic relief the impacts of topography on rainfall extremes are more complex. The interpolated extreme rainfall statistics, using no data transformation, have been used by the Australian Bureau of Meteorology to produce new IDF data for the Australian continent. The comprehensive methods presented for the evaluation of gridded design rainfall statistics will be useful for similar studies, in particular the importance of balancing the need for a continentally-optimum solution that maintains sufficient definition at the local scale.

Building resilient power grids from integrated risk governance perspective: A lesson learned from china's 2008 Ice-Snow Storm disaster

NASA Astrophysics Data System (ADS)

Ye, Qian

2014-10-01

In the past three decades, the electric energy industry made great contribution to support rapid social and economic development in China, and meanwhile has been grown at the highest rate in the human history owing to the economic reform. In its new national development plan, more investment has been put into installation of both electricity generating capacity and transmitting capacity in order to meet fast growing demand of electric energy. However, energy resources, both fossil fuel and renewable types, and energy consumption and load centers in China are not evenly distributed in both spatial and temporal dimensions. Moreover, dominated by coal as its primary energy source, the whole eastern China is now entering an environmental crisis in which pollutants emitted by coal power plants contribute a large part. To balance the regional differences in energy sources and energy consumption while meeting the steadily increasing demands for electric energy for the whole country, in addition to increase electric generating capacity, building large-scale, long-distance ultra high voltage power grids is the top priority for next five years. China is a country prone to almost all kinds of natural disasters due to its vast, complex geographical and climatic conditions. In recent years, frequent natural disasters, especially extreme weather and climate events, have threatened the safety, reliability and stability of electric energy system in China. Unfortunately, with fast growth rate but lacking of risk assessing and prevention mechanism, many infrastructure constructions, including national power grids, are facing integrated and complex economic, social, institutional and ecological risks. In this paper, based on a case analysis of the Great Ice Storm in southern China in January 2008, risks of building a resilient power grid to deal with increasing threats from extreme weathers are discussed. The paper recommends that a systematic approach based on the social-ecological system framework should be applied to assess the risk factors associated with the power grid, and the tools to deal with complex dynamic systems need to be applied to deal with constant changes in the whole social-ecological system.

Is the Mantle-Crust Transition in the Finero Complex (southern Alps) a Fossil Continental Moho?

NASA Astrophysics Data System (ADS)

Zanetti, A.; Langone, A.; Tommasi, A.; Vauchez, A.; Padron-Navarta, J. A.; Giovanardi, T.; Mazzucchelli, M.

2017-12-01

The geophysical studies indicate that the mantle-continental crust discontinuity is usually the site of complex intercalations of rocks having different physical and chemical properties. The possibility to directly characterize such rocks is extremely limited, because very few fossil continental Moho discontinuities crop out: in addition, most of them are considered to be representative of island arc environments. To address this issue, a comprehensive investigation has been carried out in the Finero Complex (Ivrea-Verbano Zone; Southern Alps), where the Phlogopite Peridotite (PP) mantle unit is surrounded by mafic-ultramafic rocks interpreted as intrusive crustal bodies. The crustal unit placed in contact with the PP is the Layered Internal Zone (LIZ), which is overlaid by the Amphibole Peridotite unit. At the contact with LIZ, the typical phlogopite-amphibole-harzburgite forming the PP unit is replaced by a weakly-deformed amphibole-biotite-bearing orthopyroxenite layer. Orthopyroxenite amphibole shows the typical LILE and LREE enrichments and the HFSE and HREE depletion observed in the rest of the mantle unit. This suggests that orthopyroxenite was segregated during the pervasive metasomatic event characterising the PP unit. The LIZ is formed by hornblendites, amphibole-garnet gabbros, pyroxenites and garnet hornblendites. The Amphibole Peridotite unit consists of peridotites, hornblendites and pyroxenites. In the LIZ, the melt intrusion locally involved the assimilation of early gabbroic cumulates, and the segregation of garnet hornblendites by substitution of pyroxenites. In the Amphibole Peridotite, late porous-flow melt migration produced secondary recrystallisation fronts, associated to the development of trace element gradients due to ion-exchange processes. Our observations suggest that the transition between PP and LIZ is primary. The LIZ and Amphibole Peridotite units record multiple events of migration of melt, whose composition varied from LREE-depleted to extremely LREE-enriched. The large variety of rocks, geochemical signatures and petrologic processes recorded by the studied mantle-crust transition evidences as it worked for a very long time as a primary lithospheric discontinuity, representing a preferential level of channelling for the uprising melts.

Accounting for Parameter Uncertainty in Complex Atmospheric Models, With an Application to Greenhouse Gas Emissions Evaluation

NASA Astrophysics Data System (ADS)

Swallow, B.; Rigby, M. L.; Rougier, J.; Manning, A.; Thomson, D.; Webster, H. N.; Lunt, M. F.; O'Doherty, S.

2016-12-01

In order to understand underlying processes governing environmental and physical phenomena, a complex mathematical model is usually required. However, there is an inherent uncertainty related to the parameterisation of unresolved processes in these simulators. Here, we focus on the specific problem of accounting for uncertainty in parameter values in an atmospheric chemical transport model. Systematic errors introduced by failing to account for these uncertainties have the potential to have a large effect on resulting estimates in unknown quantities of interest. One approach that is being increasingly used to address this issue is known as emulation, in which a large number of forward runs of the simulator are carried out, in order to approximate the response of the output to changes in parameters. However, due to the complexity of some models, it is often unfeasible to run large numbers of training runs that is usually required for full statistical emulators of the environmental processes. We therefore present a simplified model reduction method for approximating uncertainties in complex environmental simulators without the need for very large numbers of training runs. We illustrate the method through an application to the Met Office's atmospheric transport model NAME. We show how our parameter estimation framework can be incorporated into a hierarchical Bayesian inversion, and demonstrate the impact on estimates of UK methane emissions, using atmospheric mole fraction data. We conclude that accounting for uncertainties in the parameterisation of complex atmospheric models is vital if systematic errors are to be minimized and all relevant uncertainties accounted for. We also note that investigations of this nature can prove extremely useful in highlighting deficiencies in the simulator that might otherwise be missed.

Normal venous anatomy and physiology of the lower extremity.

PubMed

Notowitz, L B

1993-06-01

Venous disease of the lower extremities is common but is often misunderstood. It seems that the focus is on the exciting world of arterial anatomy and pathology, while the topic of venous anatomy and pathology comes in second place. However, venous diseases such as chronic venous insufficiency, leg ulcers, and varicose veins affect much of the population and may lead to disability and death. Nurses are often required to answer complex questions from the patients and his or her family about the patient's disease. Patients depend on nurses to provide accurate information in terms they can understand. Therefore it is important to have an understanding of the normal venous system of the legs before one can understand the complexities of venous diseases and treatments. This presents an overview of normal venous anatomy and physiology.

Ab initio atomic recombination reaction energetics on model heat shield surfaces

NASA Technical Reports Server (NTRS)

Senese, Fredrick; Ake, Robert

1992-01-01

Ab initio quantum mechanical calculations on small hydration complexes involving the nitrate anion are reported. The self-consistent field method with accurate basis sets has been applied to compute completely optimized equilibrium geometries, vibrational frequencies, thermochemical parameters, and stable site labilities of complexes involving 1, 2, and 3 waters. The most stable geometries in the first hydration shell involve in-plane waters bridging pairs of nitrate oxygens with two equal and bent hydrogen bonds. A second extremely labile local minimum involves out-of-plane waters with a single hydrogen bond and lies about 2 kcal/mol higher. The potential in the region of the second minimum is extremely flat and qualitatively sensitive to changes in the basis set; it does not correspond to a true equilibrium structure.

Extremely strong self-assembly of a bimetallic salen complex visualized at the single-molecule level.

PubMed

Salassa, Giovanni; Coenen, Michiel J J; Wezenberg, Sander J; Hendriksen, Bas L M; Speller, Sylvia; Elemans, Johannes A A W; Kleij, Arjan W

2012-04-25

A bis-Zn(salphen) structure shows extremely strong self-assembly both in solution as well as at the solid-liquid interface as evidenced by scanning tunneling microscopy, competitive UV-vis and fluorescence titrations, dynamic light scattering, and transmission electron microscopy. Density functional theory analysis on the Zn(2) complex rationalizes the very high stability of the self-assembled structures provoked by unusual oligomeric (Zn-O)(n) coordination motifs within the assembly. This coordination mode is strikingly different when compared with mononuclear Zn(salphen) analogues that form dimeric structures having a typical Zn(2)O(2) central unit. The high stability of the multinuclear structure therefore holds great promise for the development of stable self-assembled monolayers with potential for new opto-electronic materials.

The biological roots of political extremism.

PubMed

Keene, Justin Robert; Shoenberger, Heather; Berke, Collin K; Bolls, Paul D

2017-01-01

Recent research has revealed the complex origins of political identification and the possible effects of this identification on social and political behavior. This article reports the results of a structural equation analysis of national survey data that attempts to replicate the finding that an individual's negativity bias predicts conservative ideology. The analysis employs the Motivational Activation Measure (MAM) as an index of an individual's positivity offset and negativity bias. In addition, information-seeking behavior is assessed in relation to traditional and interactive media sources of political information. Results show that although MAM does not consistently predict political identification, it can be used to predict extremeness of political views. Specifically, high negativity bias was associated with extreme conservatism, whereas low negativity bias was associated with extreme liberalism. In addition, political identification was found to moderate the relationship between motivational traits and information-seeking behavior.

Bilateral medial medullary infarction due to bilateral vertebral artery dissection.

PubMed

Fukuda, Masafumi; Aiba, Toyotaka; Takahashi, Sho

2004-03-01

We describe a 52-year-old woman who experienced transient motor weakness and numbness of the left extremities and presented 2 days later with severe hemiparesis and sensory impairment of the right extremities and right lingual palsy. Magnetic resonance imaging (MRI) revealed bilateral upper medial medullary infarction, primarily in the left ventral portion. The findings of both three-dimensional (3D) computed tomographic and conventional angiography suggested dissection of both intracranial vertebral arteries (VAs). Medial medullary infarction is generally caused by atherosclerosis within a VA or anterior spinal artery. This is the first report of bilateral medial medullary infarction due to dissection of both intracranial VAs.

Mean-field potential approach for thermodynamic properties of lanthanide: Europium as a prototype

NASA Astrophysics Data System (ADS)

Kumar, Priyank; Bhatt, N. K.; Vyas, P. R.; Gohel, V. B.

2018-03-01

In the present paper, a simple conjunction scheme [mean-field potential (MFP) + local pseudopotential] is used to study the thermodynamic properties of divalent lanthanide europium (Eu) at extreme environment. Present study has been carried out due to the fact that divalent nature of Eu arises because of stable half-filled 4f-shell at ambient condition, which has great influence on the thermodynamic properties at extreme environment. Due to such electronic structure, it is different from remaining lanthanides having incomplete 4f-shell. The presently computed results of thermodynamic properties of Eu are in good agreement with the experimental results. Looking to such success, it seems that the concept of MFP approach is successful to account contribution due to nuclear motion to the total Helmholtz free energy at finite temperatures and pressure-induced inter-band transfer of electrons for condensed state of matter. The local pseudopotential is used to evaluate cold energy and hence MFP accounts the s-p-d-f hybridization properly. Looking to the reliability and transferability along with its computational and conceptual simplicity, we would like to extend the present scheme for the study of thermodynamic properties of remaining lanthanides and actinides at extreme environment.

More tornadoes in the most extreme U.S. tornado outbreaks.

PubMed

Tippett, Michael K; Lepore, Chiara; Cohen, Joel E

2016-12-16

Tornadoes and severe thunderstorms kill people and damage property every year. Estimated U.S. insured losses due to severe thunderstorms in the first half of 2016 were $8.5 billion (US). The largest U.S. effects of tornadoes result from tornado outbreaks, which are sequences of tornadoes that occur in close succession. Here, using extreme value analysis, we find that the frequency of U.S. outbreaks with many tornadoes is increasing and that it is increasing faster for more extreme outbreaks. We model this behavior by extreme value distributions with parameters that are linear functions of time or of some indicators of multidecadal climatic variability. Extreme meteorological environments associated with severe thunderstorms show consistent upward trends, but the trends do not resemble those currently expected to result from global warming. Copyright © 2016, American Association for the Advancement of Science.

Extreme Variability in a Broad Absorption Line Quasar

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stern, Daniel; Jun, Hyunsung D.; Graham, Matthew J.

CRTS J084133.15+200525.8 is an optically bright quasar at z = 2.345 that has shown extreme spectral variability over the past decade. Photometrically, the source had a visual magnitude of V ∼ 17.3 between 2002 and 2008. Then, over the following five years, the source slowly brightened by approximately one magnitude, to V ∼ 16.2. Only ∼1 in 10,000 quasars show such extreme variability, as quantified by the extreme parameters derived for this quasar assuming a damped random walk model. A combination of archival and newly acquired spectra reveal the source to be an iron low-ionization broad absorption line quasar withmore » extreme changes in its absorption spectrum. Some absorption features completely disappear over the 9 years of optical spectra, while other features remain essentially unchanged. We report the first definitive redshift for this source, based on the detection of broad H α in a Keck/MOSFIRE spectrum. Absorption systems separated by several 1000 km s{sup −1} in velocity show coordinated weakening in the depths of their troughs as the continuum flux increases. We interpret the broad absorption line variability to be due to changes in photoionization, rather than due to motion of material along our line of sight. This source highlights one sort of rare transition object that astronomy will now be finding through dedicated time-domain surveys.« less

Intercontinental difference in extreme weather events for the Northern Hemisphere over the past half century

NASA Astrophysics Data System (ADS)

Chen, A.; Tan, J.; Piao, S.

2014-12-01

Weather events that are located in the tails of a weather distribution are called weather extremes. Weather extremes, including severe drought, flooding, heat and cold waves, usually can cause greatest damage to human lives and properties, and have profound implication on ecosystem productivity and carbon cycles. There is mounting evidence suggests that the frequency of temperature and hydrological weather extremes have steadily increased over the last decades, largely due to the ongoing climate change. On the other hand, the distribution and trend of weather extremes can be regionally heterogeneous, which have not been well understood. Here we investigate the spatial distribution and temporal trend of weather extremes in the Northern Hemisphere (NH) over the past half century (1961-2010), with emphasis on the intercontinental comparisons. Our results suggest that warming extremes have increased significantly in East Asia and West Europe; while coldness extremes have decreased globally. Heavy precipitation extremes significantly increased in eastern Northern America, boreal Eurasia, and some parts of China; while drought events showed an increasing trend in northern China-southern Mongolia and some parts of western United States. Our results highlight the regional difference in the trend of weather extremes, which need to be incorporated in the mitigation measures.

Frequency and Character of Extreme Aerosol Events in the Southwestern United States: A Case Study Analysis in Arizona

PubMed Central

Lopez, David H.; Rabbani, Michael R.; Crosbie, Ewan; Raman, Aishwarya; Arellano, Avelino F.; Sorooshian, Armin

2016-01-01

This study uses more than a decade’s worth of data across Arizona to characterize the spatiotemporal distribution, frequency, and source of extreme aerosol events, defined as when the concentration of a species on a particular day exceeds that of the average plus two standard deviations for that given month. Depending on which of eight sites studied, between 5% and 7% of the total days exhibited an extreme aerosol event due to either extreme levels of PM10, PM2.5, and/or fine soil. Grand Canyon exhibited the most extreme event days (120, i.e., 7% of its total days). Fine soil is the pollutant type that most frequently impacted multiple sites at once at an extreme level. PM10, PM2.5, fine soil, non-Asian dust, and Elemental Carbon extreme events occurred most frequently in August. Nearly all Asian dust extreme events occurred between March and June. Extreme Elemental Carbon events have decreased as a function of time with statistical significance, while other pollutant categories did not show any significant change. Extreme events were most frequent for the various pollutant categories on either Wednesday or Thursday, but there was no statistically significant difference in the number of events on any particular day or on weekends versus weekdays. PMID:27088005

Extreme-Scale Bayesian Inference for Uncertainty Quantification of Complex Simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biros, George

Uncertainty quantification (UQ)—that is, quantifying uncertainties in complex mathematical models and their large-scale computational implementations—is widely viewed as one of the outstanding challenges facing the field of CS&E over the coming decade. The EUREKA project set to address the most difficult class of UQ problems: those for which both the underlying PDE model as well as the uncertain parameters are of extreme scale. In the project we worked on these extreme-scale challenges in the following four areas: 1. Scalable parallel algorithms for sampling and characterizing the posterior distribution that exploit the structure of the underlying PDEs and parameter-to-observable map. Thesemore » include structure-exploiting versions of the randomized maximum likelihood method, which aims to overcome the intractability of employing conventional MCMC methods for solving extreme-scale Bayesian inversion problems by appealing to and adapting ideas from large-scale PDE-constrained optimization, which have been very successful at exploring high-dimensional spaces. 2. Scalable parallel algorithms for construction of prior and likelihood functions based on learning methods and non-parametric density estimation. Constructing problem-specific priors remains a critical challenge in Bayesian inference, and more so in high dimensions. Another challenge is construction of likelihood functions that capture unmodeled couplings between observations and parameters. We will create parallel algorithms for non-parametric density estimation using high dimensional N-body methods and combine them with supervised learning techniques for the construction of priors and likelihood functions. 3. Bayesian inadequacy models, which augment physics models with stochastic models that represent their imperfections. The success of the Bayesian inference framework depends on the ability to represent the uncertainty due to imperfections of the mathematical model of the phenomena of interest. This is a central challenge in UQ, especially for large-scale models. We propose to develop the mathematical tools to address these challenges in the context of extreme-scale problems. 4. Parallel scalable algorithms for Bayesian optimal experimental design (OED). Bayesian inversion yields quantified uncertainties in the model parameters, which can be propagated forward through the model to yield uncertainty in outputs of interest. This opens the way for designing new experiments to reduce the uncertainties in the model parameters and model predictions. Such experimental design problems have been intractable for large-scale problems using conventional methods; we will create OED algorithms that exploit the structure of the PDE model and the parameter-to-output map to overcome these challenges. Parallel algorithms for these four problems were created, analyzed, prototyped, implemented, tuned, and scaled up for leading-edge supercomputers, including UT-Austin’s own 10 petaflops Stampede system, ANL’s Mira system, and ORNL’s Titan system. While our focus is on fundamental mathematical/computational methods and algorithms, we will assess our methods on model problems derived from several DOE mission applications, including multiscale mechanics and ice sheet dynamics.« less

A web-based study of bipolarity and impulsivity in athletes engaging in extreme and high-risk sports.

PubMed

Dudek, Dominika; Siwek, Marcin; Jaeschke, Rafał; Drozdowicz, Katarzyna; Styczeń, Krzysztof; Arciszewska, Aleksandra; Chrobak, Adrian A; Rybakowski, Janusz K

2016-06-01

We hypothesised that men and women who engage in extreme or high-risk sports would score higher on standardised measures of bipolarity and impulsivity compared to age and gender matched controls. Four-hundred and eighty extreme or high-risk athletes (255 males and 225 females) and 235 age-matched control persons (107 males and 128 females) were enrolled into the web-based case-control study. The Mood Disorder Questionnaire (MDQ) and Barratt Impulsiveness Scale (BIS-11) were administered to screen for bipolarity and impulsive behaviours, respectively. Results indicated that extreme or high-risk athletes had significantly higher scores of bipolarity and impulsivity, and lower scores on cognitive complexity of the BIS-11, compared to controls. Further, there were positive correlations between the MDQ and BIS-11 scores. These results showed greater rates of bipolarity and impulsivity, in the extreme or high-risk athletes, suggesting these measures are sensitive to high-risk behaviours.

Extreme events following bifurcation to spatiotemporal chaos in a spatially extended microcavity laser

NASA Astrophysics Data System (ADS)

Coulibaly, S.; Clerc, M. G.; Selmi, F.; Barbay, S.

2017-02-01

The occurrence of extreme events in a spatially extended microcavity laser has been recently reported [Selmi et al., Phys. Rev. Lett. 116, 013901 (2016), 10.1103/PhysRevLett.116.013901] to be correlated to emergence of spatiotemporal chaos. In this dissipative system, the role of spatial coupling through diffraction is essential to observe the onset of spatiotemporal complexity. We investigate further the formation mechanism of extreme events by comparing the statistical and dynamical analyses. Experimental measurements together with numerical simulations allow us to assign the quasiperiodicity mechanism as the route to spatiotemporal chaos in this system. Moreover, by investigating the fine structure of the maximum Lyapunov exponent, of the Lyapunov spectrum, and of the Kaplan-Yorke dimension of the chaotic attractor, we are able to deduce that intermittency plays a key role in the proportion of extreme events measured. We assign the observed mechanism of generation of extreme events to quasiperiodic extended spatiotemporal intermittency.

Future changes in Asian summer monsoon precipitation extremes as inferred from 20-km AGCM simulations

NASA Astrophysics Data System (ADS)

Lui, Yuk Sing; Tam, Chi-Yung; Lau, Ngar-Cheung

2018-04-01

This study examines the impacts of climate change on precipitation extremes in the Asian monsoon region during boreal summer, based on simulations from the 20-km Meteorological Research Institute atmospheric general circulation model. The model can capture the summertime monsoon rainfall, with characteristics similar to those from Tropical Rainfall Measuring Mission and Asian Precipitation-Highly-Resolved Observational Data Integration Towards Evaluation. By comparing the 2075-2099 with the present-day climate simulations, there is a robust increase of the mean rainfall in many locations due to a warmer climate. Over southeastern China, the Baiu rainband, Bay of Bengal and central India, extreme precipitation rates are also enhanced in the future, which can be inferred from increases of the 95th percentile of daily precipitation, the maximum accumulated precipitation in 5 consecutive days, the simple daily precipitation intensity index, and the scale parameter of the fitted gamma distribution. In these regions, with the exception of the Baiu rainband, most of these metrics give a fractional change of extreme rainfall per degree increase of the lower-tropospheric temperature of 5 to 8.5% K-1, roughly consistent with the Clausius-Clapeyron relation. However, over the Baiu area extreme precipitation change scales as 3.5% K-1 only. We have also stratified the rainfall data into those associated with tropical cyclones (TC) and those with other weather systems. The AGCM gives an increase of the accumulated TC rainfall over southeastern China, and a decrease in southern Japan in the future climate. The latter can be attributed to suppressed TC occurrence in southern Japan, whereas increased accumulated rainfall over southeastern China is due to more intense TC rain rate under global warming. Overall, non-TC weather systems are the main contributor to enhanced precipitation extremes in various locations. In the future, TC activities over southeastern China tend to further exacerbate the precipitation extremes, whereas those in the Baiu region lead to weaker changes of these extremes.

Study of Pure Proteins, Nucleic Acids and their Complexes from Extreme Halobacteria of the Dead Sea: RNA Polymerase-DNA Interaction

DTIC Science & Technology

1988-10-10

identify by block number) FIELD GROUP S OUP - Archaebacteria , Halobacteria, Proteins Nucleic Acids, 08 RNA Polymerase-DNA Interactionsi R soimal operons...objectives of our program are to isolate and characterize a fully active DNA dependent RNA polymerase from the extremely halophilic archaebacteria from...Woese and his colleagues to suggest that all living organisms can be classified into three phylogenetic kingdoms : the eukaryotes, the eubacterla and

[A case of favourable outcome of the treatment of extremely severe acute poisoning with methanol].

PubMed

Batotsyrenov, B V; Livanov, G A; Vasil'ev, S A; Fedorov, A V; Antrianov, A Iu

2013-01-01

A case of favourable outcome of the treatment of extremely severe acute poisoning after prolonged exposure to lethal doses of methanol is reported. The complex treatment included urgent and effective elimination of the poison (multiple gastric lavage, hemodialysis), antidote therapy (administration of ethanol), correction of decompensated metabolic acidosis (alkali therapy and infusion therapy with reamberin). These measures had beneficial effect on the clinical course of poisoning and ensured its favourable outcome.

Downscaling wind and wavefields for 21st century coastal flood hazard projections in a region of complex terrain

USGS Publications Warehouse

O'Neill, Andrea; Erikson, Li; Barnard, Patrick

2017-01-01

While global climate models (GCMs) provide useful projections of near-surface wind vectors into the 21st century, resolution is not sufficient enough for use in regional wave modeling. Statistically downscaled GCM projections from Multivariate Adaptive Constructed Analogues provide daily averaged near-surface winds at an appropriate spatial resolution for wave modeling within the orographically complex region of San Francisco Bay, but greater resolution in time is needed to capture the peak of storm events. Short-duration high wind speeds, on the order of hours, are usually excluded in statistically downscaled climate models and are of key importance in wave and subsequent coastal flood modeling. Here we present a temporal downscaling approach, similar to constructed analogues, for near-surface winds suitable for use in local wave models and evaluate changes in wind and wave conditions for the 21st century. Reconstructed hindcast winds (1975–2004) recreate important extreme wind values within San Francisco Bay. A computationally efficient method for simulating wave heights over long time periods was used to screen for extreme events. Wave hindcasts show resultant maximum wave heights of 2.2 m possible within the Bay. Changes in extreme over-water wind speeds suggest contrasting trends within the different regions of San Francisco Bay, but 21th century projections show little change in the overall magnitude of extreme winds and locally generated waves.

Precipitation trends in the Canary Islands

NASA Astrophysics Data System (ADS)

García-Herrera, Ricardo; Gallego, David; Hernández, Emiliano; Gimeno, Luis; Ribera, Pedro; Calvo, Natalia

2003-02-01

A strong decreasing trend in the Canary Islands' precipitation is detected by studying daily rainfall time series for the second half of the 20th century. An analysis of the extreme events shows that this trend is due mainly to a decrease in the upper percentiles of the precipitation distribution. The results suggest that local factors play a fundamental role on extreme event behaviour.

10. Southeast end; view to northwest, 65mm lens. Note evidence ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. Southeast end; view to northwest, 65mm lens. Note evidence of extreme building failure caused by adjacent railroad cut, which necessitated building demolition. (Vignetting due to extreme use of camera swing necessitated by lack of space to position camera otherwise.) - Benicia Arsenal, Powder Magazine No. 5, Junction of Interstate Highways 680 & 780, Benicia, Solano County, CA

Drug coated balloon in peripheral artery disease.

PubMed

Shanmugasundaram, Madhan; Murugapandian, Sangeetha; Truong, Huu Tam; Lotun, Kapildeo; Banerjee, Subhash

2018-04-21

Peripheral artery disease (PAD) is highly prevalent but is often underdiagnosed and undertreated. Lower extremity PAD can often be life style limiting. Revascularization in carefully selected lower extremity PAD patients improves symptoms and functional status. Surgical revascularization used to be the only available strategy, but in the recent years, endovascular strategies have gained popularity due to faster recovery times with low morbidity and mortality rates. Endovascular procedures have increased significantly in the United States in the past few years. That being said, higher restenosis rates and low long-term patency rates have been the limiting factors for this strategy. Drug eluting stents have been introduced to help with lowering restenosis, however lower extremity PAD involves long segment where the outcomes of stents are suboptimal. Also, the disease often crosses joint line that makes it less ideal for the stents. Drug coated balloons (DCB) have been introduced to improve patency rates following endovascular intervention for lower extremity PAD. They have gained popularity among endovascular specialists due to its ease of use and the concept of "leave nothing behind". This is a review of scientific evidence supporting DCB use in PAD. Published by Elsevier Inc.

Performance of High Temperature Operational Amplifier, Type LM2904WH, under Extreme Temperatures

NASA Technical Reports Server (NTRS)

Patterson, Richard; Hammoud, Ahmad; Elbuluk, Malik

2008-01-01

Operation of electronic parts and circuits under extreme temperatures is anticipated in NASA space exploration missions as well as terrestrial applications. Exposure of electronics to extreme temperatures and wide-range thermal swings greatly affects their performance via induced changes in the semiconductor material properties, packaging and interconnects, or due to incompatibility issues between interfaces that result from thermal expansion/contraction mismatch. Electronics that are designed to withstand operation and perform efficiently in extreme temperatures would mitigate risks for failure due to thermal stresses and, therefore, improve system reliability. In addition, they contribute to reducing system size and weight, simplifying its design, and reducing development cost through the elimination of otherwise required thermal control elements for proper ambient operation. A large DC voltage gain (100 dB) operational amplifier with a maximum junction temperature of 150 C was recently introduced by STMicroelectronics [1]. This LM2904WH chip comes in a plastic package and is designed specifically for automotive and industrial control systems. It operates from a single power supply over a wide range of voltages, and it consists of two independent, high gain, internally frequency compensated operational amplifiers. Table I shows some of the device manufacturer s specifications.

The natural flow regime of Hawaíi streams

NASA Astrophysics Data System (ADS)

Tsang, Y. P.; Strauch, A. M.; Clilverd, H. M.

2016-12-01

Freshwater is a critical, but limited natural resource on tropical islands; sustaining agriculture, industry, hydropower, urban development, and domestic water supply. The hydrology of Hawaíi islands is largely influenced by the health of mountain forests, which capture and absorb rain and fog drip, recharging aquifers and sustaining stream flow. Forests in Hawaíi are being degraded through the replacement of native vegetation with introduced species or conversion to another land use. Streams in the tropics frequently experience flash flooding due to extreme rainfall-runoff events and low flows due to seasonal drought. These patterns drive habitat availability for freshwater fauna, as well as sediment and nutrient export to near-shore ecosystems. Flow regimes can be used to characterize the frequency and magnitude of extreme high and low flows and are influenced by watershed climate, geology, land cover and soil composition. We examined the effect of climate extremes on stream flow from Hawaiian forests using historical flow data to characterize the spatial and temporal patterns in surface water resources. By defining flow regimes from forests we can improve our understanding of climate extremes on water resource availability across tropical island landscapes.

Impact of urban WWTP and CSO fluxes on river peak flow extremes under current and future climate conditions.

PubMed

Keupers, Ingrid; Willems, Patrick

2013-01-01

The impact of urban water fluxes on the river system outflow of the Grote Nete catchment (Belgium) was studied. First the impact of the Waste Water Treatment Plant (WWTP) and the Combined Sewer Overflow (CSO) outflows on the river system for the current climatic conditions was determined by simulating the urban fluxes as point sources in a detailed, hydrodynamic river model. Comparison was made of the simulation results on peak flow extremes with and without the urban point sources. In a second step, the impact of climate change scenarios on the urban fluxes and the consequent impacts on the river flow extremes were studied. It is shown that the change in the 10-year return period hourly peak flow discharge due to climate change (-14% to +45%) was in the same order of magnitude as the change due to the urban fluxes (+5%) in current climate conditions. Different climate change scenarios do not change the impact of the urban fluxes much except for the climate scenario that involves a strong increase in rainfall extremes in summer. This scenario leads to a strong increase of the impact of the urban fluxes on the river system.

Proton irradiation effects on gallium nitride-based devices

NASA Astrophysics Data System (ADS)

Karmarkar, Aditya P.

Proton radiation effects on state-of-the-art gallium nitride-based devices were studied using Schottky diodes and high electron-mobility transistors. The device degradation was studied over a wide range of proton fluences. This study allowed for a correlation between proton irradiation effects between different types of devices and enhanced the understanding of the mechanisms responsible for radiation damage in GaN-based devices. Proton irradiation causes reduced carrier concentration and increased series resistance and ideality factor in Schottky diodes. 1.0-MeV protons cause greater degradation than 1.8-MeV protons because of their higher non-ionizing energy loss. The displacement damage in Schottky diodes recovers during annealing. High electron-mobility transistors exhibit extremely high radiation tolerance, continuing to perform up to a fluence of ˜1014 cm-2 of 1.8-MeV protons. Proton irradiation creates defect complexes in the thin-film structure. Decreased sheet carrier mobility due to increased carrier scattering and decreased sheet carrier density due to carrier removal by the defect centers are the primary damage mechanisms. Interface disorder at either the Schottky or the Ohmic contact plays a relatively unimportant part in overall device degradation in both Schottky diodes and high electron-mobility transistors.

Real weights, bound states and duality orbits

NASA Astrophysics Data System (ADS)

Marrani, Alessio; Riccioni, Fabio; Romano, Luca

2016-01-01

We show that the duality orbits of extremal black holes in supergravity theories with symmetric scalar manifolds can be derived by studying the stabilizing subalgebras of suitable representatives, realized as bound states of specific weight vectors of the corresponding representation of the duality symmetry group. The weight vectors always correspond to weights that are real, where the reality properties are derived from the Tits-Satake diagram that identifies the real form of the Lie algebra of the duality symmetry group. Both 𝒩 = 2 magic Maxwell-Einstein supergravities and the semisimple infinite sequences of 𝒩 = 2 and 𝒩 = 4 theories in D = 4 and 5 are considered, and various results, obtained over the years in the literature using different methods, are retrieved. In particular, we show that the stratification of the orbits of these theories occurs because of very specific properties of the representations: in the case of the theory based on the real numbers, whose symmetry group is maximally noncompact and therefore all the weights are real, the stratification is due to the presence of weights of different lengths, while in the other cases it is due to the presence of complex weights.

Developing a safe on-orbit cryogenic depot

NASA Technical Reports Server (NTRS)

Bahr, Nicholas J.

1992-01-01

New U.S. space initiatives will require technology to realize planned programs such as piloted lunar and Mars missions. Key to the optimal execution of such missions are high performance orbit transfer vehicles and propellant storage facilities. Large amounts of liquid hydrogen and oxygen demand a uniquely designed on-orbit cryogenic propellant depot. Because of the inherent dangers in propellant storage and handling, a comprehensive system safety program must be established. This paper shows how the myriad and complex hazards demonstrate the need for an integrated safety effort to be applied from program conception through operational use. Even though the cryogenic depot is still in the conceptual stage, many of the hazards have been identified, including fatigue due to heavy thermal loading from environmental and operating temperature extremes, micrometeoroid and/or depot ancillary equipment impact (this is an important problem due to the large surface area needed to house the large quantities of propellant), docking and maintenance hazards, and hazards associated with extended extravehicular activity. Various safety analysis techniques were presented for each program phase. Specific system safety implementation steps were also listed. Enhanced risk assessment was demonstrated through the incorporation of these methods.

Use of Pig as a Model for Mesenchymal Stem Cell Therapies for Bone Regeneration.

PubMed

Rubessa, Marcello; Polkoff, Kathryn; Bionaz, Massimo; Monaco, Elisa; Milner, Derek J; Holllister, Scott J; Goldwasser, Michael S; Wheeler, Matthew B

2017-10-02

Bone is a plastic tissue with a large healing capability. However, extensive bone loss due to disease or trauma requires extreme therapy such as bone grafting or tissue-engineering applications. Presently, bone grafting is the gold standard for bone repair, but presents serious limitations including donor site morbidity, rejection, and limited tissue regeneration. The use of stem cells appears to be a means to overcome such limitations. Bone marrow mesenchymal stem cells (BMSC) have been the choice thus far for stem cell therapy for bone regeneration. However, adipose-derived stem cells (ASC) have similar immunophenotype, morphology, multilineage potential, and transcriptome compared to BMSC, and both types have demonstrated extensive osteogenic capacity both in vitro and in vivo in several species. The use of scaffolds in combination with stem cells and growth factors provides a valuable tool for guided bone regeneration, especially for complex anatomic defects. Before translation to human medicine, regenerative strategies must be developed in animal models to improve effectiveness and efficiency. The pig presents as a useful model due to similar macro- and microanatomy and favorable logistics of use. This review examines data that provides strong support for the clinical translation of the pig model for bone regeneration.

Interferometric interrogation of π-phase shifted fiber Bragg grating sensors

NASA Astrophysics Data System (ADS)

Srivastava, Deepa; Tiwari, Umesh; Das, Bhargab

2018-03-01

Interferometric interrogation technique realized for conventional fiber Bragg grating (FBG) sensors is historically known to offer the highest sensitivity measurements, however, it has not been yet explored for π-phase-shifted FBG (πFBG) sensors. This, we believe, is due to the complex nature of the reflection/transmission spectrum of a πFBG, which cannot be directly used for interferometric interrogation purpose. Therefore, we propose here an innovative as well as simple concept towards this direction, wherein, the transmission spectrum of a πFBG sensor is optically filtered using a specially designed fiber grating. The resulting filtered spectrum retains the entire characteristics of a πFBG sensor and hence the filtered spectrum can be interrogated with interferometric principles. Furthermore, due to the extremely narrow transmission notch of a πFBG sensor, a fiber interferometer can be realized with significantly longer path difference. This leads to substantially enhanced detection limit as compared to sensors based on a regular FBG of similar length. Theoretical analysis demonstrates that high resolution weak dynamic strain measurement down to 4 pε /√{ Hz } is easily achievable. Preliminary experimental results are also presented as proof-of-concept of the proposed interrogation principle.

Message Passing vs. Shared Address Space on a Cluster of SMPs

NASA Technical Reports Server (NTRS)

Shan, Hongzhang; Singh, Jaswinder Pal; Oliker, Leonid; Biswas, Rupak

2000-01-01

The convergence of scalable computer architectures using clusters of PCs (or PC-SMPs) with commodity networking has become an attractive platform for high end scientific computing. Currently, message-passing and shared address space (SAS) are the two leading programming paradigms for these systems. Message-passing has been standardized with MPI, and is the most common and mature programming approach. However message-passing code development can be extremely difficult, especially for irregular structured computations. SAS offers substantial ease of programming, but may suffer from performance limitations due to poor spatial locality, and high protocol overhead. In this paper, we compare the performance of and programming effort, required for six applications under both programming models on a 32 CPU PC-SMP cluster. Our application suite consists of codes that typically do not exhibit high efficiency under shared memory programming. due to their high communication to computation ratios and complex communication patterns. Results indicate that SAS can achieve about half the parallel efficiency of MPI for most of our applications: however, on certain classes of problems SAS performance is competitive with MPI. We also present new algorithms for improving the PC cluster performance of MPI collective operations.

Storms or cold fronts? What is really responsible for the extreme waves regime in the Colombian Caribbean coast

NASA Astrophysics Data System (ADS)

Otero, L. J.; Ortiz-Royero, J. C.; Ruiz-Merchan, J. K.; Higgins, A. E.; Henriquez, S. A.

2015-05-01

On Friday, 7 March 2009, a 200 m-long section of the tourist pier in Puerto Colombia collapsed under the impact of the waves generated by a cold front in the area. The aim of this study is to determine the contribution and importance of cold fronts and storms on extreme waves in different areas of the Colombian Caribbean to determine the degree of the threat posed by the flood processes to which these coastal populations are exposed and the actions to which coastal engineering constructions should be subject. In the calculation of maritime constructions, the most important parameter is the wave's height; therefore, it is necessary to definitively know the design wave height to which a coastal engineering structure should be resistant. This wave height varies according to the return period considered. Using Gumbel's extreme value methodology, the significant height values for the study area were calculated. The methodology was evaluated using data from the re-analysis of the spectral NOAA Wavewatch III (WW3) model for 15 points along the 1600 km of the Colombia Caribbean coast (continental and insular) of the last 15 years. The results demonstrated that the extreme waves caused by tropical cyclones and cold fronts have different effects along the Colombian Caribbean coast. Storms and hurricanes are of greater importance in the Guajira Peninsula (Alta Guajira). In the central area formed by Baja Guajira, Santa Marta, Barranquilla, and Cartagena, the strong influence of cold fronts on extreme waves is evident. On the other hand, in the southern region of the Colombian Caribbean coast, from the Gulf of Morrosquillo to the Gulf of Urabá, even though extreme waves are lower than in the previous regions, extreme waves are dominated mainly by the passage of cold fronts. Extreme waves in the San Andrés and Providencia insular region present a different dynamic from that in the continental area due to its geographic location. The wave heights in the extreme regime are similar in magnitude to those found in Alta Guajira, but the extreme waves associated with the passage of cold fronts in this region have lower return periods than the extreme waves associated with hurricane season. These results are of great importance when evaluating the threat of extreme waves in the coastal and port infrastructure, for purposes of the design of new constructions, and in the coastal flood processes due to run-up because, according to the site of interest in the coast, the forces that shape extreme waves are not the same.

Spatiotemporal variation in heat-related out-of-hospital cardiac arrest during the summer in Japan.

PubMed

Onozuka, Daisuke; Hagihara, Akihito

2017-04-01

Although several studies have reported the impacts of extremely high temperature on cardiovascular diseases, few studies have investigated the spatiotemporal variation in the incidence of out-of-hospital cardiac arrest (OHCA) due to extremely high temperature in Japan. Daily OHCA data from 2005 to 2014 were acquired from all 47 prefectures of Japan. We used time-series Poisson regression analysis combined with a distributed lag non-linear model to assess the temporal variability in the effects of extremely high temperature on OHCA incidence in each prefecture, adjusted for time trends. Spatial variability in the relationships between extremely high temperature and OHCA between prefectures was estimated using a multivariate random-effects meta-analysis. We analyzed 166,496 OHCA cases of presumed cardiac origin occurring during the summer (June to September) that met the inclusion criteria. The minimum morbidity percentile (MMP) was the 51st percentile of temperature during the summer in Japan. The overall cumulative relative risk at the 99th percentile vs. the MMP over lags 0-10days was 1.21 (95% CI: 1.12-1.31). There was also a strong low temperature effect during the summer periods. No substantial difference in spatial or temporal variability was observed over the study period. Our study demonstrated spatiotemporal homogeneity in the risk of OHCA during periods of extremely high temperature between 2005 and 2014 in Japan. Our findings suggest that public health strategies for OHCA due to extremely high temperatures should be finely adjusted and should particularly account for the unchanging risk during the summer. Copyright © 2017 Elsevier B.V. All rights reserved.

Aeropropulsion 1987. Session 2: Aeropropulsion Structures Research

NASA Technical Reports Server (NTRS)

1987-01-01

Aeropropulsion systems present unique problems to the structural engineer. The extremes in operating temperatures, rotational effects, and behaviors of advanced material systems combine into complexities that require advances in many scientific disciplines involved in structural analysis and design procedures. This session provides an overview of the complexities of aeropropulsion structures and the theoretical, computational, and experimental research conducted to achieve the needed advances.

Using New Models to Analyze Complex Regularities of the World: Commentary on Musso et al. (2013)

ERIC Educational Resources Information Center

Nokelainen, Petri; Silander, Tomi

2014-01-01

This commentary to the recent article by Musso et al. (2013) discusses issues related to model fitting, comparison of classification accuracy of generative and discriminative models, and two (or more) cultures of data modeling. We start by questioning the extremely high classification accuracy with an empirical data from a complex domain. There is…

DNA-PKcs is important for Akt activation and gemcitabine resistance in PANC-1 pancreatic cancer cells.

PubMed

Hu, Hao; Gu, Yuanlong; Qian, Yi; Hu, Benshun; Zhu, Congyuan; Wang, Gaohe; Li, Jianping

2014-09-12

Pancreatic cancer is one of the most aggressive human malignancies with extremely poor prognosis. The moderate activity of the current standard gemcitabine and gemcitabine-based regimens was due to pre-existing or acquired chemo-resistance of pancreatic cancer cells. In this study, we explored the potential role of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) in gemcitabine resistance, and studied the underlying mechanisms. We found that NU-7026 and NU-7441, two DNA-PKcs inhibitors, enhanced gemcitabine-induced cytotoxicity and apoptosis in PANC-1 pancreatic cancer cells. Meanwhile, PANC-1 cells with siRNA-knockdown of DNA-PKcs were more sensitive to gemcitabine than control PANC-1 cells. Through the co-immunoprecipitation (Co-IP) assay, we found that DNA-PKcs formed a complex with SIN1, the latter is an indispensable component of mammalian target of rapamycin (mTOR) complex 2 (mTORC2). DNA-PKcs-SIN1 complexation was required for Akt activation in PANC-1 cells, while inhibition of this complex by siRNA knockdown of DNA-PKcs/SIN1, or by DNA-PKcs inhibitors, prevented Akt phosphorylation in PANC-1 cells. Further, SIN1 siRNA-knockdown also facilitated gemcitabine-induced apoptosis in PANC-1 cells. Finally, DNA-PKcs and p-Akt expression was significantly higher in human pancreatic cancer tissues than surrounding normal tissues. Together, these results show that DNA-PKcs is important for Akt activation and gemcitabine resistance in PANC-1 pancreatic cancer cells. Copyright © 2014 Elsevier Inc. All rights reserved.

Ion-pair high-speed countercurrent chromatography in fractionation of a high-molecular weight variation of acyl-oligosaccharide linked betacyanins from purple bracts of Bougainvillea glabra.

PubMed

Wybraniec, Sławomir; Jerz, Gerold; Gebers, Nadine; Winterhalter, Peter

2010-02-15

The natural pigment composition of purple bracts of Bougainvillea glabra (Nyctaginaceae) consists of a highly complex mixture of betacyanins solely differing by the substitution with a variety of acyl-oligoglycoside units. This study was focused on a two-dimensional chromatography approach, a combination of preparative high-speed countercurrent chromatography (HSCCC) and analytical C18-HPLC with ESI-DAD-MS/MS detection which finally enabled a more detailed view into the pigment profile and elucidated the existence of an overwhelming amount of varying betacyanin structures occurring in Bougainvillea bracts. The detected molecular weights of the pigments reached so far unknown high values and ranged up to maximum values of 1653 and 1683 Da for the largest molecules due to oligosaccharide linkage and multiple acyl substitutions. The preparative IP-HSCCC separation yielded 15 complex fractions containing betacyanins of enhanced polarity as well as structures with highly increased lipophilicity. Betacyanin structures extended by large oligosaccharide chains with bigger number of glycoside units and also carrying a reduced number of hydroxycinnamic acid substitutions were characteristic for polar pigments occurring mainly in the early eluting CCC fractions. IP-HSCCC was proven to be extremely effective for fractionating this complex crude betalain pigment extract into more defined 'polarity-windows'. Structural analysis by analytical LC-ESI-MS/MS in the positive ionization mode detected a total sum of 146 different betacyanin pigments in the CCC fractions of reduced complexity. Copyright 2010 Elsevier B.V. All rights reserved.

Multiple-decker phthalocyaninato dinuclear lanthanoid(III) single-molecule magnets with dual-magnetic relaxation processes.

PubMed

Katoh, Keiichi; Horii, Yoji; Yasuda, Nobuhiro; Wernsdorfer, Wolfgang; Toriumi, Koshiro; Breedlove, Brian K; Yamashita, Masahiro

2012-11-28

The SMM behaviour of dinuclear Ln(III)-Pc multiple-decker complexes (Ln = Tb(3+) and Dy(3+)) with energy barriers and slow-relaxation behaviour were explained by using X-ray crystallography and static and dynamic susceptibility measurements. In particular, interactions among the 4f electrons of several dinuclear Ln(III)-Pc type SMMs have never been discussed on the basis of the crystal structure. For dinuclear Tb(III)-Pc complexes, a dual magnetic relaxation process was observed. The relaxation processes are due to the anisotropic centres. Our results clearly show that the two Tb(3+) ion sites are equivalent and are consistent with the crystal structure. On the other hand, the mononuclear Tb(III)-Pc complex exhibited only a single magnetic relaxation process. This is clear evidence that the magnetic relaxation mechanism depends heavily on the dipole-dipole (f-f) interactions between the Tb(3+) ions in the dinuclear systems. Furthermore, the SMM behaviour of dinuclear Dy(III)-Pc type SMMs with smaller energy barriers compared with that of Tb(III)-Pc and slow-relaxation behaviour was explained. Dinuclear Dy(III)-Pc SMMs exhibited single-component magnetic relaxation behaviour. The results indicate that the magnetic relaxation properties of dinuclear Ln(III)-Pc multiple-decker complexes are affected by the local molecular symmetry and are extremely sensitive to tiny distortions in the coordination geometry. In other words, the spatial arrangement of the Ln(3+) ions (f-f interactions) in the crystal is important. Our work shows that the SMM properties can be fine-tuned by introducing weak intermolecular magnetic interactions in a controlled SMM spatial arrangement.

Study on a low complexity adaptive modulation algorithm in OFDM-ROF system with sub-carrier grouping technology

NASA Astrophysics Data System (ADS)

Liu, Chong-xin; Liu, Bo; Zhang, Li-jia; Xin, Xiang-jun; Tian, Qing-hua; Tian, Feng; Wang, Yong-jun; Rao, Lan; Mao, Yaya; Li, Deng-ao

2018-01-01

During the last decade, the orthogonal frequency division multiplexing radio-over-fiber (OFDM-ROF) system with adaptive modulation technology is of great interest due to its capability of raising the spectral efficiency dramatically, reducing the effects of fiber link or wireless channel, and improving the communication quality. In this study, according to theoretical analysis of nonlinear distortion and frequency selective fading on the transmitted signal, a low-complexity adaptive modulation algorithm is proposed in combination with sub-carrier grouping technology. This algorithm achieves the optimal performance of the system by calculating the average combined signal-to-noise ratio of each group and dynamically adjusting the origination modulation format according to the preset threshold and user's requirements. At the same time, this algorithm takes the sub-carrier group as the smallest unit in the initial bit allocation and the subsequent bit adjustment. So, the algorithm complexity is only 1 /M (M is the number of sub-carriers in each group) of Fischer algorithm, which is much smaller than many classic adaptive modulation algorithms, such as Hughes-Hartogs algorithm, Chow algorithm, and is in line with the development direction of green and high speed communication. Simulation results show that the performance of OFDM-ROF system with the improved algorithm is much better than those without adaptive modulation, and the BER of the former achieves 10e1 to 10e2 times lower than the latter when SNR values gets larger. We can obtain that this low complexity adaptive modulation algorithm is extremely useful for the OFDM-ROF system.

Nitric oxide production by visible light irradiation of aqueous solution of nitrosyl ruthenium complexes.

PubMed

Sauaia, Marília Gama; de Lima, Renata Galvão; Tedesco, Antonio Claudio; da Silva, Roberto Santana

2005-12-26

[Ru(II)L(NH(3))(4)(pz)Ru(II)(bpy)(2)(NO)](PF(6))(5) (L is NH(3), py, or 4-acpy) was prepared with good yields in a straightforward way by mixing an equimolar ratio of cis-[Ru(NO(2))(bpy)(2)(NO)](PF(6))(2), sodium azide (NaN(3)), and trans-[RuL(NH(3))(4)(pz)] (PF(6))(2) in acetone. These binuclear compounds display nu(NO) at ca. 1945 cm(-)(1), indicating that the nitrosyl group exhibits a sufficiently high degree of nitrosonium ion (NO(+)). The electronic spectrum of the [Ru(II)L(NH(3))(4)(pz)Ru(II)(bpy)(2)(NO)](5+) complex in aqueous solution displays the bands in the ultraviolet and visible regions typical of intraligand and metal-to-ligand charge transfers, respectively. Cyclic voltammograms of the binuclear complexes in acetonitrile give evidence of three one-electron redox processes consisting of one oxidation due to the Ru(2+/3+) redox couple and two reductions concerning the nitrosyl ligand. Flash photolysis of the [Ru(II)L(NH(3))(4)(pz)Ru(II)(bpy)(2)(NO)](5+) complex is capable of releasing nitric oxide (NO) upon irradiation at 355 and 532 nm. NO production was detected and quantified by an amperometric technique with a selective electrode (NOmeter). The irradiation at 532 nm leads to NO release as a consequence of a photoinduced electron transfer. All species exhibit similar photochemical behavior, a feature that makes their study extremely important for their future application in the upgrade of photodynamic therapy in living organisms.

Integrating new indicators of predictors that shape the public's perception of local extreme temperature in China.

PubMed

Ban, Jie; Huang, Lei; Chen, Chen; Guo, Yuming; He, Mike Z; Li, Tiantian

2017-02-01

The public's risk perception of local extreme heat or cold plays a critical role in community health and prevention under climate change. However, there is limited evidence on such issues in China where extreme weather is occurring more frequently due to climate change. Here, a total of 2500 residents were selected using a three-step sampling method and investigated by a questionnaire in two representative cities. We investigated risk perception of extreme heat in Beijing and extreme cold in Harbin in 2013, aiming to examine their possible correlations with multiple epidemiological factors. We found that exposure, vulnerability, and adaptive ability were significant predictors in shaping public risk perceptions of local extreme temperature. In particular, a 1°C increase in daily temperature resulted in an increased odds of perceiving serious extreme heat in Beijing (OR=1.091; 95% CI: 1.032, 1.153), while a 1°C increase in daily temperature resulted in a decreased odds of perceiving serious extreme cold in Harbin (OR=0.965; 95% CI: 0.939, 0.992). Therefore for both extreme heat and cold, frequent local extreme temperature exposure may amplify a stronger communication. Health interventions for extreme temperature should consider exposure, vulnerability, and adaptive ability factors. This will help improve the public's perception of climatic changes and their willingness to balance adaption and mitigation appropriately. Copyright © 2016 Elsevier B.V. All rights reserved.

Using Space Weather for Enhanced, Extreme Terrestrial Weather Predictions.

NASA Astrophysics Data System (ADS)

McKenna, M. H.; Lee, T. A., III

2017-12-01

Considering the complexities of the Sun-Earth system, the impacts of space weather to weather here on Earth are not fully understood. This study attempts to analyze this interrelationship by providing a theoretical framework for studying the varied modalities of solar inclination and explores the extent to which they contribute, both in formation and intensity, to extreme terrestrial weather. Using basic topologic and ontology engineering concepts (TOEC), the transdisciplinary syntaxes of space physics, geophysics, and meteorology are analyzed as a seamless interrelated system. This paper reports this investigation's initial findings and examines the validity of the question "Does space weather contribute to extreme weather on Earth, and if so, to what degree?"

Evaluating teams in extreme environments: from issues to answers.

PubMed

Bishop, Sheryl L

2004-07-01

The challenge to effectively evaluating teams in extreme environments necessarily involves a wide range of physiological, psychological, and psychosocial factors. The high reliance on technology, the growing frequency of multinational and multicultural teams, and the demand for longer duration missions all further compound the complexity of the problem. The primary goal is the insurance of human health and well-being with expectations that such priorities will naturally lead to improved chances for performance and mission success. This paper provides an overview of some of the most salient immediate challenges for selecting, training, and supporting teams in extreme environments, gives exemplars of research findings concerning these challenges, and discusses the need for future research.

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

NASA Astrophysics Data System (ADS)

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

2014-12-01

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

Numerical simulation of deformation and failure processes of a complex technical object under impact loading

NASA Astrophysics Data System (ADS)

Kraus, E. I.; Shabalin, I. I.; Shabalin, T. I.

2018-04-01

The main points of development of numerical tools for simulation of deformation and failure of complex technical objects under nonstationary conditions of extreme loading are presented. The possibility of extending the dynamic method for construction of difference grids to the 3D case is shown. A 3D realization of discrete-continuum approach to the deformation and failure of complex technical objects is carried out. The efficiency of the existing software package for 3D modelling is shown.

Transposable elements as a molecular evolutionary force

NASA Technical Reports Server (NTRS)

Fedoroff, N. V.

1999-01-01

This essay addresses the paradoxes of the complex and highly redundant genomes. The central theses developed are that: (1) the distinctive feature of complex genomes is the existence of epigenetic mechanisms that permit extremely high levels of both tandem and dispersed redundancy; (2) the special contribution of transposable elements is to modularize the genome; and (3) the labilizing forces of recombination and transposition are just barely contained, giving a dynamic genetic system of ever increasing complexity that verges on the chaotic.

Computing return times or return periods with rare event algorithms

NASA Astrophysics Data System (ADS)

Lestang, Thibault; Ragone, Francesco; Bréhier, Charles-Edouard; Herbert, Corentin; Bouchet, Freddy

2018-04-01

The average time between two occurrences of the same event, referred to as its return time (or return period), is a useful statistical concept for practical applications. For instance insurances or public agencies may be interested by the return time of a 10 m flood of the Seine river in Paris. However, due to their scarcity, reliably estimating return times for rare events is very difficult using either observational data or direct numerical simulations. For rare events, an estimator for return times can be built from the extrema of the observable on trajectory blocks. Here, we show that this estimator can be improved to remain accurate for return times of the order of the block size. More importantly, we show that this approach can be generalised to estimate return times from numerical algorithms specifically designed to sample rare events. So far those algorithms often compute probabilities, rather than return times. The approach we propose provides a computationally extremely efficient way to estimate numerically the return times of rare events for a dynamical system, gaining several orders of magnitude of computational costs. We illustrate the method on two kinds of observables, instantaneous and time-averaged, using two different rare event algorithms, for a simple stochastic process, the Ornstein–Uhlenbeck process. As an example of realistic applications to complex systems, we finally discuss extreme values of the drag on an object in a turbulent flow.

Ringin' the water bell: dynamic modes of curved fluid sheets

NASA Astrophysics Data System (ADS)

Kolinski, John; Aharoni, Hillel; Fineberg, Jay; Sharon, Eran

2015-11-01

A water bell is formed by fluid flowing in a thin, coherent sheet in the shape of a bell. Experimentally, a water bell is created via the impact of a cylindrical jet on a flat surface. Its shape is set by the splash angle (the separation angle) of the resulting cylindrically symmetric water sheet. The separation angle is altered by adjusting the height of a lip surrounding the impact point, as in a water sprinkler. We drive the lip's height sinusoidally, altering the separation angle, and ringin' the water bell. This forcing generates disturbances on the steady-state water bell that propagate forward and backward in the fluid's reference frame at well-defined velocities, and interact, resulting in the emergence of an interference pattern unique to each steady-state geometry. We analytically model these dynamics by linearizing the amplitude of the bell's response about the underlying curved geometry. This simple model predicts the nodal structure over a wide range of steady-state water bell configurations and driving frequencies. Due to the curved water bell geometry, the nodal structure is quite complex; nevertheless, the predicted nodal structure agrees extremely well with the experimental data. When we drive the bell beyond perturbative separation angles, the nodal locations surprisingly persist, despite the strikingly altered underlying water bell shape. At extreme driving amplitudes the water sheet assumes a rich variety of tortuous, non-convex shapes; nevertheless, the fluid sheet remains intact.

From state dissociation to status dissociatus.

PubMed

Antelmi, Elena; Ferri, Raffaele; Iranzo, Alex; Arnulf, Isabelle; Dauvilliers, Yves; Bhatia, Kailash P; Liguori, Rocco; Schenck, Carlos H; Plazzi, Giuseppe

2016-08-01

The states of being are conventionally defined by the simultaneous occurrence of behavioral, neurophysiological and autonomic descriptors. State dissociation disorders are due to the intrusion of features typical of a different state into an ongoing state. Disorders related to these conditions are classified according to the ongoing main state and comprise: 1) Dissociation from prevailing wakefulness as seen in hypnagogic or hypnopompic hallucinations, automatic behaviors, sleep drunkenness, cataplexy and sleep paralysis 2) Dissociation from rapid eye movement (REM) sleep as seen in REM sleep behavior disorder and lucid dreaming and 3) Dissociation from NREM sleep as seen in the disorders of arousal. The extreme expression of states dissociation is characterized by the asynchronous occurrence of the various components of the different states that prevents the recognition of any state of being. This condition has been named status dissociatus. According to the underlying disorders/diseases and to their severity, among status dissociatus we may recognize disorders in which such an extreme dissociation occurs only at night time or intermittently (i.e., autoimmune encephalopathies, narcolepsy type 1 and IgLON5 parasomnia), and others in which it occurs nearly continuously with complete loss of any conventionally defined state of being, and of the circadian pattern (agrypnia excitata). Here, we render a comprehensive review of all diseases/disorders associated with state dissociation and status dissociatus and propose a critical classification of this complex scenario. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Arm is Not the Leg: Pathophysiology, Diagnosis, and Management of Upper Extremity Deep Vein Thrombosis.

PubMed

Noyes, Adam M; Dickey, John

2017-05-01

Upper extremity deep venous thrombosis (UEDVT) involves thrombosis of the deep veins of the arm as they enter the thorax. They are increasing in frequency, largely due to the rising use of central venous catheters and implantable cardiac devices, and represent more than 10% of all DVT cases, Upper extremity deep venous thrombosis has been historically misunderstood when compared to lower extremity deep vein thrombosis (LEDVT). Their associated disease states may carry devastating complications, with mortality rates often higher than that of LEDVT. Thus, education on recognition, classification and management is critical to avoid long-term sequelae and mortality from UEDVT. [Full article available at http://rimed.org/rimedicaljournal-2017-05.asp].

Arctic sea ice, Eurasia snow, and extreme winter haze in China.

PubMed

Zou, Yufei; Wang, Yuhang; Zhang, Yuzhong; Koo, Ja-Ho

2017-03-01

The East China Plains (ECP) region experienced the worst haze pollution on record for January in 2013. We show that the unprecedented haze event is due to the extremely poor ventilation conditions, which had not been seen in the preceding three decades. Statistical analysis suggests that the extremely poor ventilation conditions are linked to Arctic sea ice loss in the preceding autumn and extensive boreal snowfall in the earlier winter. We identify the regional circulation mode that leads to extremely poor ventilation over the ECP region. Climate model simulations indicate that boreal cryospheric forcing enhances the regional circulation mode of poor ventilation in the ECP region and provides conducive conditions for extreme haze such as that of 2013. Consequently, extreme haze events in winter will likely occur at a higher frequency in China as a result of the changing boreal cryosphere, posing difficult challenges for winter haze mitigation but providing a strong incentive for greenhouse gas emission reduction.

Hypothyroid-induced acute compartment syndrome in all extremities.

PubMed

Musielak, Matthew C; Chae, Jung Hee

2016-12-20

Acute compartment syndrome (ACS) is an uncommon complication of uncontrolled hypothyroidism. If unrecognized, this can lead to ischemia, necrosis and potential limb loss. A 49-year-old female presented with the sudden onset of bilateral lower and upper extremity swelling and pain. The lower extremity anterior compartments were painful and tense. The extensor surface of the upper extremities exhibited swelling and pain. Motor function was intact, however, limited due to pain. Bilateral lower extremity fasciotomies were performed. Postoperative Day 1, upper extremity motor function decreased significantly and paresthesias occurred. She therefore underwent bilateral forearm fasciotomies. The pathogenesis of hypothyroidism-induced compartment syndrome is unclear. Thyroid-stimulating hormone-induced fibroblast activation results in increased glycosaminoglycan deposition. The primary glycosaminoglycan in hypothyroid myxedematous changes is hyaluronic acid, which binds water causing edema. This increases vascular permeability, extravasation of proteins and impaired lymphatic drainage. These contribute to increased intra-compartmental pressure and subsequent ACS. Published by Oxford University Press and JSCR Publishing Ltd. All rights reserved. © The Author 2016.

Extreme cyclone events in the Arctic: Wintertime variability and trends

NASA Astrophysics Data System (ADS)

Rinke, A.; Maturilli, M.; Graham, R. M.; Matthes, H.; Handorf, D.; Cohen, L.; Hudson, S. R.; Moore, J. C.

2017-09-01

Typically 20-40 extreme cyclone events (sometimes called ‘weather bombs’) occur in the Arctic North Atlantic per winter season, with an increasing trend of 6 events/decade over 1979-2015, according to 6 hourly station data from Ny-Ålesund. This increased frequency of extreme cyclones is consistent with observed significant winter warming, indicating that the meridional heat and moisture transport they bring is a factor in rising temperatures in the region. The winter trend in extreme cyclones is dominated by a positive monthly trend of about 3-4 events/decade in November-December, due mainly to an increasing persistence of extreme cyclone events. A negative trend in January opposes this, while there is no significant trend in February. We relate the regional patterns of the trend in extreme cyclones to anomalously low sea-ice conditions in recent years, together with associated large-scale atmospheric circulation changes such as ‘blockinglike’ circulation patterns (e.g. Scandinavian blocking in December and Ural blocking during January-February).

Arctic sea ice, Eurasia snow, and extreme winter haze in China

PubMed Central

Zou, Yufei; Wang, Yuhang; Zhang, Yuzhong; Koo, Ja-Ho

2017-01-01

The East China Plains (ECP) region experienced the worst haze pollution on record for January in 2013. We show that the unprecedented haze event is due to the extremely poor ventilation conditions, which had not been seen in the preceding three decades. Statistical analysis suggests that the extremely poor ventilation conditions are linked to Arctic sea ice loss in the preceding autumn and extensive boreal snowfall in the earlier winter. We identify the regional circulation mode that leads to extremely poor ventilation over the ECP region. Climate model simulations indicate that boreal cryospheric forcing enhances the regional circulation mode of poor ventilation in the ECP region and provides conducive conditions for extreme haze such as that of 2013. Consequently, extreme haze events in winter will likely occur at a higher frequency in China as a result of the changing boreal cryosphere, posing difficult challenges for winter haze mitigation but providing a strong incentive for greenhouse gas emission reduction. PMID:28345056

Electrostatic Interactions in the Binding Pathway of a Transient Protein Complex Studied by NMR and Isothermal Titration Calorimetry*

PubMed Central

Meneses, Erick; Mittermaier, Anthony

2014-01-01

Much of our knowledge of protein binding pathways is derived from extremely stable complexes that interact very tightly, with lifetimes of hours to days. Much less is known about weaker interactions and transient complexes because these are challenging to characterize experimentally. Nevertheless, these types of interactions are ubiquitous in living systems. The combination of NMR relaxation dispersion Carr–Purcell–Meiboom–Gill (CPMG) experiments and isothermal titration calorimetry allows the quantification of rapid binding kinetics for complexes with submillisecond lifetimes that are difficult to study using conventional techniques. We have used this approach to investigate the binding pathway of the Src homology 3 (SH3) domain from the Fyn tyrosine kinase, which forms complexes with peptide targets whose lifetimes are on the order of about a millisecond. Long range electrostatic interactions have been shown to play a critical role in the binding pathways of tightly binding complexes. The role of electrostatics in the binding pathways of transient complexes is less well understood. Similarly to previously studied tight complexes, we find that SH3 domain association rates are enhanced by long range electrostatics, whereas short range interactions are formed late in the docking process. However, the extent of electrostatic association rate enhancement is several orders of magnitudes less, whereas the electrostatic-free basal association rate is significantly greater. Thus, the SH3 domain is far less reliant on electrostatic enhancement to achieve rapid association kinetics than are previously studied systems. This suggests that there may be overall differences in the role played by electrostatics in the binding pathways of extremely stable versus transient complexes. PMID:25122758

L-edge sum rule analysis on 3d transition metal sites: from d10 to d0 and towards application to extremely dilute metallo-enzymes.

PubMed

Wang, Hongxin; Friedrich, Stephan; Li, Lei; Mao, Ziliang; Ge, Pinghua; Balasubramanian, Mahalingam; Patil, Daulat S

2018-03-28

According to L-edge sum rules, the number of 3d vacancies at a transition metal site is directly proportional to the integrated intensity of the L-edge X-ray absorption spectrum (XAS) for the corresponding metal complex. In this study, the numbers of 3d holes are characterized quantitatively or semi-quantitatively for a series of manganese (Mn) and nickel (Ni) complexes, including the electron configurations 3d 10 → 3d 0 . In addition, extremely dilute (<0.1% wt/wt) Ni enzymes were examined by two different approaches: (1) by using a high resolution superconducting tunnel junction X-ray detector to obtain XAS spectra with a very high signal-to-noise ratio, especially in the non-variant edge jump region; and (2) by adding an inert tracer to the sample that provides a prominent spectral feature to replace the weak edge jump for intensity normalization. In this publication, we present for the first time: (1) L-edge sum rule analysis for a series of Mn and Ni complexes that include electron configurations from an open shell 3d 0 to a closed shell 3d 10 ; (2) a systematic analysis on the uncertainties, especially on that from the edge jump, which was missing in all previous reports; (3) a clearly-resolved edge jump between pre-L 3 and post-L 2 regions from an extremely dilute sample; (4) an evaluation of an alternative normalization standard for L-edge sum rule analysis. XAS from two copper (Cu) proteins measured using a conventional semiconductor X-ray detector are also repeated as bridges between Ni complexes and dilute Ni enzymes. The differences between measuring 1% Cu enzymes and measuring <0.1% Ni enzymes are compared and discussed. This study extends L-edge sum rule analysis to virtually any 3d metal complex and any dilute biological samples that contain 3d metals.

Abrupt shifts in ecosystem function and intensification of global biogeochemical cycle driven by hydroclimatic extremes

NASA Astrophysics Data System (ADS)

Ma, Xuanlong; Huete, Alfredo; Ponce-Campos, Guillermo; Zhang, Yongguang; Xie, Zunyi; Giovannini, Leandro; Cleverly, James; Eamus, Derek

2016-04-01

Amplification of the hydrologic cycle as a consequence of global warming is increasing the frequency, intensity, and spatial extent of extreme climate events globally. The potential influences resulting from amplification of the hydro-climatic cycle, coupled with an accelerating warming trend, pose great concerns on the sustainability of terrestrial ecosystems to sequester carbon, maintain biodiversity, provide ecosystem services, food security, and support human livelihood. Despite the great implications, the magnitude, direction, and carry-over effect of these extreme climate events on ecosystem function, remain largely uncertain. To address these pressing issues, we conducted an observational, interdisciplinary study using satellite retrievals of atmospheric CO2 and photosynthesis (chlorophyll fluorescence), and in-situ flux tower measures of ecosystem-atmosphere carbon exchange, to reveal the shifts in ecosystem function across extreme drought and wet periods. We further determine the factors that govern ecosystem sensitivity to hydroclimatic extremes. We focus on Australia but extended our analyses to other global dryland regions due to their significant role in global biogeochemical cycles. Our results revealed dramatic impacts of drought and wet hydroclimatic extremes on ecosystem function, with abrupt changes in vegetation productivity, carbon uptake, and water-use-efficiency between years. Drought resulted in widespread reductions or collapse in the normal patterns of vegetation growth seasonality such that in many cases there was no detectable phenological cycle during extreme drought years. We further identified a significant increasing trend (p < 0.001) in extreme wet year precipitation amounts over Australia and many other global regions, resulting in an increasing trend in magnitude of the episodic carbon sink pulses coupled to each La Niña-induced wet years. This finding is of global biogeochemical significance, with the consequence of amplifying the global carbon cycle. Lastly, we use landscape measurements of carbon and water fluxes from eddy-covariance towers and field sampling of aboveground net primary productivity from long-term ecological networks to verify the patterns observed by top-down approaches. Our results demonstrate the intensification of hydroclimatic extremes due to global warming is exerting important impacts on ecosystem function, which further have significant implications on global biogeochemical cycles as well as local ecosystem processes.

Quantifying population exposure to airborne particulate matter during extreme events in California due to climate change

NASA Astrophysics Data System (ADS)

Mahmud, A.; Hixson, M.; Kleeman, M. J.

2012-02-01

The effect of climate change on population-weighted concentrations of particulate matter (PM) during extreme events was studied using the Parallel Climate Model (PCM), the Weather Research and Forecasting (WRF) model and the UCD/CIT 3-D photochemical air quality model. A "business as usual" (B06.44) global emissions scenario was dynamically downscaled for the entire state of California between the years 2000-2006 and 2047-2053. Air quality simulations were carried out for 1008 days in each of the present-day and future climate conditions using year-2000 emissions. Population-weighted concentrations of PM0.1, PM2.5, and PM10 total mass, components species, and primary source contributions were calculated for California and three air basins: the Sacramento Valley air basin (SV), the San Joaquin Valley air basin (SJV) and the South Coast Air Basin (SoCAB). Results over annual-average periods were contrasted with extreme events. Climate change between 2000 vs. 2050 did not cause a statistically significant change in annual-average population-weighted PM2.5 mass concentrations within any major sub-region of California in the current study. Climate change did alter the annual-average composition of the airborne particles in the SoCAB, with notable reductions of elemental carbon (EC; -3%) and organic carbon (OC; -3%) due to increased annual-average wind speeds that diluted primary concentrations from gasoline combustion (-3%) and food cooking (-4%). In contrast, climate change caused significant increases in population-weighted PM2.5 mass concentrations in central California during extreme events. The maximum 24-h average PM2.5 concentration experienced by an average person during a ten-year period in the SJV increased by 21% due to enhanced production of secondary particulate matter (manifested as NH4NO3). In general, climate change caused increased stagnation during future extreme pollution events, leading to higher exposure to diesel engines particles (+32%) and wood combustion particles (+14%) when averaging across the population of the entire state. Enhanced stagnation also isolated populations from distant sources such as shipping (-61%) during extreme events. The combination of these factors altered the statewide population-averaged composition of particles during extreme events, with EC increasing by 23%, nitrate increasing by 58%, and sulfate decreasing by 46%.

The quasiparticle zoo

NASA Astrophysics Data System (ADS)

Venema, Liesbeth; Verberck, Bart; Georgescu, Iulia; Prando, Giacomo; Couderc, Elsa; Milana, Silvia; Maragkou, Maria; Persechini, Lina; Pacchioni, Giulia; Fleet, Luke

2016-12-01

Quasiparticles are an extremely useful concept that provides a more intuitive understanding of complex phenomena in many-body physics. As such, they appear in various contexts, linking ideas across different fields and supplying a common language.

Transportation risk management : international practices for program development and project delivery.

DOT National Transportation Integrated Search

2012-08-01

Managing transportation networks, including agency : management, program development, and project : delivery, is extremely complex and fraught with : uncertainty. Administrators, planners, and engineers : coordinate a multitude of organizational and ...

[Biomechanical air-vibration stimulation in the medical rehabilitation of patients with chronic venous insufficiency of the lower extremities].

PubMed

Zhukov, B N; Katorkin, S E

1993-01-01

Biomechanical pneumo-vibration stimulation of lower extremities was used in 146 patients with different forms and stages of chronic venous insufficiency of lower extremities during conservative treatment in preoperative preparation and the following early rehabilitation, in 106 patients with consequences of the trauma and diseases of the spinal cord as well as in 35 healthy people. The biomechanical pneumo-vibration stimulation is thought by the authors to be a promising noninvasive conservative method of medical rehabilitation. It can be recommended for clinical use with due regard for contraindications.

[Use of physical factors in the complex therapy of patients with diabetic angio- and polyneuropathies of the lower extremities].

PubMed

Shablinskaia, N B

2002-01-01

Results are submitted of treatment of 110 patients with diabetes mellitus (61 male and 49 female subjects) presenting with angio- and polyneuropathies of the lower extremities. 70 patients, in addition to a drug therapy, were administered physiotherapeutic treatments, such as amplipulsetherapy, darsonvalization, and laserotherapy. Forty patients received medicamentous therapy only. Based on clinical findings and laboratory methods of investigation expediency has been shown of employment of physiotherapeutic methods in the treatment of the above pathology.

The potential power of robotics for upper extremity stroke rehabilitation.

PubMed

Dukelow, Sean P

2017-01-01

Two decades of research on robots and upper extremity rehabilitation has resulted in recommendations from systematic reviews and guidelines on their use in stroke. Robotics are often cited for their ability to encourage mass practice as a means to enhance recovery of movement. Yet, stroke recovery is a complex process occurring across many aspects of neurologic function beyond movement. As newer devices are developed and enhanced assessments are integrated into treatment protocols, the potential of robotics to advance rehabilitation will continue to grow.

Large-scale drivers of local precipitation extremes in convection-permitting climate simulations

NASA Astrophysics Data System (ADS)

Chan, Steven C.; Kendon, Elizabeth J.; Roberts, Nigel M.; Fowler, Hayley J.; Blenkinsop, Stephen

2016-04-01

The Met Office 1.5-km UKV convective-permitting models (CPM) is used to downscale present-climate and RCP8.5 60-km HadGEM3 GCM simulations. Extreme UK hourly precipitation intensities increase with local near-surface temperatures and humidity; for temperature, the simulated increase rate for the present-climate simulation is about 6.5% K**-1, which is consistent with observations and theoretical expectations. While extreme intensities are higher in the RCP8.5 simulation as higher temperatures are sampled, there is a decline at the highest temperatures due to circulation and relative humidity changes. Extending the analysis to the broader synoptic scale, it is found that circulation patterns, as diagnosed by MSLP or circulation type, play an increased role in the probability of extreme precipitation in the RCP8.5 simulation. Nevertheless for both CPM simulations, vertical instability is the principal driver for extreme precipitation.

[Management of war orthopaedic injuries in recent armed conflicts].

PubMed

Frank, M; Mathieu, L

2013-01-01

The extremities continue to be the most frequent sites of wounding during armed conflicts despite the change of combat tactics, soldier armour and battlefield medical support. Due to the advances in prehospital care and timely transport to the hospital, orthopaedic surgeons deal with severe and challenging injuries of the limbs. In contrast to civilian extremity trauma, the most combat-related injuries are open wounds that often have infection-related complications. Data from two recent large armed conflicts (Iraq, Afghanistan) show that extremity injuries are associated with a high complication rate, morbidity and healthcare utilization. A systematic approach that consists of sequential surgical care and good transport capabilities can reduce the complication rate of these injuries. New medical technologies have been implemented in the treatment strategy during the last decade. This article reviews the published scientific data and current opinions on combat-related extremity injuries. Key words: extremity, combat, trauma, medical support system.

Validation of extremes within the Perfect-Predictor Experiment of the COST Action VALUE

NASA Astrophysics Data System (ADS)

Hertig, Elke; Maraun, Douglas; Wibig, Joanna; Vrac, Mathieu; Soares, Pedro; Bartholy, Judith; Pongracz, Rita; Mares, Ileana; Gutierrez, Jose Manuel; Casanueva, Ana; Alzbutas, Robertas

2016-04-01

Extreme events are of widespread concern due to their damaging consequences on natural and anthropogenic systems. From science to applications the statistical attributes of rare and infrequent occurrence and low probability become connected with the socio-economic aspect of strong impact. Specific end-user needs regarding information about extreme events depend on the type of application, but as a joining element there is always the request for easily accessible climate change information with a clear description of their uncertainties and limitations. Within the Perfect-Predictor Experiment of the COST Action VALUE extreme indices modelled from a wide range of downscaling methods are compared to reference indices calculated from observational data. The experiment uses reference data from a selection of 86 weather stations representative of the different climates in Europe. Results are presented for temperature and precipitation extremes and include aspects of the marginal distribution as well as spell-length related aspects.

Streamflow response to increasing precipitation extremes altered by forest management

NASA Astrophysics Data System (ADS)

Kelly, Charlene N.; McGuire, Kevin J.; Miniat, Chelcy Ford; Vose, James M.

2016-04-01

Increases in extreme precipitation events of floods and droughts are expected to occur worldwide. The increase in extreme events will result in changes in streamflow that are expected to affect water availability for human consumption and aquatic ecosystem function. We present an analysis that may greatly improve current streamflow models by quantifying the impact of the interaction between forest management and precipitation. We use daily long-term data from paired watersheds that have undergone forest harvest or species conversion. We find that interactive effects of climate change, represented by changes in observed precipitation trends, and forest management regime, significantly alter expected streamflow most often during extreme events, ranging from a decrease of 59% to an increase of 40% in streamflow, depending upon management. Our results suggest that vegetation might be managed to compensate for hydrologic responses due to climate change to help mitigate effects of extreme changes in precipitation.

Logit-normal mixed model for Indian Monsoon rainfall extremes

NASA Astrophysics Data System (ADS)

Dietz, L. R.; Chatterjee, S.

2014-03-01

Describing the nature and variability of Indian monsoon rainfall extremes is a topic of much debate in the current literature. We suggest the use of a generalized linear mixed model (GLMM), specifically, the logit-normal mixed model, to describe the underlying structure of this complex climatic event. Several GLMM algorithms are described and simulations are performed to vet these algorithms before applying them to the Indian precipitation data procured from the National Climatic Data Center. The logit-normal model was applied with fixed covariates of latitude, longitude, elevation, daily minimum and maximum temperatures with a random intercept by weather station. In general, the estimation methods concurred in their suggestion of a relationship between the El Niño Southern Oscillation (ENSO) and extreme rainfall variability estimates. This work provides a valuable starting point for extending GLMM to incorporate the intricate dependencies in extreme climate events.

Exploring Occupational Therapists’ Perceptions of the Usefulness of Musculoskeletal Sonography in Upper-Extremity Rehabilitation

PubMed Central

McLaughlin Gray, Julie; Frank, Gelya; Wolkoff, Monique

2015-01-01

OBJECTIVE. To identify the potential utility of musculoskeletal sonographic imaging in upper-extremity rehabilitation. METHOD. Two occupational therapists in an outpatient hand rehabilitation clinic were recruited by convenience, were trained in the use of sonography, and implemented sonographic imaging in their clinical practice. Qualitative data were obtained during and after the implementation period by means of questionnaires and interviews. Data collection, analysis, and interpretation were completed in an iterative process that culminated in a thematic analysis of the therapists’ perceptions. RESULTS. The data indicate four potential areas of utility for musculoskeletal sonography in upper-extremity rehabilitation: (1) mastering anatomy and pathology, (2) augmenting clinical reasoning, (3) supplementing intervention, and (4) building evidence. CONCLUSION. Numerous potential uses were identified that would benefit both therapist and client. Further exploration of complexities and efficacy for increasing patient outcomes is recommended to determine best practices for the use of musculoskeletal sonography in upper-extremity rehabilitation. PMID:26114469

Unveiling non-stationary coupling between Amazon and ocean during recent extreme events

NASA Astrophysics Data System (ADS)

Ramos, Antônio M. de T.; Zou, Yong; de Oliveira, Gilvan Sampaio; Kurths, Jürgen; Macau, Elbert E. N.

2018-02-01

The interplay between extreme events in the Amazon's precipitation and the anomaly in the temperature of the surrounding oceans is not fully understood, especially its causal relations. In this paper, we investigate the climatic interaction between these regions from 1999 until 2012 using modern tools of complex system science. We identify the time scale of the coupling quantitatively and unveil the non-stationary influence of the ocean's temperature. The findings show consistently the distinctions between the coupling in the recent major extreme events in Amazonia, such as the two droughts that happened in 2005 and 2010 and the three floods during 1999, 2009 and 2012. Interestingly, the results also reveal the influence over the anomalous precipitation of Southwest Amazon has become increasingly lagged. The analysis can shed light on the underlying dynamics of the climate network system and consequently can improve predictions of extreme rainfall events.

The impacts of climate change on the risk of natural disasters.

PubMed

van Aalst, Maarten K

2006-03-01

Human emissions of greenhouse gases are already changing our climate. This paper provides an overview of the relation between climate change and weather extremes, and examines three specific cases where recent acute events have stimulated debate on the potential role of climate change: the European heatwave of 2003; the risk of inland flooding, such as recently in Central Europe and Great Britain; and the harsh Atlantic hurricane seasons of 2004 and 2005. Furthermore, it briefly assesses the relation between climate change and El Niño, and the potential of abrupt climate change. Several trends in weather extremes are sufficiently clear to inform risk reduction efforts. In many instances, however, the potential increases in extreme events due to climate change come on top of alarming rises in vulnerability. Hence, the additional risks due to climate change should not be analysed or treated in isolation, but instead integrated into broader efforts to reduce the risk of natural disasters.