Teratology studies in the rat.

Science.gov (United States)

Leroy, Mariline; Allais, Linda

2013-01-01

The rat is the rodent species of choice for the regulatory safety testing of xenobiotics, such as medicinal products, food additives, and other chemicals. Many decades of experience and extensive data have accumulated for both general and developmental toxicology investigations in this species. The high fertility and large litter size of the rat are advantages for teratogenicity testing. The study designs are well defined in the regulatory guidelines and are relatively standardized between testing laboratories across the world. Teratology studies address maternal- and embryo-toxicity following exposure during the period of organogenesis. This chapter describes the design and conduct of a teratology study in the rat in compliance with the regulatory guidelines. The procedures for the handling and housing of the pregnant animals, the caesarean examinations and the sampling of fetuses for morphological examinations are described. The utility and design of preliminary studies and the inclusion of satellite animals in the main study for toxicokinetic sampling are discussed.

Czech Teratology Information Service: comparison of treatments by psychotropic and antiepileptic drugs.

Science.gov (United States)

Manáková, Eva; Hubicková-Heringová, Lucie; Jelínek, Richard

2006-12-01

Care, treatment and follow-up in psychiatric and epileptic pregnant women were compared with women inquiring Czech Teratology Information Service (CZTIS) due to other exposure to drugs during pregnancy. Data were collected by CZTIS, member of European Network of Teratology Information Services from 1996. Exposed groups were compared with pregnant women exposed to drugs which were not classified as major teratogens or hyperthermia. Groups do not vary in age, reproductive history and other parameters. We observed higher frequency of miscarriage and voluntary termination of pregnancy in the group of psychiatric patients. The number of malformation in prospective follow-up cases was lower than in control group. Chronic diseases as epilepsy or psychiatric disorders have to be treated during pregnancy. Women should obtain accurate information about possible risk before pregnancy. Co-operation is needed in these cases. Physicians should keep in mind that appropriate information is to be given to the patient according to her disease, education and comprehension of the problem. If there is any doubt they should organize help for their patients.

Thomas H. Shepard, M.D., pioneer in embryology and teratology.

Science.gov (United States)

Fantel, Alan G; Polifka, Janine E; Oakley, Godfrey P

2017-06-01

Dr. Thomas H. Shepard died on October 3, 2016 at the age of 93. He was a major figure in the fields of teratology, embryonic and fetal pathology, and pediatrics. He was beloved by his colleagues as he was by the many students and fellows whom he taught, mentored and befriended. His contributions to teratology are extraordinary and he is greatly missed. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

A hitchhiker's guide to the older literature of descriptive teratology.

Science.gov (United States)

Beckwith, J Bruce

2007-12-15

Though relatively neglected in the age of molecular biology, the older literature of teratology includes superb illustrations and descriptions of malformations, and other information of permanent value to science and medicine. Accessing that literature can be challenging, as most is in works that are rare, published in languages other than English, and not available in digital form. This article describes some valuable sources of information concerning the antiquarian literature of descriptive teratology. (c) 2007 Wiley-Liss, Inc.

Teratology – past, present and future

Science.gov (United States)

Mach, Mojmír; Navarová, Jana; Brucknerová, Ingrid; Dubovický, Michal

2012-01-01

Teratology is the science that studies the causes, mechanisms, and patterns of abnormal development. The authors present an updated overview of the most important milestones and stages of the development of modern teratology. Development of knowledge and society led to the recognition that causes of congenital developmental disorders (CDDs) might be caused by various mechanical effects, foetal diseases, and retarded or arrested development of the embryo and foetus. Based on the analysis of the historical development of hypotheses and theories representing a decisive contribution to this field, we present a survey of the six Wilson′s fundamental principles of teratology. The aim of observing these principles is to get insight into developmental relations and to understand mechanisms of action on the level of cell populations (elementary morphogenetic processes), tissues and organs. It is important to realise that any negative intervention into the normal course of these processes, either on genetic or non-genetic basis, inevitably leads to a sequence of subsequent changes resulting in CDDs. Moreover, the classical toxicologic monotonic dose-response paradigm recently has been challenged by the so-called “low dose-hypothesis”, particularly in the case of endocrine active substances. These include some pesticides, dioxins, polychlorobiphenyls (PCBs), and bisphenol A. Despite modern approaches of molecular biology and genetics, along with top diagnostic techniques, we are still not able to identify the actual cause in more than 65 to 70% of all congenital defects classified as having an unknown etiology. Today CDDs include any birth defect, either morphological, biochemical, or behavioural. PMID:23554558

Initiating events frequency determination

International Nuclear Information System (INIS)

Simic, Z.; Mikulicic, V.; Vukovic, I.

2004-01-01

The paper describes work performed for the Nuclear Power Station (NPS). Work is related to the periodic initiating events frequency update for the Probabilistic Safety Assessment (PSA). Data for all relevant NPS initiating events (IE) were reviewed. The main focus was on events occurring during most recent operating history (i.e., last four years). The final IE frequencies were estimated by incorporating both NPS experience and nuclear industry experience. Each event was categorized according to NPS individual plant examination (IPE) initiating events grouping approach. For the majority of the IE groups, few, or no events have occurred at the NPS. For those IE groups with few or no NPS events, the final estimate was made by means of a Bayesian update with general nuclear industry values. Exceptions are rare loss-of-coolant-accidents (LOCA) events, where evaluation of engineering aspects is used in order to determine frequency.(author)

An updated history of the Teratology Society.

Science.gov (United States)

Shepard, Thomas H; Barr, Mason; Brent, Robert L; Hendrickx, Andrew; Kochhar, Devendra; Oakley, Godfrey; Scott, William J; Rogers, John M

2010-05-01

The 49-year history of the Teratology Society is reviewed. An abbreviated history is outlined in table form, with listings of the Warkany Lectures, the Continuing Education Courses, and officers of the society. The original article was updated to include the years 2000 to 2010. A year-by-year description of the events is given, including the scientific and social content of the annual meetings and changes in the business of the society, in many cases using comments from the past presidents. The valuable and unique diversity of the members is discussed and illustrated, presenting the disciplines and main research areas of the presidents. The number of submitted abstracts and the various categories are tabulated, averaging the number and type over successive periods. A significant increase in the number of abstracts dealing with epidemiology and developmental biology is evident. The society's development is compared to that of a human, and the question was asked by Shephard et al. (2000): Have we reached the maturational stage of old age or senescence, or is the society still maturing gracefully? This question needs further discussion by all the members. By 2010, many positive changes are happening to revitalize the society. During the past 50 years, we have developed the scientific basis to prevent birth defects caused by rubella, alcoholism, and folate deficiency, as well as other prenatal exposures. We are now taking advantage of advances in many fields to begin shaping the Teratology Society of the 21st century. We must now engage in political battles to obtain the resources needed to conduct further research and to implement prevention programs, as well as to provide care and rehabilitation for persons with birth defects. 2010 Wiley-Liss, Inc.

Teratology on the crossroads: historical aspects and modern approaches.

Science.gov (United States)

Ujházy, Eduard; Mach, Mojmír; Navarová, Jana; Dubovický, Michal

2012-01-01

Teratology is the science of congenital developmental disorders (CDDs), overt or latent defects of the organism resulting from the effect of internal and external factors on developmental processes. In this article the significance and position of present-day teratology is discussed in the context of development of this branch of science and related disciplines. The authors present an updated overview of the most important milestones and stages of the development of teratology. Based on the analysis of the historical development of theses and theories that represent a decisive contribution to this field, we present a survey of the fundamental principles of experimental and clinical teratology. The aim of observing these principles is to get insight into developmental relations and to understand mechanisms of action on the level of cell populations (elementary morphogenetic processes), tissues and organs. It is important to realize that any negative intervention into the normal course of these processes, either on genetic or non-genetic basis, inevitably leads to a sequence of subsequent changes resulting in the development of congenital developmental disorders. Despite modern approaches of molecular biology and genetics, along with top diagnostic techniques, we are still not able to identify the actual cause in more than 50% of all congenital defects. One-half of the unidentified cases are referred to as "multifactorial", a term that is rather ambiguous. It either means that some of the basic principles of teratogenesis still escape our attention, or the interpretation of some of the well known principles might be misleading. A third possibility is rather pessimistic. The development of the individual is so sophisticated and dependent on a delicate network of a multitude of factors mutually affecting each other that it is extremely prone to give rise to a plethora of spontaneous errors which are unpredictable and impossible to prevent. Nevertheless, the long and

The contribution of new findings and ideas to the old principles of teratology.

Science.gov (United States)

Jelínek, Richard

2005-01-01

Although the last generally accepted concept of principles of teratology was issued more than 30 years ago, the cause of less than 50% of all congenital anomalies is known and no substantial change in their incidence has been observed worldwide. In the meantime, powerful techniques of molecular biology as well as many sophisticated preventive measures have been introduced with marginal effects on the overall birth defects numbers. In this paper, we follow the history of basic concepts of teratology starting with Isidore Geoffroy Saint-Hilaire and Dareste, followed in the 20th century by James Wilson. Since that time no bright and completely new idea, which would deserve the name principle, has emerged. The advanced molecular studies support the long-existing principles and disclose the great variability of individuals and their responses to adverse exposures. In this way, the future of teratology counseling may be seen in a deep analysis of any individual case.

Cost effectiveness of teratology counseling - the Motherisk experience.

Science.gov (United States)

Koren, Gideon; Bozzo, Pina

2014-01-01

While the benefits of evidence-based counseling to large numbers of women and physicians are intuitively evident, there is an urgent need to document that teratology counseling, in addition to improving the quality of life of women and families, also leads to cost saving. The objective of the present study was to calculate the cost effectiveness of the Motherisk Program, a large teratology information and counseling service at The Hospital for Sick Children and the University of Toronto. We analyzed data from the Motherisk Program on its 2012 activities in two domains: 1) Calculation of cost-saving in preventing unjustified pregnancy terminations; and 2) prevention of major birth defects. Cost of pregnancy termination and lifelong cost of specific birth defects were identified from primary literature and prorated for cost of living for the year 2013. Prevention of 255 pregnancy terminations per year led to cost savings of $516,630. The total estimated number of major malformations prevented by Motherisk counseling in 2012 was 8.41 cases at a total estimated cost of $9,032,492. With an estimated minimum annual prevention of 8 major malformations, and numerous unnecessary terminations of otherwise- wanted pregnancies, a cost saving of $10 million can be calculated. In 2013 the operating budget of Motherisk counseling totaled $640,000. Even based on the narrow range of activities for which we calculated cost, this service is highly cost- effective. Because most teratology counseling services are operating in a very similar method to Motherisk, it is fair to assume that these results, although dependent on the size of the service, are generalizable to other countries.

Reporting of teratology studies.

Science.gov (United States)

Barrow, Paul C; Reynaud, Lucie

2013-01-01

The regulatory toxicology report is an unusual document that requires a particular skill to write. The report must be clear, accurate, concise, and focused. A clear and direct writing style is required. The end-users of the report will hope to find the information they seek with as little effort as possible. Few, or none, will read the entire document. The author should aim to appease the user by obliging him to read as little text and turn as few pages as possible. This chapter gives tips and guidance on how to present the experimental data and write the narrative text in the final study report for a teratology study.

Digital data and the 19th century teratology collection

NARCIS (Netherlands)

Baljet, B.; Oostra, R. J.

1999-01-01

The golden age of descriptive teratology (congenital anomalies) was between 1750 and 1850. During that period, the study of human congenital malformations, especially those dramatic examples designated as 'monsters', attracted special attention. One of the finest collections in this field was Museum

The effectiveness of Teratology Information Services (TIS).

Science.gov (United States)

Hancock, Rebecca L; Koren, Gideon; Einarson, Adrienne; Ungar, Wendy J

2007-02-01

Women and their health care providers have few reliable sources of information regarding the safety of exposures in pregnancy and lactation. Evidence-based information on these topics is provided by Teratology Information Services (TIS). Access to TIS, however, is limited in many regions, and many services have difficulty maintaining ongoing funding. The objective of this review is to highlight published reports of the effectiveness of TIS in improving maternal and neonatal health. A search of the Pub Med and Econ Lit databases was performed with no date restriction, using the search terms teratology, information, counseling, pregnancy, effectiveness, birth defects. Information disseminated from TIS has been shown to prevent congenital malformations, unnecessary pregnancy terminations, and occupational risks. TIS support optimal nutritional supplementation in pregnancy and optimal drug therapy in pregnancy and breast-feeding. In addition, they correct misperceptions of risk and facilitate knowledge transfer and translation. TIS have the potential to provide health care cost savings. TIS are vital services in supporting optimal maternal and neonatal health. A formal economic evaluation of TIS is required in order to inform resource allocation decision-making and continued funding of these services.

Categorization of fetal external findings in developmental toxicology studies by the Terminology Committee of the Japanese Teratology Society.

Science.gov (United States)

Izumi, Yuko; Ooshima, Yojiro; Chihara, Kazuhiro; Fujiwara, Michio; Katsumata, Yoshihiro; Shiota, Kohei

2018-05-01

Categorization of fetal external findings in common laboratory animals, intended to make the agreement at Berlin Workshop in 2014 more practical, was proposed by the Terminology Committee of the Japanese Teratology Society at the Workshop in the 55th Japanese Teratology Society Annual Meeting in 2015. In the Workshop, 73 external findings, which had been categorized as "Gray zone" anomalies but not as "Malformation" or "Variation" in the 2014 Berlin Workshop, were discussed and classified as Malformation, "Non-structural abnormality," Variation, and "Not applicable." The proposal was based on the results of a survey conducted in 2014, where 20 facilities (including pharmaceutical, chemical, and pesticide companies and contract laboratories) and 2 selected expert teratologists in Japan were asked for their opinions on the categorization of these findings. Based on the discussion, Japanese Teratology Society members have agreed that 42 out of the 73 findings can be classified as Malformations (38), Non-structural abnormalities (3), Malformations/Non-structural abnormalities (1), and Variations (0), while the remaining 31 findings were recommended to be categorized as Not applicable for fetuses. The details of the classification are shown on the website of the Japanese Teratology Society (http://www.umin.ac.jp/cadb/External.pdf). © 2018 Japanese Teratology Society.

Development, anatomy, and genetic control of some teratological phenotypes of Ranunculaceae flowers

Directory of Open Access Journals (Sweden)

Florian Jabbour

2016-04-01

Full Text Available Teratological organisms originate from developmental anomalies, and exhibit structures and a body organization that deviate from the species standard. These monsters give essential clues about the formation and evolutionary significance of the wild-type groundplan. We focus on flower terata, which can be affected in their sterile and/or fertile organs, with special emphasis on the Ranunculaceae. The diversity of perianth shapes and organizations in flowers of this family is huge, and is even increased when anomalies occur during organo- and/or morphogenesis. To begin with, we synthesize the observations and research conducted on the Ranunculacean floral terata, following the most recent phylogenetic framework published in 2016 by our team. Then, we report results regarding the morphology of developing meristems, the anatomy of buds, and the genetic control of selected teratological phenotypes of Ranunculaceae flowers. We focus on species and horticultural varieties belonging to the genera Aquilegia, Delphinium, and Nigella. Wildtype flowers of these species are actinomorphic (Aquilegia, Nigella or zygomorphic (Delphinium, spurred (Aquilegia, Delphinium or with pocket-like petals (Nigella. Last, we discuss the evolutionary potential of such teratological phenotypes when they occur in the wild.

Event group importance measures for top event frequency analyses

International Nuclear Information System (INIS)

1995-01-01

Three traditional importance measures, risk reduction, partial derivative, nd variance reduction, have been extended to permit analyses of the relative importance of groups of underlying failure rates to the frequencies of resulting top events. The partial derivative importance measure was extended by assessing the contribution of a group of events to the gradient of the top event frequency. Given the moments of the distributions that characterize the uncertainties in the underlying failure rates, the expectation values of the top event frequency, its variance, and all of the new group importance measures can be quantified exactly for two familiar cases: (1) when all underlying failure rates are presumed independent, and (2) when pairs of failure rates based on common data are treated as being equal (totally correlated). In these cases, the new importance measures, which can also be applied to assess the importance of individual events, obviate the need for Monte Carlo sampling. The event group importance measures are illustrated using a small example problem and demonstrated by applications made as part of a major reactor facility risk assessment. These illustrations and applications indicate both the utility and the versatility of the event group importance measures

Event group importance measures for top event frequency analyses

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-07-31

Three traditional importance measures, risk reduction, partial derivative, nd variance reduction, have been extended to permit analyses of the relative importance of groups of underlying failure rates to the frequencies of resulting top events. The partial derivative importance measure was extended by assessing the contribution of a group of events to the gradient of the top event frequency. Given the moments of the distributions that characterize the uncertainties in the underlying failure rates, the expectation values of the top event frequency, its variance, and all of the new group importance measures can be quantified exactly for two familiar cases: (1) when all underlying failure rates are presumed independent, and (2) when pairs of failure rates based on common data are treated as being equal (totally correlated). In these cases, the new importance measures, which can also be applied to assess the importance of individual events, obviate the need for Monte Carlo sampling. The event group importance measures are illustrated using a small example problem and demonstrated by applications made as part of a major reactor facility risk assessment. These illustrations and applications indicate both the utility and the versatility of the event group importance measures.

[From teratology to mythology: ancient legends].

Science.gov (United States)

Stahl, A; Tourame, P

2010-12-01

The mythology of the Greeks and Romans is full of monsters of fiction: giants, cyclops, centaurs, hydras, Gorgons… The accounts of travelers, reproduced in the Natural History of Pline l'Ancien reported the existence, in distant countries, of men with a dog's head (baboons), of men with a single tall foot (sciapode), beings whose face is embedded in the chest (or acephala blemmyes), to which must be added a wide variety of men with no mouth, no nose, or equipped with giant ears or feet turned backwards, as well as hermaphrodites. Teratology reports on monstrous births, which have constituted the factual basis from which the imagination conceived adults whose morphology corresponds to the monsters of legend. Newborns sirenomelia were behind the legend of sciapode and sirens. Cyclopia have inspired the legend of the cyclops. Anencephaly probably explains the description of headless or blemmyes. The genesis of the legend of baboons may have multiple origins: firstly the existence of people suffering from congenital hypertrichosis, on the other hand, the influence of Egyptian mythology where the god Anubis has a dog's head. The acardiac fetus may explain some monstrous forms, features the work of Hieronymus Bosch. The significance of the monsters of legend, their genesis, their persistence through the ages is complex. By approaching teratology, we added a new field of exploration of real monsters of antiquity and Middle Ages. Copyright © 2010. Published by Elsevier SAS.

Studies in tropical teratology, 2nd Series, No. I

NARCIS (Netherlands)

Venema, H.J.

1937-01-01

Dr J. J. Smith is best known by his studies about Orchidaceae. But since 1904 he published regularly in collaboration with Dr J. C. Costerus in the ”Annales du Jardin Botanique de Buitenzorg“, the results of their researches in teratology of tropical plants. Some years ago, Dr J. J. Smith was so

The Teratology Society 2007 strategic planning session: a desire to inspire.

Science.gov (United States)

2008-05-01

On April 18-20, 2007, the Teratology Society held its third strategic planning session (SPS) in San Diego, CA. The purpose of this session was to build on the successful work generated by the previous strategic plans [Nashville, TN 2002 and Cincinnati, OH 1997] and importantly, to provide a path forward to inspire the Society, create deeper connections with members that speak to their individual passion for the science of teratology and to increase the Society's visibility within the larger scientific community. The following summary report provides an overview of the session's pre-work, objective, and discussions. A total of 24 attendees were present at the session. The group included representation from Council, various committees and different members constituencies. This plan and the activities subsequent to the session will provide a path forward for our Society for the next five years.

The teratology society 2012-2017 strategic plan: pushing the boundaries.

Science.gov (United States)

Curran, Christine Perdan; Lau, Christopher; Schellpfeffer, Michael A; Stodgell, Christopher J; Carney, Edward W

2013-01-01

The Teratology Society held its fourth strategic planning session in Albuquerque, NM, April 10-12, 2012, and launched the 2012-2017 Strategic Plan in conjunction with the 2012 annual meeting in Baltimore, MD. Building on the energy of the successful implementation of prior strategic plans (San Diego, 2007; Nashville,TN 2002; Cincinnati, OH 1998), session participants worked to identify barriers to success as a scientific society, as well as impending challenges and opportunities to which the Society needs to respond. The following report provides an overview of the Strategic Planning process, objectives, activities, and conclusions. A total of 23 members were present at the session, and the group included representation from Council, various committees, and different member constituencies. This plan, Pushing the Boundaries, and its three strategic intents: Broaden Our Identity, Expand Our Membership, and Increase Our Influence, will drive the direction of the Teratology Society for the next five years. Copyright © 2013 Wiley Periodicals, Inc.

Drug safety in pregnancy: utopia or achievable prospect? Risk information, risk research and advocacy in Teratology Information Services.

Science.gov (United States)

Schaefer, Christof

2011-03-01

Even though from preclinical testing to drug risk labeling, the situation with drugs in pregnancy has improved substantially since the thalidomide scandal, there is still an increasing need to provide healthcare professionals and patients with updated individualized risk information for clinical decision making. For the majority of drugs, clinical experience is still insufficient with respect to their safety in pregnancy. There is often uncertainty in how to interpret the available scientific data. Based on 20 years of experience with Teratology Information Services (TIS) cooperating in the European Network of Teratology Information Services (ENTIS) methods of risk interpretation, follow-up of exposed pregnancies through the consultation process and their evaluation is discussed. Vitamin K antagonists, isotretinoin and angiotensin (AT) II-receptor-antagonists are presented as examples of misinterpretation of drug risks and subjects of research based on observational clinical data recorded in TIS. As many TIS are poorly funded, advocacy is necessary by establishing contacts with decision makers in health politics and administration, informing them of the high return in terms of health outcomes and cost savings provided by TIS as reference institutions in clinical teratology. © 2011 The Author. Congenital Anomalies © 2011 Japanese Teratology Society.

Understanding the cone scale in Cupressaceae: insights from seed-cone teratology in Glyptostrobus pensilis.

Science.gov (United States)

Dörken, Veit Martin; Rudall, Paula J

2018-01-01

Both wild-type and teratological seed cones are described in the monoecious conifer Glyptostrobus pensilis and compared with those of other Cupressaceae sensu lato and other conifers. Some Cupressaceae apparently possess a proliferation of axillary structures in their cone scales. In our interpretation, in Glyptostrobus each bract of both typical and atypical seed cones bears two descending accessory shoots, interpreted here as seed scales (ovuliferous scales). The primary seed scale is fertile and forms the ovules, the second is sterile and forms characteristic tooth-like structures. The bract and the two axillary seed scales are each supplied with a single distinct vascular bundle that enters the cone axis as a separate strand; this vasculature also characterises the descending accessory short shoots in the vegetative parts of the crown. In wild-type seed cones, the fertile seed scale is reduced to its ovules, and the ovules are always axillary. In contrast, the ovules of some of the teratological seed cones examined were located at the centre of the cone scale. An additional tissue found on the upper surface of the sterile lower seed scale is here interpreted as the axis of the fertile seed scale. Thus, the central position of the ovules can be explained by recaulescent fusion of the upper fertile and lower sterile seed scales. In several teratological cone scales, the ovules were enveloped by an additional sterile tissue that is uniseriate and represents an epidermal outgrowth of the fertile seed scale. Close to the ovules, the epidermis was detached from lower tissue and surrounded the ovule completely, except at the micropyle. These teratological features are potentially significant in understanding seed-cone homologies among extant conifers.

Understanding the cone scale in Cupressaceae: insights from seed-cone teratology in Glyptostrobus pensilis

Directory of Open Access Journals (Sweden)

Veit Martin Dörken

2018-06-01

Full Text Available Both wild-type and teratological seed cones are described in the monoecious conifer Glyptostrobus pensilis and compared with those of other Cupressaceae sensu lato and other conifers. Some Cupressaceae apparently possess a proliferation of axillary structures in their cone scales. In our interpretation, in Glyptostrobus each bract of both typical and atypical seed cones bears two descending accessory shoots, interpreted here as seed scales (ovuliferous scales. The primary seed scale is fertile and forms the ovules, the second is sterile and forms characteristic tooth-like structures. The bract and the two axillary seed scales are each supplied with a single distinct vascular bundle that enters the cone axis as a separate strand; this vasculature also characterises the descending accessory short shoots in the vegetative parts of the crown. In wild-type seed cones, the fertile seed scale is reduced to its ovules, and the ovules are always axillary. In contrast, the ovules of some of the teratological seed cones examined were located at the centre of the cone scale. An additional tissue found on the upper surface of the sterile lower seed scale is here interpreted as the axis of the fertile seed scale. Thus, the central position of the ovules can be explained by recaulescent fusion of the upper fertile and lower sterile seed scales. In several teratological cone scales, the ovules were enveloped by an additional sterile tissue that is uniseriate and represents an epidermal outgrowth of the fertile seed scale. Close to the ovules, the epidermis was detached from lower tissue and surrounded the ovule completely, except at the micropyle. These teratological features are potentially significant in understanding seed-cone homologies among extant conifers.

Teratology studies in the mouse.

Science.gov (United States)

Marsden, Edward; Leroy, Mariline

2013-01-01

The rat is the routine species of choice as the rodent model for regulatory safety testing of xenobiotics such as medicinal products, food additives, and other chemicals. However, the rat is not always suitable for pharmacological, toxicological, immunogenic, pharmacokinetic, or even practical reasons. Under such circumstances, the mouse offers an alternative for finding a suitable rodent model acceptable to the regulatory authorities. Since all essential routes of administration are possible, the short reproductive cycle and large litter size of the mouse make it a species well adapted for use in teratology studies. Given that good quality animals, including virgin mated females, can be acquired relatively easily and inexpensively, the mouse has been used in reproductive toxicity studies for decades and study protocols are well established.

Grid Frequency Extreme Event Analysis and Modeling: Preprint

Energy Technology Data Exchange (ETDEWEB)

Florita, Anthony R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Clark, Kara [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gevorgian, Vahan [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Folgueras, Maria [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Wenger, Erin [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-11-01

Sudden losses of generation or load can lead to instantaneous changes in electric grid frequency and voltage. Extreme frequency events pose a major threat to grid stability. As renewable energy sources supply power to grids in increasing proportions, it becomes increasingly important to examine when and why extreme events occur to prevent destabilization of the grid. To better understand frequency events, including extrema, historic data were analyzed to fit probability distribution functions to various frequency metrics. Results showed that a standard Cauchy distribution fit the difference between the frequency nadir and prefault frequency (f_(C-A)) metric well, a standard Cauchy distribution fit the settling frequency (f_B) metric well, and a standard normal distribution fit the difference between the settling frequency and frequency nadir (f_(B-C)) metric very well. Results were inconclusive for the frequency nadir (f_C) metric, meaning it likely has a more complex distribution than those tested. This probabilistic modeling should facilitate more realistic modeling of grid faults.

A history of the Teratology Society.

Science.gov (United States)

Shepard, T H; Barr, M; Brent, R L; Hendrickx, A; Kochhar, D; Oakley, G; Scott, W J

2000-11-01

The 39-year history of the Teratology Society is reviewed. An abbreviated history is outlined in table form, along with listings of the Warkany Lectures, the postgraduate courses, and officers of the Society. A year-by-year description of the events, including the scientific and social content of the annual meetings and changes in the business of the Society, is given, in many cases using comments from the past presidents. The valuable and unique diversity of the members is discussed and illustrated, presenting the disciplines and main research area of the presidents. The number of submitted abstracts and the various categories are tabulated, averaging the number and type over four periods. Within the past 10 years, a significant increase in the number of abstracts dealing with epidemiology and developmental biology is evident. The Society's development is compared with that of a human, and the question is asked: Have we reached the maturational stage of old age or senescence, or is the Society still maturing gracefully? This question needs further discussion by all the members. During the past 40 years, we have developed the scientific basis to prevent birth defects caused by rubella, alcoholism, and folate deficiency, as well as many other prenatal exposures. We must now engage in the political battles to obtain the resources needed to conduct further research and to implement the prevention programs, as well as to provide care and rehabilitation for persons with birth defects. Copyright 2000 Wiley-Liss, Inc.

A mixed model framework for teratology studies.

Science.gov (United States)

Braeken, Johan; Tuerlinckx, Francis

2009-10-01

A mixed model framework is presented to model the characteristic multivariate binary anomaly data as provided in some teratology studies. The key features of the model are the incorporation of covariate effects, a flexible random effects distribution by means of a finite mixture, and the application of copula functions to better account for the relation structure of the anomalies. The framework is motivated by data of the Boston Anticonvulsant Teratogenesis study and offers an integrated approach to investigate substantive questions, concerning general and anomaly-specific exposure effects of covariates, interrelations between anomalies, and objective diagnostic measurement.

Comments from the Behavioral Teratology Committee of the Japanese Teratology Society on OECD guideline for the testing of chemicals, proposal for a new guideline 426, developmental neurotoxicity study, draft document (September 2003).

Science.gov (United States)

Fukui, Yoshihiro; Ema, Makoto; Fujiwara, Michio; Higuchi, Hashihiro; Inouye, Minoru; Iwase, Takayuki; Kihara, Takahide; Nishimura, Tatsuya; Oi, Akihide; Ooshima, Yojiro; Otani, Hiroki; Shinomiya, Mitsuhiro; Sugioka, Kozo; Yamano, Tsunekazu; Yamashita, Keisuke H; Tanimura, Takashi

2004-09-01

In September 2003, a new revision of the draft guideline (Organization for Economic Co-operation and Development [OECD] Guideline for the Testing of Chemicals, Proposal for a New Guideline 426, Developmental Neurotoxicity Study) was distributed. The draft guideline consists of 51 paragraphs and an appendix. The National Coordinators were requested to arrange national expert reviews of the guideline proposal in their member countries. The member of the Behavioral Teratology (BT) Committee of the Japanese Teratology Society (JTS) reviewed, discussed and commented on the draft Test Guideline proposal. The BT Committee of the JTS also commented that the International Collaborative Study to validate this protocol should be definitely performed. These comments were sent to the OECD Secretariat. The BT Committee of the JTS expects that the comments are useful for further discussion.

Recurrent frequency-size distribution of characteristic events

Directory of Open Access Journals (Sweden)

S. G. Abaimov

2009-04-01

Full Text Available Statistical frequency-size (frequency-magnitude properties of earthquake occurrence play an important role in seismic hazard assessments. The behavior of earthquakes is represented by two different statistics: interoccurrent behavior in a region and recurrent behavior at a given point on a fault (or at a given fault. The interoccurrent frequency-size behavior has been investigated by many authors and generally obeys the power-law Gutenberg-Richter distribution to a good approximation. It is expected that the recurrent frequency-size behavior should obey different statistics. However, this problem has received little attention because historic earthquake sequences do not contain enough events to reconstruct the necessary statistics. To overcome this lack of data, this paper investigates the recurrent frequency-size behavior for several problems. First, the sequences of creep events on a creeping section of the San Andreas fault are investigated. The applicability of the Brownian passage-time, lognormal, and Weibull distributions to the recurrent frequency-size statistics of slip events is tested and the Weibull distribution is found to be the best-fit distribution. To verify this result the behaviors of numerical slider-block and sand-pile models are investigated and the Weibull distribution is confirmed as the applicable distribution for these models as well. Exponents β of the best-fit Weibull distributions for the observed creep event sequences and for the slider-block model are found to have similar values ranging from 1.6 to 2.2 with the corresponding aperiodicities C_V of the applied distribution ranging from 0.47 to 0.64. We also note similarities between recurrent time-interval statistics and recurrent frequency-size statistics.

Teratology Public Affairs Committee position paper: maternal obesity and pregnancy.

Science.gov (United States)

Scialli, Anthony R

2006-02-01

Compared to normal-weight women, obese women have an increased risk of infertility and pregnancy complications. The most consistently described pregnancy complications are hypertensive disorders, gestational diabetes mellitus, thromboembolic events, and cesarean section. Fetal and neonatal complications may include congenital malformations, macrosomia, and shoulder dystocia. The literature suggests that women with a body mass index (BMI) >or=30 have approximately double the risk of having a child with a neural tube defect (NTD) compared to normal-weight women, and the increased risk associated with higher maternal body weight does not appear to be modified by folic acid supplementation. The Public Affairs Committee of the Teratology Society supports the public health initiatives identified by the U.S. Food and Drug Administration in 2004 and the research initiatives identified by the National Institutes of Health in 2004. The Public Affairs Committee recommends that clinicians counsel women about appropriate caloric intake and exercise and that health-care providers educate parents about appropriate childhood nutrition. Breast-feeding should be encouraged based on evidence of a protective effect against childhood obesity, as well as other health advantages. Birth Defects Research (Part A), 2006. (c) 2006 Wiley-Liss, Inc.

TERATOLOGY SOCIETY 1998 PUBLIC AFFAIRS COMMITTEE SYMPOSIUM: THE NEW THALIDOMIDE ERA: DEALING WITH THE RISKS

Science.gov (United States)

The Teratology Society Public Affairs Committee Symposium was held on June 21, 1998, during the Society's annual meeting in San Diego, California. The symposium was organized and chaired by Dr. Carole Kimmel. The sysmposium was designed to consider the medical, social, and ethi...

History and highlights of the teratological collection in the Museum Anatomicum of Leiden University, The Netherlands

NARCIS (Netherlands)

Boer, Lucas L.; Boek, Peter L. J.; van Dam, Andries J.; Oostra, Roelof-Jan

2018-01-01

The anatomical collection of the Anatomical Museum of Leiden University Medical Center (historically referred to as Museum Anatomicum Academiae Lugduno-Batavae) houses and maintains more than 13,000 unique anatomical, pathological and zoological specimens, and include the oldest teratological

Development of transient initiating event frequencies for use in probabilistic risk assessments

International Nuclear Information System (INIS)

Mackowiak, D.P.; Gentillon, C.D.; Smith, K.L.

1985-05-01

Transient initiating event frequencies are an essential input to the analysis process of a nuclear power plant probabilistic risk assessment. These frequencies describe events causing or requiring scrams. This report documents an effort to validate and update from other sources a computer-based data file developed by the Electric Power Research Institute (EPRI) describing such events at 52 United States commercial nuclear power plants. Operating information from the United States Nuclear Regulatory Commission on 24 additional plants from their date of commercial operation has been combined with the EPRI data, and the entire data base has been updated to add 1980 through 1983 events for all 76 plants. The validity of the EPRI data and data analysis methodology and the adequacy of the EPRI transient categories are examined. New transient initiating event frequencies are derived from the expanded data base using the EPRI transient categories and data display methods. Upper bounds for these frequencies are also provided. Additional analyses explore changes in the dominant transients, changes in transient outage times and their impact on plant operation, and the effects of power level and scheduled scrams on transient event frequencies. A more rigorous data analysis methodology is developed to encourage further refinement of the transient initiating event frequencies derived herein. Updating the transient event data base resulted in approx.2400 events being added to EPRI's approx.3000-event data file. The resulting frequency estimates were in most cases lower than those reported by EPRI, but no significant order-of-magnitude changes were noted. The average number of transients per year for the combined data base is 8.5 for pressurized water reactors and 7.4 for boiling water reactors

Development of transient initiating event frequencies for use in probabilistic risk assessments

Energy Technology Data Exchange (ETDEWEB)

Mackowiak, D.P.; Gentillon, C.D.; Smith, K.L.

1985-05-01

Transient initiating event frequencies are an essential input to the analysis process of a nuclear power plant probabilistic risk assessment. These frequencies describe events causing or requiring scrams. This report documents an effort to validate and update from other sources a computer-based data file developed by the Electric Power Research Institute (EPRI) describing such events at 52 United States commercial nuclear power plants. Operating information from the United States Nuclear Regulatory Commission on 24 additional plants from their date of commercial operation has been combined with the EPRI data, and the entire data base has been updated to add 1980 through 1983 events for all 76 plants. The validity of the EPRI data and data analysis methodology and the adequacy of the EPRI transient categories are examined. New transient initiating event frequencies are derived from the expanded data base using the EPRI transient categories and data display methods. Upper bounds for these frequencies are also provided. Additional analyses explore changes in the dominant transients, changes in transient outage times and their impact on plant operation, and the effects of power level and scheduled scrams on transient event frequencies. A more rigorous data analysis methodology is developed to encourage further refinement of the transient initiating event frequencies derived herein. Updating the transient event data base resulted in approx.2400 events being added to EPRI's approx.3000-event data file. The resulting frequency estimates were in most cases lower than those reported by EPRI, but no significant order-of-magnitude changes were noted. The average number of transients per year for the combined data base is 8.5 for pressurized water reactors and 7.4 for boiling water reactors.

Mutational jackpot events generate effective frequency-dependent selection in adapting populations

Science.gov (United States)

Hallatschek, Oskar

The site-frequency spectrum is one the most easily measurable quantities that characterize the genetic diversity of a population. While most neutral models predict that site frequency spectra should decay with increasing frequency, a high-frequency uptick has been reported in many populations. Anomalies in the high-frequency tail are particularly unsettling because the highest frequencies can be measured with greatest accuracy. Here, we show that an uptick in the spectrum of neutral mutations generally arises when mutant frequencies are dominated by rare jackpot events, mutational events with large descendant numbers. This leads to an effective pattern of frequency-dependent selection (or unstable internal equilibrium at one half frequency) that causes an accumulation of high-frequency polymorphic sites. We reproduce the known uptick occurring for recurrent hitchhiking (genetic draft) as well as rapid adaptation, and (in the future) generalize the shape of the high-frequency tail to other scenarios that are dominated by jackpot events, such as frequent range expansions. We also tackle (in the future) the inverse approach to use the high-frequency uptick for learning about the tail of the offspring number distribution. Positively selected alleles need to surpass, typically, an u NSF Career Award (PoLS), NIH NIGMS R01, Simons Foundation.

A Method to Quantify Plant Availability and Initiating Event Frequency Using a Large Event Tree, Small Fault Tree Model

International Nuclear Information System (INIS)

Kee, Ernest J.; Sun, Alice; Rodgers, Shawn; Popova, ElmiraV; Nelson, Paul; Moiseytseva, Vera; Wang, Eric

2006-01-01

South Texas Project uses a large fault tree to produce scenarios (minimal cut sets) used in quantification of plant availability and event frequency predictions. On the other hand, the South Texas Project probabilistic risk assessment model uses a large event tree, small fault tree for quantifying core damage and radioactive release frequency predictions. The South Texas Project is converting its availability and event frequency model to use a large event tree, small fault in an effort to streamline application support and to provide additional detail in results. The availability and event frequency model as well as the applications it supports (maintenance and operational risk management, system engineering health assessment, preventive maintenance optimization, and RIAM) are briefly described. A methodology to perform availability modeling in a large event tree, small fault tree framework is described in detail. How the methodology can be used to support South Texas Project maintenance and operations risk management is described in detail. Differences with other fault tree methods and other recently proposed methods are discussed in detail. While the methods described are novel to the South Texas Project Risk Management program and to large event tree, small fault tree models, concepts in the area of application support and availability modeling have wider applicability to the industry. (authors)

[The Teratology Information Service: medicines during pregnancy and lactation].

Science.gov (United States)

de Vries, Loes C; de Swart, Irene W; van Puijenbroek, Eugène P

2016-01-01

Many women use medication during pregnancy. Both the healthcare professional and the pregnant woman often have many questions about the possible adverse effects of the medication that are not always answered in the product information. The Teratology Information Service (TIS), a part of the Netherlands Pharmacovigilance Centre Lareb, is a centre of expertise in the field of the safety of medication use and other external influences during spermatogenesis, pregnancy and lactation. The TIS collects, interprets, and disseminates information that can contribute to patient care. Healthcare professionals can contact the TIS for information and individual risk assessments. In this article we discuss the background and positioning of the TIS, the characteristics of telephone consultations, the collection of data and the considerations that are important for the use of medication during pregnancy and lactation.

A Study on the Frequency of Initiating Event of OPR-1000 during Outage Periods

Energy Technology Data Exchange (ETDEWEB)

Hong Jae Beol; Jae, Moo Sung [Hanyang Univ., Seoul (Korea, Republic of)

2013-10-15

These sources of data did not reflect the latest event data which have occurred during the PWR outage to the frequencies of initiating event Electric Power Research Institute(EPRI) in USA collected the data of loss of decay heat removal during outage from 1989 to 2009 and published technical report. Domestic operating experiences for LOOP is gathered in Operational Performance Information System for Nuclear Power Plant(OPIS). To reduce conservatism and obtain completeness for LPSD PSA, those data should be collected and used to update the frequencies. The frequencies of LOSDC and LOOP are reevaluated using the data of EPRI and OPIS in this paper. Quantification is conducted to recalculate core damage frequency(CDF), since the rate is changed. The results are discussed below. To make an accurate estimate of the initiating events of LPSD PSA, the event data were collected and the frequencies of initiating events were updated using Bayesian approach. CDF was evaluated through quantification. Δ CDF is -40% and the dominant contributor is pressurizer PSV stuck open event. The most of the event data in EPRI TR were collected from US nuclear power plant industry. Those data are not enough to evaluate outage risk precisely. Therefore, to reduce conservatism and obtain completeness for LPSD PSA, the licensee event report and domestic data should be collected and reflected to the frequencies of the initiating events during outage.

[POETRYAND TERATOLOGY: LORENZO MASCHERONI'S "INVITO A LESBIA CIDONIA" IN ANATOMICAL PREPARATIONS].

Science.gov (United States)

Carla, Garbarino; Valentina, Cani; Stefano, Maretti; Paolo, Mazzarello

2015-01-01

In 1793 Lorenzo Mascheroni, appointed to the chair of Mathematics at the University of Pavia and well-known poet, wrote "L'invito di Dafni Orobiano a Lesbia Cidonia". In the poem he described the beauty of the University of Pavia and its wonders gathered in the scientific collections of the museums. From the beginning, one of the glass cases of the Museum for the History of the University of Pavia shows some of the preparations described in the Mascheroni's verses. In addition to some fossils, human teratological preparations are also exposed: they recall the verses of the poem dedicated to the description of "monstrous" preparations. However, after a detailed scientifc and historical research, the traditional association of the exposed anatomical preparations with the verses is questioned.

Toxicological study on the safety of DTPA as a drug, (1). Teratological study in the rat

Energy Technology Data Exchange (ETDEWEB)

Fukuda, Satoshi; Iida, Haruzo (National Inst. of Radiological Sciences, Chiba (Japan))

1983-03-01

In order to clarify the safety of Ca-DTPA and Zn-DTPA recommended to use as drugs in the therapeutic removal of incorporated radionuclides from the human body, the teratological study on these two agents was carried out in rats as one of a series of the toxicological tests. The teratological effects of DTPA were observed because the fetus is highly susceptible to any drug. The pregnant females of Wistar rat were injected subcutaneously daily on days 9-13 of gestation with 1, 6, 12, 24 and 36 H.D. (H.D. = human dose, 1 H.D. = 30..mu..mol/kg body weight) of Ca-DTPA or Zn-DTPA, respectively. In the dams, no toxic effects were observed. In the fetuses, the decrease of the survival rate was observed in only the group injected daily with 36 H.D. of Ca-DTPA. Some cases of gross defects of fetuses: the exencephaly, microphthalmia, anophthalmia and fusion of ribs were observed in the groups injected daily with 12, 24 and 36 H.D. of Ca-DTPA. The results obtained show that Ca-DTPA should not be given to a pregnant woman. However, no toxic effects of either Ca-DTPA or Zn-DTPA observed in the dams or of Zn-DTPA even in the fetuses indicate that these agents can be used by a radiation worker who usually is an adult man.

Solar micro-bursts of 22. 2 GHz and their relationship to events observed at lower frequencies

Energy Technology Data Exchange (ETDEWEB)

Blakey, J R [Universidade Mackenzie, Sao Paulo (Brazil). Centro de Radio-Astronomia e Astrofisica

1976-01-01

Observations of McMath region 10433 at 22 GHz using a telescope with a 4 minutes of arc beam during July 1974 revealed the existence events or 'microbursts' with intensities below the sensitivity limit of normal solar patrol instruments. Many of these events were simply the high frequency counterpart of more intense bursts observed at lower frequencies. This note considers the small number of events which suggest that the gyro-synchrotron mechanism alone is incapable of explaining the observations and indicates that a thermal mechanism is needed to explain the high frequency event.

Mammalian Genetics and Teratology Section

International Nuclear Information System (INIS)

Anon.

1980-01-01

The work of the Mammalian Genetics and Teratology Section includes research in mutagenesis, basic genetics, reproductive biology, and teratogenesis involving basic studies, method development, including exploration of the biological material, and testing. The basic studies make good use of the genetic material accumulated in mutagenesis experiments of various kinds, or of the findings of mutagenesis experiments themselves. In the latter category is the finding of a repair system in the fertilized egg. The genetics of repair competency or deficiency are now under study. A linear relationship between gene dosage and level of expression of an enzyme has been demonstrated. Opportunities for the study of gene action are provided by a number of X-autosome translocations which continue to be discovered in the course of mutagenesis experiments. In these rearrangements, X-chromosome inactivation extends to neighboring autosomal loci. Considerable progress has been made in developing the skeletal mutation system, which provides information on dominants that is highly useful for risk assessment. A sensitive-indicator test is now under development which will make the screening for skeletal mutations much faster and easier. Method development has also progressed on the in vivo somatic-mutation test now being widely used as an in vivo screen for mutagens. Another method developed here is the numerical sex-chromosome anomaly (NSA) test for nondisjunction. The NSA method is being used to explore the effects of female age on chromosome loss and nondisjunction. A model for estimating the misclassification error was experimentally established for the heritable translocation test. A rapid, easy, and sensitive in vivo screening test for teratogenesis was developed. An in vitro teratogenic prescreen being developed makes use of teratocarcinoma-derived cell lines

Frequency of adverse events after vaccination with different vaccinia strains.

Directory of Open Access Journals (Sweden)

Mirjam Kretzschmar

2006-08-01

Full Text Available BACKGROUND: Large quantities of smallpox vaccine have been stockpiled to protect entire nations against a possible reintroduction of smallpox. Planning for an appropriate use of these stockpiled vaccines in response to a smallpox outbreak requires a rational assessment of the risks of vaccination-related adverse events, compared to the risk of contracting an infection. Although considerable effort has been made to understand the dynamics of smallpox transmission in modern societies, little attention has been paid to estimating the frequency of adverse events due to smallpox vaccination. Studies exploring the consequences of smallpox vaccination strategies have commonly used a frequency of approximately one death per million vaccinations, which is based on a study of vaccination with the New York City Board of Health (NYCBH strain of vaccinia virus. However, a multitude of historical studies of smallpox vaccination with other vaccinia strains suggest that there are strain-related differences in the frequency of adverse events after vaccination. Because many countries have stockpiled vaccine based on the Lister strain of vaccinia virus, a quantitative evaluation of the adverse effects of such vaccines is essential for emergency response planning. We conducted a systematic review and statistical analysis of historical data concerning vaccination against smallpox with different strains of vaccinia virus. METHODS AND FINDINGS: We analyzed historical vaccination data extracted from the literature. We extracted data on the frequency of postvaccinal encephalitis and death with respect to vaccinia strain and age of vaccinees. Using a hierarchical Bayesian approach for meta-analysis, we estimated the expected frequencies of postvaccinal encephalitis and death with respect to age at vaccination for smallpox vaccines based on the NYCBH and Lister vaccinia strains. We found large heterogeneity between findings from different studies and a time-period effect

Paternal exposure and counselling: experience of a Teratology Information Service.

Science.gov (United States)

De Santis, Marco; Cesari, Elena; Cavaliere, Annafranca; Ligato, Maria Serena; Nobili, Elena; Visconti, Daniela; Caruso, Alessandro

2008-09-01

We describe paternal exposure and counselling in a selected population calling to an Italian Teratology Information Service (TIS). The majority of callers asked for paternal drug exposure (76%, drugs except chemotherapy) and treatment for cancer (17%, chemotherapy and/or radiotherapy). Others asked for exposure to diagnostic radiations (4%), recreational drugs (2%) and occupational chemicals (1%). Among paternal drugs neurological compounds, immunosuppressive drugs and antiviral agents were the main reasons for calling. In humans, there are no evidences of birth defects after paternal exposures, but to minimize any possible risk, counselling in men exposed to radio and chemotherapy should recommend delaying conception for at least 3 months after the end of the therapy. Male patients treated with drugs, whose teratogenic potential has been well assessed or suspected for maternal exposure, should be advised to practice effective birth control during therapy and up to one or two cycles of spermatogenesis and to avoid semen contact with vaginal walls during first trimester of pregnancy.

An exploration of the relationship among valence, fading affect, rehearsal frequency, and memory vividness for past personal events.

Science.gov (United States)

Lindeman, Meghan I H; Zengel, Bettina; Skowronski, John J

2017-07-01

The affect associated with negative (or unpleasant) memories typically tends to fade faster than the affect associated with positive (or pleasant) memories, a phenomenon called the fading affect bias (FAB). We conducted a study to explore the mechanisms related to the FAB. A retrospective recall procedure was used to obtain three self-report measures (memory vividness, rehearsal frequency, affective fading) for both positive events and negative events. Affect for positive events faded less than affect for negative events, and positive events were recalled more vividly than negative events. The perceived vividness of an event (memory vividness) and the extent to which an event has been rehearsed (rehearsal frequency) were explored as possible mediators of the relation between event valence and affect fading. Additional models conceived of affect fading and rehearsal frequency as contributors to a memory's vividness. Results suggested that memory vividness was a plausible mediator of the relation between an event's valence and affect fading. Rehearsal frequency was also a plausible mediator of this relation, but only via its effects on memory vividness. Additional modelling results suggested that affect fading and rehearsal frequency were both plausible mediators of the relation between an event's valence and the event's rated memory vividness.

Shallow very-low-frequency earthquakes accompany slow slip events in the Nankai subduction zone.

Science.gov (United States)

Nakano, Masaru; Hori, Takane; Araki, Eiichiro; Kodaira, Shuichi; Ide, Satoshi

2018-03-14

Recent studies of slow earthquakes along plate boundaries have shown that tectonic tremor, low-frequency earthquakes, very-low-frequency events (VLFEs), and slow-slip events (SSEs) often accompany each other and appear to share common source faults. However, the source processes of slow events occurring in the shallow part of plate boundaries are not well known because seismic observations have been limited to land-based stations, which offer poor resolution beneath offshore plate boundaries. Here we use data obtained from seafloor observation networks in the Nankai trough, southwest of Japan, to investigate shallow VLFEs in detail. Coincident with the VLFE activity, signals indicative of shallow SSEs were detected by geodetic observations at seafloor borehole observatories in the same region. We find that the shallow VLFEs and SSEs share common source regions and almost identical time histories of moment release. We conclude that these slow events arise from the same fault slip and that VLFEs represent relatively high-frequency fluctuations of slip during SSEs.

Calculation of noninformative prior of reliability parameter and initiating event frequency with Jeffreys method

International Nuclear Information System (INIS)

He Jie; Zhang Binbin

2013-01-01

In the probabilistic safety assessment (PSA) of nuclear power plants, there are few historical records on some initiating event frequencies or component failures in industry. In order to determine the noninformative priors of such reliability parameters and initiating event frequencies, the Jeffreys method in Bayesian statistics was employed. The mathematical mechanism of the Jeffreys prior and the simplified constrained noninformative distribution (SCNID) were elaborated in this paper. The Jeffreys noninformative formulas and the credible intervals of the Gamma-Poisson and Beta-Binomial models were introduced. As an example, the small break loss-of-coolant accident (SLOCA) was employed to show the application of the Jeffreys prior in determining an initiating event frequency. The result shows that the Jeffreys method is an effective method for noninformative prior calculation. (authors)

Estimation of initiating event frequency for external flood events by extreme value theorem

International Nuclear Information System (INIS)

Chowdhury, Sourajyoti; Ganguly, Rimpi; Hari, Vibha

2017-01-01

External flood is an important common cause initiating event in nuclear power plants (NPPs). It may potentially lead to severe core damage (SCD) by first causing the failure of the systems required for maintaining the heat sinks and then by contributing to failures of engineered systems designed to mitigate such failures. The sample NPP taken here is twin 220 MWe Indian standard pressurized heavy water reactor (PHWR) situated inland. A comprehensive in-house Level-1 internal event PSA for full power had already been performed. External flood assessment was further conducted in area of external hazard risk assessment in response to post-Fukushima measures taken in nuclear industries. The present paper describes the methodology to calculate initiating event (IE) frequency for external flood events for the sample inland Indian NPP. General extreme value (GEV) theory based on maximum likelihood method (MLM) and order statistics approach (OSA) is used to analyse the rainfall data for the site. Thousand-year return level and necessary return periods for extreme rainfall are evaluated. These results along with plant-specific topographical calculations quantitatively establish that external flooding resulting from upstream dam break, river flooding and heavy rainfall (flash flood) would be unlikely for the sample NPP in consideration.

Ground motion: frequency of occurrence versus amplitude of disturbing transient events

International Nuclear Information System (INIS)

Werner, K.L.

1983-01-01

Successful collider operation requires that ground motion not exceed certain tolerances. In this note it is pointed out that on occasion these tolerances are exceeded. The frequency of such events and their amplitudes, measured as a function of time of day, have been measured. An examination of the data leads one to conclude that most events are of cultural (i.e., man-made) origin. 2 references, 20 figures

MicroRNAs and fetal brain development: Implications for ethanol teratology during the second trimester period of neurogenesis.

Directory of Open Access Journals (Sweden)

Rajesh eMiranda

2012-05-01

Full Text Available Maternal ethanol consumption during pregnancy can lead to a stereotypic cluster of fetal craniofacial, cardiovascular, skeletal and neurological deficits that are collectively termed the Fetal Alcohol Spectrum Disorder (FASD. Fetal ethanol exposure is a leading non-genetic cause of mental retardation. Mechanisms underlying the etiology of ethanol teratology are varied and complex. This review will focus on the developing brain as an important and vulnerable ethanol target. Near the end of the first trimester, and during the second trimester, fetal neural stem cells (NSCs produce most of the neurons of the adult brain, and ethanol has been shown to influence NSC renewal and maturation. We will discuss the neural developmental and teratological implications of the biogenesis and function of microRNAs (miRNAs, a class of small non-protein-coding RNAs that control the expression of gene networks by translation repression. A small but growing body of research has identified ethanol-sensitive miRNAs at different stages of NSC and brain maturation. While many microRNAs appear to be vulnerable to ethanol at specific developmental stages, a few, like the miR-9 family, appear to exhibit broad vulnerability to ethanol across multiple stages of NSC differentiation. An assessment of the regulation and function of these miRNAs provides important clues about the mechanisms that underlie fetal vulnerability to alterations in the maternal-fetal environment and yields insights into the genesis of FASD.

EUROPEAN TERATOLOGY INFORMATION SERVICE: EXPERIENCE, PROBLEMS AND PERSPECTIVES

Directory of Open Access Journals (Sweden)

A.V. Ostrovskaya

2007-01-01

Full Text Available Congenital malformations are still the important medical and social issue. They take the second place among the reasons for the infant mortality and cause up to 18,3% of disablement cases among the children. Exogenous factors, effecting the growing fetus, are very essential along with the genetic matters among the reasons for the congenital malformations. The importance of information on the teratogenic potential of the medications is acknowledged by the doctors from various countries. The article outlines the information on entis activity — European network of teratology information services — a non profit organization, rendering consulting services to the pregnant women and medical staff, regarding the embryo and fetotoxic actions of the medications. The authors highlight the history of entis, its objectives, principles of operation and consulting algorithm and list the basic scientific publications by the entis members for the recent years. The article deals with the most obvious problems, which the organization members face, first of all — the quality of the information they receive. The authors also provide the substantiation for the necessity to develop such an information service in Russia and express hope for the successful development of the entis subsidiary they formed in Moscow.Key words: congenital malformations, medications, pregnancy, embryotoxicity.

Low-Frequency Type III Bursts and Solar Energetic Particle Events

Science.gov (United States)

Gopalswamy, Nat; Makela, Pertti

2010-01-01

We analyzed the coronal mass ejections (CMEs), flares, and type 11 radio bursts associated with a set of six low frequency (15 min) normally used to define these bursts. All but one of the type III bursts was not associated with a type 11 burst in the metric or longer wavelength domains. The burst without type 11 burst also lacked a solar energetic particle (SEP) event at energies >25 MeV. The 1-MHz duration of the type III burst (28 min) is near the median value of type III durations found for gradual SEP events and ground level enhancement (GLE) events. Yet, there was no sign of SEP events. On the other hand, two other type III bursts from the same active region had similar duration but accompanied by WAVES type 11 bursts; these bursts were also accompanied by SEP events detected by SOHO/ERNE. The CMEs were of similar speeds and the flares are also of similar size and duration. This study suggests that the type III burst duration may not be a good indicator of an SEP event.

Merging expert and empirical data for rare event frequency estimation: Pool homogenisation for empirical Bayes models

International Nuclear Information System (INIS)

Quigley, John; Hardman, Gavin; Bedford, Tim; Walls, Lesley

2011-01-01

Empirical Bayes provides one approach to estimating the frequency of rare events as a weighted average of the frequencies of an event and a pool of events. The pool will draw upon, for example, events with similar precursors. The higher the degree of homogeneity of the pool, then the Empirical Bayes estimator will be more accurate. We propose and evaluate a new method using homogenisation factors under the assumption that events are generated from a Homogeneous Poisson Process. The homogenisation factors are scaling constants, which can be elicited through structured expert judgement and used to align the frequencies of different events, hence homogenising the pool. The estimation error relative to the homogeneity of the pool is examined theoretically indicating that reduced error is associated with larger pool homogeneity. The effects of misspecified expert assessments of the homogenisation factors are examined theoretically and through simulation experiments. Our results show that the proposed Empirical Bayes method using homogenisation factors is robust under different degrees of misspecification.

Aesthetic appreciation: event-related field and time-frequency analyses.

Science.gov (United States)

Munar, Enric; Nadal, Marcos; Castellanos, Nazareth P; Flexas, Albert; Maestú, Fernando; Mirasso, Claudio; Cela-Conde, Camilo J

2011-01-01

Improvements in neuroimaging methods have afforded significant advances in our knowledge of the cognitive and neural foundations of aesthetic appreciation. We used magnetoencephalography (MEG) to register brain activity while participants decided about the beauty of visual stimuli. The data were analyzed with event-related field (ERF) and Time-Frequency (TF) procedures. ERFs revealed no significant differences between brain activity related with stimuli rated as "beautiful" and "not beautiful." TF analysis showed clear differences between both conditions 400 ms after stimulus onset. Oscillatory power was greater for stimuli rated as "beautiful" than those regarded as "not beautiful" in the four frequency bands (theta, alpha, beta, and gamma). These results are interpreted in the frame of synchronization studies.

Utilization of Satellite Data to Identify and Monitor Changes in Frequency of Meteorological Events

Science.gov (United States)

Mast, J. C.; Dessler, A. E.

2017-12-01

Increases in temperature and climate variability due to human-induced climate change is increasing the frequency and magnitude of extreme heat events (i.e., heatwaves). This will have a detrimental impact on the health of human populations and habitability of certain land locations. Here we seek to utilize satellite data records to identify and monitor extreme heat events. We analyze satellite data sets (MODIS and AIRS land surface temperatures (LST) and water vapor profiles (WV)) due to their global coverage and stable calibration. Heat waves are identified based on the frequency of maximum daily temperatures above a threshold, determined as follows. Land surface temperatures are gridded into uniform latitude/longitude bins. Maximum daily temperatures per bin are determined and probability density functions (PDF) of these maxima are constructed monthly and seasonally. For each bin, a threshold is calculated at the 95th percentile of the PDF of maximum temperatures. Per each bin, an extreme heat event is defined based on the frequency of monthly and seasonal days exceeding the threshold. To account for the decreased ability of the human body to thermoregulate with increasing moisture, and to assess lethality of the heat events, we determine the wet-bulb temperature at the locations of extreme heat events. Preliminary results will be presented.

Identification of homogeneous regions for rainfall regional frequency analysis considering typhoon event in South Korea

Science.gov (United States)

Heo, J. H.; Ahn, H.; Kjeldsen, T. R.

2017-12-01

South Korea is prone to large, and often disastrous, rainfall events caused by a mixture of monsoon and typhoon rainfall phenomena. However, traditionally, regional frequency analysis models did not consider this mixture of phenomena when fitting probability distributions, potentially underestimating the risk posed by the more extreme typhoon events. Using long-term observed records of extreme rainfall from 56 sites combined with detailed information on the timing and spatial impact of past typhoons from the Korea Meteorological Administration (KMA), this study developed and tested a new mixture model for frequency analysis of two different phenomena; events occurring regularly every year (monsoon) and events only occurring in some years (typhoon). The available annual maximum 24 hour rainfall data were divided into two sub-samples corresponding to years where the annual maximum is from either (1) a typhoon event, or (2) a non-typhoon event. Then, three-parameter GEV distribution was fitted to each sub-sample along with a weighting parameter characterizing the proportion of historical events associated with typhoon events. Spatial patterns of model parameters were analyzed and showed that typhoon events are less commonly associated with annual maximum rainfall in the North-West part of the country (Seoul area), and more prevalent in the southern and eastern parts of the country, leading to the formation of two distinct typhoon regions: (1) North-West; and (2) Southern and Eastern. Using a leave-one-out procedure, a new regional frequency model was tested and compared to a more traditional index flood method. The results showed that the impact of typhoon on design events might previously have been underestimated in the Seoul area. This suggests that the use of the mixture model should be preferred where the typhoon phenomena is less frequent, and thus can have a significant effect on the rainfall-frequency curve. This research was supported by a grant(2017-MPSS31

The SKI-project External events - Phase 2. Estimation of fire frequencies per plant and per building

International Nuclear Information System (INIS)

Poern, K.

1996-08-01

The Swedish-Finnish handbook for initiating event frequencies, I-Book, does not contain any fire frequencies. This matter of fact is not defensible considering the substantial risk contribution caused by fires. In the PSAs performed hitherto the initiating fire frequencies have been determined from case to case. Because data are usually very scarce in these areas it is very important to develop unique definitions, to systematically utilize both international and national experiences and to establish an appropriate statistical estimation method. It is also important to present the accumulated experience such that it can be used for different purposes, not only within PSA but also in the concrete fire preventive work. During phase 1 of the project External Events an inventory was made of existing methods for probabilistic fire analysis in general. During phase 2 of the project it was decided to initialize the work on a complementary handbook, called X-Book, in order to encompass the frequencies of system external events, i.e. initiating events that are caused by events occurring outside the system boundaries. In Version 1 of the X-Book the attention is mainly focussed on the estimation of initiating fire frequencies, per plant and per building. This estimation is basically founded on reports that the power companies have collected for this specific purpose. This report describes the statistical model and method that have been used in the estimation process. The methodological results achieved may, possibly after some modification, be applicable also to other types of system external events

Systematic review on the prevalence, frequency and comparative value of adverse events data in social media

Science.gov (United States)

Golder, Su; Norman, Gill; Loke, Yoon K

2015-01-01

Aim The aim of this review was to summarize the prevalence, frequency and comparative value of information on the adverse events of healthcare interventions from user comments and videos in social media. Methods A systematic review of assessments of the prevalence or type of information on adverse events in social media was undertaken. Sixteen databases and two internet search engines were searched in addition to handsearching, reference checking and contacting experts. The results were sifted independently by two researchers. Data extraction and quality assessment were carried out by one researcher and checked by a second. The quality assessment tool was devised in-house and a narrative synthesis of the results followed. Results From 3064 records, 51 studies met the inclusion criteria. The studies assessed over 174 social media sites with discussion forums (71%) being the most popular. The overall prevalence of adverse events reports in social media varied from 0.2% to 8% of posts. Twenty-nine studies compared the results from searching social media with using other data sources to identify adverse events. There was general agreement that a higher frequency of adverse events was found in social media and that this was particularly true for ‘symptom’ related and ‘mild’ adverse events. Those adverse events that were under-represented in social media were laboratory-based and serious adverse events. Conclusions Reports of adverse events are identifiable within social media. However, there is considerable heterogeneity in the frequency and type of events reported, and the reliability or validity of the data has not been thoroughly evaluated. PMID:26271492

Mean occurrence frequency and temporal risk analysis of solar particle events

International Nuclear Information System (INIS)

Kim, Myung-Hee Y.; Cucinotta, Francis A.; Wilson, John W.

2006-01-01

The protection of astronauts from space radiation is required on future exploratory class and long-duration missions. For the accurate projections of radiation doses, a solar cycle statistical model, which quantifies the progression level within the cycle, has been developed. The resultant future cycle projection is then applied to estimate the mean frequency of solar particle events (SPEs) in the near future using a power law function of sunspot number. Detailed temporal behaviors of the recent large event and two historically large events of the August 1972 SPE and the November 1960 SPE are analyzed for dose-rate and cumulative dose equivalent at sensitive organs. Polyethylene shielded 'storm shelters' inside spacecraft are studied to limit astronauts' total exposure at a sensitive site within 10 cSv from a large event as a potential goal that fulfills the ALARA (as low as reasonably achievable) requirement

Expression analysis of some genes regulated by retinoic acid in controls and triadimefon-exposed embryos: is the amphibian Xenopus laevis a suitable model for gene-based comparative teratology?

Science.gov (United States)

Di Renzo, Francesca; Rossi, Federica; Bacchetta, Renato; Prati, Mariangela; Giavini, Erminio; Menegola, Elena

2011-06-01

The use of nonmammal models in teratological studies is a matter of debate and seems to be justified if the embryotoxic mechanism involves conserved processes. Published data on mammals and Xenopus laevis suggest that azoles are teratogenic by altering the endogenous concentration of retinoic acid (RA). The expression of some genes (Shh, Ptch-1, Gsc, and Msx2) controlled by retinoic acid is downregulated in rat embryos exposed at the phylotypic stage to the triazole triadimefon (FON). In order to propose X. laevis as a model for gene-based comparative teratology, this work evaluates the expression of Shh, Ptch-1, Gsc, and Msx2 in FON-exposed X. laevis embryos. Embryos, exposed to a high concentration level (500 µM) of FON from stage 13 till 17, were examined at stages 17, 27, and 47. Stage 17 and 27 embryos were processed to perform quantitative RT-PCR. The developmental rate was never affected by FON at any considered stage. FON-exposed stage 47 larvae showed the typical craniofacial malformations. A significant downregulation of Gsc was observed in FON-exposed stage 17 embryos. Shh, Ptch-1, Msx2 showed a high fluctuation of expression both in control and in FON-exposed samples both at stages 17 and 27. The downregulation of Gsc mimics the effects of FON on rat embryos, showing for this gene a common effect of FON in the two vertebrate classes. The high fluctuation observed in the gene expression of the other genes, however, suggests that X. laevis at this stage has limited utility for gene-based comparative teratology. © 2011 Wiley-Liss, Inc.

The differential effects of increasing frequency and magnitude of extreme events on coral populations.

Science.gov (United States)

Fabina, Nicholas S; Baskett, Marissa L; Gross, Kevin

2015-09-01

Extreme events, which have profound ecological consequences, are changing in both frequency and magnitude with climate change. Because extreme temperatures induce coral bleaching, we can explore the relative impacts of changes in frequency and magnitude of high temperature events on coral reefs. Here, we combined climate projections and a dynamic population model to determine how changing bleaching regimes influence coral persistence. We additionally explored how coral traits and competition with macroalgae mediate changes in bleaching regimes. Our results predict that severe bleaching events reduce coral persistence more than frequent bleaching. Corals with low adult mortality and high growth rates are successful when bleaching is mild, but bleaching resistance is necessary to persist when bleaching is severe, regardless of frequency. The existence of macroalgae-dominated stable states reduces coral persistence and changes the relative importance of coral traits. Building on previous studies, our results predict that management efforts may need to prioritize protection of "weaker" corals with high adult mortality when bleaching is mild, and protection of "stronger" corals with high bleaching resistance when bleaching is severe. In summary, future reef projections and conservation targets depend on both local bleaching regimes and biodiversity.

Effects of the major sudden stratospheric warming event of 2009 on the subionospheric very low frequency/low frequency radio signals

Science.gov (United States)

Pal, S.; Hobara, Y.; Chakrabarti, S. K.; Schnoor, P. W.

2017-07-01

This paper presents effects of the major sudden stratospheric warming (SSW) event of 2009 on the subionospheric very low frequency/low frequency (VLF/LF) radio signals propagating in the Earth-ionosphere waveguide. Signal amplitudes from four transmitters received by VLF/LF radio networks of Germany and Japan corresponding to the major SSW event are investigated for possible anomalies and atmospheric influence on the high- to middle-latitude ionosphere. Significant anomalous increase or decrease of nighttime and daytime amplitudes of VLF/LF signals by ˜3-5 dB during the SSW event have been found for all propagation paths associated with stratospheric temperature rise at 10 hPa level. Increase or decrease in VLF/LF amplitudes during daytime and nighttime is actually due to the modification of the lower ionospheric boundary conditions in terms of electron density and electron-neutral collision frequency profiles and associated modal interference effects between the different propagating waveguide modes during the SSW period. TIMED/SABER mission data are also used to investigate the upper mesospheric conditions over the VLF/LF propagation path during the same time period. We observe a decrease in neutral temperature and an increase in pressure at the height of 75-80 km around the peak time of the event. VLF/LF anomalies are correlated and in phase with the stratospheric temperature and mesospheric pressure variation, while minimum of mesospheric cooling shows a 2-3 day delay with maximum VLF/LF anomalies. Simulations of VLF/LF diurnal variation are performed using the well-known Long Wave Propagating Capability (LWPC) code within the Earth-ionosphere waveguide to explain the VLF/LF anomalies qualitatively.

Analysis of core damage frequency due to external events at the DOE [Department of Energy] N-Reactor

International Nuclear Information System (INIS)

Lambright, J.A.; Bohn, M.P.; Daniel, S.L.; Baxter, J.T.; Johnson, J.J.; Ravindra, M.K.; Hashimoto, P.O.; Mraz, M.J.; Tong, W.H.; Conoscente, J.P.; Brosseau, D.A.

1990-11-01

A complete external events probabilistic risk assessment has been performed for the N-Reactor power plant, making full use of all insights gained during the past ten years' developments in risk assessment methodologies. A detailed screening analysis was performed which showed that all external events had negligible contribution to core damage frequency except fires, seismic events, and external flooding. A limited scope analysis of the external flooding risk indicated that it is not a major risk contributor. Detailed analyses of the fire and seismic risks resulted in total (mean) core damage frequencies of 1.96E-5 and 4.60E-05 per reactor year, respectively. Detailed uncertainty analyses were performed for both fire and seismic risks. These results show that the core damage frequency profile for these events is comparable to that found for existing commercial power plants if proposed fixes are completed as part of the restart program. 108 refs., 85 figs., 80 tabs

Analysis of core damage frequency due to external events at the DOE (Department of Energy) N-Reactor

Energy Technology Data Exchange (ETDEWEB)

Lambright, J.A.; Bohn, M.P.; Daniel, S.L. (Sandia National Labs., Albuquerque, NM (USA)); Baxter, J.T. (Westinghouse Hanford Co., Richland, WA (USA)); Johnson, J.J.; Ravindra, M.K.; Hashimoto, P.O.; Mraz, M.J.; Tong, W.H.; Conoscente, J.P. (EQE, Inc., San Francisco, CA (USA)); Brosseau, D.A. (ERCE, Inc., Albuquerque, NM (USA))

1990-11-01

A complete external events probabilistic risk assessment has been performed for the N-Reactor power plant, making full use of all insights gained during the past ten years' developments in risk assessment methodologies. A detailed screening analysis was performed which showed that all external events had negligible contribution to core damage frequency except fires, seismic events, and external flooding. A limited scope analysis of the external flooding risk indicated that it is not a major risk contributor. Detailed analyses of the fire and seismic risks resulted in total (mean) core damage frequencies of 1.96E-5 and 4.60E-05 per reactor year, respectively. Detailed uncertainty analyses were performed for both fire and seismic risks. These results show that the core damage frequency profile for these events is comparable to that found for existing commercial power plants if proposed fixes are completed as part of the restart program. 108 refs., 85 figs., 80 tabs.

Probe-controlled soliton frequency shift in the regime of optical event horizon

DEFF Research Database (Denmark)

Gu, Jie; Guo, Hairun; Wang, Shaofei

2015-01-01

In optical analogy of the event horizon, temporal pulse collision and mutual interactions are mainly between an intense solitary wave (soliton) and a dispersive probe wave. In such a regime, here we numerically investigate the probe-controlled soliton frequency shift as well as the soliton self...

Acute, reproductive toxicity and two-generation teratology studies of a standardized quassinoid-rich extract of Eurycoma longifolia Jack in Sprague-Dawley rats.

Science.gov (United States)

Low, Bin-Seng; Das, Prashanta Kumar; Chan, Kit-Lam

2014-07-01

The roots of Eurycoma longifolia Jack are popularly sought as herbal medicinal supplements to improve libido and general health amongst the local ethnic population. The major quassinoids of E. longifolia improved spermatogenesis and fertility but toxicity studies have not been well documented. The reproductive toxicity, two generation of foetus teratology and the up-and-down acute toxicity were investigated in Sprague-Dawley rats orally treated with quassinoid-rich E. longifolia extract (TAF273). The results showed that the median lethal dose (LD50 ) of TAF273 for female and male rats was 1293 and >2000 mg/kg, respectively. Fertility index and litter size of the TAF273 treated were significantly increased when compared with those of the non-treated animals. The TAF273-treated dams decreased in percentage of pre-implantation loss, post-implantation loss and late resorption. No toxic symptoms were observed on the TAF273-treated pregnant female rats and their foetuses were normal. The no-observed adverse effect level (NOAEL) obtained from reproductive toxicity and teratology studies of TAF273 in rats was 100 mg/kg body weight/day, being more than 10-fold lower than the LD50 value. Thus, any human dose derived from converting the rat doses of 100 mg/kg and below may be considered as safe for further clinical studies. Copyright © 2013 John Wiley & Sons, Ltd.

On the Onset Frequency of Metric Type II Radio Bursts and the Longitudinal Extent of the Associated SEP Events

Science.gov (United States)

Makela, P. A.; Gopalswamy, N.; Yashiro, S.; Thakur, N.; Akiyama, S.; Xie, H.

2017-12-01

In a recent study Gopalswamy et al. (2017, J. Phys. Conf. Ser., Proc. 16th AIAC) found that the ground level enhancements (GLEs), regular solar energetic particle (SEP) events and filament eruption (FE) associated SEP events have distinct average starting frequencies of the associated type II bursts, although the distributions overlap. They also found that the initial acceleration of the coronal mass ejections (CMEs) associated with the three groups were distinct. Based on these earlier results emphasizing a hierarchical relationship of CME kinematics and SEP events, we studied the possible dependence between the longitudinal spread of the SEP events and the onset frequency of metric type II. The studied >25 MeV SEP events are from the list of Richardson et al. (2014, Sol. Phys. 289) covering the first seven years of the STEREO mission. However, our preliminary results show only a weak correlation between the extent of the SEP event and the onset frequency of the metric type II radio burst.

Financial system loss as an example of high consequence, high frequency events

Energy Technology Data Exchange (ETDEWEB)

McGovern, D.E.

1996-07-01

Much work has been devoted to high consequence events with low frequency of occurrence. Characteristic of these events are bridge failure (such as that of the Tacoma Narrows), building failure (such as the collapse of a walkway at a Kansas City hotel), or compromise of a major chemical containment system (such as at Bhopal, India). Such events, although rare, have an extreme personal, societal, and financial impact. An interesting variation is demonstrated by financial losses due to fraud and abuse in the money management system. The impact can be huge, entailing very high aggregate costs, but these are a result of the contribution of many small attacks and not the result of a single (or few) massive events. Public awareness is raised through publicized events such as the junk bond fraud perpetrated by Milikin or gross mismanagement in the failure of the Barings Bank through unsupervised trading activities by Leeson in Singapore. These event,s although seemingly large (financial losses may be on the order of several billion dollars), are but small contributors to the estimated $114 billion loss to all types of financial fraud in 1993. This paper explores the magnitude of financial system losses and identifies new areas for analysis of high consequence events including the potential effect of malevolent intent.

[Teratologic cranio-encephalic effects of chronic thinner inhalation in progenitors, in rats and humans].

Science.gov (United States)

Barroso-Moguel, R; Villeda-Hernández, J; Méndez-Armenta, M

1991-01-01

Inhalation of thinner by youngsters and adolescents is an increasing drug abuse problem in Mexico. It presents serious repercussions upon socio-economic, cultural, legal and health (neurologic and psychiatric) problems. We report a comparative study in humans and rats which demonstrate the embryotoxic and craneo encephalic teratologic effects in the children and brood of progenitors who have chronically inhaled thinner (in the case of pregnant women, before, at the beginning and throughout pregnancy). Inhaled thinner passes directly to the blood stream and crosses the placentary barrier freely reaching the embryo. It may cause craneal bone and partial or total encephalon agenesia, added to macro and microscopic lesions secondary to direct aggression to the neuroepithelial germ cells. Abortions and premature labor with weight and size underdeveloped products and placentary hemorrhages occur. Usually these die, but if they survive they show trascendental mental retardation, as well as neurologic and psychiatric sequels.

Increased risk of severe hypoglycemic events with increasing frequency of non-severe hypoglycemic events in patients with Type 1 and Type 2 diabetes.

LENUS (Irish Health Repository)

Sreenan, Seamus

2014-07-15

Severe hypoglycemic events (SHEs) are associated with significant morbidity, mortality and costs. However, the more common non-severe hypoglycemic events (NSHEs) are less well explored. We investigated the association between reported frequency of NSHEs and SHEs among patients with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) in the PREDICTIVE study.

Very low frequency earthquakes (VLFEs) detected during episodic tremor and slip (ETS) events in Cascadia using a match filter method indicate repeating events

Science.gov (United States)

Hutchison, A. A.; Ghosh, A.

2016-12-01

Very low frequency earthquakes (VLFEs) occur in transitional zones of faults, releasing seismic energy in the 0.02-0.05 Hz frequency band over a 90 s duration and typically have magntitudes within the range of Mw 3.0-4.0. VLFEs can occur down-dip of the seismogenic zone, where they can transfer stress up-dip potentially bringing the locked zone closer to a critical failure stress. VLFEs also occur up-dip of the seismogenic zone in a region along the plate interface that can rupture coseismically during large megathrust events, such as the 2011 Tohoku-Oki earthquake [Ide et al., 2011]. VLFEs were first detected in Cascadia during the 2011 episodic tremor and slip (ETS) event, occurring coincidentally with tremor [Ghosh et al., 2015]. However, during the 2014 ETS event, VLFEs were spatially and temporally asynchronous with tremor activity [Hutchison and Ghosh, 2016]. Such contrasting behaviors remind us that the mechanics behind such events remain elusive, yet they are responsible for the largest portion of the moment release during an ETS event. Here, we apply a match filter method using known VLFEs as template events to detect additional VLFEs. Using a grid-search centroid moment tensor inversion method, we invert stacks of the resulting match filter detections to ensure moment tensor solutions are similar to that of the respective template events. Our ability to successfully employ a match filter method to VLFE detection in Cascadia intrinsically indicates that these events can be repeating, implying that the same asperities are likely responsible for generating multiple VLFEs.

Procedures for the external event core damage frequency analyses for NUREG-1150

International Nuclear Information System (INIS)

Bohn, M.P.; Lambright, J.A.

1990-11-01

This report presents methods which can be used to perform the assessment of risk due to external events at nuclear power plants. These methods were used to perform the external events risk assessments for the Surry and Peach Bottom nuclear power plants as part of the NRC-sponsored NUREG-1150 risk assessments. These methods apply to the full range of hazards such as earthquakes, fires, floods, etc. which are collectively known as external events. The methods described in this report have been developed under NRC sponsorship and represent, in many cases, both advancements and simplifications over techniques that have been used in past years. They also include the most up-to-date data bases on equipment seismic fragilities, fire occurrence frequencies and fire damageability thresholds. The methods described here are based on making full utilization of the power plant systems logic models developed in the internal events analyses. By making full use of the internal events models one obtains an external event analysis that is consistent both in nomenclature and in level of detail with the internal events analyses, and in addition, automatically includes all the appropriate random and tests/maintenance unavailabilities as appropriate. 50 refs., 9 figs., 11 tabs

Characterization of the frequency and nature of bleed air contamination events in commercial aircraft.

Science.gov (United States)

Shehadi, M; Jones, B; Hosni, M

2016-06-01

Contamination of the bleed air used to pressurize and ventilate aircraft cabins is of concern due to the potential health and safety hazards for passengers and crew. Databases from the Federal Aviation Administration, NASA, and other sources were examined in detail to determine the frequency of bleed air contamination incidents. The frequency was examined on an aircraft model basis with the intent of identifying aircraft make and models with elevated frequencies of contamination events. The reported results herein may help investigators to focus future studies of bleed air contamination incidents on smaller number of aircrafts. Incident frequency was normalized by the number of aircraft, number of flights, and flight hours for each model to account for the large variations in the number of aircraft of different models. The focus of the study was on aircraft models that are currently in service and are used by major airlines in the United States. Incidents examined in this study include those related to smoke, oil odors, fumes, and any symptom that might be related to exposure to such contamination, reported by crew members, between 2007 and 2012, for US-based carriers for domestic flights and all international flights that either originated or terminated in the US. In addition to the reported frequency of incidents for different aircraft models, the analysis attempted to identify propulsion engines and auxiliary power units associated with aircrafts that had higher frequencies of incidents. While substantial variations were found in frequency of incidents, it was found that the contamination events were widely distributed across nearly all common models of aircraft. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Memory for past public events depends on retrieval frequency but not memory age in Alzheimer's disease.

Science.gov (United States)

Müller, Stephan; Mychajliw, Christian; Hautzinger, Martin; Fallgatter, Andreas J; Saur, Ralf; Leyhe, Thomas

2014-01-01

Alzheimer's disease (AD) is characterized by retrograde memory deficits primarily caused by dysfunction of the hippocampal complex. Unresolved questions exist concerning the time course of hippocampal involvement in conscious recollection of declarative knowledge, as reports of temporal gradients of retrograde amnesia have been inconclusive. The aim of this study was to examine whether the extent and severity of retrograde amnesia is mediated by retrieval frequency or, in contrast, whether it depends on the age of the memory according to the assumptions of the main current theories of memory formation. We compared recall of past public events in patients with AD and healthy control (HC) individuals using the Historic Events Test (HET). The HET assesses knowledge about famous public events of the past 60 years divided into four time segments and consists of subjective memory rating, dating accuracy, and contextual memory tasks. Although memory for public events was impaired in AD patients, there was a strong effect of retrieval frequency across all time segments and both groups. As AD and HC groups derived similar benefits from greater retrieval frequency, cortical structures other than the hippocampal complex may mediate memory retrieval. These findings suggest that more frequently retrieved events and facts become more independent of the hippocampal complex and thus better protected against early damage of AD. This could explain why cognitive activity may delay the onset of memory decline in persons who develop AD.

Variability and trends in dry day frequency and dry event length in the southwestern United States

Science.gov (United States)

McCabe, Gregory J.; Legates, David R.; Lins, Harry F.

2010-01-01

Daily precipitation from 22 National Weather Service first-order weather stations in the southwestern United States for water years 1951 through 2006 are used to examine variability and trends in the frequency of dry days and dry event length. Dry events with minimum thresholds of 10 and 20 consecutive days of precipitation with less than 2.54 mm are analyzed. For water years and cool seasons (October through March), most sites indicate negative trends in dry event length (i.e., dry event durations are becoming shorter). For the warm season (April through September), most sites also indicate negative trends; however, more sites indicate positive trends in dry event length for the warm season than for water years or cool seasons. The larger number of sites indicating positive trends in dry event length during the warm season is due to a series of dry warm seasons near the end of the 20th century and the beginning of the 21st century. Overall, a large portion of the variability in dry event length is attributable to variability of the El Niño–Southern Oscillation, especially for water years and cool seasons. Our results are consistent with analyses of trends in discharge for sites in the southwestern United States, an increased frequency in El Niño events, and positive trends in precipitation in the southwestern United States.

Providing information regarding exposures in pregnancy: a survey of North American Teratology Information Services.

Science.gov (United States)

Hancock, Rebecca L; Ungar, Wendy J; Einarson, Adrienne; Goodstadt, Michael; Koren, Gideon

2008-04-01

Teratology Information Services (TIS) provide information on exposures during pregnancy and breast-feeding. Maintaining ongoing funding is a challenge. The purpose was to gather descriptive information on current TIS operations. All North American TIS (16 American, 2 Canadian) completed a detailed survey. Service goal ranked as most important was correction of risk misperceptions. Inquiries were primarily for medications (mean 43.5%, S.D. 14.1), lactation exposures, and workplace exposures. Median employees per TIS: three (range 1-12.5). Two TIS only counsel health care professionals (HCPs). Main callers to remaining TIS were pregnant women (mean 46.8%, S.D. 22.8), physicians, and nurses. Calls per week varied (median 20, range 4-600). Median annual budget: US dollars 69,000 (range dollars 3000-335,000). Seventeen TIS collect patient data for research. This survey was the first to document TIS operations in North America and demonstrates a spectrum of clinical and research activities, and provides data for a future cost-benefit analysis of TIS.

Frequency shifting at fiber-optical event horizons: The effect of Raman deceleration

International Nuclear Information System (INIS)

Robertson, S.; Leonhardt, U.

2010-01-01

Pulses in fibers establish analogs of the event horizon [Philbin et al., Science 319, 1367 (2008)]. At a group-velocity horizon, the frequency of a probe wave is shifted. We present a theoretical model of this frequency shifting, taking into account the deceleration of the pulse caused by the Raman effect. The theory shows that the probe-wave spectrum is sensitive to details of the probe-pulse interaction. Our results indicate an additional loss mechanism in the experiment [Philbin et al., Science 319, 1367 (2008)] that has not been accounted for. Our analysis is also valid for more general cases of the interaction of dispersive waves with decelerated solitons.

Estimation of average hazardous-event-frequency for allocation of safety-integrity levels

International Nuclear Information System (INIS)

Misumi, Y.; Sato, Y.

1999-01-01

One of the fundamental concepts of the draft international standard, IEC 61508, is target failure measures to be allocated to Electric/Electronic/Programmable Electronic Safety-Related Systems, i.e. Safety Integrity Levels. The Safety Integrity Levels consist of four discrete probabilistic levels for specifying the safety integrity requirements or the safety functions to be allocated to Electric/Electronic/Programmable Electronic Safety-Related Systems. In order to select the Safety Integrity Levels the draft standard classifies Electric/Electronic/Programmable Electronic Safety-Related Systems into two modes of operation using demand frequencies only. It is not clear which modes of operation should be applied to Electric/Electronic/Programmable Electronic Safety-Related Systems taking into account the demand-state probability and the spurious demand frequency. It is essential for the allocation of Safety Integrity Levels that generic algorithms be derived by involving possible parameters, which make it possible to model the actuality of real systems. The present paper addresses this issue. First of all, the overall system including Electric/Electronic/programmable Electronic Safety-Related Systems is described using a simplified fault-tree. Then, the relationships among demands, demand-states and proof-tests are studied. Overall systems are classified into two groups: a non-demand-state-at-proof-test system which includes both repairable and non-repairable demand states and a constant-demand-frequency system. The new ideas such as a demand-state, spurious demand-state, mean time between detections, rates of d-failure and h-failure, and an h/d ratio are introduced in order to make the Safety Integrity Levels and modes of operation generic and comprehensive. Finally, the overall system is simplified and modeled by fault-trees using Priority-AND gates. At the same time the assumptions for modeling are described. Generic algorithms to estimate hazardous-event

Analysis of core damage frequency: Surry, Unit 1 internal events

International Nuclear Information System (INIS)

Bertucio, R.C.; Julius, J.A.; Cramond, W.R.

1990-04-01

This document contains the accident sequence analysis of internally initiated events for the Surry Nuclear Station, Unit 1. This is one of the five plant analyses conducted as part of the NUREG-1150 effort by the Nuclear Regulatory Commission. NUREG-1150 documents the risk of a selected group of nuclear power plants. The work performed and described here is an extensive of that published in November 1986 as NUREG/CR-4450, Volume 3. It addresses comments form numerous reviewers and significant changes to the plant systems and procedures made since the first report. The uncertainty analysis and presentation of results are also much improved. The context and detail of this report are directed toward PRA practitioners who need to know how the work was performed and the details for use in further studies. The mean core damage frequency at Surry was calculated to be 4.05-E-5 per year, with a 95% upper bound of 1.34E-4 and 5% lower bound of 6.8E-6 per year. Station blackout type accidents (loss of all AC power) were the largest contributors to the core damage frequency, accounting for approximately 68% of the total. The next type of dominant contributors were Loss of Coolant Accidents (LOCAs). These sequences account for 15% of core damage frequency. No other type of sequence accounts for more than 10% of core damage frequency. 49 refs., 52 figs., 70 tabs

In honor of the Teratology Society's 50th anniversary: The role of Teratology Society members in the development and evolution of in vivo developmental toxicity test guidelines.

Science.gov (United States)

Tyl, Rochelle W

2010-06-01

Members of the Teratology Society (established in 1960) were involved in the first governmental developmental and reproductive toxicity testing guidelines (1966) by FDA following the thalidomide epidemic, followed by other national and international governmental testing guidelines. The Segment II (developmental toxicity) study design, described in rodents and rabbits, has evolved with additional enhanced endpoints and better descriptions, mechanistic insights, range-finding studies, and toxico/pharmacokinetic ADME information (especially for pharmaceuticals). Society members were also involved in the development of the current screening assays and tests for endocrine disruptors (beginning in 1996) and are now involved with developing new testing guidelines (e.g., the extended one-generation protocol), and evaluating the current test guidelines and new initiatives under ILSI/HESI sponsorship. New initiatives include ToxCast from the U.S. EPA to screen, prioritize, and predict toxic chemicals by high throughput and high-content in vitro assays, bioinformation, and modeling to reduce (or eliminate) in vivo whole animal studies. Our Society and its journal have played vital roles in the scientific and regulatory accomplishments in birth defects research over the past 50 years and will continue to do so in the future. Happy 50th anniversary! (c) 2010 Wiley-Liss, Inc.

Multivariate hydrological frequency analysis for extreme events using Archimedean copula. Case study: Lower Tunjuelo River basin (Colombia)

Science.gov (United States)

Gómez, Wilmar

2017-04-01

By analyzing the spatial and temporal variability of extreme precipitation events we can prevent or reduce the threat and risk. Many water resources projects require joint probability distributions of random variables such as precipitation intensity and duration, which can not be independent with each other. The problem of defining a probability model for observations of several dependent variables is greatly simplified by the joint distribution in terms of their marginal by taking copulas. This document presents a general framework set frequency analysis bivariate and multivariate using Archimedean copulas for extreme events of hydroclimatological nature such as severe storms. This analysis was conducted in the lower Tunjuelo River basin in Colombia for precipitation events. The results obtained show that for a joint study of the intensity-duration-frequency, IDF curves can be obtained through copulas and thus establish more accurate and reliable information from design storms and associated risks. It shows how the use of copulas greatly simplifies the study of multivariate distributions that introduce the concept of joint return period used to represent the needs of hydrological designs properly in frequency analysis.

Pattern recognition based on time-frequency analysis and convolutional neural networks for vibrational events in φ-OTDR

Science.gov (United States)

Xu, Chengjin; Guan, Junjun; Bao, Ming; Lu, Jiangang; Ye, Wei

2018-01-01

Based on vibration signals detected by a phase-sensitive optical time-domain reflectometer distributed optical fiber sensing system, this paper presents an implement of time-frequency analysis and convolutional neural network (CNN), used to classify different types of vibrational events. First, spectral subtraction and the short-time Fourier transform are used to enhance time-frequency features of vibration signals and transform different types of vibration signals into spectrograms, which are input to the CNN for automatic feature extraction and classification. Finally, by replacing the soft-max layer in the CNN with a multiclass support vector machine, the performance of the classifier is enhanced. Experiments show that after using this method to process 4000 vibration signal samples generated by four different vibration events, namely, digging, walking, vehicles passing, and damaging, the recognition rates of vibration events are over 90%. The experimental results prove that this method can automatically make an effective feature selection and greatly improve the classification accuracy of vibrational events in distributed optical fiber sensing systems.

Under-Frequency Load Shedding Technique Considering Event-Based for an Islanded Distribution Network

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Hasmaini Mohamad

2016-06-01

Full Text Available One of the biggest challenge for an islanding operation is to sustain the frequency stability. A large power imbalance following islanding would cause under-frequency, hence an appropriate control is required to shed certain amount of load. The main objective of this research is to develop an adaptive under-frequency load shedding (UFLS technique for an islanding system. The technique is designed considering an event-based which includes the moment system is islanded and a tripping of any DG unit during islanding operation. A disturbance magnitude is calculated to determine the amount of load to be shed. The technique is modeled by using PSCAD simulation tool. A simulation studies on a distribution network with mini hydro generation is carried out to evaluate the UFLS model. It is performed under different load condition: peak and base load. Results show that the load shedding technique have successfully shed certain amount of load and stabilized the system frequency.

Effects of Sound Frequency on Audiovisual Integration: An Event-Related Potential Study.

Science.gov (United States)

Yang, Weiping; Yang, Jingjing; Gao, Yulin; Tang, Xiaoyu; Ren, Yanna; Takahashi, Satoshi; Wu, Jinglong

2015-01-01

A combination of signals across modalities can facilitate sensory perception. The audiovisual facilitative effect strongly depends on the features of the stimulus. Here, we investigated how sound frequency, which is one of basic features of an auditory signal, modulates audiovisual integration. In this study, the task of the participant was to respond to a visual target stimulus by pressing a key while ignoring auditory stimuli, comprising of tones of different frequencies (0.5, 1, 2.5 and 5 kHz). A significant facilitation of reaction times was obtained following audiovisual stimulation, irrespective of whether the task-irrelevant sounds were low or high frequency. Using event-related potential (ERP), audiovisual integration was found over the occipital area for 0.5 kHz auditory stimuli from 190-210 ms, for 1 kHz stimuli from 170-200 ms, for 2.5 kHz stimuli from 140-200 ms, 5 kHz stimuli from 100-200 ms. These findings suggest that a higher frequency sound signal paired with visual stimuli might be early processed or integrated despite the auditory stimuli being task-irrelevant information. Furthermore, audiovisual integration in late latency (300-340 ms) ERPs with fronto-central topography was found for auditory stimuli of lower frequencies (0.5, 1 and 2.5 kHz). Our results confirmed that audiovisual integration is affected by the frequency of an auditory stimulus. Taken together, the neurophysiological results provide unique insight into how the brain processes a multisensory visual signal and auditory stimuli of different frequencies.

Potential Indoor Worker Exposure From Handling Area Leakage: Example Event Sequence Frequency Analysis

International Nuclear Information System (INIS)

Benke, Roland R.; Adams, George R.

2008-01-01

potential event sequences. A hypothetical case is presented for failure of the HVAC exhaust system to provide confinement for contaminated air from otherwise normal operations. This paper presents an example calculation of frequencies for a potential event sequence involving HVAC system failure during otherwise routine wet transfer operations of spent nuclear fuel assemblies from an open container. For the simplified HVAC exhaust system model, the calculation indicated that the potential event sequence may or may not be a Category 1 event sequence, in light of current uncertainties (e.g., final HVAC system design and duration of facility operations). Categorization of potential event sequences is important because different regulatory requirements and performance objectives are specified based on the categorization of event sequences. A companion paper presents a dose calculation methodology and example calculations of indoor worker consequences for the posed example event sequence. Together, the two companion papers demonstrate capabilities for performing confirmatory calculations of frequency and consequence, which may assist the assessment of worker safety during a risk-informed regulatory review of a potential DOE license application

Determination of the frequency and direct cost of the adverse drug events in Argentina.

Science.gov (United States)

Izquierdo, Estela; Rodríguez, Claudio; Pampliega, Eneas; Filinger, Ester

2009-05-01

To determine the frequency and the direct costs of adverse drug reactions, in an ambulatory population of the City of Buenos Aires, Argentina and its area of influence. A retrospective study was done during a period of three months on approximately 300.000 residents of the Buenos Aires area, gathering data according to the selected variables by means of the electronic capture of prescriptions dispensed in pharmacies of the area. This method enables the detection and registration of potential conflicts that may arise between a prescribed drug and factors such as: patient's demographic, clinical and drug profile. The analysis unit was defined as the happening of a moderate or severe adverse event reported by the system. The selected variables were the incidence of these effects and the direct cost was calculated as the value of the drugs that induced the adverse event. The events were classified according to the following interactions: a) drug-drug, b) drug-pediatrics, c) drug-gender, d) drug-pregnancy and abuse of controlled substances. The observed frequency shows great variability and the shortage of available data for ambulatory populations. We found 6.74% of reported events over the total of processed items, which generated an additional cost equivalent to 4.58% of the total pharmaceutical expenses. This study has only evaluated the cost occurred by the use of a drug that will lead to an adverse reaction. Moderate and severe reactions were included regardless of the important indirect costs, hospitalization costs, tests, physician fees, etc.

Attitudes of Montenegrin Consumers Toward Advertising Through Sport Among the Frequency of Watching Sports Events

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Bojan Masanovic

2018-01-01

Full Text Available It is proposed that potential consumers form attitudes based on advertising through sport can influence decisions to purchase a particular advertiser’s product. From this reason, it is important to analyse their general attitudes toward advertising through sport among various questions, and this investigation was aimed at gaining relevant knowledge about the attitudes of Montenegrin consumers toward advertising through sport among. The sample included 342 respondents, divided into six subsample groups: consumers, who do not watch sports events at all, then consumers who watch sports events 1-30 minutes, next 31-60 minutes, 61-90 minutes, 91-120 minutes, as well as consumers who watch sports events more than 120 minutes during the typical day. The sample of variables contained the system of three general attitudes which were modelled by seven-point Likert scale. The results of the measuring were analysed by multivariate analysis (MANOVA and univariate analysis (ANOVA and Post Hoc test. Based on the statistical analyses it was found that significant differences occur at multivariate level, as well as between all three variables at a significance level of p=.00. Hence, it is interesting to highlight that it was found there are significant differences showed up between the attitudes of consumers toward advertising through sport among the frequency of watching sports events. These results are so important for the marketers, mostly due to the reason they can’t merge all the potential consumers regarding the frequency they watch the sports events. On the other hand, this is the case in previous investigations and this observation presents relevant information.

Analysis of core damage frequency, Surry, Unit 1 internal events appendices

International Nuclear Information System (INIS)

Bertucio, R.C.; Julius, J.A.; Cramond, W.R.

1990-04-01

This document contains the appendices for the accident sequence analyses of internally initiated events for the Surry Nuclear Station, Unit 1. This is one of the five plant analyses conducted as part of the NUREG-1150 effort by the Nuclear Regulatory Commission. NUREG-1150 documents the risk of a selected group of nuclear power plants. The work performed is an extensive reanalysis of that published in November 1986 as NUREG/CR-4450, Volume 3. It addresses comments from numerous reviewers and significant changes to the plant systems and procedures made since the first report. The uncertainty analysis and presentation of results are also much improved. The context and detail of this report are directed toward PRA practitioners who need to know how the work was performed and the details for use in further studies. The mean core damage frequency at Surry was calculated to be 4.0E-5 per year, with a 95% upper bound of 1.3E-4 and 5% lower bound of 6.8E-6 per year. Station blackout type accidents (loss of all AC power) were the largest contributors to the core damage frequency, accounting for approximately 68% of the total. The next type of dominant contributors were Loss of Coolant Accidents (LOCAs). These sequences account for 15% of core damage frequency. No other type of sequence accounts for more than 10% of core damage frequency

Towards a Unified Understanding of Event-Related Changes in the EEG: The Firefly Model of Synchronization through Cross-Frequency Phase Modulation

Science.gov (United States)

Burgess, Adrian P.

2012-01-01

Although event-related potentials (ERPs) are widely used to study sensory, perceptual and cognitive processes, it remains unknown whether they are phase-locked signals superimposed upon the ongoing electroencephalogram (EEG) or result from phase-alignment of the EEG. Previous attempts to discriminate between these hypotheses have been unsuccessful but here a new test is presented based on the prediction that ERPs generated by phase-alignment will be associated with event-related changes in frequency whereas evoked-ERPs will not. Using empirical mode decomposition (EMD), which allows measurement of narrow-band changes in the EEG without predefining frequency bands, evidence was found for transient frequency slowing in recognition memory ERPs but not in simulated data derived from the evoked model. Furthermore, the timing of phase-alignment was frequency dependent with the earliest alignment occurring at high frequencies. Based on these findings, the Firefly model was developed, which proposes that both evoked and induced power changes derive from frequency-dependent phase-alignment of the ongoing EEG. Simulated data derived from the Firefly model provided a close match with empirical data and the model was able to account for i) the shape and timing of ERPs at different scalp sites, ii) the event-related desynchronization in alpha and synchronization in theta, and iii) changes in the power density spectrum from the pre-stimulus baseline to the post-stimulus period. The Firefly Model, therefore, provides not only a unifying account of event-related changes in the EEG but also a possible mechanism for cross-frequency information processing. PMID:23049827

Analysis of core damage frequency from internal events: Peach Bottom, Unit 2

International Nuclear Information System (INIS)

Kolaczkowski, A.M.; Lambright, J.A.; Ferrell, W.L.; Cathey, N.G.; Najafi, B.; Harper, F.T.

1986-10-01

This document contains the internal event initiated accident sequence analyses for Peach Bottom, Unit 2; one of the reference plants being examined as part of the NUREG-1150 effort by the Nuclear Regulatory Commission. NUREG-1150 will document the risk of a selected group of nuclear power plants. As part of that work, this report contains the overall core damage frequency estimate for Peach Bottom, Unit 2, and the accompanying plant damage state frequencies. Sensitivity and uncertainty analyses provided additional insights regarding the dominant contributors to the Peach Bottom core damage frequency estimate. The mean core damage frequency at Peach Bottom was calculated to be 8.2E-6. Station blackout type accidents (loss of all ac power) were found to dominate the overall results. Anticipated Transient Without Scram accidents were also found to be non-negligible contributors. The numerical results are largely driven by common mode failure probability estimates and to some extent, human error. Because of significant data and analysis uncertainties in these two areas (important, for instance, to the most dominant scenario in this study), it is recommended that the results of the uncertainty and sensitivity analyses be considered before any actions are taken based on this analysis

Modelado del transformador para eventos de alta frecuencia; Transformer model for high frequency events

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Verónica Adriana Galván Sánchez

2012-07-01

Full Text Available La función de un transformador es cambiar el nivel de tensión a través de un acoplamiento magnético. Debido a su construcción física, su representación como un circuito y su modelo matemático son muy complejos. El comportamiento electromagnético del transformador, al igual que todos los elementos de la red eléctrica de potencia, depende de la frecuencia involucrada. Por esta razón cuando se tienen fenómenos de alta frecuencia su modelo debe ser muy detallado para que reproduzca el comportamientodel estado transitorio. En este trabajo se analiza cómo se pasa de un modelo muy simple, a un modelo muy detallado para hacer simulación de eventos de alta frecuencia. Los eventos que se simulan son la operación de un interruptor por una falla en el sistema y el impacto de una descarga atmosférica sobre la línea de transmisión a una distancia de 5 km de una subestación de potencia. The transformer’s function is to change the voltage level through a magnetic coupling. Due to its physical construction, its representation as a circuit and its mathematical model are very complex. The electromagnetic behavior and all the elements in the power network depend on the involved frequency. So, for high frequency events, its model needs to be very detailed to reproduce the electromagnetic transient behavior. This work analyzes how to pass from a simple model to a very detailed model to simulated high frequency events. The simulated events are the switch operation due to a fault in the system and the impact of an atmospheric discharge (direct stroke in the transmission line, five km far away from the substation.

Time-Frequency Data Reduction for Event Related Potentials: Combining Principal Component Analysis and Matching Pursuit

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Selin Aviyente

2010-01-01

Full Text Available Joint time-frequency representations offer a rich representation of event related potentials (ERPs that cannot be obtained through individual time or frequency domain analysis. This representation, however, comes at the expense of increased data volume and the difficulty of interpreting the resulting representations. Therefore, methods that can reduce the large amount of time-frequency data to experimentally relevant components are essential. In this paper, we present a method that reduces the large volume of ERP time-frequency data into a few significant time-frequency parameters. The proposed method is based on applying the widely used matching pursuit (MP approach, with a Gabor dictionary, to principal components extracted from the time-frequency domain. The proposed PCA-Gabor decomposition is compared with other time-frequency data reduction methods such as the time-frequency PCA approach alone and standard matching pursuit methods using a Gabor dictionary for both simulated and biological data. The results show that the proposed PCA-Gabor approach performs better than either the PCA alone or the standard MP data reduction methods, by using the smallest amount of ERP data variance to produce the strongest statistical separation between experimental conditions.

Disruption of perineuronal nets increases the frequency of sharp wave ripple events.

Science.gov (United States)

Sun, Zhi Yong; Bozzelli, P Lorenzo; Caccavano, Adam; Allen, Megan; Balmuth, Jason; Vicini, Stefano; Wu, Jian-Young; Conant, Katherine

2018-01-01

Hippocampal sharp wave ripples (SWRs) represent irregularly occurring synchronous neuronal population events that are observed during phases of rest and slow wave sleep. SWR activity that follows learning involves sequential replay of training-associated neuronal assemblies and is critical for systems level memory consolidation. SWRs are initiated by CA2 or CA3 pyramidal cells (PCs) and require initial excitation of CA1 PCs as well as participation of parvalbumin (PV) expressing fast spiking (FS) inhibitory interneurons. These interneurons are relatively unique in that they represent the major neuronal cell type known to be surrounded by perineuronal nets (PNNs), lattice like structures composed of a hyaluronin backbone that surround the cell soma and proximal dendrites. Though the function of the PNN is not completely understood, previous studies suggest it may serve to localize glutamatergic input to synaptic contacts and thus influence the activity of ensheathed cells. Noting that FS PV interneurons impact the activity of PCs thought to initiate SWRs, and that their activity is critical to ripple expression, we examine the effects of PNN integrity on SWR activity in the hippocampus. Extracellular recordings from the stratum radiatum of horizontal murine hippocampal hemisections demonstrate SWRs that occur spontaneously in CA1. As compared with vehicle, pre-treatment (120 min) of paired hemislices with hyaluronidase, which cleaves the hyaluronin backbone of the PNN, decreases PNN integrity and increases SWR frequency. Pre-treatment with chondroitinase, which cleaves PNN side chains, also increases SWR frequency. Together, these data contribute to an emerging appreciation of extracellular matrix as a regulator of neuronal plasticity and suggest that one function of mature perineuronal nets could be to modulate the frequency of SWR events. © 2017 Wiley Periodicals, Inc.

Do the frequencies of adverse events increase, decrease, or stay the same with long-term use of statins?

Science.gov (United States)

Huddy, Karlyn; Dhesi, Pavittarpaul; Thompson, Paul D

2013-02-01

Statins are widely used for their cholesterol-lowering properties and proven reduction of cardiovascular disease risk. Many patients take statins as long-term treatment for a variety of conditions without a clear-cut understanding of how treatment duration affects the frequency of adverse effects. We aimed to evaluate whether the frequencies of documented adverse events increase, decrease, or remain unchanged with long-term statin use. We reviewed the established literature to define the currently known adverse effects of statin therapy, including myopathy, central nervous system effects, and the appearance of diabetes, and the frequency of these events with long-term medication use. The frequency of adverse effects associated with long-term statin therapy appears to be low. Many patients who develop side effects from statin therapy do so relatively soon after initiation of therapy, so the frequency of side effects from statin therapy when expressed as a percentage of current users decreases over time. Nevertheless, patients may develop side effects such as muscle pain and weakness years after starting statin therapy; however, the absolute number of patients affected by statin myopathy increases with treatment duration. Also, clinical trials of statin therapy rarely exceed 5 years, so it is impossible to determine with certainty the frequency of long-term side effects with these drugs.

Attitudes of Turkish Consumers toward Advertising through Sport among the Frequency of Watching Sports Events

Directory of Open Access Journals (Sweden)

Bojan Masanovic

2017-08-01

Full Text Available It is proposed that potential consumers form attitudes based on advertising through sport can influence decisions to purchase a particular advertiser’s product. From this reason, it is important to analyse their general attitudes toward advertising through sport among various questions, and this investigation was aimed at gaining relevant knowledge about the attitudes of Serbian consumers toward advertising through sport among. The sample included 173 respondents, divided into six subsample groups: consumers, who do not watch sports events at all, then consumers who watch sports events 1-30 minutes, next 31-60 minutes, 61-90 minutes, 91-120 minutes, as well as consumers who watch sports events more than 120 minutes during the typical day. The sample of variables contained the system of three general attitudes which were modelled by seven-point Likert scale. The results of the measuring were analysed by multivariate analysis (MANOVA and univariate analysis (ANOVA and Post Hoc test. Based on the statistical analyses it was found that significant differences occur at multivariate level, as well as between two out of three variables at a significance level of p=.05. Hence, it is interesting to highlight that it was found there are significant differences showed up between the attitudes of consumers toward advertising through sport among the frequency of watching sports events. These results are so important for the marketers, mostly due to the reason they can’t merge all the potential consumers regarding the frequency they watch the sports events. On the other hand, this is the case in previous investigations and this observation presents relevant information.

Sperm characteristics and teratology in rats following vas deferens occlusion with RISUG and its reversal.

Science.gov (United States)

Lohiya, N K; Suthar, R; Khandelwal, A; Goyal, S; Ansari, A S; Manivannan, B

2010-02-01

The functional success of the reversal of vas occlusion by styrene maleic anhydride (RISUG), using the solvent vehicle, Dimethyl Sulphoxide (DMSO), has been investigated. Reversal with DMSO was carried out in Wistar albino rats 90 days after bilateral vas occlusion. The body weight, organ weight, sperm characteristics, fertility test and teratology, including skeletal morphology were evaluated in vas occlusion and reversal animals and in F(1) progenies to assess the functional success of the occlusion and reversal. Body weight, organ weight and the cauda epididymal sperm characteristics of vas occlusion and reversal animals and of F(1) progenies were comparable to control. Ejaculated spermatozoa in the vaginal smear showed detached head/tail, acrosomal damage, bent midpiece, bent tail and morphological aberrations in sperm head after vas occlusion, which returned to normal, 90 days after reversal. Monthly fertility test, post-injection showed 0% fertility, which improved gradually and 100% fertility was achieved 90 days after reversal. The fertility/pregnancy/implantation record and skeletal morphology of the offspring were comparable to control. The results suggest functional success and safety of vas occlusion reversal by DMSO.

Comparison between Japan and the United States in the frequency of events in equipment and components at nuclear power plants

International Nuclear Information System (INIS)

Shimada, Yoshio

2007-01-01

The Institute of Nuclear Safety System, Incorporated (INSS) conducted trend analyses until 2005 to compare the frequency of events in certain electrical components and instrumentation components at nuclear power plants between Japan and the United States. The results revealed that events have occurred approximately an order of magnitude less often in Japan than in the United States. This paper compared Japan and the United States in more detail in terms of how often events - events reported under the reporting standards of the Nuclear Information Archive (NUCIA) or the Institute of Nuclear Power Operations (INPO) - occurred in electrical components, instrumentation components and mechanical components at nuclear power plants. The results were as follows: (1) In regard to electrical components and instrumentation components, events have occurred one-eighth less frequently in Japan than in the United States, suggesting that the previous results were correct. (2) Events have occurred more often in mechanical components than electrical components and instrumentation components in both Japan and the United States, and there was a smaller difference in the frequency of events in mechanical components between the two countries. (3) Regarding mechanical components, it was found that events in the pipes for critical systems and equipment, such as reactor coolant systems, emergency core cooling systems, instrument and control systems, ventilating and air-conditioning systems, and turbine equipment, have occurred more often in Japan than in the United States. (4) The above observations suggest that there is little scope for reducing the frequency of events in electrical components and instrumentation components, but that mechanical components such as pipes for main systems like emergency core cooling systems and turbine equipment in the case of PWRs, could be improved by re-examining inspection methods and intervals. (author)

Increased frequency of FBN1 truncating and splicing variants in Marfan syndrome patients with aortic events.

Science.gov (United States)

Baudhuin, Linnea M; Kotzer, Katrina E; Lagerstedt, Susan A

2015-03-01

Marfan syndrome is a systemic disorder that typically involves FBN1 mutations and cardiovascular manifestations. We investigated FBN1 genotype-phenotype correlations with aortic events (aortic dissection and prophylactic aortic surgery) in patients with Marfan syndrome. Genotype and phenotype information from probands (n = 179) with an FBN1 pathogenic or likely pathogenic variant were assessed. A higher frequency of truncating or splicing FBN1 variants was observed in Ghent criteria-positive patients with an aortic event (n = 34) as compared with all other probands (n = 145) without a reported aortic event (79 vs. 39%; P Marfan syndrome patients with FBN1 truncating and splicing variants.Genet Med 17 3, 177-187.

Shallow very-low-frequency earthquakes accompanied with slow slip event along the plate boundary of the Nankai trough

Science.gov (United States)

Nakano, M.; Hori, T.; Araki, E.; Kodaira, S.; Ide, S.

2017-12-01

Recent improvements of seismic and geodetic observations have revealed the existence of a new family of slow earthquakes occurring along or close to the plate boundary worldwide. In the viewpoint of the characteristic time scales, the slow earthquakes can be classified into several groups as low-frequency tremor or tectonic tremor (LFT) dominated in several hertz, very-low-frequency earthquake (VLFE) dominated in 10 to 100 s, and short- and long-term slow-slip event (SSE) with durations of days to years. In many cases, these slow earthquakes are accompanied with other types of slow events. However, the events occurring offshore, especially beneath the toe of accretionary prism, are poorly understood because of the difficulty to detect signals. Utilizing the data captured from oceanfloor observation networks which many efforts have recently been taken to develop is necessary to improve our understandings for these events. Here, we investigated CMT analysis of shallow VLFEs using data obtained from DONET oceanfloor observation networks along the Nankai trough, southwest of Japan. We found that shallow VLFEs have almost identical history of moment release with that of synchronous SSE which occurred at the same region recently found by Araki et al. (2017). VLFE sources show updip migrations during the activity, coincident with the migration of SSE source. From these findings we conclude that these slow events share the same fault slip, and VLFE represent high-frequency fluctuations of slip during SSE. This result imply that shallow SSE along the plate interface would have occurred in the background during the shallow VLFE activities repeatedly observed along the Nankai trough, but the SSE was not reported because of difficult detections.

Seasonal variability of stream water quality response to storm events captured using high-frequency and multi-parameter data

Science.gov (United States)

Fovet, O.; Humbert, G.; Dupas, R.; Gascuel-Odoux, C.; Gruau, G.; Jaffrezic, A.; Thelusma, G.; Faucheux, M.; Gilliet, N.; Hamon, Y.; Grimaldi, C.

2018-04-01

The response of stream chemistry to storm is of major interest for understanding the export of dissolved and particulate species from catchments. The related challenge is the identification of active hydrological flow paths during these events and of the sources of chemical elements for which these events are hot moments of exports. An original four-year data set that combines high frequency records of stream flow, turbidity, nitrate and dissolved organic carbon concentrations, and piezometric levels was used to characterize storm responses in a headwater agricultural catchment. The data set was used to test to which extend the shallow groundwater was impacting the variability of storm responses. A total of 177 events were described using a set of quantitative and functional descriptors related to precipitation, stream and groundwater pre-event status and event dynamics, and to the relative dynamics between water quality parameters and flow via hysteresis indices. This approach led to identify different types of response for each water quality parameter which occurrence can be quantified and related to the seasonal functioning of the catchment. This study demonstrates that high-frequency records of water quality are precious tools to study/unique in their ability to emphasize the variability of catchment storm responses.

Characterizing the Frequency and Elevation of Rapid Drainage Events in West Greenland

Science.gov (United States)

Cooley, S.; Christoffersen, P.

2016-12-01

Rapid drainage of supraglacial lakes on the Greenland Ice Sheet is critical for the establishment of surface-to-bed hydrologic connections and the subsequent transfer of water from surface to bed. Yet, estimates of the number and spatial distribution of rapidly draining lakes vary widely due to limitations in the temporal frequency of image collection and obscureness by cloud. So far, no study has assessed the impact of these observation biases. In this study, we examine the frequency and elevation of rapidly draining lakes in central West Greenland, from 68°N to 72.6°N, and we make a robust statistical analysis to estimate more accurately the likelihood of lakes draining rapidly. Using MODIS imagery and a fully automated lake detection method, we map more than 500 supraglacial lakes per year over a 63000 km2 study area from 2000-2015. Through testing four different definitions of rapidly draining lakes from previously published studies, we find that the number of rapidly draining lakes varies from 3% to 38%. Logistic regression between rapid drainage events and image sampling frequency demonstrates that the number of rapid drainage events is strongly dependent on cloud-free observation percentage. We then develop three new drainage criteria and apply an observation bias correction that suggests a true rapid drainage probability between 36% and 45%, considerably higher than previous studies without bias assessment have reported. We find rapid-draining lakes are on average larger and disappear earlier than slow-draining lakes, and we also observe no elevation differences for the lakes detected as rapidly draining. We conclude a) that methodological problems in rapid drainage research caused by observation bias and varying detection methods have obscured large-scale rapid drainage characteristics and b) that the lack of evidence for an elevation limit on rapid drainage suggests surface-to-bed hydrologic connections may continue to propagate inland as climate warms.

The development on the methodology of the initiating event frequencies for liquid metal reactor KALIMER

International Nuclear Information System (INIS)

Jeong, K. S.; Yang, Z. A.; Ah, Y. B.; Jang, W. P.; Jeong, H. Y.; Ha, K. S.; Han, D. H.

2002-01-01

In this paper, the PSA methodology of PRISM,Light Water Reactor, Pressurized Heavy Water Reactor are analyzed and the methodology of Initiating Events for KALIMER are suggested. Also,the reliability assessment of assumptions for Pipes Corrosion Frequency is set up. The reliability assessment of Passive Safety System, one of Main Safety System of KALIMER, are discussed and analyzed

Clinical usefulness and feasibility of time-frequency analysis of chemosensory event-related potentials.

Science.gov (United States)

Huart, C; Rombaux, Ph; Hummel, T; Mouraux, A

2013-09-01

The clinical usefulness of olfactory event-related brain potentials (OERPs) to assess olfactory function is limited by the relatively low signal-to-noise ratio of the responses identified using conventional time-domain averaging. Recently, it was shown that time-frequency analysis of the obtained EEG signals can markedly improve the signal-to-noise ratio of OERPs in healthy controls, because it enhances both phase-locked and non phase-locked EEG responses. The aim of the present study was to investigate the clinical usefulness of this approach and evaluate its feasibility in a clinical setting. We retrospectively analysed EEG recordings obtained from 45 patients (15 anosmic, 15 hyposmic and 15 normos- mic). The responses to olfactory stimulation were analysed using conventional time-domain analysis and joint time-frequency analysis. The ability of the two methods to discriminate between anosmic, hyposmic and normosmic patients was assessed using a Receiver Operating Characteristic analysis. The discrimination performance of OERPs identified using conventional time-domain averaging was poor. In contrast, the discrimination performance of the EEG response identified in the time-frequency domain was relatively high. Furthermore, we found a significant correlation between the magnitude of this response and the psychophysical olfactory score. Time-frequency analysis of the EEG responses to olfactory stimulation could be used as an effective and reliable diagnostic tool for the objective clinical evaluation of olfactory function in patients.

An expert elicitation process to project the frequency and magnitude of Florida manatee mortality events caused by red tide (Karenia brevis)

Science.gov (United States)

Martin, Julien; Runge, Michael C.; Flewelling, Leanne J.; Deutsch, Charles J.; Landsberg, Jan H.

2017-11-20

Red tides (blooms of the harmful alga Karenia brevis) are one of the major sources of mortality for the Florida manatee (Trichechus manatus latirostris), especially in southwest Florida. It has been hypothesized that the frequency and severity of red tides may increase in the future because of global climate change and other factors. To improve our ecological forecast for the effects of red tides on manatee population dynamics and long-term persistence, we conducted a formal expert judgment process to estimate probability distributions for the frequency and relative magnitude of red-tide-related manatee mortality (RTMM) events over a 100-year time horizon in three of the four regions recognized as manatee management units in Florida. This information was used to update a population viability analysis for the Florida manatee (the Core Biological Model). We convened a panel of 12 experts in manatee biology or red-tide ecology; the panel met to frame, conduct, and discuss the elicitation. Each expert provided a best estimate and plausible low and high values (bounding a confidence level of 80 percent) for each parameter in each of three regions (Northwest, Southwest, and Atlantic) of the subspecies’ range (excluding the Upper St. Johns River region) for two time periods (0−40 and 41−100 years from present). We fitted probability distributions for each parameter, time period, and expert by using these three elicited values. We aggregated the parameter estimates elicited from individual experts and fitted a parametric distribution to the aggregated results.Across regions, the experts expected the future frequency of RTMM events to be higher than historical levels, which is consistent with the hypothesis that global climate change (among other factors) may increase the frequency of red-tide blooms. The experts articulated considerable uncertainty, however, about the future frequency of RTMM events. The historical frequency of moderate and intense RTMM (combined) in

A glance at Spanish embryology and teratology during the XX century through the academic life of Francisco Orts-Llorca (1905-1993).

Science.gov (United States)

Aréchaga, Juan; Jiménez-Collado, Juan; Ruano-Gil, Domingo

2009-01-01

Francisco Ort-Llorca (1905-1993) was one of the most outstanding Spanish embryologists of the XX century. He was disciple of Henri Rouvire in Paris (France), Alfred Fischel in Vienna (Austria), Walther Vogt in Munich (Germany) and Pedro Ara in Madrid (Spain). From 1935, he was professor of Human Anatomy at the Faculty of Medicine of Cadiz, belonged then to the University of Seville (accidentally, in the University of Valencia, during the Spanish Civil War from 1936-1939) and, later on, at the Faculty of Medicine of Madrid (Complutense University) from 1954 to 1975. He was internationally recognized in anatomical sciences and stood out for his contributions to descriptive and experimental Embryology and Teratology, particularly in those aspects connected to the normal and pathological development of the heart and visual organs.

A multispacecraft event study of Pc5 ultralow-frequency waves in the magnetosphere and their external drivers

International Nuclear Information System (INIS)

Wang, Chih-Ping; Thorne, Richard; Liu, Terry Z.; Hartinger, Michael D.; Nagai, Tsugunobu

2017-01-01

We investigate a quiet time event of magnetospheric Pc5 ultralow-frequency (ULF) waves and their likely external drivers using multiple spacecraft observations. Enhancements of electric and magnetic field perturbations in two narrow frequency bands, 1.5–2 mHz and 3.5–4 mHz, were observed over a large radial distance range from r ~ 5 to 11 RE. During the first half of this event, perturbations were mainly observed in the transverse components and only in the 3.5–4 mHz band. In comparison, enhancements were stronger during the second half in both transverse and compressional components and in both frequency bands. No indication of field line resonances was found for these magnetic field perturbations. Perturbations in these two bands were also observed in the magnetosheath, but not in the solar wind dynamic pressure perturbations. For the first interval, good correlations between the flow perturbations in the magnetosphere and magnetosheath and an indirect signature for Kelvin-Helmholtz (K-H) vortices suggest K-H surface waves as the driver. For the second interval, good correlations are found between the magnetosheath dynamic pressure perturbations, magnetopause deformation, and magnetospheric waves, all in good correspondence to interplanetary magnetic field (IMF) discontinuities. The characteristics of these perturbations can be explained by being driven by foreshock perturbations resulting from these IMF discontinuities. This event shows that even during quiet periods, K-H-unstable magnetopause and ion foreshock perturbations can combine to create a highly dynamic magnetospheric ULF wave environment

Tracking the time course of word-frequency effects in auditory word recognition with event-related potentials.

Science.gov (United States)

Dufour, Sophie; Brunellière, Angèle; Frauenfelder, Ulrich H

2013-04-01

Although the word-frequency effect is one of the most established findings in spoken-word recognition, the precise processing locus of this effect is still a topic of debate. In this study, we used event-related potentials (ERPs) to track the time course of the word-frequency effect. In addition, the neighborhood density effect, which is known to reflect mechanisms involved in word identification, was also examined. The ERP data showed a clear frequency effect as early as 350 ms from word onset on the P350, followed by a later effect at word offset on the late N400. A neighborhood density effect was also found at an early stage of spoken-word processing on the PMN, and at word offset on the late N400. Overall, our ERP differences for word frequency suggest that frequency affects the core processes of word identification starting from the initial phase of lexical activation and including target word selection. They thus rule out any interpretation of the word frequency effect that is limited to a purely decisional locus after word identification has been completed. Copyright © 2012 Cognitive Science Society, Inc.

Assessing loss event frequencies of smart grid cyber threats: Encoding flexibility into FAIR using Bayesian network approach

NARCIS (Netherlands)

Le, Anhtuan; Chen, Yue; Chai, Kok Keong; Vasenev, Alexandr; Montoya, L.

Assessing loss event frequencies (LEF) of smart grid cyber threats is essential for planning cost-effective countermeasures. Factor Analysis of Information Risk (FAIR) is a well-known framework that can be applied to consider threats in a structured manner by using look-up tables related to a

ATTITUDES OF SERBIAN CONSUMERS TOWARD ADVERTISING THROUGH SPORT WITH REGARD TO THE FREQUENCY OF WATCHING SPORTS EVENTS

Directory of Open Access Journals (Sweden)

Stevo Popović

2015-05-01

Full Text Available It is proposed that potential cosumers form attitudes based on advertising through sport can influence decisions to purchase a particular advertiser’s product (Pyun, 2006. From this reason, it is important to analyse their general attitudes toward advertising through sport among various questions, and this investigation was aimed at gaining relevant knowledge about the attitudes of Serbian consumers toward advertising through sport among. Methods: The sample included 127 respondents, divided into six subsample groups: cconsumers, who do not watch sports events at all, then consumers who watch sports events 1-30 minutes, next 31-60 minutes, 61-90 minutes, 91-120 minutes, as well as consumers who watch sports events more than 120 minutes during the typical day. The sample of variables contained the system of three general attitudes which were modeled by seven-point Likert scale. The results of the measuring were analyzed by multivariate analysis (MANOVA and univariate analysis (ANOVA and Post Hoc test. Results: Based on the statistical analyses it was found that significant differences didn’t occur at multivariate level, as well as between all three variables at a significance level of p=.05. Hence, it is interesting to highlight that it was found there are no significant differences showed up between the attitudes of consumers toward advertising through sport among the frequency of watching sports events. Discussion: These results are so important for the marketers, mostly due to the reason they can merge all the potential consumers regarding the frequency they watch the sports events. On the other hand, this wasn’t the case in previous investigations (Bjelica and Popović, 2011 and this observation presents relevant information.

Evolution in Intensity and Frequency of Extreme Events of Precipitation in Northeast Region and Brazilian Amazon in XXI Century

Science.gov (United States)

Fonseca, P. M.; Veiga, J. A.; Correia, F. S.; Brito, A. L.

2013-05-01

The aim of this research was evaluate changes in frequency and intensity of extreme events of precipitation in Brazilian Amazon and Northeast Region, doubling CO2 concentration in agreement of IPCC A2 emissions scenarios (Nakicenovic et al., 2001). For this evaluation was used ETA model (Chou et al., 2011), forced with CCSM3 Global model data (Meehl, 2006) to run 4 experiments, only for January, February and March: 1980-1990, 2000-2010, 2040-2050 and 2090-2100. Using the first decade as reference (1980-1990), was evaluated changes occurred in following decades, with a methodology to classify extremes events adapted from Frich (2002) and Gao (2006). Higher was the class, more intense is the event. An increase of 25% was observed in total precipitation in Brazilian Amazon for the end of XXI century and 12% for extreme events type 1, 9% for events type 2 and 10% for type 3. By the other hand, a 17% decrease of precipitation in Brazilian Northeast was observed, and a pronounced decay of 24% and 15% in extreme events contribution type 1 and 2 to total amount of precipitation, respectively. The difference between total normal type events was positive in this three decades compared with reference decade 1980-1990, varying positively from 4 to 6 thousand events included in normality by decade, these events was decreased in your majority of Class 1 events, which presented a decay of at least 3.500 events by each decade. This suggests an intensification of extreme events, considering that the amount of precipitation by class increased, and the number of events by class decreased. To Northeast region, an increasing in 9% of contribution to events type 3 class was observed, as well as in the frequency of this type of events (about of 700 more events). Major decreasing in number of classes extreme events occur in 2000-2010, to classes 1 and 3, with 7,2 and 5,6%, and by the end of century in class 3, with 4,5%. For the three analyzed decades a total decrease of 8.400 events was

Modelado del transformador para eventos de alta frecuencia ;Transformer model for high frequency events

Directory of Open Access Journals (Sweden)

Verónica Adriana – Galván Sanchez

2012-07-01

Full Text Available La función de un transformador es cambiar el nivel de tensión a través de un acoplamiento magnético.Debido a su construcción física, su representación como un circuito y su modelo matemático son muycomplejos. El comportamiento electromagnético del transformador, al igual que todos los elementos de lared eléctrica de potencia, depende de la frecuencia involucrada. Por esta razón cuando se tienenfenómenos de alta frecuencia su modelo debe ser muy detallado para que reproduzca el comportamientodel estado transitorio. En este trabajo se analiza cómo se pasa de un modelo muy simple, a un modelo muydetallado para hacer simulación de eventos de alta frecuencia. Los eventos que se simulan son la operaciónde un interruptor por una falla en el sistema y el impacto de una descarga atmosférica sobre la línea detransmisión a una distancia de 5 km de una subestación de potencia.The transformer’s function is to change the voltage level through a magnetic coupling. Due to its physicalconstruction, its representation as a circuit and its mathematical model are very complex. Theelectromagnetic behavior and all the elements in the power network depend on the involved frequency. So,for high frequency events, its model needs to be very detailed to reproduce the electromagnetic transientbehavior. This work analyzes how to pass from a simple model to a very detailed model to simulated highfrequency events. The simulated events are the switch operation due to a fault in the system and the impactof an atmospheric discharge (direct stroke in the transmission line, five km far away from the substation.

Adequate engineering for lowering the frequency of initiating events at Siemens/KWU

International Nuclear Information System (INIS)

Gremm, O.

1988-01-01

The analysis of TMI and Chernobyl events shows weak points and deficits in the field of preventive safety features. This should not be forgotten during the ongoing discussion on severe accidents. Therefore the paper explains special preventive safety features which were the results of the development of Siemens/KWU reactor technology. With respect to the present discussion on new reactor concepts special attention is given to the inherent and passive safety features and the engineering which results in low core melt frequency. Such an analysis leads to knowledge modules which are based on experience during licensing procedures and plant operation and should be the starting points for reactor technology of the future

Probe-controlled soliton frequency shift in the regime of optical event horizon.

Science.gov (United States)

Gu, Jie; Guo, Hairun; Wang, Shaofei; Zeng, Xianglong

2015-08-24

In optical analogy of the event horizon, temporal pulse collision and mutual interactions are mainly between an intense solitary wave (soliton) and a dispersive probe wave. In such a regime, here we numerically investigate the probe-controlled soliton frequency shift as well as the soliton self-compression. In particular, in the dispersion landscape with multiple zero dispersion wavelengths, bi-directional soliton spectral tunneling effects is possible. Moreover, we propose a mid-infrared soliton self-compression to the generation of few-cycle ultrashort pulses, in a bulk of quadratic nonlinear crystals in contrast to optical fibers or cubic nonlinear media, which could contribute to the community with a simple and flexible method to experimental implementations.

Frequency of Extreme Heat Event as a Surrogate Exposure Metric for Examining the Human Health Effects of Climate Change.

Directory of Open Access Journals (Sweden)

Crystal Romeo Upperman

Full Text Available Epidemiological investigation of the impact of climate change on human health, particularly chronic diseases, is hindered by the lack of exposure metrics that can be used as a marker of climate change that are compatible with health data. Here, we present a surrogate exposure metric created using a 30-year baseline (1960-1989 that allows users to quantify long-term changes in exposure to frequency of extreme heat events with near unabridged spatial coverage in a scale that is compatible with national/state health outcome data. We evaluate the exposure metric by decade, seasonality, area of the country, and its ability to capture long-term changes in weather (climate, including natural climate modes. Our findings show that this generic exposure metric is potentially useful to monitor trends in the frequency of extreme heat events across varying regions because it captures long-term changes; is sensitive to the natural climate modes (ENSO events; responds well to spatial variability, and; is amenable to spatial/temporal aggregation, making it useful for epidemiological studies.

Effects of low-frequency repetitive transcranial magnetic stimulation on event-related potential P300

Science.gov (United States)

Torii, Tetsuya; Sato, Aya; Iwahashi, Masakuni; Iramina, Keiji

2012-04-01

The present study analyzed the effects of repetitive transcranial magnetic stimulation (rTMS) on brain activity. P300 latency of event-related potential (ERP) was used to evaluate the effects of low-frequency and short-term rTMS by stimulating the supramarginal gyrus (SMG), which is considered to be the related area of P300 origin. In addition, the prolonged stimulation effects on P300 latency were analyzed after applying rTMS. A figure-eight coil was used to stimulate left-right SMG, and intensity of magnetic stimulation was 80% of motor threshold. A total of 100 magnetic pulses were applied for rTMS. The effects of stimulus frequency at 0.5 or 1 Hz were determined. Following rTMS, an odd-ball task was performed and P300 latency of ERP was measured. The odd-ball task was performed at 5, 10, and 15 min post-rTMS. ERP was measured prior to magnetic stimulation as a control. Electroencephalograph (EEG) was measured at Fz, Cz, and Pz that were indicated by the international 10-20 electrode system. Results demonstrated that different effects on P300 latency occurred between 0.5-1 Hz rTMS. With 1 Hz low-frequency magnetic stimulation to the left SMG, P300 latency decreased. Compared to the control, the latency time difference was approximately 15 ms at Cz. This decrease continued for approximately 10 min post-rTMS. In contrast, 0.5 Hz rTMS resulted in delayed P300 latency. Compared to the control, the latency time difference was approximately 20 ms at Fz, and this delayed effect continued for approximately 15 min post-rTMS. Results demonstrated that P300 latency varied according to rTMS frequency. Furthermore, the duration of the effect was not similar for stimulus frequency of low-frequency rTMS.

Event-related desynchronization and synchronization in MEG: Framework for analysis and illustrative datasets related to discrimination of frequency-modulated tones.

Science.gov (United States)

Zygierewicz, J; Sieluzycki, C; König, R; Durka, P J

2008-02-15

We introduce a complete framework for the calculation of statistically significant event-related desynchronization and synchronization (ERD/ERS) in the time-frequency plane for magnetoencephalographic (MEG) data, and provide free Internet access to software and illustrative datasets related to a classification task of frequency-modulated (FM) tones. Event-related changes in MEG were analysed on the basis of the normal component of the magnetic field acquired by the 148 magnetometers of the hardware configuration of our whole-head MEG device, and by computing planar gradients in longitudinal and latitudinal direction. Time-frequency energy density for the magnetometer as well as the two gradient configurations is first approximated using short-time Fourier transform. Subsequently, detailed information is obtained from high-resolution time-frequency maps for the most interesting sensors by means of the computationally much more demanding matching pursuit parametrization. We argue that the ERD/ERS maps are easier to interpret in the gradient approaches and discuss the superior resolution of the matching pursuit time-frequency representation compared to short-time Fourier and wavelet transforms. Experimental results are accompanied by the following resources, available from http://brain.fuw.edu.pl/MEG: (a) 48 high-resolution figures presenting the results of four subjects in all applicable settings, (b) raw datasets, and (c) complete software environment, allowing to recompute these figures from the raw datasets.

Attitudes of Consumers from Podgorica toward Advertising through Sport among the Frequency of Watching Sports Events

Directory of Open Access Journals (Sweden)

Nikola Milovic

2018-04-01

Full Text Available This investigation was aimed at gaining relevant knowledge about the attitudes of Podgorica consumers toward advertising through sport among. The sample included 330 students from Faculty of Economics in Podgorica, divided into six subsample groups: consumers, who do not watch sports events at all, then consumers who watch sports events 1-30 minutes, next 31-60 minutes, 61-90 minutes, 91-120 minutes, as well as consumers who watch sports events more than 120 minutes during the typical day. The sample of variables contained the system of three general attitudes which were modelled by seven-point Likert scale. The results of the measuring were analyzed by multivariate analysis (MANOVA and univariate analysis (ANOVA and Post Hoc test. Based on the statistical analyses it was found that significant differences occur at multivariate level, as well as between all three variables at a significance level of p=.00. Hence, it is interesting to highlight that it was found there are significant differences showed up between the attitudes of consumers toward advertising through sport among the frequency of watching sports events. The significant differences were found in two of three variables, while the consumers who do not watch sports events had much more negative attitudes toward advertising though sport.

Behavioral teratologic studies using microwave radiation: is there an increased risk from exposure to cellular phones and microwave ovens?

Science.gov (United States)

Jensh, R P

1997-01-01

The objective of the investigations presented in this review was to determine if there are adverse effects due to chronic prenatal microwave exposure in rats at term and/or alterations in neonatal and adult offspring psychophysiologic development and growth. Following the establishment of a nonhyperthermal power density level of microwave radiation, pregnant rats were exposed throughout pregnancy to continuous wave 915 MHz, 2450 MHz, or 6000 MHz radiation at power density levels of 10, 20, or 35 mW/cm2, respectively. Teratologic evaluation included the following parameters: maternal weight and weight gain; mean litter size; maternal organ weight and organ weight/body weight ratios; body weight ratios of brain, liver, kidneys, and ovaries; maternal peripheral blood parameters including hematocrit, hemoglobin, and white cell counts; number of resorptions and resorption rate; number of abnormalities and abnormality rate; mean term fetal weight. Mothers were rebred, and the second, nonexposed litters were evaluated for teratogenic effects. Exposed offspring were evaluated using the following perinatal and adult tests: eye opening, surface righting, negative geotaxis, auditory startle, air righting, open field, activity wheel, swimming, and forelimb hanging. Offspring were also monitored for weekly weight and weight gain. Animals exposed to 915 MHz did not exhibit any consistent significant alterations in any of the above parameters. Exposure to 2450 MHz resulted only in a significantly increased adult offspring activity level compared to nonexposed offspring. Offspring exposed to 6000 MHz radiation exhibited an initial slight, but significant, retardation in term weight, while mothers had a significantly reduced monocyte count. No changes in any of the other term parameters were observed. A few postnatal parameters were affected in offspring exposed to 6000 MHz. Weekly weights were lower in the exposed offspring, but they recovered by the fifth week. Eye opening was

Managing fertile women under lithium treatment: the challenge of a Teratology Information Service.

Science.gov (United States)

Neri, Caterina; De Luca, Carmen; D'oria, Luisa; Licameli, Angelo; Nucci, Marta; Pellegrino, Marcella; Caruso, Alessandro; De Santis, Marco

2018-06-01

The objective of the present study is to review the literature regarding the management of fertile patients under lithium treatment for bipolar disorder and to report the experience of our Teratology Information Service over the past thirteen years in managing women treated with lithium during preconception, pregnancy and breastfeeding. This research focuses on a selective review of the literature and a retrospective survey has been carried out on fertile women under lithium treatment who called our service at A. Gemelli University Hospital in Rome from May 2002 to December 2015. A total of 140 women under lithium treatment called our TIS. A complete follow-up has been performed on 34 patients: 29 called during pregnancy and 5 called during preconception. None of the patients called during breastfeeding, while half of the patients were taking concomitant drugs during pregnancy. One major cardiac malformation (hypoplastic left heart syndrome) has been reported. No minor malformations have been detected. Twenty-one patients delivered a living child, with one premature neonate. Two patients underwent voluntary interruption of pregnancy and six patients had early spontaneous abortion. In one patient, intrauterine growth retardation occurred, but with no adverse neonatal outcomes. Four neonates experienced transient respiratory distress at birth. Two children developed mild to severe language delay, but normal motor development. Lithium treatment in fertile women is a very delicate topic, where risks and benefits of discontinuing therapy when women plan to become pregnant should be accurately evaluated. Thorough peri-conceptional counselling is crucial for the outcome of pregnancy and for maternal health status during preconception, gestation and breastfeeding.

Twitter data analysis: temporal and term frequency analysis with real-time event

Science.gov (United States)

Yadav, Garima; Joshi, Mansi; Sasikala, R.

2017-11-01

From the past few years, World Wide Web (www) has become a prominent and huge source for user generated content and opinionative data. Among various social media, Twitter gained popularity as it offers a fast and effective way of sharing users’ perspective towards various critical and other issues in different domain. As the data is hugely generated on cloud, it has opened doors for the researchers in the field of data science and analysis. There are various domains such as ‘Political’ domain, ‘Entertainment’ domain and ‘Business’ domain. Also there are various APIs that Twitter provides for developers 1) Search API, focus on the old tweets 2) Rest API, focuses on user details and allow to collect the user profile, friends and followers 3) Streaming API, which collects details like tweets, hashtags, geo locations. In our work we are accessing Streaming API in order to fetch real-time tweets for the dynamic happening event. For this we are focusing on ‘Entertainment’ domain especially ‘Sports’ as IPL-T20 is currently the trending on-going event. We are collecting these numerous amounts of tweets and storing them in MongoDB database where the tweets are stored in JSON document format. On this document we are performing time-series analysis and term frequency analysis using different techniques such as filtering, information extraction for text-mining that fulfils our objective of finding interesting moments for temporal data in the event and finding the ranking among the players or the teams based on popularity which helps people in understanding key influencers on the social media platform.

Do changes in the frequency, magnitude and timing of extreme climatic events threaten the population viability of coastal birds?

NARCIS (Netherlands)

van de Pol, Martijn; Ens, Bruno J.; Heg, Dik; Brouwer, Lyanne; Krol, Johan; Maier, Martin; Exo, Klaus-Michael; Oosterbeek, Kees; Lok, Tamar; Eising, Corine M.; Koffijberg, Kees

P>1. Climate change encompasses changes in both the means and the extremes of climatic variables, but the population consequences of the latter are intrinsically difficult to study. 2. We investigated whether the frequency, magnitude and timing of rare but catastrophic flooding events have changed

Analysis of core damage frequency: Peach Bottom, Unit 2 internal events appendices

International Nuclear Information System (INIS)

Kolaczkowski, A.M.; Cramond, W.R.; Sype, T.T.; Maloney, K.J.; Wheeler, T.A.; Daniel, S.L.

1989-08-01

This document contains the appendices for the accident sequence analysis of internally initiated events for the Peach Bottom, Unit 2 Nuclear Power Plant. This is one of the five plant analyses conducted as part of the NUREG-1150 effort for the Nuclear Regulatory Commission. The work performed and described here is an extensive reanalysis of that published in October 1986 as NUREG/CR-4550, Volume 4. It addresses comments from numerous reviewers and significant changes to the plant systems and procedures made since the first report. The uncertainty analysis and presentation of results are also much improved, and considerable effort was expended on an improved analysis of loss of offsite power. The content and detail of this report is directed toward PRA practitioners who need to know how the work was done and the details for use in further studies. The mean core damage frequency is 4.5E-6 with 5% and 95% uncertainty bounds of 3.5E-7 and 1.3E-5, respectively. Station blackout type accidents (loss of all ac power) contributed about 46% of the core damage frequency with Anticipated Transient Without Scram (ATWS) accidents contributing another 42%. The numerical results are driven by loss of offsite power, transients with the power conversion system initially available operator errors, and mechanical failure to scram. 13 refs., 345 figs., 171 tabs

Estimation of frequency of occurrence of extreme natural external events of very high intensity on the base of (non)available data - Estimation of frequency of rare natural external events of very high intensity on the base of (non)available data

International Nuclear Information System (INIS)

Holy, J.; Kolar, L.; Jaros, M.; Hladky, M.; Mlady, O.

2014-01-01

The relatively frequent natural external events are usually of minor safety importance, because the NPPs are, with a significant safety margin, constructed and operated to withstand the effects of them. Thus, risk analysis is typically devoted to the natural events of exceptional intensity, which mostly have not occurred up to now, but which still could happen with some low probability, but critical consequences. Since 'direct' plant specific data providing evidence about such events to occur is not at disposal, special data treatment and extrapolation methods have to be employed for frequency estimation. The paper summarizes possible approach to estimation of rate event frequency by means of extrapolation from available data and points out the potential problems and challenges encountered during the analysis. The general framework is commented in the presentation, regarding the effects of choice of probabilistic distribution (Gumbel distribution versus the others), methods of work with data records (To take out some observations and why?) and analysis of quality of input data sets (To mix the data sets from different sources or not? To use 'old' observations?) In the first part of the paper, the approach to creation of NPP Dukovany deterministic design basis regarding natural external events, which was used in past, is summarized. The second, major part of the paper, is devoted to involvement of the ideas of probabilistic safety assessment into safety assessment of external hazards, including such specific topics as addressing the quality of available data records, discussion on possible violation of common assumptions expected to be valid by the rules of statistical data analysis and the ways how to fix it, the choice of probabilistic distribution modeling data variability etc. The examples of results achieved for NPP Dukovany site in Czech republic are given in the final section. This paper represents a coordinated effort with participation of experts and staff

Evaluation of Frequency and Restoration time for Loss of Offsite Power events based on domestic operation experience

International Nuclear Information System (INIS)

Park, Jin-Hee; Han, Sang-Hoon; Lee, Ho Joong

2006-01-01

It is recognized that the availability of AC power to nuclear power plants is essential for safe operation and shutdown and accident recovery of commercial nuclear power plants (NPPs). Unavailability of AC power can be a important adverse impact on a plant's ability to recover accident sequences and maintain safe shutdown. The probabilistic safety assessment (PSA or PRA) performed for Korea NPPs also indicated that a loss of offsite power (LOOP) event and a station blackout (SBO) event can be a important contributors to total risk at nuclear power plant, contributing from 30% to 70% of the total risk at some NPPs in Korea. But, up to now, the LOOP and subsequent restoration time are important inputs to plant probabilistic risk assessment have relied upon foreign data. Therefore, in this paper, the actual LOOP events that have occurred from 1978 to 2004 at commercial nuclear power plants in Korea are collected. A statistical analysis for LOOP frequency and restoration time are performed to apply NPPs's specific and realistic risk model in Korea. Additionally, an engineering analysis is also performed to obtain the insights about the LOOP events

[Frequency and Type of Traumatic Events in Children and Adolescents with a Posttraumatic Stress Disorder].

Science.gov (United States)

Loos, Sabine; Wolf, Saskia; Tutus, Dunja; Goldbeck, Lutz

2015-01-01

The risk for children and adolescents to be exposed to a potentially traumatic event (PTE) is high. The present study examines the frequency of PTEs in children and adolescents with Posttraumatic Stress Disorder (PTSD), the type of index trauma, and its relation to PTSD symptom severity and gender. A clinical sample of 159 children and adolescents between 7-16 years was assessed using the Clinician-Administered PTSD Scale for Children and Adolescents (CAPS-CA). All reported PTEs from the checklist were analyzed according to frequency. The index events were categorized according to the following categories: cause (random vs. intentional), relation to offender (intrafamilial vs. extrafamilial), patient's role (victim, witness or vicarious traumatization), and type of PTE (physical or sexual violence). Relation between categories and PTSD symptom severity and sex were analyzed with inferential statistics. On average participants reported five PTEs, most frequently physical violence without weapons (57.9%), loss of loved person through death (45.9%), and sexual abuse/assaults (44%). The most frequent index traumata were intentional (76.7%). Regarding trauma type, there was a significant difference concerning higher symptom severity in children and adolescents who experienced sexual abuse/assault compared to physical violence (t=-1.913(109), p=0.05). A significantly higher symptom severity was found for girls compared to boys for the trauma categories extrafamilial offender (z=-2,27, p=0.02), victim (z=-2,11, p=0,04), and sexual abuse/assault (z=-2,43, p=0,01). Clinical and diagnostic implications are discussed in relation to the amendments of PTSD diagnostic criteria in DSM-5.

Study of Updating Initiating Event Frequency using Prognostics

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyeonmin; Lee, Sang-Hwan; Park, Jun-seok; Kim, Hyungdae; Chang, Yoon-Suk; Heo, Gyunyoung [Kyung Hee Univ., Yongin (Korea, Republic of)

2014-10-15

The Probabilistic Safety Assessment (PSA) model enables to find the relative priority of accident scenarios, weak points in achieving accident prevention or mitigation, and insights to improve those vulnerabilities. Thus, PSA consider realistic calculation for precise and confidence results. However, PSA model still 'conservative' aspects in the procedures of developing a PSA model. One of the sources for the conservatism is caused by the assumption of safety analysis and the estimation of failure frequency. Recently, Surveillance, Diagnosis, and Prognosis (SDP) is a growing trend in applying space and aviation systems in particular. Furthermore, a study dealing with the applicable areas and state-of-the-art status of the SDP in nuclear industry was published. SDP utilizing massive database and information technology among such enabling techniques is worthwhile to be highlighted in terms of the capability of alleviating the conservatism in the conventional PSA. This paper review the concept of integrating PSA and SDP and suggest the updated methodology of Initiating Event (IE) using prognostics. For more detailed, we focus on IE of the Steam Generator Tube Rupture (SGTR) considering tube degradation. This paper is additional research of previous our suggested the research. In this paper, the concept of integrating PSA and SDP are suggested. Prognostics algorithms in SDP are applied at IE, Bes in the Level 1 PSA. As an example, updating SGTR IE and its ageing were considered. Tube ageing were analyzed by using PASTA and Monte Carlo method. After analyzing the tube ageing, conventional SGTR IE were updated by using Bayesian approach. The studied method can help to cover the static and conservatism in PSA.

Study of Updating Initiating Event Frequency using Prognostics

International Nuclear Information System (INIS)

Kim, Hyeonmin; Lee, Sang-Hwan; Park, Jun-seok; Kim, Hyungdae; Chang, Yoon-Suk; Heo, Gyunyoung

2014-01-01

The Probabilistic Safety Assessment (PSA) model enables to find the relative priority of accident scenarios, weak points in achieving accident prevention or mitigation, and insights to improve those vulnerabilities. Thus, PSA consider realistic calculation for precise and confidence results. However, PSA model still 'conservative' aspects in the procedures of developing a PSA model. One of the sources for the conservatism is caused by the assumption of safety analysis and the estimation of failure frequency. Recently, Surveillance, Diagnosis, and Prognosis (SDP) is a growing trend in applying space and aviation systems in particular. Furthermore, a study dealing with the applicable areas and state-of-the-art status of the SDP in nuclear industry was published. SDP utilizing massive database and information technology among such enabling techniques is worthwhile to be highlighted in terms of the capability of alleviating the conservatism in the conventional PSA. This paper review the concept of integrating PSA and SDP and suggest the updated methodology of Initiating Event (IE) using prognostics. For more detailed, we focus on IE of the Steam Generator Tube Rupture (SGTR) considering tube degradation. This paper is additional research of previous our suggested the research. In this paper, the concept of integrating PSA and SDP are suggested. Prognostics algorithms in SDP are applied at IE, Bes in the Level 1 PSA. As an example, updating SGTR IE and its ageing were considered. Tube ageing were analyzed by using PASTA and Monte Carlo method. After analyzing the tube ageing, conventional SGTR IE were updated by using Bayesian approach. The studied method can help to cover the static and conservatism in PSA

Short-Term Effects of Changing Precipitation Patterns on Shrub-Steppe Grasslands: Seasonal Watering Is More Important than Frequency of Watering Events.

Science.gov (United States)

Densmore-McCulloch, Justine A; Thompson, Donald L; Fraser, Lauchlan H

2016-01-01

Climate change is expected to alter precipitation patterns. Droughts may become longer and more frequent, and the timing and intensity of precipitation may change. We tested how shifting precipitation patterns, both seasonally and by frequency of events, affects soil nitrogen availability, plant biomass and diversity in a shrub-steppe temperate grassland along a natural productivity gradient in Lac du Bois Grasslands Protected Area near Kamloops, British Columbia, Canada. We manipulated seasonal watering patterns by either exclusively watering in the spring or the fall. To simulate spring precipitation we restricted precipitation inputs in the fall, then added 50% more water than the long term average in the spring, and vice-versa for the fall precipitation treatment. Overall, the amount of precipitation remained roughly the same. We manipulated the frequency of rainfall events by either applying water weekly (frequent) or monthly (intensive). After 2 years, changes in the seasonality of watering had greater effects on plant biomass and diversity than changes in the frequency of watering. Fall watering reduced biomass and increased species diversity, while spring watering had little effect. The reduction in biomass in fall watered treatments was due to a decline in grasses, but not forbs. Plant available N, measured by Plant Root Simulator (PRS)-probes, increased from spring to summer to fall, and was higher in fall watered treatments compared to spring watered treatments when measured in the fall. The only effect observed due to frequency of watering events was greater extractable soil N in monthly applied treatments compared to weekly watering treatments. Understanding the effects of changing precipitation patterns on grasslands will allow improved grassland conservation and management in the face of global climatic change, and here we show that if precipitation is more abundant in the fall, compared to the spring, grassland primary productivity will likely be

Calculation of the n-th coincidences frequency

International Nuclear Information System (INIS)

Mercier, C.

1959-01-01

Events can occur randomly with a given frequency. Each event lasts a Θ-time. During this Θ-time other events can occur. A coincidence beginning of order n at a t-time is when an event occurs while n other events already occurred between t-Θ and t. In this work the frequency of coincidence beginnings with an order greater than or equal to n is established

Radar network communication through sensing of frequency hopping

Science.gov (United States)

Dowla, Farid; Nekoogar, Faranak

2013-05-28

In one embodiment, a radar communication system includes a plurality of radars having a communication range and being capable of operating at a sensing frequency and a reporting frequency, wherein the reporting frequency is different than the sensing frequency, each radar is adapted for operating at the sensing frequency until an event is detected, each radar in the plurality of radars has an identification/location frequency for reporting information different from the sensing frequency, a first radar of the radars which senses the event sends a reporting frequency corresponding to its identification/location frequency when the event is detected, and all other radars in the plurality of radars switch their reporting frequencies to match the reporting frequency of the first radar upon detecting the reporting frequency switch of a radar within the communication range. In another embodiment, a method is presented for communicating information in a radar system.

Gait Event Detection in Real-World Environment for Long-Term Applications: Incorporating Domain Knowledge Into Time-Frequency Analysis.

Science.gov (United States)

Khandelwal, Siddhartha; Wickstrom, Nicholas

2016-12-01

Detecting gait events is the key to many gait analysis applications that would benefit from continuous monitoring or long-term analysis. Most gait event detection algorithms using wearable sensors that offer a potential for use in daily living have been developed from data collected in controlled indoor experiments. However, for real-word applications, it is essential that the analysis is carried out in humans' natural environment; that involves different gait speeds, changing walking terrains, varying surface inclinations and regular turns among other factors. Existing domain knowledge in the form of principles or underlying fundamental gait relationships can be utilized to drive and support the data analysis in order to develop robust algorithms that can tackle real-world challenges in gait analysis. This paper presents a novel approach that exhibits how domain knowledge about human gait can be incorporated into time-frequency analysis to detect gait events from long-term accelerometer signals. The accuracy and robustness of the proposed algorithm are validated by experiments done in indoor and outdoor environments with approximately 93 600 gait events in total. The proposed algorithm exhibits consistently high performance scores across all datasets in both, indoor and outdoor environments.

Transportation planning for planned special events

Science.gov (United States)

2011-05-01

Unique among planned special event activities are those events that carry the National Special Security Event (NSSE) designation. NSSEs occur with some frequency, with 35 of these events held between September 1998 and February 2010. These events inc...

Towards Real-Time Detection of Gait Events on Different Terrains Using Time-Frequency Analysis and Peak Heuristics Algorithm.

Science.gov (United States)

Zhou, Hui; Ji, Ning; Samuel, Oluwarotimi Williams; Cao, Yafei; Zhao, Zheyi; Chen, Shixiong; Li, Guanglin

2016-10-01

Real-time detection of gait events can be applied as a reliable input to control drop foot correction devices and lower-limb prostheses. Among the different sensors used to acquire the signals associated with walking for gait event detection, the accelerometer is considered as a preferable sensor due to its convenience of use, small size, low cost, reliability, and low power consumption. Based on the acceleration signals, different algorithms have been proposed to detect toe off (TO) and heel strike (HS) gait events in previous studies. While these algorithms could achieve a relatively reasonable performance in gait event detection, they suffer from limitations such as poor real-time performance and are less reliable in the cases of up stair and down stair terrains. In this study, a new algorithm is proposed to detect the gait events on three walking terrains in real-time based on the analysis of acceleration jerk signals with a time-frequency method to obtain gait parameters, and then the determination of the peaks of jerk signals using peak heuristics. The performance of the newly proposed algorithm was evaluated with eight healthy subjects when they were walking on level ground, up stairs, and down stairs. Our experimental results showed that the mean F1 scores of the proposed algorithm were above 0.98 for HS event detection and 0.95 for TO event detection on the three terrains. This indicates that the current algorithm would be robust and accurate for gait event detection on different terrains. Findings from the current study suggest that the proposed method may be a preferable option in some applications such as drop foot correction devices and leg prostheses.

AN EMPIRICAL ANALYSIS OF THE INFLUENCE OF RISK FACTORS ON THE FREQUENCY AND IMPACT OF SEVERE EVENTS ON THE SUPPLY CHAIN IN THE CZECH REPUBLIC

Directory of Open Access Journals (Sweden)

José María Caridad

2014-12-01

Full Text Available Purpose: This paper is focused on an analysis and evaluation of severe events according to their frequency of occurrence and their impact on the company's manufacturing and distribution supply chains performance in the Czech Republic. Risk factors are introduced for critical events.Design/methodology: An identification and classification of severe events are realized on the basis of median mapping and mapping of ordinal variability acquired through the questionnaire survey of 82 companies. Analysis of 46 risk factors was sorted into 5 groups. We used asymmetric Somers's d statistics for testing the dependence of frequency and impact of a severe event on selected risk sources. The hierarchical cluster analysis is performed to identify relatively homogeneous groups of critical severe events according to their dependency on risk factors and its strength.Findings: Results showed that ‘a lack of contracts’ is considered to be the most critical severe event. Groups of demand and supply side and an external risk factor group were identified to be the most significant sources of risk factors. The worst cluster encompasses 11% of examined risk factors which should be prevented. We concluded that organizations need to adopt appropriate precautions and risk management methods in logistics.Originality: In this paper, the methodology for severe events evaluation in supply chain is designed. This methodology involves assessing the critical factors which influence the critical events and which should be prevented.

Estimation of core-damage frequency to evolutionary ALWR [advanced light water reactor] due to seismic initiating events: Task 4.3.3

International Nuclear Information System (INIS)

Brooks, R.D.; Harrison, D.G.; Summitt, R.L.

1990-04-01

The Electric Power Research Institute (EPRI) is presently developing a requirements document for the design of advanced light water reactors (ALWRs). One of the basic goals of the EPRI ALWR Requirements Document is that the core-damage frequency for an ALWR shall be less than 1.0E-5. To aid in this effort, the Department of Energy's Advanced Reactor Severe Accident Program (ARSAP) initiated a functional probabilistic risk assessment (PRA) to determine how effectively the evolutionary plant requirements contained in the existing EPRI Requirements Document assure that this safety goal will be met. This report develops an approximation of the core-damage frequency due to seismic events for both evolutionary plant designs (pressurized-water reactor (PWR) and boiling-water reactor(BWR)) as modeled in the corresponding functional PRAs. Component fragility values were taken directly form information which has been submitted for inclusion in Appendix A to Volume 1 of the EPRI Requirements Document. The results show a seismic core-damage frequency of 5.2E-6 for PWRS and 5.0E-6 for BWRs. Combined with the internal initiators from the functional PRAs, the overall core-damage frequencies are 6.0E-6 for the pwr and BWR, both of which satisfy the 1.0E-5 EPRI goal. In addition, site-specific considerations, such as more rigid components and less conservative fragility data and seismic hazard curves, may further reduce these frequencies. The effect of seismic events on structures are not addressed in this generic evaluation and should be addressed separately on a design-specific basis. 7 refs., 6 figs., 3 tabs

Memory Processes in Frequency Judgment: The impact of pre-experimental frequencies and co-occurrences on frequency estimates.

OpenAIRE

Renkewitz, Frank

2004-01-01

Contemporary theories on frequency processing have been developed in different sub-disciplines of psychology and have shown remarkable discrepancies. Thus, in judgment and decision making, frequency estimates on serially encoded events are mostly traced back to the availability heuristic (Tversky & Kahneman, 1973). Evidence for the use of this heuristic comes from several popular demonstrations of biased frequency estimates. In the area of decision making, these demonstrations led to the ...

Attitudes of Consumers from the Mostar Canton in Bosnia and Herzegovina toward Advertising through Sport among the Frequency of Watching Sports Events

Directory of Open Access Journals (Sweden)

Marina Vukotic

2018-04-01

Full Text Available It is proposed that potential consumers form attitudes based on advertising through sport can influence decisions to purchase a particular advertiser’s product. From this reason, it is important to analyse their general attitudes toward advertising through sport among various questions, and this investigation was aimed at gaining relevant knowledge about the attitudes of Mostar consumers toward advertising through sport among. The sample included 228 respondents, divided into six subsample groups: consumers, who do not watch sports events at all, then consumers who watch sports events 1-30 minutes, next 31-60 minutes, 61-90 minutes, 91-120 minutes, as well as consumers who watch sports events more than 120 minutes during the typical day. The sample of variables contained the system of three general attitudes which were modelled by seven-point Likert scale. The results of the measuring were analysed by multivariate analysis (MANOVA and univariate analysis (ANOVA and Post Hoc test. Based on the statistical analyses it was found that significant differences occur at multivariate level, as well as between all three variables at a significance level of p=.006. Hence, it is interesting to highlight that it was found there are significant differences showed up between the attitudes of consumers toward advertising through sport among the frequency of watching sports events. These results are so important for the marketers, mostly due to the reason they can’t merge all the potential consumers regarding the frequency they watch the sports events. On the other hand, this is the case in previous investigations and this observation presents relevant information.

Attitudes of Consumers from the Sarajevo Canton in Bosnia and Herzegovina toward Advertising through Sport among the Frequency of Watching Sports Events

Directory of Open Access Journals (Sweden)

Izet Bajramovic

2018-04-01

Full Text Available It is proposed that potential consumers form attitudes based on advertising through sport can influence decisions to purchase a particular advertiser’s product. From this reason, it is important to analyse their general attitudes toward advertising through sport among various questions, and this investigation was aimed at gaining relevant knowledge about the attitudes of Sarajevo consumers toward advertising through sport among. The sample included 358 respondents, divided into six subsample groups: consumers, who do not watch sports events at all, then consumers who watch sports events 1-30 minutes, next 31-60 minutes, 61-90 minutes, 91-120 minutes, as well as consumers who watch sports events more than 120 minutes during the typical day. The sample of variables contained the system of three general attitudes which were modelled by seven-point Likert scale. The results of the measuring were analysed by multivariate analysis (MANOVA and univariate analysis (ANOVA and Post Hoc test. Based on the statistical analyses it was found that significant differences occur at multivariate level, as well as between all three variables at a significance level of p=.00. Hence, it is interesting to highlight that it was found there are significant differences showed up between the attitudes of consumers toward advertising through sport among the frequency of watching sports events. These results are so important for the marketers, mostly due to the reason they can’t merge all the potential consumers regarding the frequency they watch the sports events. On the other hand, this is the case in previous investigations and this observation presents relevant information.

Low-level contrast statistics of natural images can modulate the frequency of event-related potentials (ERP in humans

Directory of Open Access Journals (Sweden)

Masoud Ghodrati

2016-12-01

Full Text Available Humans are fast and accurate in categorizing complex natural images. It is, however, unclear what features of visual information are exploited by brain to perceive the images with such speed and accuracy. It has been shown that low-level contrast statistics of natural scenes can explain the variance of amplitude of event-related potentials (ERP in response to rapidly presented images. In this study, we investigated the effect of these statistics on frequency content of ERPs. We recorded ERPs from human subjects, while they viewed natural images each presented for 70 ms. Our results showed that Weibull contrast statistics, as a biologically plausible model, explained the variance of ERPs the best, compared to other image statistics that we assessed. Our time-frequency analysis revealed a significant correlation between these statistics and ERPs’ power within theta frequency band (~3-7 Hz. This is interesting, as theta band is believed to be involved in context updating and semantic encoding. This correlation became significant at ~110 ms after stimulus onset, and peaked at 138 ms. Our results show that not only the amplitude but also the frequency of neural responses can be modulated with low-level contrast statistics of natural images and highlights their potential role in scene perception.

Analysis of core damage frequency from internal events: Methodology guidelines: Volume 1

International Nuclear Information System (INIS)

Drouin, M.T.; Harper, F.T.; Camp, A.L.

1987-09-01

NUREG-1150 examines the risk to the public from a selected group of nuclear power plants. This report describes the methodology used to estimate the internal event core damage frequencies of four plants in support of NUREG-1150. In principle, this methodology is similar to methods used in past probabilistic risk assessments; however, based on past studies and using analysts that are experienced in these techniques, the analyses can be focused in certain areas. In this approach, only the most important systems and failure modes are modeled in detail. Further, the data and human reliability analyses are simplified, with emphasis on the most important components and human actions. Using these methods, an analysis can be completed in six to nine months using two to three full-time systems analysts and part-time personnel in other areas, such as data analysis and human reliability analysis. This is significantly faster and less costly than previous analyses and provides most of the insights that are obtained by the more costly studies. 82 refs., 35 figs., 27 tabs

Neural network approach to the prediction of seismic events based on low-frequency signal monitoring of the Kuril-Kamchatka and Japanese regions

Directory of Open Access Journals (Sweden)

Irina Popova

2013-08-01

Full Text Available Very-low-frequency/ low-frequency (VLF/LF sub-ionospheric radiowave monitoring has been widely used in recent years to analyze earthquake preparatory processes. The connection between earthquakes with M ≥5.5 and nighttime disturbances of signal amplitude and phase has been established. Thus, it is possible to use nighttime anomalies of VLF/LF signals as earthquake precursors. Here, we propose a method for estimation of the VLF/LF signal sensitivity to seismic processes using a neural network approach. We apply the error back-propagation technique based on a three-level perceptron to predict a seismic event. The back-propagation technique involves two main stages to solve the problem; namely, network training, and recognition (the prediction itself. To train a neural network, we first create a so-called ‘training set’. The ‘teacher’ specifies the correspondence between the chosen input and the output data. In the present case, a representative database includes both the LF data received over three years of monitoring at the station in Petropavlovsk-Kamchatsky (2005-2007, and the seismicity parameters of the Kuril-Kamchatka and Japanese regions. At the first stage, the neural network established the relationship between the characteristic features of the LF signal (the mean and dispersion of a phase and an amplitude at nighttime for a few days before a seismic event and the corresponding level of correlation with a seismic event, or the absence of a seismic event. For the second stage, the trained neural network was applied to predict seismic events from the LF data using twelve time intervals in 2004, 2005, 2006 and 2007. The results of the prediction are discussed.

LOSP-initiated event tree analysis for BWR

International Nuclear Information System (INIS)

Watanabe, Norio; Kondo, Masaaki; Uno, Kiyotaka; Chigusa, Takeshi; Harami, Taikan

1989-03-01

As a preliminary study of 'Japanese Model Plant PSA', a LOSP (loss of off-site power)-initiated Event Tree Analysis for a Japanese typical BWR was carried out solely based on the open documents such as 'Safety Analysis Report'. The objectives of this analysis are as follows; - to delineate core-melt accident sequences initiated by LOSP, - to evaluate the importance of core-melt accident sequences in terms of occurrence frequency, and - to develop a foundation of plant information and analytical procedures for efficiently performing further 'Japanese Model Plant PSA'. This report describes the procedure and results of the LOSP-initiated Event Tree Analysis. In this analysis, two types of event trees, Functional Event Tree and Systemic Event Tree, were developed to delineate core-melt accident sequences and to quantify their frequencies. Front-line System Event Tree was prepared as well to provide core-melt sequence delineation for accident progression analysis of Level 2 PSA which will be followed in a future. Applying U.S. operational experience data such as component failure rates and a LOSP frequency, we obtained the following results; - The total frequency of core-melt accident sequences initiated by LOSP is estimated at 5 x 10 -4 per reactor-year. - The dominant sequences are 'Loss of Decay Heat Removal' and 'Loss of Emergency Electric Power Supply', which account for more than 90% of the total core-melt frequency. In this analysis, a higher value of 0.13/R·Y was used for the LOSP frequency than experiences in Japan and any recovery action was not considered. In fact, however, there has been no experience of LOSP event in Japanese nuclear power plants so far and it is also expected that offsite power and/or PCS would be recovered before core melt. Considering Japanese operating experience and recovery factors will reduce the total core-melt frequency to less than 10 -6 per reactor-year. (J.P.N.)

Eastern Frequency Response Study

Energy Technology Data Exchange (ETDEWEB)

Miller, N.W.; Shao, M.; Pajic, S.; D' Aquila, R.

2013-05-01

This study was specifically designed to investigate the frequency response of the Eastern Interconnection that results from large loss-of-generation events of the type targeted by the North American Electric Reliability Corp. Standard BAL-003 Frequency Response and Frequency Bias Setting (NERC 2012a), under possible future system conditions with high levels of wind generation.

HYPOCENTER DISTRIBUTION OF LOW FREQUENCY EVENT AT PAPANDAYAN VOLCANO

Directory of Open Access Journals (Sweden)

Muhammad Mifta Hasan

2016-10-01

Full Text Available Papandayan volcano is a stratovolcano with irregular cone-shaped has eight craters around the peak. The most active crater in Papandayan is a Mas crater. Distribution of relocated event calculated using Geiger Adaptive Damping Algorithm (GAD shows that the epicenter of the event centered below Mas crater with maximum rms 0.114. While depth of the hypocenter range between 0-2 km and 5-6 km due to activity of steam and gas.

Common time-frequency analysis of local field potential and pyramidal cell activity in seizure-like events of the rat hippocampus

Science.gov (United States)

Cotic, M.; Chiu, A. W. L.; Jahromi, S. S.; Carlen, P. L.; Bardakjian, B. L.

2011-08-01

To study cell-field dynamics, physiologists simultaneously record local field potentials and the activity of individual cells from animals performing cognitive tasks, during various brain states or under pathological conditions. However, apart from spike shape and spike timing analyses, few studies have focused on elucidating the common time-frequency structure of local field activity relative to surrounding cells across different periods of phenomena. We have used two algorithms, multi-window time frequency analysis and wavelet phase coherence (WPC), to study common intracellular-extracellular (I-E) spectral features in spontaneous seizure-like events (SLEs) from rat hippocampal slices in a low magnesium epilepsy model. Both algorithms were applied to 'pairs' of simultaneously observed I-E signals from slices in the CA1 hippocampal region. Analyses were performed over a frequency range of 1-100 Hz. I-E spectral commonality varied in frequency and time. Higher commonality was observed from 1 to 15 Hz, and lower commonality was observed in the 15-100 Hz frequency range. WPC was lower in the non-SLE region compared to SLE activity; however, there was no statistical difference in the 30-45 Hz band between SLE and non-SLE modes. This work provides evidence of strong commonality in various frequency bands of I-E SLEs in the rat hippocampus, not only during SLEs but also immediately before and after.

The effects of high-frequency oscillations in hippocampal electrical activities on the classification of epileptiform events using artificial neural networks

Science.gov (United States)

Chiu, Alan W. L.; Jahromi, Shokrollah S.; Khosravani, Houman; Carlen, Peter L.; Bardakjian, Berj L.

2006-03-01

The existence of hippocampal high-frequency electrical activities (greater than 100 Hz) during the progression of seizure episodes in both human and animal experimental models of epilepsy has been well documented (Bragin A, Engel J, Wilson C L, Fried I and Buzsáki G 1999 Hippocampus 9 137-42 Khosravani H, Pinnegar C R, Mitchell J R, Bardakjian B L, Federico P and Carlen P L 2005 Epilepsia 46 1-10). However, this information has not been studied between successive seizure episodes or utilized in the application of seizure classification. In this study, we examine the dynamical changes of an in vitro low Mg2+ rat hippocampal slice model of epilepsy at different frequency bands using wavelet transforms and artificial neural networks. By dividing the time-frequency spectrum of each seizure-like event (SLE) into frequency bins, we can analyze their burst-to-burst variations within individual SLEs as well as between successive SLE episodes. Wavelet energy and wavelet entropy are estimated for intracellular and extracellular electrical recordings using sufficiently high sampling rates (10 kHz). We demonstrate that the activities of high-frequency oscillations in the 100-400 Hz range increase as the slice approaches SLE onsets and in later episodes of SLEs. Utilizing the time-dependent relationship between different frequency bands, we can achieve frequency-dependent state classification. We demonstrate that activities in the frequency range 100-400 Hz are critical for the accurate classification of the different states of electrographic seizure-like episodes (containing interictal, preictal and ictal states) in brain slices undergoing recurrent spontaneous SLEs. While preictal activities can be classified with an average accuracy of 77.4 ± 6.7% utilizing the frequency spectrum in the range 0-400 Hz, we can also achieve a similar level of accuracy by using a nonlinear relationship between 100-400 Hz and <4 Hz frequency bands only.

A Bayesian approach to unanticipated events frequency estimation in the decision making context of a nuclear research reactor facility

International Nuclear Information System (INIS)

Chatzidakis, S.; Staras, A.

2013-01-01

Highlights: • The Bayes’ theorem is employed to support the decision making process in a research reactor. • The intention is to calculate parameters related to unanticipated occurrence of events. • Frequency, posterior distribution and confidence limits are calculated. • The approach is demonstrated using two real-world numerical examples. • The approach can be used even if no failures have been observed. - Abstract: Research reactors are considered as multi-tasking environments having the multiple roles of commercial, research and training facilities. Yet, reactor managers have to make decisions, frequently with high economic impact, based on little available knowledge. A systematic approach employing the Bayes’ theorem is proposed to support the decision making process in a research reactor environment. This approach is characterized by low level complexity, appropriate for research reactor facilities. The methodology is demonstrated through the study of two characteristic events that lead to unanticipated system shutdown, namely the de-energization of the control rod magnet and the flapper valve opening. The results obtained demonstrate the suitability of the Bayesian approach in the decision making context when unanticipated events are considered

FREQUENCY OF SOLAR-LIKE SYSTEMS AND OF ICE AND GAS GIANTS BEYOND THE SNOW LINE FROM HIGH-MAGNIFICATION MICROLENSING EVENTS IN 2005-2008

International Nuclear Information System (INIS)

Gould, A.; Dong, Subo; Gaudi, B. S.; Han, C.

2010-01-01

We present the first measurement of the planet frequency beyond the 'snow line', for the planet-to-star mass-ratio interval -4.5 2 N pl )/(d log q d log s) = (0.36±0.15) dex -2 at the mean mass ratio q = 5 x 10 -4 with no discernible deviation from a flat (Oepik's law) distribution in log-projected separation s. The determination is based on a sample of six planets detected from intensive follow-up observations of high-magnification (A>200) microlensing events during 2005-2008. The sampled host stars have a typical mass M host ∼ 0.5 M sun , and detection is sensitive to planets over a range of planet-star-projected separations (s -1 max R E , s max R E ), where R E ∼ 3.5 AU(M host /M sun ) 1/2 is the Einstein radius and s max ∼ (q/10 -4.3 ) 1/3 . This corresponds to deprojected separations roughly three times the 'snow line'. We show that the observations of these events have the properties of a 'controlled experiment', which is what permits measurement of absolute planet frequency. High-magnification events are rare, but the survey-plus-follow-up high-magnification channel is very efficient: half of all high-mag events were successfully monitored and half of these yielded planet detections. The extremely high sensitivity of high-mag events leads to a policy of monitoring them as intensively as possible, independent of whether they show evidence of planets. This is what allows us to construct an unbiased sample. The planet frequency derived from microlensing is a factor 8 larger than the one derived from Doppler studies at factor ∼25 smaller star-planet separations (i.e., periods 2-2000 days). However, this difference is basically consistent with the gradient derived from Doppler studies (when extrapolated well beyond the separations from which it is measured). This suggests a universal separation distribution across 2 dex in planet-star separation, 2 dex in mass ratio, and 0.3 dex in host mass. Finally, if all planetary systems were 'analogs' of the solar

Survey on Prognostics Techniques for Updating Initiating Event Frequency in PSA

International Nuclear Information System (INIS)

Kim, Hyeonmin; Heo, Gyunyoung

2015-01-01

One of the applications using PSA is a risk monito. The risk monitoring is real-time analysis tool to decide real-time risk based on real state of components and systems. In order to utilize more effective, the methodologies that manipulate the data from Prognostics was suggested. Generally, Prognostic comprehensively includes not only prognostic but also monitoring and diagnostic. The prognostic method must need condition monitoring. In case of applying PHM to a PSA model, the latest condition of NPPs can be identified more clearly. For reducing the conservatism and uncertainties, we suggested the concept that updates the initiating event frequency in a PSA model by using Bayesian approach which is one of the prognostics techniques before. From previous research, the possibility that PSA is updated by using data more correctly was found. In reliability theory, the Bathtub curve divides three parts (infant failure, constant and random failure, wareout failure). In this paper, in order to investigate the applicability of prognostic methods in updating quantitative data in a PSA model, the OLM acceptance criteria from NUREG, the concept of how to using prognostic in PSA, and the enabling prognostic techniques are suggested. The prognostic has the motivation that improved the predictive capabilities using existing monitoring systems, data, and information will enable more accurate equipment risk assessment for improved decision-making

Survey on Prognostics Techniques for Updating Initiating Event Frequency in PSA

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyeonmin; Heo, Gyunyoung [Kyung Hee University, Yongin (Korea, Republic of)

2015-05-15

One of the applications using PSA is a risk monito. The risk monitoring is real-time analysis tool to decide real-time risk based on real state of components and systems. In order to utilize more effective, the methodologies that manipulate the data from Prognostics was suggested. Generally, Prognostic comprehensively includes not only prognostic but also monitoring and diagnostic. The prognostic method must need condition monitoring. In case of applying PHM to a PSA model, the latest condition of NPPs can be identified more clearly. For reducing the conservatism and uncertainties, we suggested the concept that updates the initiating event frequency in a PSA model by using Bayesian approach which is one of the prognostics techniques before. From previous research, the possibility that PSA is updated by using data more correctly was found. In reliability theory, the Bathtub curve divides three parts (infant failure, constant and random failure, wareout failure). In this paper, in order to investigate the applicability of prognostic methods in updating quantitative data in a PSA model, the OLM acceptance criteria from NUREG, the concept of how to using prognostic in PSA, and the enabling prognostic techniques are suggested. The prognostic has the motivation that improved the predictive capabilities using existing monitoring systems, data, and information will enable more accurate equipment risk assessment for improved decision-making.

Framework for Modeling High-Impact, Low-Frequency Power Grid Events to Support Risk-Informed Decisions

Energy Technology Data Exchange (ETDEWEB)

Veeramany, Arun; Unwin, Stephen D.; Coles, Garill A.; Dagle, Jeffery E.; Millard, W. David; Yao, Juan; Glantz, Clifford S.; Gourisetti, Sri Nikhil Gup

2015-12-03

Natural and man-made hazardous events resulting in loss of grid infrastructure assets challenge the electric power grid’s security and resilience. However, the planning and allocation of appropriate contingency resources for such events requires an understanding of their likelihood and the extent of their potential impact. Where these events are of low likelihood, a risk-informed perspective on planning can be problematic as there exists an insufficient statistical basis to directly estimate the probabilities and consequences of their occurrence. Since risk-informed decisions rely on such knowledge, a basis for modeling the risk associated with high-impact low frequency events (HILFs) is essential. Insights from such a model can inform where resources are most rationally and effectively expended. The present effort is focused on development of a HILF risk assessment framework. Such a framework is intended to provide the conceptual and overarching technical basis for the development of HILF risk models that can inform decision makers across numerous stakeholder sectors. The North American Electric Reliability Corporation (NERC) 2014 Standard TPL-001-4 considers severe events for transmission reliability planning, but does not address events of such severity that they have the potential to fail a substantial fraction of grid assets over a region, such as geomagnetic disturbances (GMD), extreme seismic events, and coordinated cyber-physical attacks. These are beyond current planning guidelines. As noted, the risks associated with such events cannot be statistically estimated based on historic experience; however, there does exist a stable of risk modeling techniques for rare events that have proven of value across a wide range of engineering application domains. There is an active and growing interest in evaluating the value of risk management techniques in the State transmission planning and emergency response communities, some of this interest in the context of

Activated Very Low Frequency Earthquakes By the Slow Slip Events in the Ryukyu Subduction Zone

Science.gov (United States)

Nakamura, M.; Sunagawa, N.

2014-12-01

The Ryukyu Trench (RT), where the Philippine Sea plate is subducting, has had no known thrust earthquakes with a Mw>8.0 in the last 300 years. However, the rupture source of the 1771 tsunami has been proposed as an Mw > 8.0 earthquake in the south RT. Based on the dating of tsunami boulders, it has been estimated that large tsunamis occur at intervals of 150-400 years in the south Ryukyu arc (RA) (Araoka et al., 2013), although they have not occurred for several thousand years in the central and northern Ryukyu areas (Goto et al., 2014). To address the discrepancy between recent low moment releases by earthquakes and occurrence of paleo-tsunamis in the RT, we focus on the long-term activity of the very low frequency earthquakes (VLFEs), which are good indicators of the stress release in the shallow plate interface. VLFEs have been detected along the RT (Ando et al., 2012), which occur on the plate interface or at the accretionary prism. We used broadband data from the F-net of NIED along the RT and from the IRIS network. We applied two filters to all the raw broadband seismograms: a 0.02-0.05 Hz band-pass filter and a 1 Hz high-pass filter. After identification of the low-frequency events from the band-pass-filtered seismograms, the local and teleseismic events were removed. Then we picked the arrival time of the maximum amplitude of the surface wave of the VLFEs and determined the epicenters. VLFEs occurred on the RA side within 100 km from the trench axis along the RT. Distribution of the 6670 VLFEs from 2002 to 2013 could be divided to several clusters. Principal large clusters were located at 27.1°-29.0°N, 25.5°-26.6°N, and 122.1°-122.4°E (YA). We found that the VLFEs of the YA are modulated by repeating slow slip events (SSEs) which occur beneath south RA. The activity of the VLFEs increased to two times of its ordinary rate in 15 days after the onset of the SSEs. Activation of the VLFEs could be generated by low stress change of 0.02-20 kPa increase in

Analysis of system and of course of events

International Nuclear Information System (INIS)

Hoertner, H.; Kersting, E.J.; Puetter, B.M.

1986-01-01

The analysis of the system and of the course of events is used to determine the frequency of core melt-out accidents and to describe the safety-related boundary conditions of appropriate accidents. The lecture is concerned with the effect of system changes in the reference plant and the effect of triggering events not assessed in detail or not sufficiently assessed in detail in phase A of the German Risk Study on the frequency of core melt-out accidents, the minimum requirements for system functions for controlling triggering events, i.e. to prevent core melt-out accidents, the reliability data important for reliability investigations and frequency assessments. (orig./DG) [de

SPREAD: a high-resolution daily gridded precipitation dataset for Spain – an extreme events frequency and intensity overview

Directory of Open Access Journals (Sweden)

R. Serrano-Notivoli

2017-09-01

Full Text Available A high-resolution daily gridded precipitation dataset was built from raw data of 12 858 observatories covering a period from 1950 to 2012 in peninsular Spain and 1971 to 2012 in Balearic and Canary islands. The original data were quality-controlled and gaps were filled on each day and location independently. Using the serially complete dataset, a grid with a 5 × 5 km spatial resolution was constructed by estimating daily precipitation amounts and their corresponding uncertainty at each grid node. Daily precipitation estimations were compared to original observations to assess the quality of the gridded dataset. Four daily precipitation indices were computed to characterise the spatial distribution of daily precipitation and nine extreme precipitation indices were used to describe the frequency and intensity of extreme precipitation events. The Mediterranean coast and the Central Range showed the highest frequency and intensity of extreme events, while the number of wet days and dry and wet spells followed a north-west to south-east gradient in peninsular Spain, from high to low values in the number of wet days and wet spells and reverse in dry spells. The use of the total available data in Spain, the independent estimation of precipitation for each day and the high spatial resolution of the grid allowed for a precise spatial and temporal assessment of daily precipitation that is difficult to achieve when using other methods, pre-selected long-term stations or global gridded datasets. SPREAD dataset is publicly available at https://doi.org/10.20350/digitalCSIC/7393.

Counselling pregnant women at the crossroads of Europe and Asia: effect of Teratology Information Service in Turkey.

Science.gov (United States)

Kaplan, Yusuf Cem; Karadaş, Barış; Küçüksolak, Gözde; Ediz, Bartu; Demir, Ömer; Sozmen, Kaan; Nordeng, Hedvig

2017-08-01

Background Previous studies from western countries demonstrated the effectiveness of Teratology Information Service (TIS) counselling in reducing the teratogenic risk perception of pregnant women. Objective To assess whether TIS counselling would be effective in reducing the teratogenic risk perception of the Turkish pregnant women. Setting A TIS (Terafar) operating in a university hospital in Turkey. Methods A cross-sectional survey study. Pregnant women with non-teratogenic medication exposures were asked to assign scores on visual analogue scales (VAS) in response to the questions aiming to measure their teratogenic risk perception. The mean score before and after counselling were compared and the associations with maternal socio-demographic characteristics were analysed using SPSS (Version 20.0). Main outcome measures The differences in the mean scores of the perception regarding the baseline risk of pregnancy, own teratogenic risk and the likelihood of termination of pregnancy before and after counselling and their possible associations with maternal socio-demographic characteristics. Results 102 pregnant women participated in the study. The counselling significantly reduced the mean own teratogenic risk perception score and the mean score for the likelihood of termination of pregnancy whereas the mean baseline risk perception score was not significantly changed. Pregnancy week <8 and the exposed number of active ingredients <3 were significantly associated with the difference in the mean score for the likelihood of termination of pregnancy. Conclusions TIS counselling lowers the teratogenic risk perception of Turkish pregnant women and increases their likelihood to continue the pregnancy as it does in the western countries.

Rapid Active Power Control of Photovoltaic Systems for Grid Frequency Support

Energy Technology Data Exchange (ETDEWEB)

Hoke, Anderson; Shirazi, Mariko; Chakraborty, Sudipta; Muljadi, Eduard; Maksimovic, Dragan

2017-01-01

As deployment of power electronic coupled generation such as photovoltaic (PV) systems increases, grid operators have shown increasing interest in calling on inverter-coupled generation to help mitigate frequency contingency events by rapidly surging active power into the grid. When responding to contingency events, the faster the active power is provided, the more effective it may be for arresting the frequency event. This paper proposes a predictive PV inverter control method for very fast and accurate control of active power. This rapid active power control method will increase the effectiveness of various higher-level controls designed to mitigate grid frequency contingency events, including fast power-frequency droop, inertia emulation, and fast frequency response, without the need for energy storage. The rapid active power control method, coupled with a maximum power point estimation method, is implemented in a prototype PV inverter connected to a PV array. The prototype inverter's response to various frequency events is experimentally confirmed to be fast (beginning within 2 line cycles and completing within 4.5 line cycles of a severe test event) and accurate (below 2% steady-state error).

Paleo-event data standards for dendrochronology

Science.gov (United States)

Elaine Kennedy Sutherland; P. Brewer; W. Gross

2017-01-01

Extreme environmental events, such as storm winds, landslides, insect infestations, and wildfire, cause loss of life, resources, and human infrastructure. Disaster riskreduction analysis can be improved with information about past frequency, intensity, and spatial patterns of extreme events. Tree-ring analyses can provide such information: tree rings reflect events as...

ELF whistler events with a reduced intensity observed by the DEMETER spacecraft

Science.gov (United States)

Zahlava, J.; Nemec, F.; Santolik, O.; Kolmasova, I.; Parrot, M.

2017-12-01

A survey of VLF frequency-time spectrograms obtained by the DEMETER spacecraft (2004-2010, altitude about 700 km) revealed that the intensity of fractional hop whistlers is sometimes significantly reduced at specific frequencies. These frequencies are typically above about 3.4 kHz (second cutoff frequency of the Earth-ionosphere waveguide), and they vary smoothly in time. The events were explained by the wave propagation in the Earth-ionosphere waveguide, and a resulting interference of the first few waveguide modes. We analyze the events whose frequency-time structure is rather similar, but at frequencies below 1 kHz. Altogether, 284 events are identified during the periods with active Burst mode, when high resolution data are measured by DEMETER. The vast majority of events (93%) occurs during the nighttime. All six electromagnetic field components are available, which allows us to perform a detailed wave analysis. An overview of the properties of these events is presented, and their possible origin is discussed.

A Fourier analysis of extreme events

DEFF Research Database (Denmark)

Mikosch, Thomas Valentin; Zhao, Yuwei

2014-01-01

The extremogram is an asymptotic correlogram for extreme events constructed from a regularly varying stationary sequence. In this paper, we define a frequency domain analog of the correlogram: a periodogram generated from a suitable sequence of indicator functions of rare events. We derive basic ...... properties of the periodogram such as the asymptotic independence at the Fourier frequencies and use this property to show that weighted versions of the periodogram are consistent estimators of a spectral density derived from the extremogram....

Nonlinear optics of fibre event horizons.

Science.gov (United States)

Webb, Karen E; Erkintalo, Miro; Xu, Yiqing; Broderick, Neil G R; Dudley, John M; Genty, Goëry; Murdoch, Stuart G

2014-09-17

The nonlinear interaction of light in an optical fibre can mimic the physics at an event horizon. This analogue arises when a weak probe wave is unable to pass through an intense soliton, despite propagating at a different velocity. To date, these dynamics have been described in the time domain in terms of a soliton-induced refractive index barrier that modifies the velocity of the probe. Here we complete the physical description of fibre-optic event horizons by presenting a full frequency-domain description in terms of cascaded four-wave mixing between discrete single-frequency fields, and experimentally demonstrate signature frequency shifts using continuous wave lasers. Our description is confirmed by the remarkable agreement with experiments performed in the continuum limit, reached using ultrafast lasers. We anticipate that clarifying the description of fibre event horizons will significantly impact on the description of horizon dynamics and soliton interactions in photonics and other systems.

Study on LOOP and SBO Frequency for Multi-Unit PSA

Energy Technology Data Exchange (ETDEWEB)

Jin, Kyung Ho; Heo, Gyun Young [Kyunghee University, Yongin (Korea, Republic of)

2016-05-15

In conventional single unit PSA, it was assumed that all accidents or events are independent and the risk of only one unit has been evaluated. In other words, the possibility that simultaneous events occur on multiple units was excluded because it was assumed that the probability of concurrent events were extremely low. After Fukushima accidents, however, it was found that external hazards such as tsunami may impact on multiple units; that means, for the sake of proper mitigation the risk of accidents in shared SSCs should be reevaluated. New risk metrics to improve conventional CDF (Core Damage frequency) based on reactor-year is needed to perform MUPSA (Multi-Unit Probabilistic Safety Assessment). IAEA suggested SCDF (Site CDF) as a risk metrics for MUPSA. The frequency based on reactor-year was converted to the frequency based on site-year. In addition, shared SSCs were modeled in single unit PSA as if those units have independent shared SSCs. Therefore, the risk of shared SSCs should be reevaluated. In this paper, the frequency of LOOP (Loss of Offsite Power), which is typically a multi-unit event, was evaluated and the frequency of SBO (Station Blackout) depending on LOOP frequency and emergency power systems such as EDG (Emergency Diesel Generator) and AAC (Alternate AC), that can mitigate SBO events, was modeled. This paper describes how to calculate LOOP and SBO frequency from the simple example for two-unit site with shared AAC. The events impacting on multiple units, which were excluded in conventional PSA, should be considered for MUPSA.

Technical basis document for external events

International Nuclear Information System (INIS)

OBERG, B.D.

2003-01-01

This document supports the Tank Farms Documented Safety Analysis and presents the technical basis for the FR-equencies of externally initiated accidents. The consequences of externally initiated events are discussed in other documents that correspond to the accident that was caused by the external event. The external events include aircraft crash, vehicle accident, range fire, and rail accident

Interaction between Gender and Skill on Competitive State Anxiety Using the Time-to-Event Paradigm: What Roles Do Intensity, Direction, and Frequency Dimensions Play?

Directory of Open Access Journals (Sweden)

John E. Hagan

2017-05-01

Full Text Available Background and purpose: The functional understanding and examination of competitive anxiety responses as temporal events that unfold as time-to-competition moves closer has emerged as a topical research area within the domains of sport psychology. However, little is known from an inclusive and interaction oriented perspective. Using the multidimensional anxiety theory as a framework, the present study examined the temporal patterning of competitive anxiety, focusing on the dimensions of intensity, direction, and frequency of intrusions in athletes across gender and skill level.Methods: Elite and semi-elite table tennis athletes from the Ghanaian league (N = 90 completed a modified version of Competitive State Anxiety Inventory-2 (CSAI-2 with the inclusion of the directional and frequency of intrusion scales at three temporal phases (7 days, 2 days, and 1 h prior to a competitive fixture.Results: Multivariate Analyses of Variance repeated measures with follow-up analyses revealed significant interactions for between-subjects factors on all anxiety dimensions (intensity, direction, and frequency. Notably, elite (international female athletes were less cognitively anxious, showed more facilitative interpretation toward somatic anxiety symptoms and experienced less frequency of somatic anxiety symptoms than their male counterparts. However, both elite groups displayed appreciable level of self-confidence. For time-to-event effects, both cognitive and somatic anxiety intensity fluctuated whereas self-confidence showed a steady rise as competition neared. Somatic anxiety debilitative interpretation slightly improved 1 h before competition whereas cognitive anxiety frequencies also increased progressively during the entire preparatory phase.Conclusion: Findings suggest a more dynamic image of elite athletes’ pre-competitive anxiety responses than suggested by former studies, potentially influenced by cultural differences. The use of psychological

Statistical analysis of hydrodynamic cavitation events

Science.gov (United States)

Gimenez, G.; Sommer, R.

1980-10-01

The frequency (number of events per unit time) of pressure pulses produced by hydrodynamic cavitation bubble collapses is investigated using statistical methods. The results indicate that this frequency is distributed according to a normal law, its parameters not being time-evolving.

Dynamic event Tress applied to sequences Full Spectrum LOCA. Calculating the frequency of excedeence of damage by integrated Safety Analysis Methodology

International Nuclear Information System (INIS)

Gomez-Magan, J. J.; Fernandez, I.; Gil, J.; Marrao, H.; Queral, C.; Gonzalez-Cadelo, J.; Montero-Mayorga, J.; Rivas, J.; Ibane-Llano, C.; Izquierdo, J. M.; Sanchez-Perea, M.; Melendez, E.; Hortal, J.

2013-01-01

The Integrated Safety Analysis (ISA) methodology, developed by the Spanish Nuclear Safety council (CSN), has been applied to obtain the dynamic Event Trees (DETs) for full spectrum Loss of Coolant Accidents (LOCAs) of a Westinghouse 3-loop PWR plant. The purpose of this ISA application is to obtain the Damage Excedence Frequency (DEF) for the LOCA Event Tree by taking into account the uncertainties in the break area and the operator actuation time needed to cool down and de pressurize reactor coolant system by means of steam generator. Simulations are performed with SCAIS, a software tool which includes a dynamic coupling with MAAP thermal hydraulic code. The results show the capability of the ISA methodology to obtain the DEF taking into account the time uncertainty in human actions. (Author)

Teratology study of amide derivatives of branched aliphatic carboxylic acids with 4-aminobenzensulfonamide in NMRI mice.

Science.gov (United States)

Onishi, Yuko; Okada, Akinobu; Noyori, Hiroko; Okamura, Ai; Hen, Naama; Yagen, Boris; Bialer, Meir; Fujiwara, Michio

2013-08-01

Valproic acid (VPA), widely used to treat epilepsy, bipolar disorders, and migraine prophylaxis, is known to cause neural tube and skeletal defects in humans and animals. Aminobenzensulfonamide derivatives of VPA with branched aliphatic carboxylic acids, namely 2-methyl-N-(4-sulfamoyl-phenyl)-pentanamide (MSP), 2-ethyl-N-(4-sulfamoyl-phenyl)-butyramide (ESB), 2-ethyl-4-methyl-N-(4-sulfamoyl-phenyl)-pentanamide (EMSP), and 2-ethyl-N-(4-sulfamoyl-benzyl)-butyramide (ESBB), have shown more potent anticonvulsant activity than VPA in preclinical testing. Here, we investigated the teratogenic effects of these analogous compounds of VPA in NMRI mice. Pregnant NMRI mice were given a single subcutaneous injection of either VPA at 1.8 or 3.6 mmol/kg, or MSP, ESB, EMSP, or ESBB at 1.8, 3.6, or 4.8 mmol/kg on gestation day (GD) 8. Cesarean section was performed on GD 18, and the live fetuses were examined for external and skeletal malformations. Compared with VPA, which induced neural tube defects (NTDs) in fetuses at 1.8 and 3.6 mmol/kg, the analog derivatives induced no NTDs at dose levels up to 4.8 mmol/kg (except for a single case of exencephaly at 4.8 mmol/kg MSP). Skeletal examination showed several abnormalities mainly at the axial skeletal level with VPA at 1.8 mmol/kg. Fused vertebrae and/or fused ribs were also observed with MSP, ESB, EMSP, and ESBB, they were less severe and seen at a lower incidence that those induced by VPA at the same dose level. In addition to exerting more potent preclinical antiepileptic activity, teratology comparison indicates that aminobenzensulfonamide analogs are generally more weakly teratogenic than VPA. © 2013 Wiley Periodicals, Inc.

Component external leakage and rupture frequency estimates

International Nuclear Information System (INIS)

Eide, S.A.; Khericha, S.T.; Calley, M.B.; Johnson, D.A.; Marteeny, M.L.

1991-11-01

In order to perform detailed internal flooding risk analyses of nuclear power plants, external leakage and rupture frequencies are needed for various types of components - piping, valves, pumps, flanges, and others. However, there appears to be no up-to-date, comprehensive source for such frequency estimates. This report attempts to fill that void. Based on a comprehensive search of Licensee Event Reports (LERs) contained in Nuclear Power Experience (NPE), and estimates of component populations and exposure times, component external leakage and rupture frequencies were generated. The remainder of this report covers the specifies of the NPE search for external leakage and rupture events, analysis of the data, a comparison with frequency estimates from other sources, and a discussion of the results

Classification of hydromagnetic emissions based on frequency--time spectra

International Nuclear Information System (INIS)

Fukunishi, H.; Toya, T.; Koike, K.; Kuwashima, M.; Kawamura, M.

1981-01-01

By using 3035 hydromagnetic emission events observed in the frequency range of 0.1--2.0 Hz at Syowa (Lapprox.6), HM emissions have been classified into eight subtypes based on their spectral structures, i.e., HM whistler, periodic HM emission, HM chorus, HM emission burst, IPDP, morning IPDP, Pc 1--2 band, and irregular HM emission. It is seen that each subtype has a preferential magnetic local time interval and also a frequency range for its occurrence. Morning IPDP events and irregular HM emissions occur in the magnetic morning hours, while dispersive periodic HM emissions and HM emission bursts occur around magnetic local noon, then HM chorus emissions occur in the afternoon hours and IPDP events occur in the evening hours. Furthermore, it is noticed that the mid-frequencies of these emissions vary from high frequencies in the morning hours to low frequencies in the afternoon hours. On the basis of these results, the generation mechanisms of each subtype are discussed

Effect of lunar phase on frequency of psychogenic nonepileptic events in the EMU.

Science.gov (United States)

Bolen, Robert D; Campbell, Zeke; Dennis, William A; Koontz, Elizabeth H; Pritchard, Paul B

2016-06-01

Studies of the effect of a full moon on seizures have yielded mixed results, despite a continuing prevailing belief regarding the association of lunar phase with human behavior. The potential effect of a full moon on psychogenic nonepileptic events has not been as well studied, despite what anecdotal accounts from most epilepsy monitoring unit (EMU) staff would suggest. We obtained the dates and times of all events from patients diagnosed with psychogenic nonepileptic events discharged from our EMU over a two-year period. The events were then plotted on a 29.5-day lunar calendar. Events were also broken down into lunar quarters for statistical analysis. We found a statistically significant increase in psychogenic nonepileptic events during the new moon quarter in our EMU during our studied timeframe. Our results are not concordant with the results of a similarly designed past study, raising the possibility that psychogenic nonepileptic events are not influenced by lunar phase. Copyright © 2016 Elsevier Inc. All rights reserved.

Numeracy, frequency, and Bayesian reasoning

Directory of Open Access Journals (Sweden)

Gretchen B. Chapman

2009-02-01

Full Text Available Previous research has demonstrated that Bayesian reasoning performance is improved if uncertainty information is presented as natural frequencies rather than single-event probabilities. A questionnaire study of 342 college students replicated this effect but also found that the performance-boosting benefits of the natural frequency presentation occurred primarily for participants who scored high in numeracy. This finding suggests that even comprehension and manipulation of natural frequencies requires a certain threshold of numeracy abilities, and that the beneficial effects of natural frequency presentation may not be as general as previously believed.

Dynamics of large-scale cortical interactions at high gamma frequencies during word production: event related causality (ERC) analysis of human electrocorticography (ECoG).

Science.gov (United States)

Korzeniewska, Anna; Franaszczuk, Piotr J; Crainiceanu, Ciprian M; Kuś, Rafał; Crone, Nathan E

2011-06-15

Intracranial EEG studies in humans have shown that functional brain activation in a variety of functional-anatomic domains of human cortex is associated with an increase in power at a broad range of high gamma (>60Hz) frequencies. Although these electrophysiological responses are highly specific for the location and timing of cortical processing and in animal recordings are highly correlated with increased population firing rates, there has been little direct empirical evidence for causal interactions between different recording sites at high gamma frequencies. Such causal interactions are hypothesized to occur during cognitive tasks that activate multiple brain regions. To determine whether such causal interactions occur at high gamma frequencies and to investigate their functional significance, we used event-related causality (ERC) analysis to estimate the dynamics, directionality, and magnitude of event-related causal interactions using subdural electrocorticography (ECoG) recorded during two word production tasks: picture naming and auditory word repetition. A clinical subject who had normal hearing but was skilled in American Signed Language (ASL) provided a unique opportunity to test our hypothesis with reference to a predictable pattern of causal interactions, i.e. that language cortex interacts with different areas of sensorimotor cortex during spoken vs. signed responses. Our ERC analyses confirmed this prediction. During word production with spoken responses, perisylvian language sites had prominent causal interactions with mouth/tongue areas of motor cortex, and when responses were gestured in sign language, the most prominent interactions involved hand and arm areas of motor cortex. Furthermore, we found that the sites from which the most numerous and prominent causal interactions originated, i.e. sites with a pattern of ERC "divergence", were also sites where high gamma power increases were most prominent and where electrocortical stimulation mapping

How Metastrategic Considerations Influence the Selection of Frequency Estimation Strategies

Science.gov (United States)

Brown, Norman R.

2008-01-01

Prior research indicates that enumeration-based frequency estimation strategies become increasingly common as memory for relevant event instances improves and that moderate levels of context memory are associated with moderate rates of enumeration [Brown, N. R. (1995). Estimation strategies and the judgment of event frequency. Journal of…

Separate representation of stimulus frequency, intensity, and duration in auditory sensory memory: an event-related potential and dipole-model analysis.

Science.gov (United States)

Giard, M H; Lavikahen, J; Reinikainen, K; Perrin, F; Bertrand, O; Pernier, J; Näätänen, R

1995-01-01

Abstract The present study analyzed the neural correlates of acoustic stimulus representation in echoic sensory memory. The neural traces of auditory sensory memory were indirectly studied by using the mismatch negativity (MMN), an event-related potential component elicited by a change in a repetitive sound. The MMN is assumed to reflect change detection in a comparison process between the sensory input from a deviant stimulus and the neural representation of repetitive stimuli in echoic memory. The scalp topographies of the MMNs elicited by pure tones deviating from standard tones by either frequency, intensity, or duration varied according to the type of stimulus deviance, indicating that the MMNs for different attributes originate, at least in part, from distinct neural populations in the auditory cortex. This result was supported by dipole-model analysis. If the MMN generator process occurs where the stimulus information is stored, these findings strongly suggest that the frequency, intensity, and duration of acoustic stimuli have a separate neural representation in sensory memory.

Modeling time to recovery and initiating event frequency for loss of off-site power incidents at nuclear power plants

International Nuclear Information System (INIS)

Iman, R.L.; Hora, S.C.

1988-01-01

Industry data representing the time to recovery of loss of off-site power at nuclear power plants for 63 incidents caused by plant-centered losses, grid losses, or severe weather losses are fit with exponential, lognormal, gamma and Weibull probability models. A Bayesian analysis is used to compare the adequacy of each of these models and to provide uncertainty bounds on each of the fitted models. A composite model that combines the probability models fitted to each of the three sources of data is presented as a method for predicting the time to recovery of loss of off-site power. The composite model is very general and can be made site specific by making adjustments on the models used, such as might occur due to the type of switchyard configuration or type of grid, and by adjusting the weights on the individual models, such as might occur with weather conditions existing at a particular plant. Adjustments in the composite model are shown for different models used for switchyard configuration and for different weights due to weather. Bayesian approaches are also presented for modeling the frequency of initiating events leading to loss of off-site power. One Bayesian model assumes that all plants share a common incidence rate for loss of off-site power, while the other Bayesian approach models the incidence rate for each plant relative to the incidence rates of all other plants. Combining the Bayesian models for the frequency of the initiating events with the composite Bayesian model for recovery provides the necessary vehicle for a complete model that incorporates uncertainty into a probabilistic risk assessment

Analysis of core damage frequency from internal events: Surry, Unit 1

International Nuclear Information System (INIS)

Harper, F.T.

1986-11-01

This document contains the accident sequence analyses for Surry, Unit 1; one of the reference plants being examined as part of the NUREG-1150 effort by the Nuclear Regulatory Commission (NRC). NUREG-1150 will document the risk of a selected group of nuclear power plants. As part of that work, this report contains the overall core damage frequency estimate for Surry, Unit 1, and the accompanying plant damage state frequencies. Sensitivity and uncertainty analyses provide additional insights regarding the dominant contributors to the Surry core damage frequency estimate. The numerical results are driven to some degree by modeling assumptions and data selection for issues such as reactor coolant pump seal LOCAs, common cause failure probabilities, and plant response to station blackout and loss of electrical bust initiators. The sensitivity studies explore the impact of alternate theories and data on these issues

Frequency Response Analysis Tool

Energy Technology Data Exchange (ETDEWEB)

Etingov, Pavel V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kosterev, Dmitry [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Dai, T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2014-12-01

Frequency response has received a lot of attention in recent years at the national level, which culminated in the development and approval of North American Electricity Reliability Corporation (NERC) BAL-003-1 Frequency Response and Frequency Bias Setting Reliability Standard. This report is prepared to describe the details of the work conducted by Pacific Northwest National Laboratory (PNNL) in collaboration with the Bonneville Power Administration and Western Electricity Coordinating Council (WECC) Joint Synchronized Information Subcommittee (JSIS) to develop a frequency response analysis tool (FRAT). The document provides the details on the methodology and main features of the FRAT. The tool manages the database of under-frequency events and calculates the frequency response baseline. Frequency response calculations are consistent with frequency response measure (FRM) in NERC BAL-003-1 for an interconnection and balancing authority. The FRAT can use both phasor measurement unit (PMU) data, where available, and supervisory control and data acquisition (SCADA) data. The tool is also capable of automatically generating NERC Frequency Response Survey (FRS) forms required by BAL-003-1 Standard.

Has the frequency of bleeding changed over time for patients presenting with an acute coronary syndrome? The global registry of acute coronary events.

OpenAIRE

Fox, KA; Carruthers, K; Steg, PG; Avezum, A; Granger, CB; Montalescot, G; Goodman, SG; Gore, JM; Quill, AL; Eagle, KA; GRACE Investigators,

2010-01-01

08.09.14 KB. Ok to add published version to spiral, OA paper AIMS: To determine whether changes in practice, over time, are associated with altered rates of major bleeding in acute coronary syndromes (ACS). METHODS AND RESULTS: Patients from the Global Registry of Acute Coronary Events were enrolled between 2000 and 2007. The main outcome measures were frequency of major bleeding, including haemorrhagic stroke, over time, after adjustment for patient characteristics, and impact of major b...

Frequencies and trends of significant characteristics of reported events in Germany

Energy Technology Data Exchange (ETDEWEB)

Farber, G.; Matthes, H. [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Koln (Germany)

2001-07-01

In the frame of its support to the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety the GRS continuously performs in-depth technical analyses of reported events at operating nuclear power reactors in Germany which can be used for the determination of plant weaknesses with regard to reactor safety. During the last 18 months, in addition to those activities, the GRS has developed a data bank model for the statistical assessment of events. This model is based on a hierarchically structured, detailed coding system with respect to technical and safety relevant characteristics of the plants and the systematic characterization of plant-specific events. The data bank model is ready for practical application. Results of a first statistical evaluation, taking into account the data sets from the time period 1996 to 1999, are meanwhile available. By increasing the amount of data it will become possible to herewith improve the statements concerning trends of safety aspects. This report describes the coding system, the evaluation model, the data input and the evaluations performed during the period beginning in April 2000. (authors)

Frequencies and trends of significant characteristics of reported events in Germany

International Nuclear Information System (INIS)

Farber, G.; Matthes, H.

2001-01-01

In the frame of its support to the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety the GRS continuously performs in-depth technical analyses of reported events at operating nuclear power reactors in Germany which can be used for the determination of plant weaknesses with regard to reactor safety. During the last 18 months, in addition to those activities, the GRS has developed a data bank model for the statistical assessment of events. This model is based on a hierarchically structured, detailed coding system with respect to technical and safety relevant characteristics of the plants and the systematic characterization of plant-specific events. The data bank model is ready for practical application. Results of a first statistical evaluation, taking into account the data sets from the time period 1996 to 1999, are meanwhile available. By increasing the amount of data it will become possible to herewith improve the statements concerning trends of safety aspects. This report describes the coding system, the evaluation model, the data input and the evaluations performed during the period beginning in April 2000. (authors)

Low-frequency repetitive transcranial magnetic stimulation (rTMS) affects event-related potential measures of novelty processing in autism.

Science.gov (United States)

Sokhadze, Estate; Baruth, Joshua; Tasman, Allan; Mansoor, Mehreen; Ramaswamy, Rajesh; Sears, Lonnie; Mathai, Grace; El-Baz, Ayman; Casanova, Manuel F

2010-06-01

In our previous study on individuals with autism spectrum disorder (ASD) (Sokhadze et al., Appl Psychophysiol Biofeedback 34:37-51, 2009a) we reported abnormalities in the attention-orienting frontal event-related potentials (ERP) and the sustained-attention centro-parietal ERPs in a visual oddball experiment. These results suggest that individuals with autism over-process information needed for the successful differentiation of target and novel stimuli. In the present study we examine the effects of low-frequency, repetitive Transcranial Magnetic Stimulation (rTMS) on novelty processing as well as behavior and social functioning in 13 individuals with ASD. Our hypothesis was that low-frequency rTMS application to dorsolateral prefrontal cortex (DLFPC) would result in an alteration of the cortical excitatory/inhibitory balance through the activation of inhibitory GABAergic double bouquet interneurons. We expected to find post-TMS differences in amplitude and latency of early and late ERP components. The results of our current study validate the use of low-frequency rTMS as a modulatory tool that altered the disrupted ratio of cortical excitation to inhibition in autism. After rTMS the parieto-occipital P50 amplitude decreased to novel distracters but not to targets; also the amplitude and latency to targets increased for the frontal P50 while decreasing to non-target stimuli. Low-frequency rTMS minimized early cortical responses to irrelevant stimuli and increased responses to relevant stimuli. Improved selectivity in early cortical responses lead to better stimulus differentiation at later-stage responses as was made evident by our P3b and P3a component findings. These results indicate a significant change in early, middle-latency and late ERP components at the frontal, centro-parietal, and parieto-occipital regions of interest in response to target and distracter stimuli as a result of rTMS treatment. Overall, our preliminary results show that rTMS may prove to

Sensitivity studies on the approaches for addressing multiple initiating events in fire events PSA

Energy Technology Data Exchange (ETDEWEB)

Kang, Dae Il; Lim, Ho Gon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

A single fire event within a fire compartment or a fire scenario can cause multiple initiating events (IEs). As an example, a fire in a turbine building fire area can cause a loss of the main feed-water (LOMF) and loss of off-site power (LOOP) IEs. Previous domestic fire events PSA had considered only the most severe initiating event among multiple initiating events. NUREG/CR-6850 and ANS/ASME PRA Standard require that multiple IEs are to be addressed in fire events PSA. In this paper, sensitivity studies on the approaches for addressing multiple IEs in fire events PSA for Hanul Unit 3 were performed and their results were presented. In this paper, sensitivity studies on the approaches for addressing multiple IEs in fire events PSA are performed and their results were presented. From the sensitivity analysis results, we can find that the incorporations of multiple IEs into fire events PSA model result in the core damage frequency (CDF) increase and may lead to the generation of the duplicate cutsets. Multiple IEs also can occur at internal flooding event or other external events such as seismic event. They should be considered in the constructions of PSA models in order to realistically estimate risk due to flooding or seismic events.

Impact of climate change on extreme rainfall events and flood risk

Indian Academy of Sciences (India)

The analysis of the frequency of rainy days, rain days and heavy rainfall days as well as one-day extreme rainfall and return period has been carried out in this study to observe the impact of climate change on extreme rainfall events and flood risk in India. The frequency of heavy rainfall events are decreasing in major parts ...

External events analysis for the Savannah River Site K reactor

International Nuclear Information System (INIS)

Brandyberry, M.D.; Wingo, H.E.

1990-01-01

The probabilistic external events analysis performed for the Savannah River Site K-reactor PRA considered many different events which are generally perceived to be ''external'' to the reactor and its systems, such as fires, floods, seismic events, and transportation accidents (as well as many others). Events which have been shown to be significant contributors to risk include seismic events, tornados, a crane failure scenario, fires and dam failures. The total contribution to the core melt frequency from external initiators has been found to be 2.2 x 10 -4 per year, from which seismic events are the major contributor (1.2 x 10 -4 per year). Fire initiated events contribute 1.4 x 10 -7 per year, tornados 5.8 x 10 -7 per year, dam failures 1.5 x 10 -6 per year and the crane failure scenario less than 10 -4 per year to the core melt frequency. 8 refs., 3 figs., 5 tabs

Editorial

DEFF Research Database (Denmark)

Hass, Ulla

2010-01-01

Special Issue: 38th Annual Conference of the European Teratology Society 5-8th September, 2010 Barcelona, Spain......Special Issue: 38th Annual Conference of the European Teratology Society 5-8th September, 2010 Barcelona, Spain...

Extreme Precipitation Estimation with Typhoon Morakot Using Frequency and Spatial Analysis

Directory of Open Access Journals (Sweden)

Hone-Jay Chu

2011-01-01

Full Text Available Typhoon Morakot lashed Taiwan and produced copious amounts of precipitation in 2009. From the point view of hydrological statistics, the impact of the precipitation from typhoon Morakot using a frequency analysis can be analyzed and discussed. The frequency curve, which was fitted mathematically to historical observed data, can be used to estimate the probability of exceedance for runoff events of a certain magnitude. The study integrates frequency analysis and spatial analysis to assess the effect of Typhoon Morakot event on rainfall frequency in the Gaoping River basin of southern Taiwan. First, extreme rainfall data are collected at sixteen stations for durations of 1, 3, 6, 12, and 24 hours and then an appropriate probability distribution was selected to analyze the impact of the extreme hydrological event. Spatial rainfall patterns for a return period of 200-yr with 24-hr duration with and without Typhoon Morakot are estimated. Results show that the rainfall amount is significantly different with long duration with and without the event for frequency analysis. Furthermore, spatial analysis shows that extreme rainfall for a return period of 200-yr is highly dependent on topography and is smaller in the southwest than that in the east. The results not only demonstrate the distinct effect of Typhoon Morakot on frequency analysis, but also could provide reference in future planning of hydrological engineering.

Atmospheric dust events in central Asia: Relationship to wind, soil type, and land use

Science.gov (United States)

Pi, Huawei; Sharratt, Brenton; Lei, Jiaqiang

2017-06-01

Xinjiang Province in northwest China is one of the most important source regions of atmospheric dust in the world. Spatial-temporal characteristics of dust events in the province were investigated by time series analysis of annual dust event frequency and meteorological data collected at 101 meteorological stations from 1960 to 2007. Blowing dust frequency (BDF) and dust storm frequency (DSF) decreased with time in North, South, and East Xinjiang whereas floating dust frequency (FDF) decreased with time only in South and East Xinjiang. Dust concentrations were lower in North than in South Xinjiang and decreased with time in East Xinjiang. Wind significantly influenced the temporal trend in FDF, BDF, and DSF in South Xinjiang and DSF in North Xinjiang. Frequency of dust events was smaller by an order of magnitude in North (10.9 d yr-1) than in South Xinjiang (111.3 d yr-1), possibly due in part to higher annual precipitation in North Xinjiang. Floating dust was most frequently observed in East and South Xinjiang, while blowing dust was most frequently observed in North Xinjiang. The high frequency of floating dust in East and South Xinjiang is likely due to the enclosed terrain that characterizes these regions. Land use and soil type also influenced dust events. Although climate influences frequency of dust events, the occurrence of these events may be reduced most effectively by imposing better land management practices in deciduous forests or orchards characterized by saline soils in respectively North and East Xinjiang and meadows characterized by Guanyu soils in South Xinjiang.

Analysis for Human-related Events during the Overhaul

Energy Technology Data Exchange (ETDEWEB)

Kim, Ji Tae; Kim, Min Chull; Choi, Dong Won; Lee, Durk Hun [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2011-10-15

The event frequency due to human error is decreasing among 20 operating Nuclear Power Plants (NPPs) excluding the NPP (Shin-Kori unit-1) in the commissioning stage since 2008. However, the events due to human error during an overhaul (O/H) occur annually (see Table I). An analysis for human-related events during the O/H was performed. Similar problems were identified for each event from the analysis and also, organizational and safety cultural factors were also identified

EVNTRE, Code System for Event Progression Analysis for PRA

International Nuclear Information System (INIS)

2002-01-01

1 - Description of program or function: EVNTRE is a generalized event tree processor that was developed for use in probabilistic risk analysis of severe accident progressions for nuclear power plants. The general nature of EVNTRE makes it applicable to a wide variety of analyses that involve the investigation of a progression of events which lead to a large number of sets of conditions or scenarios. EVNTRE efficiently processes large, complex event trees. It can assign probabilities to event tree branch points in several different ways, classify pathways or outcomes into user-specified groupings, and sample input distributions of probabilities and parameters. PSTEVNT, a post-processor program used to sort and reclassify the 'binned' data output from EVNTRE and generate summary tables, is included. 2 - Methods: EVNTRE processes event trees that are cast in the form of questions or events, with multiple choice answers for each question. Split fractions (probabilities or frequencies that sum to unity) are either supplied or calculated for the branches of each question in a path-dependent manner. EVNTRE traverses the tree, enumerating the leaves of the tree and calculating their probabilities or frequencies based upon the initial probability or frequency and the split fractions for the branches taken along the corresponding path to an individual leaf. The questions in the event tree are usually grouped to address specific phases of time regimes in the progression of the scenario or severe accident. Grouping or binning of each path through the event tree in terms of a small number of characteristics or attributes is allowed. Boolean expressions of the branches taken are used to select the appropriate values of the characteristics of interest for the given path. Typically, the user specifies a cutoff tolerance for the frequency of a pathway to terminate further exploration. Multiple sets of input to an event tree can be processed by using Monte Carlo sampling to generate

Frequency deviations and generation scheduling in the nordic system

DEFF Research Database (Denmark)

Li, Zhongwei; Samuelsson, Olaf; Garcia-Valle, Rodrigo

2011-01-01

to be considered, the disturbances caused to this control by the hourly dispatch of generation has received less attention and is the focus of this paper. Based on years of recorded PMU data, statistics of frequency events and analysis of frequency quality are made to demonstrate the relation between the frequency...

Hierarchical Control of Thermostatically Controller Loads for Primary Frequency Control

DEFF Research Database (Denmark)

Zhao, Haoran; Wu, Qiuwei; Huang, Shaojun

2016-01-01

reserve references. At the middle level, distribution substations estimate the available power of TCLs based on the aggregated bin model, and dispatch control signals to individual TCLs. At the local level, a supplementary frequency control loop is implemented at the local controller, which makes TCLs...... respond to the frequency event autonomously. Case studies show that the proposed controller can efficiently respond to frequency events and fulfill the requirement specified by the system operator. The users’ comforts are not compromised and the short cycling of TCLs is largely reduced. Due...... to the autonomous control, the communication requirement is minimized....

Event generators for address event representation transmitters

Science.gov (United States)

Serrano-Gotarredona, Rafael; Serrano-Gotarredona, Teresa; Linares Barranco, Bernabe

2005-06-01

Address Event Representation (AER) is an emergent neuromorphic interchip communication protocol that allows for real-time virtual massive connectivity between huge number neurons located on different chips. By exploiting high speed digital communication circuits (with nano-seconds timings), synaptic neural connections can be time multiplexed, while neural activity signals (with mili-seconds timings) are sampled at low frequencies. Also, neurons generate 'events' according to their activity levels. More active neurons generate more events per unit time, and access the interchip communication channel more frequently, while neurons with low activity consume less communication bandwidth. In a typical AER transmitter chip, there is an array of neurons that generate events. They send events to a peripheral circuitry (let's call it "AER Generator") that transforms those events to neurons coordinates (addresses) which are put sequentially on an interchip high speed digital bus. This bus includes a parallel multi-bit address word plus a Rqst (request) and Ack (acknowledge) handshaking signals for asynchronous data exchange. There have been two main approaches published in the literature for implementing such "AER Generator" circuits. They differ on the way of handling event collisions coming from the array of neurons. One approach is based on detecting and discarding collisions, while the other incorporates arbitration for sequencing colliding events . The first approach is supposed to be simpler and faster, while the second is able to handle much higher event traffic. In this article we will concentrate on the second arbiter-based approach. Boahen has been publishing several techniques for implementing and improving the arbiter based approach. Originally, he proposed an arbitration squeme by rows, followed by a column arbitration. In this scheme, while one neuron was selected by the arbiters to transmit his event out of the chip, the rest of neurons in the array were

Comparison of a modified mid-coronal sectioning technique and Wilson's technique when conducting eye and brain examinations in rabbit teratology studies.

Science.gov (United States)

Ziejewski, Mary K; Solomon, Howard M; Rendemonti, Joyce; Stanislaus, Dinesh

2015-02-01

There are two methods used when examining fetal rabbit eyes and brain in teratology studies. One method employs prior fixation before serial sectioning (Wilson's technique) and the other uses fresh tissue (mid-coronal sectioning). We modified the mid-coronal sectioning technique to include removal of eyes and brain for closer examination and to increase the number of structures that can be evaluated and compared it to the Wilson's technique. We found that external examination of the head, in conjunction with either sectioning method, is equally sensitive in identifying developmental defects. We evaluated 40,401 New Zealand White (NZW) and Dutch-Belted (DB) rabbit fetuses for external head alterations, of which 28,538 fetuses were further examined for eye and brain alterations using the modified mid-coronal sectioning method (16,675 fetuses) or Wilson's technique (11,863 fetuses). The fetuses were from vehicle control or drug-treated pregnant rabbits in embryo-fetal development studies conducted to meet international regulatory requirements for the development of new drugs. Both methods detected the more common alterations (microphthalmia and dilated lateral cerebral ventricles) and other less common findings (changes in size and/or shape of eye and brain structures). While both methods are equally sensitive at detecting common and rare developmental defects, the modified mid-coronal sectioning technique eliminates the use of chemicals and concomitant fixation artifacts that occur with the Wilson's technique and allows for examination of 100% intact fetuses thereby increasing potential for detecting eye and brain alterations as these findings occur infrequently in rabbits. © 2015 Wiley Periodicals, Inc.

High frequency energy measurements

International Nuclear Information System (INIS)

Stotlar, S.C.

1981-01-01

High-frequency (> 100 MHz) energy measurements present special problems to the experimenter. Environment or available electronics often limit the applicability of a given detector type. The physical properties of many detectors are frequency dependent and in some cases, the physical effect employed can be frequency dependent. State-of-the-art measurements generally involve a detection scheme in association with high-speed electronics and a method of data recording. Events can be single or repetitive shot requiring real time, sampling, or digitizing data recording. Potential modification of the pulse by the detector and the associated electronics should not be overlooked. This presentation will review typical applications, methods of choosing a detector, and high-speed detectors. Special considerations and limitations of some applications and devices will be described

Automatic Detection and Classification of Audio Events for Road Surveillance Applications

Directory of Open Access Journals (Sweden)

Noor Almaadeed

2018-06-01

Full Text Available This work investigates the problem of detecting hazardous events on roads by designing an audio surveillance system that automatically detects perilous situations such as car crashes and tire skidding. In recent years, research has shown several visual surveillance systems that have been proposed for road monitoring to detect accidents with an aim to improve safety procedures in emergency cases. However, the visual information alone cannot detect certain events such as car crashes and tire skidding, especially under adverse and visually cluttered weather conditions such as snowfall, rain, and fog. Consequently, the incorporation of microphones and audio event detectors based on audio processing can significantly enhance the detection accuracy of such surveillance systems. This paper proposes to combine time-domain, frequency-domain, and joint time-frequency features extracted from a class of quadratic time-frequency distributions (QTFDs to detect events on roads through audio analysis and processing. Experiments were carried out using a publicly available dataset. The experimental results conform the effectiveness of the proposed approach for detecting hazardous events on roads as demonstrated by 7% improvement of accuracy rate when compared against methods that use individual temporal and spectral features.

Adaptive Tuning of Frequency Thresholds Using Voltage Drop Data in Decentralized Load Shedding

DEFF Research Database (Denmark)

Hoseinzadeh, Bakhtyar; Faria Da Silva, Filipe Miguel; Bak, Claus Leth

2015-01-01

Load shedding (LS) is the last firewall and the most expensive control action against power system blackout. In the conventional under frequency LS (UFLS) schemes, the load drop locations are already determined independently of the event location. Furthermore, the frequency thresholds of LS relays...... are prespecified and constant values which may not be a comprehensive solution for widespread range of possible events. This paper addresses the decentralized LS in which the instantaneous voltage deviation of load buses is used to determine the frequency thresholds of LS relays. The higher frequency thresholds...

High frequency system project implementation plan

International Nuclear Information System (INIS)

Moon, L.L.

1976-01-01

The High Frequency System is a new mobile, digital diagnostic recording system for use at the Nevada Test Site. Many different kinds of event data will be digitized in real-time by this system, and these data will be recorded and stored for later read-out and transmission to NADCEN. The hardware and software requirements of the High Frequency System are examined, and the parameters of the system are proposed

Energy intake and obesity: ingestive frequency outweighs portion size.

Science.gov (United States)

Mattes, Richard

2014-07-01

Energy intake is a function of the quantity of energy consumed per ingestive event and the number of these events. The marked increase of energy intake and body weight over the past 35 years indicates that there has been poor precision in the reciprocity of these two facets of intake. With recent study of the associations between gut "satiation" peptides and energy intake, there has been an emphasis on the contribution of portion size to positive energy balance. However, this orientation may not appropriately weight the contribution of ingestive frequency. Gut peptides are not purely satiation factors and metabolic and environmental cues may more strongly guide the onset and number of ingestive events. Evidence is presented that while both portion size and ingestive frequency have increased in the population, the latter may be more problematic for weight gain. The magnitude and time course of increments in ingestive frequency map better onto energy intake and BMI trends than changes of portion size. This may occur, in part, because dietary compensation and thermogenic effects are weaker for increases in ingestive frequency than portion size. Though not to the exclusion of consideration of portion size effects, improved weight management may be achieved with greater attention to the drivers of eating and drinking frequency. Copyright © 2013 Elsevier Inc. All rights reserved.

Research Models in Developmental Behavioral Toxicology.

Science.gov (United States)

Dietrich, Kim N.; Pearson, Douglas T.

Developmental models currently used by child behavioral toxicologists and teratologists are inadequate to address current issues in these fields. Both child behavioral teratology and toxicology scientifically study the impact of exposure to toxic agents on behavior development: teratology focuses on prenatal exposure and postnatal behavior…

Analysis of Loss-of-Offsite-Power Events 1997-2015

Energy Technology Data Exchange (ETDEWEB)

Johnson, Nancy Ellen [Idaho National Lab. (INL), Idaho Falls, ID (United States); Schroeder, John Alton [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2016-07-01

Loss of offsite power (LOOP) can have a major negative impact on a power plant’s ability to achieve and maintain safe shutdown conditions. LOOP event frequencies and times required for subsequent restoration of offsite power are important inputs to plant probabilistic risk assessments. This report presents a statistical and engineering analysis of LOOP frequencies and durations at U.S. commercial nuclear power plants. The data used in this study are based on the operating experience during calendar years 1997 through 2015. LOOP events during critical operation that do not result in a reactor trip, are not included. Frequencies and durations were determined for four event categories: plant-centered, switchyard-centered, grid-related, and weather-related. Emergency diesel generator reliability is also considered (failure to start, failure to load and run, and failure to run more than 1 hour). There is an adverse trend in LOOP durations. The previously reported adverse trend in LOOP frequency was not statistically significant for 2006-2015. Grid-related LOOPs happen predominantly in the summer. Switchyard-centered LOOPs happen predominantly in winter and spring. Plant-centered and weather-related LOOPs do not show statistically significant seasonality. The engineering analysis of LOOP data shows that human errors have been much less frequent since 1997 than in the 1986 -1996 time period.

Bivariate frequency analysis of rainfall intensity and duration for urban stormwater infrastructure design

Science.gov (United States)

Jun, Changhyun; Qin, Xiaosheng; Gan, Thian Yew; Tung, Yeou-Koung; De Michele, Carlo

2017-10-01

This study presents a storm-event based bivariate frequency analysis approach to determine design rainfalls in which, the number, intensity and duration of actual rainstorm events were considered. To derive more realistic design storms, the occurrence probability of an individual rainstorm event was determined from the joint distribution of storm intensity and duration through a copula model. Hourly rainfall data were used at three climate stations respectively located in Singapore, South Korea and Canada. It was found that the proposed approach could give a more realistic description of rainfall characteristics of rainstorm events and design rainfalls. As results, the design rainfall quantities from actual rainstorm events at the three studied sites are consistently lower than those obtained from the conventional rainfall depth-duration-frequency (DDF) method, especially for short-duration storms (such as 1-h). It results from occurrence probabilities of each rainstorm event and a different angle for rainfall frequency analysis, and could offer an alternative way of describing extreme rainfall properties and potentially help improve the hydrologic design of stormwater management facilities in urban areas.

Frequency and consequences of violence in community pharmacies in Ireland.

LENUS (Irish Health Repository)

Fitzgerald, D

2012-09-11

BackgroundViolence in community pharmacies in Ireland is thought to be common but underreported. The frequency and consequences of violence has not been studied previously.AimsTo establish the frequency and nature of violence in community pharmacies over 12 months, and to investigate the impact of violence on employees and possible consequence for the industry.MethodsA two-part survey was distributed to community pharmacies in Ireland in 2011 (n = 200). The first part related to pharmacy demographics, the frequency of various violent events (verbal abuse, threats etc.), the respondents\\' worry regarding violence and its impact on their co-workers. The second part concerned individual employees\\' subjective response to a violent event, using the Impact of Event Scale-Revised (IES-R).ResultsFifty-seven per cent of the pharmacies responded, with 77% reporting some violent event (verbal or physical), over the past year. Eighteen per cent reported physical assault, and 63% were worried about workplace violence. There was no association between late night opening hours or pharmacy size and violence frequency. Positive statistically significant correlations were present between all types of violence and absenteeism and employee fear levels. An IES-R score could be calculated for 75 respondents; the median IES-R score was 8 with 19% reporting clinically significant scores.ConclusionsViolence is common in Irish community pharmacies and impacts on employees and the industry.

Frequency-time behavior of artificially stimulated vlf emissions

International Nuclear Information System (INIS)

Stiles, G.S.; Helliwell, R.A.

1975-01-01

Artificially stimulated VLF emissions (ASE's) are emissions triggered in the magnetosphere by the whistler mode signals from VLF transmitters. These emissions may be separated into two classes, rising and falling, depending on whether the final value of df/dt is positive or negative. Several hundred ASE's triggered by three transmitters have been analyzed using the fast Fourier transform with a filter spacing of 25 Hz and an effective filter width of about 45 Hz. The study was limited to the initial frequency-time behavior of ASE's. Averages taken over many events reveal that both rising and falling tones show the same initial behavior. The emissions begin at the frequency of the triggering signal. Both tones initially rise in frequency, falling tones reversing slope at a point 25--300 Hz above the triggering signal. The slope of rising tones, particularly those triggered by NAA, often abruptly levels off in this same frequency range; as a result, a short (approximately 40 ms) plateau is formed that precedes the final rising phase. The initial frequency offset commonly observed in individual events appears to result from the frequent coincidence with this plateau of a peak in amplitude. Emissions stimulated by all three transmitters show essentially the same features; this finding indicates that their frequency behavior does not depend strongly on transmitter power. The process appears to be asymmetric in frequency; no evidence of initial growth below the triggering frequency has been found. (U.S.)

Developing future precipitation events from historic events: An Amsterdam case study.

Science.gov (United States)

Manola, Iris; van den Hurk, Bart; de Moel, Hans; Aerts, Jeroen

2016-04-01

Due to climate change, the frequency and intensity of extreme precipitation events is expected to increase. It is therefore of high importance to develop climate change scenarios tailored towards the local and regional needs of policy makers in order to develop efficient adaptation strategies to reduce the risks from extreme weather events. Current approaches to tailor climate scenarios are often not well adopted in hazard management, since average changes in climate are not a main concern to policy makers, and tailoring climate scenarios to simulate future extremes can be complex. Therefore, a new concept has been introduced recently that uses known historic extreme events as a basis, and modifies the observed data for these events so that the outcome shows how the same event would occur in a warmer climate. This concept is introduced as 'Future Weather', and appeals to the experience of stakeholders and users. This research presents a novel method of projecting a future extreme precipitation event, based on a historic event. The selected precipitation event took place over the broader area of Amsterdam, the Netherlands in the summer of 2014, which resulted in blocked highways, disruption of air transportation, flooded buildings and public facilities. An analysis of rain monitoring stations showed that an event of such intensity has a 5 to 15 years return period. The method of projecting a future event follows a non-linear delta transformation that is applied directly on the observed event assuming a warmer climate to produce an "up-scaled" future precipitation event. The delta transformation is based on the observed behaviour of the precipitation intensity as a function of the dew point temperature during summers. The outcome is then compared to a benchmark method using the HARMONIE numerical weather prediction model, where the boundary conditions of the event from the Ensemble Prediction System of ECMWF (ENS) are perturbed to indicate a warmer climate. The two

Post-event spontaneous intrusive recollections and strength of memory for emotional events in men and women

Science.gov (United States)

Ferree, Nikole K.; Cahill, Larry

2009-01-01

Spontaneous intrusive recollections (SIRs) follow traumatic events in clinical and non-clinical populations. To determine whether any relationship exists between SIRs and enhanced memory for emotional events, participants viewed emotional or neutral films, had their memory for the films tested two days later, and estimated the number of SIRs they experienced for each film. SIR frequency related positively to memory strength, an effect more pronounced in the emotional condition. These findings represent the first demonstration of a relationship between SIRs occurring after an emotional experience and subsequent memory strength for that experience. The results are consistent with the possibility that emotional arousal leads both to elevated SIR frequency and better memory, and that the covert rehearsal associated with SIRs enhances memory for emotional relative to neutral stimuli. Additional evidence of menstrual cycle influences on SIR incidence in female participants appears to merit consideration in future work. PMID:19131257

International practices in the provision of teratology information: a survey of international teratogen information programmes and comparisons with the North American model.

Science.gov (United States)

Hancock, Rebecca L; Ungar, Wendy J; Einarson, Adrienne; Koren, Gideon

2010-10-01

Teratology Information Services (TIS) provide health care professionals and the public with information regarding the safety and/or risk of exposures during pregnancy and lactation, mainly via telephone consultations. An international comparison of clinical practices at TIS has never been conducted. The survey objective was to compare international TIS to North American TIS, with an aim to identify strengths and challenges that can lead to service improvement. Twenty-two international TIS were approached for participation during an international conference. TIS were surveyed on information in six categories: services, staffing, operations, data collection, knowledge transfer activities and additional information. Data were summarized using descriptive statistics. Statistical tests were conducted using SPSS®. Sixteen TIS from 12 countries participated. Survey results were compared with previously reported results from a similar survey of North American TIS (16 US, two Canadian). TIS exist in a variety of departments and settings, but most commonly are in university hospitals. Pregnant women were the most commonly counselled group worldwide. International TIS spent significantly more time fielding inquiries regarding medications, while North American TIS had a wider variety of inquiry categories. All TIS could improve budget tracking. Overall, service practices and goals were similar, although international TIS conducted more follow-up with service users than North American TIS. This report offers TIS the first ever opportunity to compare practices. Increased dialogue between TIS encourages sharing of best practices and improves the ability of these important public health programmes to support women and health care providers. © 2010 Blackwell Publishing Ltd.

External event Probabilistic Risk Assessment for the High Flux Isotope Reactor (HFIR)

International Nuclear Information System (INIS)

Flanagan, G.F.; Johnson, D.H.; Buttemer, D.; Perla, H.F.; Chien, S.H.

1989-01-01

The High Flux Isotope Reactor (HFIR) is a high performance isotope production and research reactor which has been in operation at Oak Ridge National Laboratory (ORNL) since 1965. In late 1986 the reactor was shut down as a result of discovery of unexpected neutron embrittlement of the reactor vessel. In January of 1988 a level 1 Probabilistic Risk Assessment (PRA) (excluding external events) was published as part of the response to the many reviews that followed the shutdown and for use by ORNL to prioritize action items intended to upgrade the safety of the reactor. A conservative estimate of the core damage frequency initiated by internal events for HFIR was 3.11 x 10 -4 . In June 1989 a draft external events initiated PRA was published. The dominant contributions from external events came from seismic, wind, and fires. The overall external event contribution to core damage frequency is about 50% of the internal event initiated contribution and is dominated by seismic events

Spatially explicit modelling of extreme weather and climate events ...

African Journals Online (AJOL)

The reality of climate change continues to influence the intensity and frequency of extreme weather events such as heat waves, droughts, floods, and landslides. The impacts of the cumulative interplay of these extreme weather and climate events variation continue to perturb governments causing a scramble into formation ...

Statistical Prediction of Solar Particle Event Frequency Based on the Measurements of Recent Solar Cycles for Acute Radiation Risk Analysis

Science.gov (United States)

Myung-Hee, Y. Kim; Shaowen, Hu; Cucinotta, Francis A.

2009-01-01

Large solar particle events (SPEs) present significant acute radiation risks to the crew members during extra-vehicular activities (EVAs) or in lightly shielded space vehicles for space missions beyond the protection of the Earth's magnetic field. Acute radiation sickness (ARS) can impair performance and result in failure of the mission. Improved forecasting capability and/or early-warning systems and proper shielding solutions are required to stay within NASA's short-term dose limits. Exactly how to make use of observations of SPEs for predicting occurrence and size is a great challenge, because SPE occurrences themselves are random in nature even though the expected frequency of SPEs is strongly influenced by the time position within the solar activity cycle. Therefore, we developed a probabilistic model approach, where a cumulative expected occurrence curve of SPEs for a typical solar cycle was formed from a non-homogeneous Poisson process model fitted to a database of proton fluence measurements of SPEs that occurred during the past 5 solar cycles (19 - 23) and those of large SPEs identified from impulsive nitrate enhancements in polar ice. From the fitted model, the expected frequency of SPEs was estimated at any given proton fluence threshold (Phi(sub E)) with energy (E) >30 MeV during a defined space mission period. Corresponding Phi(sub E) (E=30, 60, and 100 MeV) fluence distributions were simulated with a random draw from a gamma distribution, and applied for SPE ARS risk analysis for a specific mission period. It has been found that the accurate prediction of deep-seated organ doses was more precisely predicted at high energies, Phi(sub 100), than at lower energies such as Phi(sub 30) or Phi(sub 60), because of the high penetration depth of high energy protons. Estimates of ARS are then described for 90th and 95th percentile events for several mission lengths and for several likely organ dose-rates. The ability to accurately measure high energy protons

TEMAC, Top Event Sensitivity Analysis

International Nuclear Information System (INIS)

Iman, R.L.; Shortencarier, M.J.

1988-01-01

1 - Description of program or function: TEMAC is designed to permit the user to easily estimate risk and to perform sensitivity and uncertainty analyses with a Boolean expression such as produced by the SETS computer program. SETS produces a mathematical representation of a fault tree used to model system unavailability. In the terminology of the TEMAC program, such a mathematical representation is referred to as a top event. The analysis of risk involves the estimation of the magnitude of risk, the sensitivity of risk estimates to base event probabilities and initiating event frequencies, and the quantification of the uncertainty in the risk estimates. 2 - Method of solution: Sensitivity and uncertainty analyses associated with top events involve mathematical operations on the corresponding Boolean expression for the top event, as well as repeated evaluations of the top event in a Monte Carlo fashion. TEMAC employs a general matrix approach which provides a convenient general form for Boolean expressions, is computationally efficient, and allows large problems to be analyzed. 3 - Restrictions on the complexity of the problem - Maxima of: 4000 cut sets, 500 events, 500 values in a Monte Carlo sample, 16 characters in an event name. These restrictions are implemented through the FORTRAN 77 PARAMATER statement

Repeating Deep Very Low Frequency Earthquakes: An Evidence of Transition Zone between Brittle and Ductile Zone along Plate Boundary

Science.gov (United States)

Ishihara, Y.; Yamamoto, Y.; Arai, R.

2017-12-01

Recently slow or low frequency seismic and geodetic events are focused under recognition of important role in tectonic process. The most western region of Ryukyu trench, Yaeyama Islands, is very active area of these type events. It has semiannual-like slow slip (Heki et.al., 2008; Nishimura et.al.,2014) and very frequent shallow very low frequency earthquakes near trench zone (Ando et.al.,2012; Nakamura et.al.,2014). Arai et.al.(2016) identified clear reverse phase discontinuity along plate boundary by air-gun survey, suggesting existence of low velocity layer including fluid. The subducting fluid layer is considered to control slip characteristics. On the other hand, deep low frequency earthquake and tremor observed at south-western Honshu and Shikoku of Japan are not identified well due to lack of high-quality seismic network. A broadband seismic station(ISG/PS) of Pacific21 network is operating in last 20 years that locates on occurrence potential area of low frequency earthquake. We tried to review continuous broadband record, searching low frequency earthquakes. In pilot survey, we found three very low frequency seismic events which are dominant in less than 0.1Hz component and are not listed in earthquake catalogue. Source locates about 50km depth and at transition area between slow slip event and active area of general earthquake along plate boundary. To detect small and/or hidden very low frequency earthquake, we applied matched filter analysis to continuous three components waveform data using pre-reviewed seismogram as template signal. 12 events with high correlation are picked up in last 10 years. Most events have very similar waveform, which means characteristics of repeating deep very low frequency earthquake. The event history of very low frequency earthquake is not related with one of slow slip event in this region. In Yaeyama region, low frequency earthquake, general earthquake and slow slip event occur dividing in space and have apparent

Lessons derived from two high-frequency sea level events in the Atlantic: implications for coastal risk analysis and tsunami detection

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Begoña Pérez-Gómez

2016-11-01

Full Text Available The upgrade and enhancement of sea level networks worldwide for integration in sea level hazard warning systems have significantly increased the possibilities for measuring and analyzing high frequency sea level oscillations, with typical periods ranging from a few minutes to a few hours. Many tide gauges now afford 1 min or more frequent sampling and have shown such events to be a common occurrence. Their origins and spatial distribution are diverse and must be well understood in order to correctly design and interpret, for example, the automatic detection algorithms used by tsunami warning centers. Two events recorded recently in European Atlantic waters are analyzed here: possible wave-induced seiches that occurred along the North coast of Spain during the storms of January and February of 2014, and oscillations detected after an earthquake in the mid-Atlantic the 13th of February of 2015. The former caused significant flooding in towns and villages and a huge increase in wave-induced coastal damage that was reported in the media for weeks. The second was a smaller signal present in several tide gauges along the Atlantic coast that, that coincided with the occurrence of this earthquake, leading to a debate on the potential detection of a very small tsunami and how it might yield significant information for tsunami wave modelers and for the development of tsunami detection software. These kinds of events inform us about the limitations of automatic algorithms for tsunami warning and help to improve the information provided to tsunami warning centers, whilst also emphasizing the importance of other forcings in generating extreme sea levels and their associated potential for causing damage to infrastructure.

Cobalamin (Vitamin B12) Role on the Biochemical, Histological and Teratological Changes Induced in Diabetic Irradiated Pregnant Rats

International Nuclear Information System (INIS)

Ramadan, F.L.

2013-01-01

Vitamin B 12 called Cobalamin, is a water soluble vitamin with a key role in the normal function of the brain, nervous system, cell division and for the formation of blood. It is normally involved in the metabolism of every cell of the human body especially affecting DNA synthesis and regulation, fatty acid synthesis and energy production.The aim of the present study was to evaluate the role of vitamin B 12 intake on radiation induced damage in diabetic mothers.Diabetes was induced in female rats by intra-peritoneal injection of alloxan 150 mg/kg b.wt. dissolved in saline. Pregnant diabetic mothers were received vitamin B 12 0.1 mg/100 g b.wt. from the 1st up to 19th day of gestation. Meanwhile, pregnant diabetic rats were exposed to 0.6 Gy on the 7th and the 14th days of gestation. The increased incidence of malformations in diabetic pregnancy with an excess of free oxygen radicals in the embryos was recorded .Vitamin B12 supplementation to diabetic mother ameliorated radiation-induced damage which was obvious by diminishing the increase in glucose level, improving serum insulin level, glycogen content in the liver and ameliorating the decrease in glutathione (GSH) content in the liver of pregnant rats and their fetuses.In addition, vitamin B 12 treatment improved the decrease in red blood cells (RBCs), white blood cells (WBCs) and hemoglobin (Hb) of fetuses and DNA content in the liver tissues. Moreover, vitamin B 12 treatment lead to the regeneration of normal architecture of maternal and fetuses hepatic cells and blood vessels. It could be concluded that vitamin B 12 supplementation to diabetic mothers ameliorated the radiation effect which induced biochemical, histochemical, histological and teratological disorders.Furthermore, the results obtained showed that vitamin B 12 administration caused a protection to diabetic pregnant rats against embryo malformations induced by gamma rays

Research on Visual Analysis Methods of Terrorism Events

Science.gov (United States)

Guo, Wenyue; Liu, Haiyan; Yu, Anzhu; Li, Jing

2016-06-01

Under the situation that terrorism events occur more and more frequency throughout the world, improving the response capability of social security incidents has become an important aspect to test governments govern ability. Visual analysis has become an important method of event analysing for its advantage of intuitive and effective. To analyse events' spatio-temporal distribution characteristics, correlations among event items and the development trend, terrorism event's spatio-temporal characteristics are discussed. Suitable event data table structure based on "5W" theory is designed. Then, six types of visual analysis are purposed, and how to use thematic map and statistical charts to realize visual analysis on terrorism events is studied. Finally, experiments have been carried out by using the data provided by Global Terrorism Database, and the results of experiments proves the availability of the methods.

An estimation of core damage frequency of a pressurized water reactor during mid-loop operation

International Nuclear Information System (INIS)

Chao, C.C.; Chen, C.T.; Lee, M.

2004-01-01

The core damage frequency during mid-loop operation of a Westinghouse designed 3-loop Pressurizer Water Reactor (PWR) due to loss of Residual Heat Removal (RHR) events was assessed. The assessment considers two types of outages (refueling and drained maintenance), and uses failure data collected specifically for shutdown condition. Event trees were developed for five categories of loss of RHR events. Human actions to mitigate the loss of RHR events was identified and human error probabilities were quantified using HCR and THERP model. The result showed that the core damage frequency due to loss of RHR events during mid-loop operation is 3.1x10 -5 per year. The results also showed that the core damage frequency can be reduced significantly by removing a pressurizer safety valve before entering mid-loop operation. The establishment of reflux cooling, i.e. decay heat removal through steam generator secondary side also plays important role in mitigating the loss of RHR events. (author)

Optimising 4-D surface change detection: an approach for capturing rockfall magnitude–frequency

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J. G. Williams

2018-02-01

Full Text Available We present a monitoring technique tailored to analysing change from near-continuously collected, high-resolution 3-D data. Our aim is to fully characterise geomorphological change typified by an event magnitude–frequency relationship that adheres to an inverse power law or similar. While recent advances in monitoring have enabled changes in volume across more than 7 orders of magnitude to be captured, event frequency is commonly assumed to be interchangeable with the time-averaged event numbers between successive surveys. Where events coincide, or coalesce, or where the mechanisms driving change are not spatially independent, apparent event frequency must be partially determined by survey interval.The data reported have been obtained from a permanently installed terrestrial laser scanner, which permits an increased frequency of surveys. Surveying from a single position raises challenges, given the single viewpoint onto a complex surface and the need for computational efficiency associated with handling a large time series of 3-D data. A workflow is presented that optimises the detection of change by filtering and aligning scans to improve repeatability. An adaptation of the M3C2 algorithm is used to detect 3-D change to overcome data inconsistencies between scans. Individual rockfall geometries are then extracted and the associated volumetric errors modelled. The utility of this approach is demonstrated using a dataset of  ∼  9  ×  103 surveys acquired at  ∼  1 h intervals over 10 months. The magnitude–frequency distribution of rockfall volumes generated is shown to be sensitive to monitoring frequency. Using a 1 h interval between surveys, rather than 30 days, the volume contribution from small (< 0.1 m3 rockfalls increases from 67 to 98 % of the total, and the number of individual rockfalls observed increases by over 3 orders of magnitude. High-frequency monitoring therefore holds considerable

Optimising 4-D surface change detection: an approach for capturing rockfall magnitude-frequency

Science.gov (United States)

Williams, Jack G.; Rosser, Nick J.; Hardy, Richard J.; Brain, Matthew J.; Afana, Ashraf A.

2018-02-01

We present a monitoring technique tailored to analysing change from near-continuously collected, high-resolution 3-D data. Our aim is to fully characterise geomorphological change typified by an event magnitude-frequency relationship that adheres to an inverse power law or similar. While recent advances in monitoring have enabled changes in volume across more than 7 orders of magnitude to be captured, event frequency is commonly assumed to be interchangeable with the time-averaged event numbers between successive surveys. Where events coincide, or coalesce, or where the mechanisms driving change are not spatially independent, apparent event frequency must be partially determined by survey interval.The data reported have been obtained from a permanently installed terrestrial laser scanner, which permits an increased frequency of surveys. Surveying from a single position raises challenges, given the single viewpoint onto a complex surface and the need for computational efficiency associated with handling a large time series of 3-D data. A workflow is presented that optimises the detection of change by filtering and aligning scans to improve repeatability. An adaptation of the M3C2 algorithm is used to detect 3-D change to overcome data inconsistencies between scans. Individual rockfall geometries are then extracted and the associated volumetric errors modelled. The utility of this approach is demonstrated using a dataset of ˜ 9 × 103 surveys acquired at ˜ 1 h intervals over 10 months. The magnitude-frequency distribution of rockfall volumes generated is shown to be sensitive to monitoring frequency. Using a 1 h interval between surveys, rather than 30 days, the volume contribution from small (< 0.1 m3) rockfalls increases from 67 to 98 % of the total, and the number of individual rockfalls observed increases by over 3 orders of magnitude. High-frequency monitoring therefore holds considerable implications for magnitude-frequency derivatives, such as hazard return

Does acute radio-frequency electromagnetic field exposure affect visual event-related potentials in healthy adults?

Science.gov (United States)

Dalecki, Anna; Loughran, Sarah P; Verrender, Adam; Burdon, Catriona A; Taylor, Nigel A S; Croft, Rodney J

2018-05-01

To use improved methods to address the question of whether acute exposure to radio-frequency (RF) electromagnetic fields (RF-EMF) affects early (80-200 ms) sensory and later (180-600 ms) cognitive processes as indexed by event-related potentials (ERPs). Thirty-six healthy subjects completed a visual discrimination task during concurrent exposure to a Global System for Mobile Communications (GSM)-like, 920 MHz signal with peak-spatial specific absorption rate for 10 g of tissue of 0 W/kg of body mass (Sham), 1 W/kg (Low RF) and 2 W/kg (High RF). A fully randomised, counterbalanced, double-blind design was used. P1 amplitude was reduced (p = .02) and anterior N1 latency was increased (p = .04) during Exposure compared to Sham. There were no effects on any other ERP latencies or amplitudes. RF-EMF exposure may affect early perceptual (P1) and preparatory motor (anterior N1) processes. However, only two ERP indices, out of 56 comparisons, were observed to differ between RF-EMF exposure and Sham, suggesting that these observations may be due to chance. These observations are consistent with previous findings that RF-EMF exposure has no reliable impact on cognition (e.g., accuracy and response speed). Copyright © 2018 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

A mathematical model for the occurrence of historical events

Science.gov (United States)

Ohnishi, Teruaki

2017-12-01

A mathematical model was proposed for the frequency distribution of historical inter-event time τ. A basic ingredient was constructed by assuming the significance of a newly occurring historical event depending on the magnitude of a preceding event, the decrease of its significance by oblivion during the successive events, and an independent Poisson process for the occurrence of the event. The frequency distribution of τ was derived by integrating the basic ingredient with respect to all social fields and to all stake holders. The function of such a distribution was revealed as the forms of an exponential type, a power law type or an exponential-with-a-tail type depending on the values of constants appearing in the ingredient. The validity of this model was studied by applying it to the two cases of Modern China and Northern Ireland Troubles, where the τ-distribution varies depending on the different countries interacting with China and on the different stage of history of the Troubles, respectively. This indicates that history is consisted from many components with such different types of τ-distribution, which are the similar situation to the cases of other general human activities.

An Application of Spectral Kurtosis to Separate Hybrid Power Quality Events

Directory of Open Access Journals (Sweden)

Juan José González de la Rosa

2015-09-01

Full Text Available For the development of the future smart grid, the detection of power quality events is a key issue for the power system monitoring. Voltage sags, swells, harmonics (variations and interruptions, which produce large losses for commercial and industrial consumers, are the main events to be considered due to the sensitivity of equipment to these electrical anomalies. The steady-state events are even more frequently accompanied by transients, the discrimination and localization being far more exigent and requiring advanced signal separating tools to be incorporated in the measurement equipment. This paper shows the event detection performance of the spectral kurtosis as a signal separating tool in the frequency domain. The disturbances under test are hybrid signals resulting from the coupling between amplitude defects and non-desired higher frequencies. Being a fourth-order spectrum, the kurtosis is confirmed as a noise-resistant tool that enhances impulsiveness, therefore characterizing the electrical anomalies. In the beginning of the analysis, the voltage sag is established as a reference; then, the disturbances (oscillatory transients and harmonics are coupled at the starting and ending instants of the sag, resulting in complex hybrid events. The results show that the spectral kurtosis enhances the detection Energies 2015, 8 9778 of both types of events (steady state and transients, which are outlined in a bump shape in the fourth-order frequency pattern and centered in the main carrier frequency. Indeed, while the oscillatory transients are associated with softer and lower-amplitude peaks, the harmonics correspond to crisper and higher ones. As these mixed electrical faults are very common in the actual power grid, the article postulates the higher-order spectra to be implemented in prospective online measurement instruments.

Methods for tornado frequency calculation of nuclear power plant

International Nuclear Information System (INIS)

Liu Haibin; Li Lin

2012-01-01

In order to take probabilistic safety assessment of nuclear power plant tornado attack event, a method to calculate tornado frequency of nuclear power plant is introduced based on HAD 101/10 and NUREG/CR-4839 references. This method can consider history tornado frequency of the plant area, construction dimension, intensity various along with tornado path and area distribution and so on and calculate the frequency of different scale tornado. (authors)

Type III Radio Burst Duration and SEP Events

Science.gov (United States)

Gopalswamy, N.; Makela, P.; Xie, H.

2010-01-01

Long-duration (>15 min), low-frequency (25 MeV. The 1-MHz duration of the type III burst (28 rein) is near the median value of type III durations found for gradual SEP events and ground level enhancement (GLE) events. Yet, there was no sign of SEP events. On the other hand, two other type III bursts from the same active region had similar duration but accompanied by WAVES type 11 bursts; these bursts were also accompanied by SEP events detected by SOHO/ERNE. This study suggests that the type III burst duration may not be a good indicator of an SEP event, consistent with the statistical study of Cliver and Ling (2009, ApJ ).

Initiating events in the safety probabilistic analysis of nuclear power plants

International Nuclear Information System (INIS)

Stasiulevicius, R.

1989-01-01

The importance of the initiating event in the probabilistic safety analysis of nuclear power plants are discussed and the basic procedures necessary for preparing reports, quantification and grouping of the events are described. The examples of initiating events with its occurence medium frequency, included those calculated for OCONEE reactor and Angra-1 reactor are presented. (E.G.)

Low and high frequency Madden-Julian oscillations in austral summer: interannual variations

Energy Technology Data Exchange (ETDEWEB)

Izumo, Takeshi [Research Institute For Global Change (JAMSTEC), Yokohama (Japan); LOCEAN, IRD-CNRS-UPMC, Paris (France); Masson, Sebastien; Vialard, Jerome; Madec, Gurvan [LOCEAN, IRD-CNRS-UPMC, Paris (France); Boyer Montegut, Clement de [IFREMER, Brest (France); Behera, Swadhin K. [Research Institute For Global Change (JAMSTEC), Yokohama (Japan); Takahashi, Keiko [Earth Simulator Center (JAMSTEC), Yokohama (Japan); Yamagata, Toshio [Research Institute For Global Change (JAMSTEC), Yokohama (Japan); University of Tokyo, Tokyo (Japan)

2010-09-15

The Madden-Julian oscillation (MJO) is the main component of intraseasonal variability of the tropical convection, with clear climatic impacts at an almost-global scale. Based on satellite observations, it is shown that there are two types of austral-summer MJO events (broadly defined as 30-120 days convective variability with eastward propagation of about 5 m/s). Equatorial MJO events have a period of 30-50 days and tend to be symmetric about the equator, whereas MJO events centered near 8 S tend to have a longer period of 55-100 days. The lower-frequency variability is associated with a strong upper-ocean response, having a clear signature in both sea surface temperature and its diurnal cycle. These two MJO types have different interannual variations, and are modulated by the Indian Ocean Dipole (IOD). Following a negative IOD event, the lower-frequency southern MJO variability increases, while the higher-frequency equatorial MJO strongly diminishes. We propose two possible explanations for this change in properties of the MJO. One possibility is that changes in the background atmospheric circulation after an IOD favour the development of the low-frequency MJO. The other possibility is that the shallower thermocline ridge and mixed layer depth, by enhancing SST intraseasonal variability and thus ocean-atmosphere coupling in the southwest Indian Ocean (the breeding ground of southern MJO onset), favour the lower-frequency southern MJO variability. (orig.)

Frequency of adverse events in plateletpheresis donors in regional transfusion centre in North India.

Science.gov (United States)

Patidar, Gopal Kumar; Sharma, Ratti Ram; Marwaha, Neelam

2013-10-01

Although automated cell separators have undergone a lot of technical refinements, attention has been focused on the quality of platelet concentrates than on donor safety. We planned this prospective study to look into donor safety aspect by studying adverse events in normal healthy plateletpheresis donors. The study included 500 healthy, first-time (n=301) and repeat (n=199) plateletpheresis donors after informed consent. The plateletpheresis procedures were performed on Trima Accel (5.1 version, GAMBRO BCT) and Amicus (3.2 version FENWAL) cell separators. The adverse events during procedure were recorded and classified according to their nature. The pre and post procedure hematological and biochemical profiles of these donors were also assessed with the help of automated cell counter and analyser respectively. A total of 18% (n=90) adverse events were recorded in 500 plateletpheresis donors, of which 9% of were hypocalcaemia in nature followed by hematoma (7.4%), vasovagal reaction (0.8%) and kit related adverse events in (0.8%). There was significant post procedure drop in Hb, Hct, platelet count of the donors (padverse events in Trima Accel (5.1 version, GAMBRO BCT) and Amicus (3.2 version FENWAL) cell separators. Donor reactions can adversely affect the voluntary donor recruitment strategies to increase the public awareness regarding constant need for blood and blood products. Commonly observed adverse events in plateletpheresis donors were hypocalcemia, hematoma formation and vasovagal reactions which can be prevented by pre-donation education of the donors and change of machine configuration. Nevertheless, more prospective studies on this aspect are required in order to establish guidelines for donor safety in apheresis and also to help in assessing donor suitability, especially given the present trend of double product apheresis collections. Copyright © 2013 Elsevier Ltd. All rights reserved.

Application of precursor methodology in initiating frequency estimates

International Nuclear Information System (INIS)

Kohut, P.; Fitzpatrick, R.G.

1991-01-01

The precursor methodology developed in recent years provides a consistent technique to identify important accident sequence precursors. It relies on operational events (extracting information from actual experience) and infers core damage scenarios based on expected safety system responses. The ranking or categorization of each precursor is determined by considering the full spectrum of potential core damage sequences. The methodology estimates the frequency of severe core damage based on the approach suggested by Apostolakis and Mosleh, which may lead to a potential overestimation of the severe-accident sequence frequency due to the inherent dependencies between the safety systems and the initiating events. The methodology is an encompassing attempt to incorporate most of the operating information available from nuclear power plants and is an attractive tool from the point of view of risk management. In this paper, a further extension of this methodology is discussed with regard to the treatment of initiating frequency of the accident sequences

Low-frequency (0.7-7.4 mHz geomagnetic field fluctuations at high latitude: frequency dependence of the polarization pattern

Directory of Open Access Journals (Sweden)

L. Cafarella

2001-06-01

Full Text Available A statistical analysis of the polarization pattern of low-frequency geomagnetic field fluctuations (0.7-7.4 mHz covering the entire 24-h interval was performed at the Antarctic station Terra Nova Bay (80.0°S geomagnetic latitude throughout 1997 and 1998. The results show that the polarization pattern exhibits a frequency dependence, as can be expected from the frequency dependence of the latitude where the coupling between the magnetospheric compressional mode and the field line resonance takes place. The polarization analysis of single pulsation events shows that wave packets with different polarization sense, depending on frequency, can be simultaneously observed.

Thermal ambience of expanding event horizon in Minkowski space-time

International Nuclear Information System (INIS)

Gerlach, U.H.

1983-01-01

It is shown that in flat space-time the thermal ambience of accelerated observers is not associated exclusively with flat event horizons, but arises also with (observer-dependent) event horizons that are light cones. The quanta of this ambience are characterized by a generalized frequency which identifies the representation of the Lorentz group. Global and local model detectors capable of responding to quanta of any given generalized frequency are exhibited. The discussion of the thermal ambience is implemented in terms of a partial-wave analysis using a set of harmonics on the hyperboloid x 2 +y 2 +z 2 -t 2 = 1

Single event burnout sensitivity of embedded field effect transistors

International Nuclear Information System (INIS)

Koga, R.; Crain, S.H.; Crawford, K.B.; Yu, P.; Gordon, M.J.

1999-01-01

Observations of single event burnout (SEB) in embedded field effect transistors are reported. Both SEB and other single event effects are presented for several pulse width modulation and high frequency devices. The microscope has been employed to locate and to investigate the damaged areas. A model of the damage mechanism based on the results so obtained is described

Single event burnout sensitivity of embedded field effect transistors

Energy Technology Data Exchange (ETDEWEB)

Koga, R.; Crain, S.H.; Crawford, K.B.; Yu, P.; Gordon, M.J.

1999-12-01

Observations of single event burnout (SEB) in embedded field effect transistors are reported. Both SEB and other single event effects are presented for several pulse width modulation and high frequency devices. The microscope has been employed to locate and to investigate the damaged areas. A model of the damage mechanism based on the results so obtained is described.

Radio frequency picosecond phototube

International Nuclear Information System (INIS)

Margaryan, A.; Carlini, R.; Ent, R.; Grigoryan, N.; Gyunashyan, K.; Hashimoto, O.; Hovater, K.; Ispiryan, M.; Knyazyan, S.; Kross, B.; Majewski, S.; Marikyan, G.; Mkrtchyan, M.; Parlakyan, L.; Popov, V.; Tang, L.; Vardanyan, H.; Yan, C.; Zhamkochyan, S.; Zorn, C.

2006-01-01

We propose a photon detector for recording low-level and ultra-fast optical signals, based on radio frequency (RF) analysis of low-energy photoelectrons (PEs). By using currently developed 500 MHz RF deflector, it is possible to scan circularly and detect single PEs, amplified in multi-channel plates (MCPs). The operation of the tube is investigated by means of thermionic electron source. It is demonstrated that the signals generated in the MCP can be processed event by event; by using available nanosecond electronics and that time resolution better than 20 ps can be achieved. Timing characteristics of the Cherenkov detector with RF phototube in a 'head-on' geometry is investigated by means of Monte Carlo simulation

Radio frequency picosecond phototube

Energy Technology Data Exchange (ETDEWEB)

Margaryan, A. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia)]. E-mail: mat@mail.yerphi.am; Carlini, R. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Ent, R. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Grigoryan, N. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Gyunashyan, K. [Yerevan State University of Architecture and Construction, Yerevan (Armenia); Hashimoto, O. [Tohoku University, Sendai 98-77 (Japan); Hovater, K. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Ispiryan, M. [University of Houston, 4800 Calhoun Rd, Houston TX 77204 (United States); Knyazyan, S. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Kross, B. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Majewski, S. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Marikyan, G. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Mkrtchyan, M. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Parlakyan, L. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Popov, V. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Tang, L. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Vardanyan, H. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Yan, C. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States); Zhamkochyan, S. [Yerevan Physics Institute, 2 Alikhanian Brothers Street, Yerevan 375036 (Armenia); Zorn, C. [Thomas Jefferson National Accelerator Facility, Newport News VA 23606 (United States)

2006-10-15

We propose a photon detector for recording low-level and ultra-fast optical signals, based on radio frequency (RF) analysis of low-energy photoelectrons (PEs). By using currently developed 500 MHz RF deflector, it is possible to scan circularly and detect single PEs, amplified in multi-channel plates (MCPs). The operation of the tube is investigated by means of thermionic electron source. It is demonstrated that the signals generated in the MCP can be processed event by event; by using available nanosecond electronics and that time resolution better than 20 ps can be achieved. Timing characteristics of the Cherenkov detector with RF phototube in a 'head-on' geometry is investigated by means of Monte Carlo simulation.

Providing frequency regulation reserve services using demand response scheduling

International Nuclear Information System (INIS)

Motalleb, Mahdi; Thornton, Matsu; Reihani, Ehsan; Ghorbani, Reza

2016-01-01

Highlights: • Proposing a market model for contingency reserve services using demand response. • Considering transient limitations of grid frequency for inverter-based generations. • Price-sensitive scheduling of residential batteries and water heaters using dynamic programming. • Calculating the profits of both generation companies and demand response aggregators. - Abstract: During power grid contingencies, frequency regulation is a primary concern. Historically, frequency regulation during contingency events has been the sole responsibility of the power utility. We present a practical method of using distributed demand response scheduling to provide frequency regulation during contingency events. This paper discusses the implementation of a control system model for the use of distributed energy storage systems such as battery banks and electric water heaters as a source of ancillary services. We present an algorithm which handles the optimization of demand response scheduling for normal operation and during contingency events. We use dynamic programming as an optimization tool. A price signal is developed using optimal power flow calculations to determine the locational marginal price of electricity, while sensor data for water usage is also collected. Using these inputs to dynamic programming, the optimal control signals are given as output. We assume a market model in which distributed demand response resources are sold as a commodity on the open market and profits from demand response aggregators as brokers of distributed demand response resources can be calculated. In considering control decisions for regulation of transient changes in frequency, we focus on IEEE standard 1547 in order to prevent the safety shut-off of inverter-based generation and further exacerbation of frequency droop. This method is applied to IEEE case 118 as a demonstration of the method in practice.

Multiple linear regression to estimate time-frequency electrophysiological responses in single trials.

Science.gov (United States)

Hu, L; Zhang, Z G; Mouraux, A; Iannetti, G D

2015-05-01

Transient sensory, motor or cognitive event elicit not only phase-locked event-related potentials (ERPs) in the ongoing electroencephalogram (EEG), but also induce non-phase-locked modulations of ongoing EEG oscillations. These modulations can be detected when single-trial waveforms are analysed in the time-frequency domain, and consist in stimulus-induced decreases (event-related desynchronization, ERD) or increases (event-related synchronization, ERS) of synchrony in the activity of the underlying neuronal populations. ERD and ERS reflect changes in the parameters that control oscillations in neuronal networks and, depending on the frequency at which they occur, represent neuronal mechanisms involved in cortical activation, inhibition and binding. ERD and ERS are commonly estimated by averaging the time-frequency decomposition of single trials. However, their trial-to-trial variability that can reflect physiologically-important information is lost by across-trial averaging. Here, we aim to (1) develop novel approaches to explore single-trial parameters (including latency, frequency and magnitude) of ERP/ERD/ERS; (2) disclose the relationship between estimated single-trial parameters and other experimental factors (e.g., perceived intensity). We found that (1) stimulus-elicited ERP/ERD/ERS can be correctly separated using principal component analysis (PCA) decomposition with Varimax rotation on the single-trial time-frequency distributions; (2) time-frequency multiple linear regression with dispersion term (TF-MLRd) enhances the signal-to-noise ratio of ERP/ERD/ERS in single trials, and provides an unbiased estimation of their latency, frequency, and magnitude at single-trial level; (3) these estimates can be meaningfully correlated with each other and with other experimental factors at single-trial level (e.g., perceived stimulus intensity and ERP magnitude). The methods described in this article allow exploring fully non-phase-locked stimulus-induced cortical

Induction of somatic mutations by low-dose X-rays: the challenge in recognizing radiation-induced events.

Science.gov (United States)

Nagashima, Haruki; Shiraishi, Kumiko; Ohkawa, Saori; Sakamoto, Yuki; Komatsu, Kenshi; Matsuura, Shinya; Tachibana, Akira; Tauchi, Hiroshi

2017-10-19

It is difficult to distinguish radiation-induced events from spontaneous events during induction of stochastic effects, especially in the case of low-dose or low-dose-rate exposures. By using a hypersensitive system for detecting somatic mutations at the HPRT1 locus, we investigated the frequency and spectrum of mutations induced by low-dose X-rays. The mutant frequencies induced by doses of >0.15 Gy were statistically significant when compared with the spontaneous frequency, and a clear dose dependency was also observed for mutant frequencies at doses of >0.15 Gy. In contrast, mutant frequencies at doses of 0.2 Gy. Our observations suggest that there could be a critical dose for mutation induction at between 0.1 Gy and 0.2 Gy, where mutagenic events are induced by multiple DNA double-strand breaks (DSBs). These observations also suggest that low-dose radiation delivered at doses of <0.1 Gy may not result in DSB-induced mutations but may enhance spontaneous mutagenesis events. © The Author 2017. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

High frequency induction of mitotic recombination by ionizing radiation in Mlh1 null mouse cells

International Nuclear Information System (INIS)

Wang Qi; Ponomareva, Olga N.; Lasarev, Michael; Turker, Mitchell S.

2006-01-01

Mitotic recombination in somatic cells involves crossover events between homologous autosomal chromosomes. This process can convert a cell with a heterozygous deficiency to one with a homozygous deficiency if a mutant allele is present on one of the two homologous autosomes. Thus mitotic recombination often represents the second mutational step in tumor suppressor gene inactivation. In this study we examined the frequency and spectrum of ionizing radiation (IR)-induced autosomal mutations affecting Aprt expression in a mouse kidney cell line null for the Mlh1 mismatch repair (MMR) gene. The mutant frequency results demonstrated high frequency induction of mutations by IR exposure and the spectral analysis revealed that most of this response was due to the induction of mitotic recombinational events. High frequency induction of mitotic recombination was not observed in a DNA repair-proficient cell line or in a cell line with an MMR-independent mutator phenotype. These results demonstrate that IR exposure can initiate a process leading to mitotic recombinational events and that MMR function suppresses these events from occurring

Probabilistic safety analysis for fire events for the NPP Isar 2

International Nuclear Information System (INIS)

Schmaltz, H.; Hristodulidis, A.

2007-01-01

The 'Probabilistic Safety Analysis for Fire Events' (Fire-PSA KKI2) for the NPP Isar 2 was performed in addition to the PSA for full power operation and considers all possible events which can be initiated due to a fire. The aim of the plant specific Fire-PSA was to perform a quantitative assessment of fire events during full power operation, which is state of the art. Based on simplistic assumptions referring to the fire induced failures, the influence of system- and component-failures on the frequency of the core damage states was analysed. The Fire-PSA considers events, which will result due to fire-induced failures of equipment on the one hand in a SCRAM and on the other hand in events, which will not have direct operational effects but because of the fire-induced failure of safety related installations the plant will be shut down as a precautionary measure. These events are considered because they may have a not negligible influence on the frequency of core damage states in case of failures during the plant shut down because of the reduced redundancy of safety related systems. (orig.)

Frequency Calculation For Loss Coolant Accident In The Nuclear Reactor

International Nuclear Information System (INIS)

Sony, DT

1996-01-01

LOCA as initiating event is engineering judgement, because it is rare condition. So, to determine LOCA frequency used be probability and statistic method. By probability and statistic method was estimated from size, weld, age, learning curve and quality, etc. it has been calculated for LOCA frequency in the simplified piping system model, especially estimates from size and weld factors. From calculation, LOCA frequency is 9,82.10 - 6/year

Initiating Event Rates at U.S. Nuclear Power Plants. 1988 - 2013

International Nuclear Information System (INIS)

Schroeder, John A.; Bower, Gordon R.

2014-01-01

Analyzing initiating event rates is important because it indicates performance among plants and also provides inputs to several U.S. Nuclear Regulatory Commission (NRC) risk-informed regulatory activities. This report presents an analysis of initiating event frequencies at U.S. commercial nuclear power plants since each plant's low-power license date. The evaluation is based on the operating experience from fiscal year 1988 through 2013 as reported in licensee event reports. Engineers with nuclear power plant experience staff reviewed each event report since the last update to this report for the presence of valid scrams or reactor trips at power. To be included in the study, an event had to meet all of the following criteria: includes an unplanned reactor trip (not a scheduled reactor trip on the daily operations schedule), sequence of events starts when reactor is critical and at or above the point of adding heat, occurs at a U.S. commercial nuclear power plant (excluding Fort St. Vrain and LaCrosse), and is reported by a licensee event report. This report displays occurrence rates (baseline frequencies) for the categories of initiating events that contribute to the NRC's Industry Trends Program. Sixteen initiating event groupings are trended and displayed. Initiators are plotted separately for initiating events with different occurrence rates for boiling water reactors and pressurized water reactors. p-values are given for the possible presence of a trend over the most recent 10 years.

Effects of methodic deficiencies on the quantification of core meltdown frequency

International Nuclear Information System (INIS)

Hahn, L.

1984-01-01

The application of sequence of events and fault tree analyses for the assessment of the core meltdown frequency raises problems, most of which can be classified under: - Completeness and representativeness of sequences and cuases of events - Modelling of conditional outages (common-mode outages) - Modelling of human behaviour - Reliability data and models. All of the weak points of the German Risk Study related to these problems which are mentioned by the Ecological Institute show a tendency to underestimate the core meltdown frequency by a factor at least 6. (RF) [de

The Frequency of Voluntary and Involuntary Autobiographical Memories across the Lifespan

Science.gov (United States)

Rubin, David C.; Berntsen, Dorthe

2011-01-01

Ratings of the memory of an important event from the last week on the frequency of voluntary and involuntary retrieval, belief in its accuracy, visual imagery, auditory imagery, setting, emotional intensity, valence, narrative coherence, and centrality to the life story were obtained from 988 adults whose age ranged from 15 to over 90. Another 992 adults provided the same ratings for a memory from their confirmation day when they were about age 14. The frequencies of involuntary and voluntary retrieval were similar. Both frequencies were predicted by emotional intensity and centrality to the life story. The results from this study, which is the first to measure the frequency of voluntary and involuntary retrieval for the same events, are counter to both cognitive and clinical theories, which consistently claim that involuntary memories are infrequent compared to voluntary memories. Age and gender differences are noted. PMID:19487759

Uncertainty Measures of Regional Flood Frequency Estimators

DEFF Research Database (Denmark)

Rosbjerg, Dan; Madsen, Henrik

1995-01-01

Regional flood frequency models have different assumptions regarding homogeneity and inter-site independence. Thus, uncertainty measures of T-year event estimators are not directly comparable. However, having chosen a particular method, the reliability of the estimate should always be stated, e...

A spatial and nonstationary model for the frequency of extreme rainfall events

DEFF Research Database (Denmark)

Gregersen, Ida Bülow; Madsen, Henrik; Rosbjerg, Dan

2013-01-01

of extreme rainfall events, a statistical model is tested for this purpose. The model is built on the theory of generalized linear models and uses Poisson regression solved by generalized estimation equations. Spatial and temporal explanatory variables can be included simultaneously, and their relative...

Shallow repeating seismic events under an alpine glacier at Mount Rainier, Washington, USA

Science.gov (United States)

Thelen, Weston A.; Allstadt, Kate E.; De Angelis, Silvio; Malone, Stephen D.; Moran, Seth C.; Vidale, John

2013-01-01

We observed several swarms of repeating low-frequency (1–5 Hz) seismic events during a 3 week period in May–June 2010, near the summit of Mount Rainier, Washington, USA, that likely were a result of stick–slip motion at the base of alpine glaciers. The dominant set of repeating events ('multiplets') featured >4000 individual events and did not exhibit daytime variations in recurrence interval or amplitude. Volcanoes and glaciers around the world are known to produce seismic signals with great variability in both frequency content and size. The low-frequency character and periodic recurrence of the Mount Rainier multiplets mimic long-period seismicity often seen at volcanoes, particularly during periods of unrest. However, their near-surface location, lack of common spectral peaks across the recording network, rapid attenuation of amplitudes with distance, and temporal correlation with weather systems all indicate that ice-related source mechanisms are the most likely explanation. We interpret the low-frequency character of these multiplets to be the result of trapping of seismic energy under glacial ice as it propagates through the highly heterogeneous and attenuating volcanic material. The Mount Rainier multiplet sequences underscore the difficulties in differentiating low-frequency signals due to glacial processes from those caused by volcanic processes on glacier-clad volcanoes.

Intraoperative adverse events associated with extremely preterm cesarean deliveries.

Science.gov (United States)

Bertholdt, Charline; Menard, Sophie; Delorme, Pierre; Lamau, Marie-Charlotte; Goffinet, François; Le Ray, Camille

2018-05-01

At the same time as survival is increasing among premature babies born before 26 weeks of gestation, the rates of cesarean deliveries before 26 weeks is also rising. Our purpose was to compare the frequency of intraoperative adverse events during cesarean deliveries in two gestational age groups: 24-25 weeks and 26-27 weeks. This single-center retrospective cohort study included all women with cesarean deliveries performed before 28 +0 weeks from 2007 through 2015. It compared the frequency of intraoperative adverse events between two groups: those at 24-25 weeks of gestation and at 26-27 weeks. Intraoperative adverse events were a classical incision, transplacental incision, difficulty in fetal extraction (explicitly mentioned in the surgical report), postpartum hemorrhage (≥500 mL of blood loss), and injury to internal organs. A composite outcome including at least one of these events enabled us to analyze the risk factors for intraoperative adverse events with univariate and multivariable analysis. Stratified analyses by the indication for the cesarean were performed. We compared 74 cesarean deliveries at 24-25 weeks of gestation and 214 at 26-27 weeks. Intraoperative adverse events occurred at higher rates in the 24-25-week group (63.5 vs. 30.8%, p cesarean. These results should help obstetricians and women making decisions about cesarean deliveries at these extremely low gestational ages. © 2018 Nordic Federation of Societies of Obstetrics and Gynecology.

Memory for frequency of hearing popular songs.

Science.gov (United States)

Fidler, J R; Zechmeister, E B; Shaughnessy, J J

1988-01-01

In two experiments college students were asked to provide situational frequency estimates of 10-s excerpts from rock songs. In both experiments familiarity of the musical selections heard one, two, three, or four times was varied. In Experiment 2 the nature of instructions given to subjects prior to presentation of the musical excerpts was also manipulated. Across both experiments subjects' estimates were less accurate for unfamiliar than for familiar rock music. In Experiment 2 instructions to remember frequency, as well as general memory instructions, resulted in better memory for presentation frequency than did instructions to "ignore" music while working on math problems. Memory for situational frequency was also related to knowledge of rock music as defined by subjects' ability to identify the titles and artists of the presented songs. The present pattern of results with popular music is viewed as similar to that obtained in experiments investigating memory for frequency of verbal stimuli. Although providing support for an automatic processing view of frequency encoding, the results also implicate meaningful elaboration of stimuli as an important determinant of memory for frequency of events.

The potential for very high-frequency gravitational wave detection

International Nuclear Information System (INIS)

Cruise, A M

2012-01-01

The science case for observing gravitational waves at frequencies in the millihertz-kilohertz range using LIGO, VIRGO, GEO600 or LISA is very strong and the first results are expected at these frequencies. However, as gravitational wave astronomy progresses beyond the first detections, other frequency bands may be worth exploring. Early predictions of gravitational wave emission from discrete sources at very much higher frequencies (megahertz and above) have been published and more recent studies of cosmological signals from inflation, Kaluza-Klein modes from gravitational interactions in brane worlds and plasma instabilities surrounding violent astrophysical events, are all possible sources. This communication examines current observational possibilities and the detector technology required to make meaningful observations at these frequencies. (paper)

On the identification of substructure in phase space using orbital frequencies

NARCIS (Netherlands)

Gomez, Facundo A.; Helmi, Amina

2010-01-01

We study the evolution of satellite debris to establish the most suitable space to identify past merger events. We confirm that the space of orbital frequencies is very promising in this respect. In frequency space individual streams can be easily identified, and their separation provides a direct

Evaluation of potential severe accidents during low power and shutdown operations at Grand Gulf, Unit 1: Analysis of core damage frequency from internal fire events for Plant Operational State 5 during a refueling outage. Volume 3

International Nuclear Information System (INIS)

Lambright, J.; Yakle, J.

1994-07-01

This report, Volume 3, presents the details of the analysis of core damage frequency due to fire during shutdown Plant Operational State 5 at the Grand Gulf Nuclear Station. Insights from previous fire analyses (Peach Bottom, Surry, LaSalle) were used to the greatest extent possible in this analysis. The fire analysis was fully integrated utilizing the same event trees and fault trees that were used in the internal events analysis. In assessing shutdown risk due to fire at Grand Gulf, a detailed screening was performed which included the following elements: (a) Computer-aided vital area analysis; (b) Plant inspections; (c) Credit for automatic fire protection systems; (d) Recovery of random failures; (e) Detailed fire propagation modeling. This screening process revealed that all plant areas had a negligible (<1.0E-8 per year) contribution to fire-induced core damage frequency

Lessons-Learned from an Event during Overhaul

Energy Technology Data Exchange (ETDEWEB)

Kim, Jitae [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2013-05-15

The event frequency, also including portion of human errors, has been decreasing compared to last ten years. However, events due to human errors during overhaul occur every year. From analyzed results for human-related events during overhaul, similar problems were identified. And organizational and safety cultural factors were also identified. On the other hand, another event during overhaul is analyzed and Lessons-Learned is drawn in an aspect of the operators' situation awareness. There was an event during overhaul and the analyzed results drawn Lessons-Learned in the aspect of the operators' situation awareness. From the analysis, several alarms and variation of plant parameters during overhaul can occur due to various maintenance works and tests. And in the aspect of the situation awareness, operators can miss, neglect, or not recognize the abnormal situation due to other maintenance activities occurring simultaneously. Therefore, countermeasures such as operator education or training, development of operator support systems, and further researches should be necessary to cope with these problems.

Lessons-Learned from an Event during Overhaul

International Nuclear Information System (INIS)

Kim, Jitae

2013-01-01

The event frequency, also including portion of human errors, has been decreasing compared to last ten years. However, events due to human errors during overhaul occur every year. From analyzed results for human-related events during overhaul, similar problems were identified. And organizational and safety cultural factors were also identified. On the other hand, another event during overhaul is analyzed and Lessons-Learned is drawn in an aspect of the operators' situation awareness. There was an event during overhaul and the analyzed results drawn Lessons-Learned in the aspect of the operators' situation awareness. From the analysis, several alarms and variation of plant parameters during overhaul can occur due to various maintenance works and tests. And in the aspect of the situation awareness, operators can miss, neglect, or not recognize the abnormal situation due to other maintenance activities occurring simultaneously. Therefore, countermeasures such as operator education or training, development of operator support systems, and further researches should be necessary to cope with these problems

Probabilistic analysis of external events with focus on the Fukushima event

International Nuclear Information System (INIS)

Kollasko, Heiko; Jockenhoevel-Barttfeld, Mariana; Klapp, Ulrich

2014-01-01

External hazards are those natural or man-made hazards to a site and facilities that are originated externally to both the site and its processes, i.e. the duty holder may have very little or no control over the hazard. External hazards can have the potential of causing initiating events at the plant, typically transients like e.g., loss of offsite power. Simultaneously, external events may affect safety systems required to control the initiating event and, where applicable, also back-up systems implemented for risk-reduction. The plant safety may especially be threatened when loads from external hazards exceed the load assumptions considered in the design of safety-related systems, structures and components. Another potential threat is given by hazards inducing initiating events not considered in the safety demonstration otherwise. An example is loss of offsite power combined with prolonged plant isolation. Offsite support, e.g., delivery of diesel fuel oil, usually credited in the deterministic safety analysis may not be possible in this case. As the Fukushima events have shown, the biggest threat is likely given by hazards inducing both effects. Such hazards may well be dominant risk contributors even if their return period is very high. In order to identify relevant external hazards for a certain Nuclear Power Plant (NPP) location, a site specific screening analysis is performed, both for single events and for combinations of external events. As a result of the screening analysis, risk significant and therefore relevant (screened-in) single external events and combinations of them are identified for a site. The screened-in events are further considered in a detailed event tree analysis in the frame of the Probabilistic Safety Analysis (PSA) to calculate the core damage/large release frequency resulting from each relevant external event or from each relevant combination. Screening analyses of external events performed at AREVA are based on the approach provided

The Persian Checklist of Pleasant Events (PCPE: ‎Development, Validity and Reliability

Directory of Open Access Journals (Sweden)

Sepideh Bakht

2015-12-01

Full Text Available Objective: Experiencing ‎pleasant events during daily life ‎has a significant positive role in ‎the personal mental health and ‎acts as a keystone for “behavioral ‎activation” (BA interventions. ‎There are serious differences in ‎the pleasant event schedules in ‎different cultures and countries. ‎We aimed to develop a Persian ‎checklist of pleasant events ‎‎(PCPE to provide and validate a ‎culturally compatible checklist for ‎Iranians.‎Methods: To develop a checklist ‎of pleasant events, inspired by ‎Pleasant Events Schedule (PES ‎‎(MacPhillamy & Lewinsohn, ‎‎1982, we held three focused ‎group discussions with 24 normal ‎healthy participants from both ‎genders (female = 12 and asked ‎them to mention as much ‎pleasant events as possible. ‎When the list reached saturation ‎level, the inappropriate items with ‎respect to legal, cultural and ‎religious concerns were omitted. ‎The final checklist of PCPE ‎consists of two subscales: ‎Frequency (frequency of events ‎during last month and ‎pleasantness (perceived ‎pleasantness of events. The total ‎score consists of frequency ‎multiplied by pleasantness. To ‎test the reliability and validity of ‎the checklist, the PCPE, ‎Depression, Anxiety and Stress ‎Scale (DASS, the Persian ‎version of WHO Quality of Life ‎and the Demographic ‎Questionnaire were administered ‎in a sample of 104 participants ‎‎(50 male and 54 female.‎Results: Frequency, ‎pleasantness and the total scores ‎of PCPE showed high levels of ‎internal consistency (Cronbach’s ‎alpha, .976, .976 & .974, ‎respectively. Further support for ‎the convergent validity of the ‎PCPE was obtained via ‎moderate negative correlations ‎with depression, anxiety, stress ‎scores in DASS and positive ‎correlation with quality of life as ‎well as respondent’s perceived ‎happiness. There were negative ‎correlations between

The significance of water hammer events to public dose from reactor accidents: A probabilistic assessment

International Nuclear Information System (INIS)

Amico, P.J.; Ferrell, W.L.; Rubin, M.P.

1984-01-01

A probabilistic assessment was made of the effects on public dose of water hammer events in LWRs. The analysis utilized actual historical water hammer data to determine if the water hammer events contributed either to system failure rates or initiating event frequencies. Representative PRAs were used to see if changes in initiating events and/or system failures caused by water hammer resulted in new values for the dominant sequences in the PRAs. New core melt frequencies were determined and carried out to the subsequent increase in public dose. It is concluded that water hammer is not a significant problem with respect to risk to the public for either BWRs or PWRs. (orig./HP)

The null-event method in computer simulation

International Nuclear Information System (INIS)

Lin, S.L.

1978-01-01

The simulation of collisions of ions moving under the influence of an external field through a neutral gas to non-zero temperatures is discussed as an example of computer models of processes in which a probe particle undergoes a series of interactions with an ensemble of other particles, such that the frequency and outcome of the events depends on internal properties of the second particles. The introduction of null events removes the need for much complicated algebra, leads to a more efficient simulation and reduces the likelihood of logical error. (Auth.)

ATWS: a reappraisal. Part 3. Frequency of anticipated transients

International Nuclear Information System (INIS)

McClymont, A.S.; Poehlman, B.W.

1982-01-01

This document is the first revision of Part 3 of the EPRI study of the anticipated transients without scram question. This revision includes an update of events at nuclear power plants which had led to fast reactor shutdowns (scrams). The purpose of this document is to present the nuclear power plant operating experience, reflecting the frequency of these events identified by their principal characteristics

Aerosol events in the broader Mediterranean basin based on 7-year (2000–2007 MODIS C005 data

Directory of Open Access Journals (Sweden)

A. Gkikas

2009-09-01

Full Text Available Aerosol events (their frequency and intensity in the broader Mediterranean basin were studied using 7-year (2000–2007 aerosol data of optical depth (AOD at 550 nm from the MODerate Resolution Imaging Spectroradiometer (MODIS Terra. The complete spatial coverage of data revealed a significant spatial variability of aerosol events which is also dependent on their intensity. Strong events occur more often in the western and central Mediterranean basin (up to 14 events/year whereas extreme events (AOD up to 5.0 are systematically observed in the eastern Mediterranean basin throughout the year. There is also a significant seasonal variability with strong aerosol events occurring most frequently in the western part of the basin in summer and extreme episodes in the eastern part during spring. The events were also analyzed separately over land and sea revealing differences that are due to the different natural and anthropogenic processes, like dust transport (producing maximum frequencies of extreme episodes in spring over both land and sea or forest fires (producing maximum frequencies in strong episodes in summer over land. The inter-annual variability shows a gradual decrease in the frequency of all aerosol episodes over land and sea areas of the Mediterranean during the period 2000–2007, associated with an increase in their intensity (increased AOD values. The strong spatiotemporal variability of aerosol events indicates the need for monitoring them at the highest spatial and temporal coverage and resolution.

Extreme Weather Events and Climate Change Attribution

Energy Technology Data Exchange (ETDEWEB)

Thomas, Katherine [National Academy of Sciences, Washington, DC (United States)

2016-03-31

A report from the National Academies of Sciences, Engineering, and Medicine concludes it is now possible to estimate the influence of climate change on some types of extreme events. The science of extreme event attribution has advanced rapidly in recent years, giving new insight to the ways that human-caused climate change can influence the magnitude or frequency of some extreme weather events. This report examines the current state of science of extreme weather attribution, and identifies ways to move the science forward to improve attribution capabilities. Confidence is strongest in attributing types of extreme events that are influenced by climate change through a well-understood physical mechanism, such as, the more frequent heat waves that are closely connected to human-caused global temperature increases, the report finds. Confidence is lower for other types of events, such as hurricanes, whose relationship to climate change is more complex and less understood at present. For any extreme event, the results of attribution studies hinge on how questions about the event's causes are posed, and on the data, modeling approaches, and statistical tools chosen for the analysis.

Rainfall and runoff Intensity-Duration-Frequency Curves for Washington State considering the change and uncertainty of observed and anticipated extreme rainfall and snow events

Science.gov (United States)

Demissie, Y. K.; Mortuza, M. R.; Li, H. Y.

2015-12-01

The observed and anticipated increasing trends in extreme storm magnitude and frequency, as well as the associated flooding risk in the Pacific Northwest highlighted the need for revising and updating the local intensity-duration-frequency (IDF) curves, which are commonly used for designing critical water infrastructure. In Washington State, much of the drainage system installed in the last several decades uses IDF curves that are outdated by as much as half a century, making the system inadequate and vulnerable for flooding as seen more frequently in recent years. In this study, we have developed new and forward looking rainfall and runoff IDF curves for each county in Washington State using recently observed and projected precipitation data. Regional frequency analysis coupled with Bayesian uncertainty quantification and model averaging methods were used to developed and update the rainfall IDF curves, which were then used in watershed and snow models to develop the runoff IDF curves that explicitly account for effects of snow and drainage characteristic into the IDF curves and related designs. The resulted rainfall and runoff IDF curves provide more reliable, forward looking, and spatially resolved characteristics of storm events that can assist local decision makers and engineers to thoroughly review and/or update the current design standards for urban and rural storm water management infrastructure in order to reduce the potential ramifications of increasing severe storms and resulting floods on existing and planned storm drainage and flood management systems in the state.

USE OF RFID AT LARGE-SCALE EVENTS

Directory of Open Access Journals (Sweden)

Yuusuke KAWAKITA

2005-01-01

Full Text Available Radio Frequency Identification (RFID devices and related technologies have received a great deal of attention for their ability to perform non-contact object identification. Systems incorporating RFID have been evaluated from a variety of perspectives. The authors constructed a networked RFID system to support event management at NetWorld+Interop 2004 Tokyo, an event that received 150,000 visitors. The system used multiple RFID readers installed at the venue and RFID tags carried by each visitor to provide a platform for running various management and visitor support applications. This paper presents the results of this field trial of RFID readability rates. It further addresses the applicability of RFID systems to visitor management, a problematic aspect of large-scale events.

Large natural geophysical events: planetary planning

International Nuclear Information System (INIS)

Knox, J.B.; Smith, J.V.

1984-09-01

Geological and geophysical data suggest that during the evolution of the earth and its species, that there have been many mass extinctions due to large impacts from comets and large asteroids, and major volcanic events. Today, technology has developed to the stage where we can begin to consider protective measures for the planet. Evidence of the ecological disruption and frequency of these major events is presented. Surveillance and warning systems are most critical to develop wherein sufficient lead times for warnings exist so that appropriate interventions could be designed. The long term research undergirding these warning systems, implementation, and proof testing is rich in opportunities for collaboration for peace

Augmentation therapy with alpha1-antitrypsin: patterns of use and adverse events.

Science.gov (United States)

Stoller, James K; Fallat, Robert; Schluchter, Mark D; O'Brien, Ralph G; Connor, Jason T; Gross, Nicholas; O'Neil, Kevin; Sandhaus, Robert; Crystal, Ronald G

2003-05-01

To describe patterns of prescribing augmentation therapy, and types and rates of adverse events in the National Heart, Lung, and Blood Institute Registry for Individuals with Severe Deficiency of Alpha(1)-Antitrypsin. Observational cohort study with follow-up visits every 6 to 12 months for up to 7 years. The rate and dosing frequency with which Registry participants were prescribed to receive augmentation therapy by their managing physicians, and the type and frequency of adverse events, classified in two ways: severity of self-reported symptoms, and actions taken as a consequence of the symptom. Over the course of Registry follow-up, 66% (n = 747) of the participants received augmentation therapy at some time. In keeping with recommendations made in the 1989 American Thoracic Society (ATS) statement, 75% of participants with airflow obstruction at first visit (defined as FEV(1) or = 80% predicted (14%) also received augmentation therapy. Among those with COPD for whom augmentation therapy was not prescribed, financial constraints were the reported cause in 30%. Observed patterns also varied from approved practice, in that dosing frequencies other than the US Food and Drug Administration-approved, once-weekly regimen were frequently prescribed. The overall rate of reported adverse events was 0.02 per patient-month, with 83% of participants reporting no events. This overall rate was composed of 16% considered mild events, 76% moderate events, and 9% severe events. We conclude that augmentation therapy was generally well tolerated and, consistent with ATS guidelines, physicians generally did not prescribe augmentation therapy for subjects with FEV(1) > or = 80% predicted. However, the large percentage of subjects with FEV(1) <80% predicted not receiving augmentation therapy and the frequent use of 2- to 3-week or monthly dosing reflects variation of practice from suggested treatment guidelines.

Spatial-Temporal Event Detection from Geo-Tagged Tweets

Directory of Open Access Journals (Sweden)

Yuqian Huang

2018-04-01

Full Text Available As one of the most popular social networking services in the world, Twitter allows users to post messages along with their current geographic locations. Such georeferenced or geo-tagged Twitter datasets can benefit location-based services, targeted advertising and geosocial studies. Our study focused on the detection of small-scale spatial-temporal events and their textual content. First, we used Spatial-Temporal Density-Based Spatial Clustering of Applications with Noise (ST-DBSCAN to spatially-temporally cluster the tweets. Then, the word frequencies were summarized for each cluster and the potential topics were modeled by the Latent Dirichlet Allocation (LDA algorithm. Using two years of Twitter data from four college cities in the U.S., we were able to determine the spatial-temporal patterns of two known events, two unknown events and one recurring event, which then were further explored and modeled to identify the semantic content about the events. This paper presents our process and recommendations for both finding event-related tweets as well as understanding the spatial-temporal behaviors and semantic natures of the detected events.

Investigating casino event management integration: The case of East and South Asia casinos

Directory of Open Access Journals (Sweden)

Tzu-Wei (Arwen Huang

2017-03-01

Full Text Available The aim of this study is to investigate the gap of event management in East and South Asia’s casinos throughout the information provided by casinos on their websites. Main objective is to identify the differences and similarities of event holding in East and South Asia’s casinos and suggest future directions for casino managers and event organizers. Four research questions were developed to provide ourselves a goal, as well as to further our understanding of our investigation. There are two steps to structure our study. First is to evaluate the performance of 138 casino’s websites, which were obtained from worldcasinodirectory. com by using a website evaluation tool that we have constructed. In the second step, we conduct a content analysis for the website so we can identify what kind of events are organized in the area on our samples. The data of the content analysis provides a comparison of events in our sampling, such as the event’s size, type, and frequency of holding an event. We believe that our research would contribute to event organizers and large scale corporations to give them an insight on the overall efficiency of websites, as well as the frequency of events around East and South Asian casinos.

Initiating Events Modeling for On-Line Risk Monitoring Application

International Nuclear Information System (INIS)

Simic, Z.; Mikulicic, V.

1998-01-01

In order to make on-line risk monitoring application of Probabilistic Risk Assessment more complete and realistic, a special attention need to be dedicated to initiating events modeling. Two different issues are of special importance: one is how to model initiating events frequency according to current plant configuration (equipment alignment and out of service status) and operating condition (weather and various activities), and the second is how to preserve dependencies between initiating events model and rest of PRA model. First, the paper will discuss how initiating events can be treated in on-line risk monitoring application. Second, practical example of initiating events modeling in EPRI's Equipment Out of Service on-line monitoring tool will be presented. Gains from application and possible improvements will be discussed in conclusion. (author)

Post-event processing in social anxiety.

Science.gov (United States)

Dannahy, Laura; Stopa, Lusia

2007-06-01

Clark and Wells' [1995. A cognitive model of social phobia. In: R. Heimberg, M. Liebowitz, D.A. Hope, & F.R. Schneier (Eds.) Social phobia: Diagnosis, assessment and treatment (pp. 69-93). New York: Guildford Press.] cognitive model of social phobia proposes that following a social event, individuals with social phobia will engage in post-event processing, during which they conduct a detailed review of the event. This study investigated the relationship between self-appraisals of performance and post-event processing in individuals high and low in social anxiety. Participants appraised their performance immediately after a conversation with an unknown individual and prior to an anticipated second conversation task 1 week later. The frequency and valence of post-event processing during the week following the conversation was also assessed. The study also explored differences in the metacognitive processes of high and low socially anxious participants. The high socially anxious group experienced more anxiety, predicted worse performance, underestimated their actual performance, and engaged in more post-event processing than low socially anxious participants. The degree of negative post-event processing was linked to the extent of social anxiety and negative appraisals of performance, both immediately after the conversation task and 1 week later. Differences were also observed in some metacognitive processes. The results are discussed in relation to current theory and previous research.

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

Science.gov (United States)

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.

Analysis of core damage frequency from internal events: Expert judgment elicitation. Part 1: Expert panel results. Part 2: Project staff results

Energy Technology Data Exchange (ETDEWEB)

Wheeler, T A; Cramond, W R [Sandia National Laboratories, Albuquerque, NM (United States); Hora, S C [University of Hawii at Hilo (United States); Unwin, S D [Brookhaven National Laboratory (United States)

1989-04-01

Quantitative modeling techniques have limitations as to the resolution of important issues in probabilistic risk assessment (PRA). Not all issues can be resolved via the existing set of methods such as fault trees, event trees, statistical analyses, data collection, and computer simulation. Therefore, an expert judgment process was developed to address issues perceived as important to risk in the NUREG-1150 analysis but which could not be resolved with existing techniques. This process was applied to several issues that could significantly affect the internal event core damage frequencies of the PRAs performed on six light water reactors. Detailed descriptions of these issues and the results of the expert judgment elicitation are reported here, as well as an explanation of the methodology used and the procedure followed in performing the overall elicitation task. The process is time-consuming and expensive. However, the results are very useful, and represent an improvement over the draft NUREG-1150 analysis in the areas of expert selection, elicitation training, issue selection and presentation, elicitation of judgment and aggregation of results. The results are presented in two parts. Part documents the expert panel elicitations, where the most important issues were presented to a panel of experts convened from throughout the nuclear power risk assessment community. Part 2 documents the process by which the project staff performed expert judgment on other important issues, using the project staff as panel members. (author)

Joint time-frequency analysis of EEG signals based on a phase-space interpretation of the recording process

Science.gov (United States)

Testorf, M. E.; Jobst, B. C.; Kleen, J. K.; Titiz, A.; Guillory, S.; Scott, R.; Bujarski, K. A.; Roberts, D. W.; Holmes, G. L.; Lenck-Santini, P.-P.

2012-10-01

Time-frequency transforms are used to identify events in clinical EEG data. Data are recorded as part of a study for correlating the performance of human subjects during a memory task with pathological events in the EEG, called spikes. The spectrogram and the scalogram are reviewed as tools for evaluating spike activity. A statistical evaluation of the continuous wavelet transform across trials is used to quantify phase-locking events. For simultaneously improving the time and frequency resolution, and for representing the EEG of several channels or trials in a single time-frequency plane, a multichannel matching pursuit algorithm is used. Fundamental properties of the algorithm are discussed as well as preliminary results, which were obtained with clinical EEG data.

Defining Extreme Events: A Cross-Disciplinary Review

Science.gov (United States)

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.

Spectral characteristics of the nearshore waves off Paradip, India during monsoon and extreme events

Digital Repository Service at National Institute of Oceanography (India)

Aboobacker, V.M.; Vethamony, P.; Sudheesh, K.; Rupali, S.P.

and directional wave energy spectra distinctly separate out the wave conditions that prevailed off Paradip in the monsoon, fair weather and extreme weather events during the above period. Frequency-energy spectra during extreme events are single peaked...

U.S. Hail Frequency and the Global Wind Oscillation

Science.gov (United States)

Gensini, Vittorio A.; Allen, John T.

2018-02-01

Changes in Earth relative atmospheric angular momentum can be described by an index known as the Global Wind Oscillation. This global index accounts for changes in Earth's atmospheric budget of relative angular momentum through interactions of tropical convection anomalies, extratropical dynamics, and engagement of surface torques (e.g., friction and mountain). It is shown herein that U.S. hail events are more (less) likely to occur in low (high) atmospheric angular momentum base states when excluding weak Global Wind Oscillation days, with the strongest relationships found in the boreal spring and fall. Severe, significant severe, and giant hail events are more likely to occur during Global Wind Oscillation phases 8, 1, 2, and 3 during the peak of U.S. severe weather season. Lower frequencies of hail events are generally found in Global Wind Oscillation phases 4-7 but vary based on Global Wind Oscillation amplitude and month. In addition, probabilistic anomalies of atmospheric ingredients supportive of hail producing supercell thunderstorms closely mimic locations of reported hail frequency, helping to corroborate report results.

Impacts of extreme weather events on transport infrastructure in Norway

Science.gov (United States)

Frauenfelder, Regula; Solheim, Anders; Isaksen, Ketil; Romstad, Bård; Dyrrdal, Anita V.; Ekseth, Kristine H. H.; Gangstø Skaland, Reidun; Harbitz, Alf; Harbitz, Carl B.; Haugen, Jan E.; Hygen, Hans O.; Haakenstad, Hilde; Jaedicke, Christian; Jónsson, Árni; Klæboe, Ronny; Ludvigsen, Johanna; Meyer, Nele K.; Rauken, Trude; Sverdrup-Thygeson, Kjetil

2016-04-01

With the latest results on expected future increase in air temperature and precipitation changes reported by the Intergovernmental Panel on Climate Change (IPCC), the climate robustness of important infrastructure is of raising concern in Norway, as well as in the rest of Europe. Economic consequences of natural disasters have increased considerably since 1950. In addition to the effect of demographic changes such as population growth, urbanization and more and more concentration of valuable assets, this increase is also related to an augmenting frequency of extreme events, such as storms, flooding, drought, and landslides. This change is also observable in Norway, where the increased frequency of strong precipitation has led to frequent flooding and landslide events during the last 20 years. A number of studies show that climate change causes an increase in both frequency and intensity of several types of extreme weather, especially when it comes to precipitation. Such extreme weather events greatly affect the transport infrastructure, with numerous and long closures of roads and railroads, in addition to damage and repair costs. Frequent closures of railroad and roads lead to delay or failure in delivery of goods, which again may lead to a loss of customers and/or - eventually - markets. Much of the Norwegian transport infrastructure is more than 50 years old and therefore not adequately dimensioned, even for present climatic conditions. In order to assess these problems and challenges posed to the Norwegian transport infrastructure from present-day and future extreme weather events, the project "Impacts of extreme weather events on infrastructure in Norway (InfraRisk)" was performed under the research Council of Norway program 'NORKLIMA', between 2009 and 2013. The main results of the project are: - Moderate to strong precipitation events have become more frequent and more intense in Norway over the last 50 years, and this trend continues throughout the 21st

Event-related potentials reflecting the frequency of unattended spoken words

DEFF Research Database (Denmark)

Shtyrov, Yury; Kimppa, Lilli; Pulvermüller, Friedemann

2011-01-01

, in passive non-attend conditions, with acoustically matched high- and low-frequency words along with pseudo-words. Using factorial and correlation analyses, we found that already at ~120 ms after the spoken stimulus information was available, amplitude of brain responses was modulated by the words' lexical...... for the most frequent word stimuli, later-on (~270 ms), a more global lexicality effect with bilateral perisylvian sources was found for all stimuli, suggesting faster access to more frequent lexical entries. Our results support the account of word memory traces as interconnected neuronal circuits, and suggest......How are words represented in the human brain and can these representations be qualitatively assessed with respect to their structure and properties? Recent research demonstrates that neurophysiological signatures of individual words can be measured when subjects do not focus their attention...

External event analysis methods for NUREG-1150

International Nuclear Information System (INIS)

Bohn, M.P.; Lambright, J.A.

1989-01-01

The US Nuclear Regulatory Commission is sponsoring probabilistic risk assessments of six operating commercial nuclear power plants as part of a major update of the understanding of risk as provided by the original WASH-1400 risk assessments. In contrast to the WASH-1400 studies, at least two of the NUREG-1150 risk assessments will include an analysis of risks due to earthquakes, fires, floods, etc., which are collectively known as eternal events. This paper summarizes the methods to be used in the external event analysis for NUREG-1150 and the results obtained to date. The two plants for which external events are being considered are Surry and Peach Bottom, a PWR and BWR respectively. The external event analyses (through core damage frequency calculations) were completed in June 1989, with final documentation available in September. In contrast to most past external event analyses, wherein rudimentary systems models were developed reflecting each external event under consideration, the simplified NUREG-1150 analyses are based on the availability of the full internal event PRA systems models (event trees and fault trees) and make use of extensive computer-aided screening to reduce them to sequence cut sets important to each external event. This provides two major advantages in that consistency and scrutability with respect to the internal event analysis is achieved, and the full gamut of random and test/maintenance unavailabilities are automatically included, while only those probabilistically important survive the screening process. Thus, full benefit of the internal event analysis is obtained by performing the internal and external event analyses sequentially

Measures of Disease Frequency: Prevalence and Incidence

NARCIS (Netherlands)

Noordzij, Marlies; Dekker, Friedo W.; Zoccali, Carmine; Jager, Kitty J.

2010-01-01

To describe how often a disease or another health event occurs in a population, different measures of disease frequency can be used. The prevalence reflects the number of existing cases of a disease. In contrast to the prevalence, the incidence reflects the number of new cases of disease and can be

Changes in "hotter and wetter" events across China

Science.gov (United States)

Liu, C.; Deng, H.; Lu, Y.; Qiu, X.; Wang, D.

2017-12-01

As global warming intensifies, efforts to understand the changes in extreme climate events have increased in recent years. A combined analysis of the changes in extreme temperature and precipitation events is presented in this paper. Using observational data from 1961 to 2015, a set of hotter and wetter (HW) events is defined, and we examine the changes in these events across China. The results show that more HW events occur in Central and Eastern China than in other subregions, especially in South China (SC). The rate of increase in HW events is 2.7 and 1.9 per decade in SC and East China (EC), respectively. In China, most HW events occurred in the last 20 years of the study period, indicating that China entered a period of high-frequency HW events. Indeed, the range in anomalies in the torrential rain days is greater than that of the high-temperature days in Northwest China (NWC), Central China (CC), and EC after the mid- to late 1990s. The opposite pattern is found in Northeast China (NEC), Southwest China-region 1 (SWC1), Southwest China-region 2 (SWC2), and SC. Finally, the increase in HW events in most regions of China is closely associated with warming.

Review of licensee event reports, 1976 to 1978

International Nuclear Information System (INIS)

1979-09-01

This report was prepared in response to a request by the Chairman of the US Nuclear Regulatory Commission for the Advisory Committee on Reactor Safeguards to review, with specific objectives, the Licensee Event Reports (LERs) issued fom 1976 through 1978. A principal objective of the present study was to identify those events which have implications for improved reactor safety. Approximately 8,700 LERs were filed during the three-year period under review. These described events ranging from the trivial to those of major safety significance. This study has confirmed that LERs represent a source of valuable data and information. However, it must be recognized that a detailed review of LERs will not identify all safety problems likely to be encountered in the operation of nuclear power plants. As a result of this review, a number of classes of events were identified. These classes were subsequently categorized into three groups: (a) those having potentially serious safety implications, (b) events that must be regarded as matters of concern, and (c) events of lower safety significance but with excessive frequency

Frequency modulation reveals the phasing of orbital eccentricity during Cretaceous Oceanic Anoxic Event II and the Eocene hyperthermals

Science.gov (United States)

Laurin, Jiří; Meyers, Stephen R.; Galeotti, Simone; Lanci, Luca

2016-05-01

Major advances in our understanding of paleoclimate change derive from a precise reconstruction of the periods, amplitudes and phases of the 'Milankovitch cycles' of precession, obliquity and eccentricity. While numerous quantitative approaches exist for the identification of these astronomical cycles in stratigraphic data, limitations in radioisotopic dating, and instability of the theoretical astronomical solutions beyond ∼50 Myr ago, can challenge identification of the phase relationships needed to constrain climate response and anchor floating astrochronologies. Here we demonstrate that interference patterns accompanying frequency modulation (FM) of short eccentricity provide a robust basis for identifying the phase of long eccentricity forcing in stratigraphic data. One- and two-dimensional models of sedimentary distortion of the astronomical signal are used to evaluate the veracity of the FM method, and indicate that pristine eccentricity FM can be readily distinguished in paleo-records. Apart from paleoclimatic implications, the FM approach provides a quantitative technique for testing and calibrating theoretical astronomical solutions, and for refining chronologies for the deep past. We present two case studies that use the FM approach to evaluate major carbon-cycle perturbations of the Eocene and Late Cretaceous. Interference patterns in the short-eccentricity band reveal that Eocene hyperthermals ETM2 ('Elmo'), H2, I1 and ETM3 (X; ∼52-54 Myr ago) were associated with maxima in the 405-kyr cycle of orbital eccentricity. The same eccentricity configuration favored regional anoxic episodes in the Mediterranean during the Middle and Late Cenomanian (∼94.5-97 Myr ago). The initial phase of the global Oceanic Anoxic Event II (OAE II; ∼93.9-94.5 Myr ago) coincides with maximum and falling 405-kyr eccentricity, and the recovery phase occurs during minimum and rising 405-kyr eccentricity. On a Myr scale, the event overlaps with a node in eccentricity

Detection and frequency of recombination in tomato-infecting begomoviruses of South and Southeast Asia

Directory of Open Access Journals (Sweden)

Rai Mathura

2007-10-01

Full Text Available Abstract Background Tomato-infecting begomoviruses are widely distributed across the world and cause diseases of high economic impact on wide range of agriculturally important crops. Though recombination plays a pivotal role in diversification and evolution of these viruses, it is currently unknown whether there are differences in the number and quality of recombination events amongst different tomato-infecting begomovirus species. To examine this we sought to characterize the recombination events, estimate the frequency of recombination, and map recombination hotspots in tomato-infecting begomoviruses of South and Southeast Asia. Results Different methods used for recombination breakpoint analysis provided strong evidence for presence of recombination events in majority of the sequences analyzed. However, there was a clear evidence for absence or low Recombination events in viruses reported from North India. In addition, we provide evidence for non-random distribution of recombination events with the highest frequency of recombination being mapped in the portion of the N-terminal portion of Rep. Conclusion The variable recombination observed in these viruses signified that all begomoviruses are not equally prone to recombination. Distribution of recombination hotspots was found to be reliant on the relatedness of the genomic region involved in the exchange. Overall the frequency of phylogenetic violations and number of recombination events decreased with increasing parental sequence diversity. These findings provide valuable new information for understanding the diversity and evolution of tomato-infecting begomoviruses in Asia.

CNE (Embalse nuclear power plant): probabilistic safety study. Electric power supply. Events sequence

International Nuclear Information System (INIS)

Figueroa, N.

1987-01-01

The plant response to the occurrence of the starting event 'total loss of electric power supply to class IV and class III' is analyzed. This involves the study of automatical actions of safety and process systems as well as the operator actions. The probabilistic evaluation of starting event frequency is performed through fault-tree techniques. The frequency of occurrence 'loss of electric power supply to class IV (λIV = 0.56/year) and the probability of failure to demand of 'reserve' generating groups (Pd III 6.79 x 10 -3 ) contribute to the mentioned frequency. As soon as the starting event occurs, the reactor power must be reduced to 0%, the fuel must be cooled through the thermo siphon and decay heat has to be removed. The events sequence analysis leads to the conclusion that the non shutting down of the reactor with any of the shutdown systems is 'incredible' (10 -6 /year). In all cases the fuel is cooled by building the thermo siphon except when a substantial inventory loss exist due to a closure failure of some valve of pressure and inventory control system. The order of magnitude of the failure of decay heat removal through the steam generators is 4 x 10 -4 . This removal would be assured by the emergency water system. Therefore, the frequency of the sequence of possible core meltdown, when the reactor does not shut down is: λ = 5 x 10 -9 /year and for the failure of heat removal: λ = 2 x 10 -6 /year. (Author)

Study of the oscillations event of the CNLV-U1 with Wavelets techniques

International Nuclear Information System (INIS)

Amador G, R.; Nunez C, A.; Prieto G, A.; Espinosa P, G.

2004-01-01

Presently work is described and the techniques are applied of the Fourier Transformation in Short Time, the Continuous Transformation of Wavelets and the Multi resolution Analysis for the analysis of the event of oscillations of power in the Nuclear Power station of Laguna Verde Unit 1 happened in January of 1995. In general, the wavelets techniques allows to carry out studies of the different signals generated by a nuclear plant in the plane Time-frequency, Time-scale as well as the decomposition of the signals. The results obtained study presently demonstrate that the frequency of the event of oscillations in the Nuclear Power station of Laguna Verde Unit 1 are approximately 0.52 Hz for the 3 analysis techniques, besides being observed the evolution of the frequency in function of the time. (Author)

Final Scientific Report, Integrated Seismic Event Detection and Location by Advanced Array Processing

Energy Technology Data Exchange (ETDEWEB)

Kvaerna, T.; Gibbons. S.J.; Ringdal, F; Harris, D.B.

2007-01-30

primarily the result of spurious identification and incorrect association of phases, and of excessive variability in estimates for the velocity and direction of incoming seismic phases. The mitigation of these causes has led to the development of two complimentary techniques for classifying seismic sources by testing detected signals under mutually exclusive event hypotheses. Both of these techniques require appropriate calibration data from the region to be monitored, and are therefore ideally suited to mining areas or other sites with recurring seismicity. The first such technique is a classification and location algorithm where a template is designed for each site being monitored which defines which phases should be observed, and at which times, for all available regional array stations. For each phase, the variability of measurements (primarily the azimuth and apparent velocity) from previous events is examined and it is determined which processing parameters (array configuration, data window length, frequency band) provide the most stable results. This allows us to define optimal diagnostic tests for subsequent occurrences of the phase in question. The calibration of templates for this project revealed significant results with major implications for seismic processing in both automatic and analyst reviewed contexts: • one or more fixed frequency bands should be chosen for each phase tested for. • the frequency band providing the most stable parameter estimates varies from site to site and a frequency band which provides optimal measurements for one site may give substantially worse measurements for a nearby site. • slowness corrections applied depend strongly on the frequency band chosen. • the frequency band providing the most stable estimates is often neither the band providing the greatest SNR nor the band providing the best array gain. For this reason, the automatic template location estimates provided here are frequently far better than those obtained by

Final Scientific Report, Integrated Seismic Event Detection and Location by Advanced Array Processing

International Nuclear Information System (INIS)

Kvaerna, T.; Gibbons. S.J.; Ringdal, F; Harris, D.B.

2007-01-01

primarily the result of spurious identification and incorrect association of phases, and of excessive variability in estimates for the velocity and direction of incoming seismic phases. The mitigation of these causes has led to the development of two complimentary techniques for classifying seismic sources by testing detected signals under mutually exclusive event hypotheses. Both of these techniques require appropriate calibration data from the region to be monitored, and are therefore ideally suited to mining areas or other sites with recurring seismicity. The first such technique is a classification and location algorithm where a template is designed for each site being monitored which defines which phases should be observed, and at which times, for all available regional array stations. For each phase, the variability of measurements (primarily the azimuth and apparent velocity) from previous events is examined and it is determined which processing parameters (array configuration, data window length, frequency band) provide the most stable results. This allows us to define optimal diagnostic tests for subsequent occurrences of the phase in question. The calibration of templates for this project revealed significant results with major implications for seismic processing in both automatic and analyst reviewed contexts: (1) one or more fixed frequency bands should be chosen for each phase tested for; (2) the frequency band providing the most stable parameter estimates varies from site to site and a frequency band which provides optimal measurements for one site may give substantially worse measurements for a nearby site; (3) slowness corrections applied depend strongly on the frequency band chosen; (4) the frequency band providing the most stable estimates is often neither the band providing the greatest SNR nor the band providing the best array gain. For this reason, the automatic template location estimates provided here are frequently far better than those obtained by

Event-related oscillations (EROs) and event-related potentials (ERPs) comparison in facial expression recognition.

Science.gov (United States)

Balconi, Michela; Pozzoli, Uberto

2007-09-01

The study aims to explore the significance of event-related potentials (ERPs) and event-related brain oscillations (EROs) (delta, theta, alpha, beta, gamma power) in response to emotional (fear, happiness, sadness) when compared with neutral faces during 180-250 post-stimulus time interval. The ERP results demonstrated that the emotional face elicited a negative peak at approximately 230 ms (N2). Moreover, EEG measures showed that motivational significance of face (emotional vs. neutral) could modulate the amplitude of EROs, but only for some frequency bands (i.e. theta and gamma bands). In a second phase, we considered the resemblance of the two EEG measures by a regression analysis. It revealed that theta and gamma oscillations mainly effect as oscillation activity at the N2 latency. Finally, a posterior increased power of theta was found for emotional faces.

Event Management of RFID Data Streams: Fast Moving Consumer Goods Supply Chains

Science.gov (United States)

Mo, John P. T.; Li, Xue

Radio Frequency Identification (RFID) is a wireless communication technology that uses radio-frequency waves to transfer information between tagged objects and readers without line of sight. This creates tremendous opportunities for linking real world objects into a world of "Internet of things". Application of RFID to Fast Moving Consumer Goods sector will introduce billions of RFID tags in the world. Almost everything is tagged for tracking and identification purposes. This phenomenon will impose a new challenge not only to the network capacity but also to the scalability of processing of RFID events and data. This chapter uses two national demonstrator projects in Australia as case studies to introduce an event managementframework to process high volume RFID data streams in real time and automatically transform physical RFID observations into business-level events. The model handles various temporal event patterns, both simple and complex, with temporal constraints. The model can be implemented in a data management architecture that allows global RFID item tracking and enables fast, large-scale RFID deployment.

Prediction problem for target events based on the inter-event waiting time

Science.gov (United States)

Shapoval, A.

2010-11-01

In this paper we address the problem of forecasting the target events of a time series given the distribution ξ of time gaps between target events. Strong earthquakes and stock market crashes are the two types of such events that we are focusing on. In the series of earthquakes, as McCann et al. show [W.R. Mc Cann, S.P. Nishenko, L.R. Sykes, J. Krause, Seismic gaps and plate tectonics: seismic potential for major boundaries, Pure and Applied Geophysics 117 (1979) 1082-1147], there are well-defined gaps (called seismic gaps) between strong earthquakes. On the other hand, usually there are no regular gaps in the series of stock market crashes [M. Raberto, E. Scalas, F. Mainardi, Waiting-times and returns in high-frequency financial data: an empirical study, Physica A 314 (2002) 749-755]. For the case of seismic gaps, we analytically derive an upper bound of prediction efficiency given the coefficient of variation of the distribution ξ. For the case of stock market crashes, we develop an algorithm that predicts the next crash within a certain time interval after the previous one. We show that this algorithm outperforms random prediction. The efficiency of our algorithm sets up a lower bound of efficiency for effective prediction of stock market crashes.

Recurring events - Volume 2

International Nuclear Information System (INIS)

2003-04-01

known, thus the actions taken were not effective in preventing recurrence of an event, - The contributing factors or causes of the event were not taken into account in defining the actions to be taken. Several good practices were identified to prevent recurring events. These practices are part of related guides provided by national and international bodies. Some of these are: - NPPs should analyse recurring events in-depth, in order to identify root causes and contributing factors to prevent further recurrence. The specific factors that failed to prevent recurrence should be investigated and identified (that is, why prior operating experience was not effectively applied). - For minor events, trend analyses should be performed to monitor the frequency of component failures (which may be unavoidable) or the frequency of minor human performance problems (which may indicate weaknesses in error prevention processes and programs). - Analysis of external operating experiences from other NPPs should be strengthened to broaden the basis for preventive measures; - Actions taken after events should be assessed regarding their effectiveness in preventing recurrence of similar events. Subsequent to the workshop, a more detailed search of reports of operating experience, including IRS and other reports from national sources, resulted in the determination of a number of recurring categories: - Loss of RHR at mid-loop (in the 1999 report also); - BWR instability (in the 1999 report also); - PWR vessel corrosion due to boric acid effects; - Hydrogen detonation in BWR piping; - Steam Generator Tube Rupture; - Multiple valve failures in ECCS; - Service Water Failure due to Marine Biofouling (in the 1999 report also); - System Level Failures with Human Factors Considerations; - Strainer Clogging (sources of emergency injection or recirculation). Five conclusions were established on the basis of the workshop and the recurring event analysis: Conclusion 1: Recurring events continue to be

Solar Type II Radio Bursts and IP Type II Events

Science.gov (United States)

Cane, H. V.; Erickson, W. C.

2005-01-01

We have examined radio data from the WAVES experiment on the Wind spacecraft in conjunction with ground-based data in order to investigate the relationship between the shocks responsible for metric type II radio bursts and the shocks in front of coronal mass ejections (CMEs). The bow shocks of fast, large CMEs are strong interplanetary (IP) shocks, and the associated radio emissions often consist of single broad bands starting below approx. 4 MHz; such emissions were previously called IP type II events. In contrast, metric type II bursts are usually narrowbanded and display two harmonically related bands. In addition to displaying complete dynamic spectra for a number of events, we also analyze the 135 WAVES 1 - 14 MHz slow-drift time periods in 2001-2003. We find that most of the periods contain multiple phenomena, which we divide into three groups: metric type II extensions, IP type II events, and blobs and bands. About half of the WAVES listings include probable extensions of metric type II radio bursts, but in more than half of these events, there were also other slow-drift features. In the 3 yr study period, there were 31 IP type II events; these were associated with the very fastest CMEs. The most common form of activity in the WAVES events, blobs and bands in the frequency range between 1 and 8 MHz, fall below an envelope consistent with the early signatures of an IP type II event. However, most of this activity lasts only a few tens of minutes, whereas IP type II events last for many hours. In this study we find many examples in the radio data of two shock-like phenomena with different characteristics that occur simultaneously in the metric and decametric/hectometric bands, and no clear example of a metric type II burst that extends continuously down in frequency to become an IP type II event. The simplest interpretation is that metric type II bursts, unlike IP type II events, are not caused by shocks driven in front of CMEs.

GRAVITATIONAL MICROLENSING EVENTS AS A TARGET FOR THE SETI PROJECT

Energy Technology Data Exchange (ETDEWEB)

Rahvar, Sohrab, E-mail: rahvar@sharif.edu [Department of Physics, Sharif University of Technology, P.O. Box 11365–9161, Tehran (Iran, Islamic Republic of)

2016-09-01

The detection of signals from a possible extrasolar technological civilization is one of the most challenging efforts of science. In this work, we propose using natural telescopes made of single or binary gravitational lensing systems to magnify leakage of electromagnetic signals from a remote planet that harbors Extraterrestrial Intelligent (ETI) technology. Currently, gravitational microlensing surveys are monitoring a large area of the Galactic bulge to search for microlensing events, finding more than 2000 events per year. These lenses are capable of playing the role of natural telescopes, and, in some instances, they can magnify radio band signals from planets orbiting around the source stars in gravitational microlensing systems. Assuming that the frequency of electromagnetic waves used for telecommunication in ETIs is similar to ours, we propose follow-up observation of microlensing events with radio telescopes such as the Square Kilometre Array (SKA), the Low Frequency Demonstrators, and the Mileura Wide-Field Array. Amplifying signals from the leakage of broadcasting by an Earth-like civilization will allow us to detect them as far as the center of the Milky Way galaxy. Our analysis shows that in binary microlensing systems, the probability of amplification of signals from ETIs is more than that in single microlensing events. Finally, we propose the use of the target of opportunity mode for follow-up observations of binary microlensing events with SKA as a new observational program for searching ETIs. Using optimistic values for the factors of the Drake equation provides detection of about one event per year.

Modelling substorm chorus events in terms of dispersive azimuthal drift

Directory of Open Access Journals (Sweden)

A. B. Collier

2004-12-01

Full Text Available The Substorm Chorus Event (SCE is a radio phenomenon observed on the ground after the onset of the substorm expansion phase. It consists of a band of VLF chorus with rising upper and lower cutoff frequencies. These emissions are thought to result from Doppler-shifted cyclotron resonance between whistler mode waves and energetic electrons which drift into a ground station's field of view from an injection site around midnight. The increasing frequency of the emission envelope has been attributed to the combined effects of energy dispersion due to gradient and curvature drifts, and the modification of resonance conditions and variation of the half-gyrofrequency cutoff resulting from the radial component of the ExB drift. A model is presented which accounts for the observed features of the SCE in terms of the growth rate of whistler mode waves due to anisotropy in the electron distribution. This model provides an explanation for the increasing frequency of the SCE lower cutoff, as well as reproducing the general frequency-time signature of the event. In addition, the results place some restrictions on the injected particle source distribution which might lead to a SCE. Key words. Space plasma physics (Wave-particle interaction – Magnetospheric physics (Plasma waves and instabilities; Storms and substorms

Alcohol marketing in televised international football: frequency analysis.

Science.gov (United States)

Adams, Jean; Coleman, James; White, Martin

2014-05-20

Alcohol marketing includes sponsorship of individuals, organisations and sporting events. Football (soccer) is one of the most popular spectator sports worldwide. No previous studies have quantified the frequency of alcohol marketing in a high profile international football tournament. The aims were to determine: the frequency and nature of visual references to alcohol in a representative sample of EURO2012 matches broadcast in the UK; and if frequency or nature varied between matches broadcast on public service and commercial channels, or between matches that did and did not feature England. Eight matches selected by stratified random sampling were recorded. All visual references to alcohol were identified using a tool with high inter-rater reliability. 1846 visual references to alcohol were identified over 1487 minutes of broadcast--an average of 1.24 references per minute. The mean number of references per minute was higher in matches that did vs did not feature England (p = 0.004), but did not differ between matches broadcast on public service vs commercial channels (p = 0.92). The frequency of visual references to alcohol was universally high and higher in matches featuring the only UK home team--England--suggesting that there may be targeting of particularly highly viewed matches. References were embedded in broadcasts, and not particular to commercial channels including paid-for advertising. New UK codes-of-conduct on alcohol marketing at sporting events will not reduce the level of marketing reported here.

Solar observations with a low frequency radio telescope

Science.gov (United States)

Myserlis, I.; Seiradakis, J.; Dogramatzidis, M.

2012-01-01

We have set up a low frequency radio monitoring station for solar bursts at the Observatory of the Aristotle University in Thessaloniki. The station consists of a dual dipole phased array, a radio receiver and a dedicated computer with the necessary software installed. The constructed radio receiver is based on NASA's Radio Jove project. It operates continuously, since July 2010, at 20.1 MHz (close to the long-wavelength ionospheric cut-off of the radio window) with a narrow bandwidth (~5 kHz). The system is properly calibrated, so that the recorded data are expressed in antenna temperature. Despite the high interference level of an urban region like Thessaloniki (strong broadcasting shortwave radio stations, periodic experimental signals, CBs, etc), we have detected several low frequency solar radio bursts and correlated them with solar flares, X-ray events and other low frequency solar observations. The received signal is monitored in ordinary ASCII format and as audio signal, in order to investigate and exclude man-made radio interference. In order to exclude narrow band interference and calculate the spectral indices of the observed events, a second monitoring station, working at 36 MHz, is under construction at the village of Nikiforos near the town of Drama, about 130 km away of Thessaloniki. Finally, we plan to construct a third monitoring station at 58 MHz, in Thessaloniki. This frequency was revealed to be relatively free of interference, after a thorough investigation of the region.

Fast oscillations in cortical-striatal networks switch frequency following rewarding events and stimulant drugs.

Science.gov (United States)

Berke, J D

2009-09-01

Oscillations may organize communication between components of large-scale brain networks. Although gamma-band oscillations have been repeatedly observed in cortical-basal ganglia circuits, their functional roles are not yet clear. Here I show that, in behaving rats, distinct frequencies of ventral striatal local field potential oscillations show coherence with different cortical inputs. The approximately 50 Hz gamma oscillations that normally predominate in awake ventral striatum are coherent with piriform cortex, whereas approximately 80-100 Hz high-gamma oscillations are coherent with frontal cortex. Within striatum, entrainment to gamma rhythms is selective to fast-spiking interneurons, with distinct fast-spiking interneuron populations entrained to different gamma frequencies. Administration of the psychomotor stimulant amphetamine or the dopamine agonist apomorphine causes a prolonged decrease in approximately 50 Hz power and increase in approximately 80-100 Hz power. The same frequency switch is observed for shorter epochs spontaneously in awake, undrugged animals and is consistently provoked for reward receipt. Individual striatal neurons can participate in these brief high-gamma bursts with, or without, substantial changes in firing rate. Switching between discrete oscillatory states may allow different modes of information processing during decision-making and reinforcement-based learning, and may also be an important systems-level process by which stimulant drugs affect cognition and behavior.

Location of long-period events below Kilauea Volcano using seismic amplitudes and accurate relative relocation

Science.gov (United States)

Battaglia, J.; Got, J.-L.; Okubo, P.

2003-01-01

We present methods for improving the location of long-period (LP) events, deep and shallow, recorded below Kilauea Volcano by the permanent seismic network. LP events might be of particular interest to understanding eruptive processes as their source mechanism is assumed to directly involve fluid transport. However, it is usually difficult or impossible to locate their source using traditional arrival time methods because of emergent wave arrivals. At Kilauea, similar LP waveform signatures suggest the existence of LP multiplets. The waveform similarity suggests spatially close sources, while catalog solutions using arrival time estimates are widely scattered beneath Kilauea's summit caldera. In order to improve estimates of absolute LP location, we use the distribution of seismic amplitudes corrected for station site effects. The decay of the amplitude as a function of hypocentral distance is used for inferring LP location. In a second stage, we use the similarity of the events to calculate their relative positions. The analysis of the entire LP seismicity recorded between January 1997 and December 1999 suggests that a very large part of the LP event population, both deep and shallow, is generated by a small number of compact sources. Deep events are systematically composed of a weak high-frequency onset followed by a low-frequency wave train. Aligning the low-frequency wave trains does not lead to aligning the onsets indicating the two parts of the signal are dissociated. This observation favors an interpretation in terms of triggering and resonance of a magmatic conduit. Instead of defining fault planes, the precise relocation of similar LP events, based on the alignment of the high-energy low-frequency wave trains, defines limited size volumes. Copyright 2003 by the American Geophysical Union.

Control Method for Variable Speed Wind Turbines to Support Temporary Primary Frequency Control

DEFF Research Database (Denmark)

Wang, Haijiao; Chen, Zhe; Jiang, Quanyuan

2014-01-01

This paper develops a control method for variable speed wind turbines (VSWTs) to support temporary primary frequency control of power system. The control method contains two parts: (1) up-regulate support control when a frequency drop event occurs; (2) down-regulate support control when a frequen...

Self-reported non-severe hypoglycaemic events in Europe

DEFF Research Database (Denmark)

Östenson, C G; Geelhoed-Duijvestijn, P; Lahtela, J

2014-01-01

AIMS: Hypoglycaemia presents a barrier to optimum diabetes management but data are limited on the frequency of hypoglycaemia incidents outside of clinical trials. The present study investigated the rates of self-reported non-severe hypoglycaemic events, hypoglycaemia awareness and physician...... discussion of events in people with Type 1 diabetes mellitus or insulin-treated Type 2 diabetes mellitus. METHODS: People in seven European countries aged >15 years with Type 1 diabetes or insulin-treated Type 2 diabetes (basal-only, basal-bolus and other insulin regimens) were recruited via consumer panels......, nurses, telephone recruitment and family referrals. Respondents completed four online questionnaires. The first questionnaire collected background information on demographics and hypoglycaemia-related behaviour, whilst all four questionnaires collected data on non-severe hypoglycaemic events...

Estimative of core damage frequency in IPEN's IEA-R1 research reactor (PSA level 1) due to the initiating event of loss of coolant caused by large rupture in the pipe of the primary circuit

International Nuclear Information System (INIS)

Hirata, Daniel Massami

2009-01-01

This work applies the methodology of probabilistic safety assessment level 1 to the research reactor IEA-R1 IPEN-CNEN/SP. Two categories of identified initiating events of accidents in the reactor are studied: loss of flow and loss of primary coolant. Among the initiating events, blockage of flow channel and loss of cooling fluid by major pipe rupture in the primary circuit are chosen for a detailed analysis. The event tree technique is used to analyze the evolution of the accident, including the actuation or the fail of actuation of the safety systems and the reactor damages. Using the fault tree the reliability of the following reactor safety systems is evaluated: reactor shutdown system, isolation of the reactor pool, emergency core cooling system (ECCS) and the electric system. Estimative for the frequency of damage to the reactor core and the probability of failure of the analyzed systems are calculated. The estimated values for the frequencies of core damage are within the expected margins and are of the same order of magnitude as those found for similar reactors. The reliability of the reactor shutdown system, isolation of the reactor pool and ECCS are satisfactory for the conditions these systems are required. However, for the electric system it is suggested an upgrade to increase its reliability. (author)

Rare event techniques applied in the Rasmussen study

International Nuclear Information System (INIS)

Vesely, W.E.

1977-01-01

The Rasmussen Study estimated public risks from commercial nuclear power plant accidents, and therefore the statistics of rare events had to be treated. Two types of rare events were specifically handled, those rare events which were probabilistically rare events and those which were statistically rare events. Four techniques were used to estimate probabilities of rare events. These techniques were aggregating data samples, discretizing ''continuous'' events, extrapolating from minor to catastrophic severities, and decomposing events using event trees and fault trees. In aggregating or combining data the goal was to enlarge the data sample so that the rare event was no longer rare, i.e., so that the enlarged data sample contained one or more occurrences of the event of interest. This aggregation gave rise to random variable treatments of failure rates, occurrence frequencies, and other characteristics estimated from data. This random variable treatment can be interpreted as being comparable to an empirical Bayes technique or a Bayesian technique. In the discretizing event technique, events of a detailed nature were grouped together into a grosser event for purposes of analysis as well as for data collection. The treatment of data characteristics as random variables helped to account for the uncertainties arising from this discretizing. In the severity extrapolation technique a severity variable was associated with each event occurrence for the purpose of predicting probabilities of catastrophic occurrences. Tail behaviors of distributions therefore needed to be considered. Finally, event trees and fault trees were used to express accident occurrences and system failures in terms of more basic events for which data existed. Common mode failures and general dependencies therefore needed to be treated. 2 figures

Economic impact and market analysis of a special event: The Great New England Air Show

Science.gov (United States)

Rodney B. Warnick; David C. Bojanic; Atul Sheel; Apurv Mather; Deepak Ninan

2010-01-01

We conducted a post-event evaluation for the Great New England Air Show to assess its general economic impact and to refine economic estimates where possible. In addition to the standard economic impact variables, we examined travel distance, purchase decision involvement, event satisfaction, and frequency of attendance. Graphic mapping of event visitors' home ZIP...

The comparison of SRs' variation affected by solar events observed in America and in China

Science.gov (United States)

Yu, H.; Williams, E.

2017-12-01

Schumann Resonances(SRs) are the electromagnetic resonance wave propagating in the earth-ionosphere cavity. Its characteristic of propagation are modified by the variation of ionosphere. So SRs can be the tools of monitoring the ionosphere which is often perturbed by solar events, x-ray emission and some other space-weather events (Roldugin et.al., 2004, De et al., 2010; Satori et.al., 2015). In present work, the amplitude and intrinsic frequencies of SRs observed at RID station in America and YSH station in China are compared. The variation of SRs during the solar flare on Feb. 15, 2011 are analyzed. Two-Dimensional Telegraph Equation(TDTE) method is used to simulate the perturbation of ionosphere by solar proton events. From the simulation and observation, the asymmetric construction of ionoshphere which is perturbed by the solar event will affect the amplitudes and frequencies of SRs. Due to the interfere influence of forward and backward propagation of electromagnetic field, the SR amplitude on different station will present different variation. The distance among the lightning source, observer and perturbed area will produce the different variation of amplitude and frequency for different station' SR.

Clinical teratology

International Nuclear Information System (INIS)

McCormack, M.K.

1983-01-01

Of particular importance in teratogenesis is the time of exposure to the offending environmental agent, route of exposure, and genotype of the embryo and the mother. The major teratogens include irradiation, maternal infections, other illnesses in pregnancy (diabetes, thyroid disease, maternal phenylketonuria, virilizing diseases), a host of pharmacologic agents and environmental contaminants. Teratogen exposure carries the potential for cancer in later life. Several sources of information on teratogens are now available

Clinical teratology

Energy Technology Data Exchange (ETDEWEB)

McCormack, M.K.

1983-12-01

Of particular importance in teratogenesis is the time of exposure to the offending environmental agent, route of exposure, and genotype of the embryo and the mother. The major teratogens include irradiation, maternal infections, other illnesses in pregnancy (diabetes, thyroid disease, maternal phenylketonuria, virilizing diseases), a host of pharmacologic agents and environmental contaminants. Teratogen exposure carries the potential for cancer in later life. Several sources of information on teratogens are now available.

Major life events and risk of Parkinson's disease

DEFF Research Database (Denmark)

Rod, Naja Hulvej; Hansen, Johnni; Schernhammer, Eva

2010-01-01

major life events are risk factors for Parkinson's disease. Between 1986 and 2006, we identified 13,695 patients with a (PD) primary diagnosis of PD in the Danish National Hospital Register. Each case was frequency matched by age and gender to five population controls. Information on major life events...... before onset of PD was ascertained from national registries. Among men, number of life events was associated with risk of Parkinson's disease in an inverse dose-response manner (P ....34-0.99). Life events were not associated with PD in women. In contrast, a higher risk of PD was observed among women who had never been married (1.16; 1.04-1.29) and among men (1.47; 1.18-1.82) and women (1.30; 1.05-1.61) who have never been employees. The lower risk of Parkinson's disease among men who had...

The Exponent of High-frequency Source Spectral Falloff and Contribution to Source Parameter Estimates

Science.gov (United States)

Kiuchi, R.; Mori, J. J.

2015-12-01

As a way to understand the characteristics of the earthquake source, studies of source parameters (such as radiated energy and stress drop) and their scaling are important. In order to estimate source parameters reliably, often we must use appropriate source spectrum models and the omega-square model is most frequently used. In this model, the spectrum is flat in lower frequencies and the falloff is proportional to the angular frequency squared. However, Some studies (e.g. Allmann and Shearer, 2009; Yagi et al., 2012) reported that the exponent of the high frequency falloff is other than -2. Therefore, in this study we estimate the source parameters using a spectral model for which the falloff exponent is not fixed. We analyze the mainshock and larger aftershocks of the 2008 Iwate-Miyagi Nairiku earthquake. Firstly, we calculate the P wave and SH wave spectra using empirical Green functions (EGF) to remove the path effect (such as attenuation) and site effect. For the EGF event, we select a smaller earthquake that is highly-correlated with the target event. In order to obtain the stable results, we calculate the spectral ratios using a multitaper spectrum analysis (Prieto et al., 2009). Then we take a geometric mean from multiple stations. Finally, using the obtained spectra ratios, we perform a grid search to determine the high frequency falloffs, as well as corner frequency of both of events. Our results indicate the high frequency falloff exponent is often less than 2.0. We do not observe any regional, focal mechanism, or depth dependencies for the falloff exponent. In addition, our estimated corner frequencies and falloff exponents are consistent between the P wave and SH wave analysis. In our presentation, we show differences in estimated source parameters using a fixed omega-square model and a model allowing variable high-frequency falloff.

PRELIMINARY SELECTION OF MGR DESIGN BASIS EVENTS

International Nuclear Information System (INIS)

Kappes, J.A.

1999-01-01

The purpose of this analysis is to identify the preliminary design basis events (DBEs) for consideration in the design of the Monitored Geologic Repository (MGR). For external events and natural phenomena (e.g., earthquake), the objective is to identify those initiating events that the MGR will be designed to withstand. Design criteria will ensure that radiological release scenarios resulting from these initiating events are beyond design basis (i.e., have a scenario frequency less than once per million years). For internal (i.e., human-induced and random equipment failures) events, the objective is to identify credible event sequences that result in bounding radiological releases. These sequences will be used to establish the design basis criteria for MGR structures, systems, and components (SSCs) design basis criteria in order to prevent or mitigate radiological releases. The safety strategy presented in this analysis for preventing or mitigating DBEs is based on the preclosure safety strategy outlined in ''Strategy to Mitigate Preclosure Offsite Exposure'' (CRWMS M andO 1998f). DBE analysis is necessary to provide feedback and requirements to the design process, and also to demonstrate compliance with proposed 10 CFR 63 (Dyer 1999b) requirements. DBE analysis is also required to identify and classify the SSCs that are important to safety (ITS)

Water regime history drives responses of soil Namib Desert microbial communities to wetting events

Science.gov (United States)

Frossard, Aline; Ramond, Jean-Baptiste; Seely, Mary; Cowan, Don A.

2015-07-01

Despite the dominance of microorganisms in arid soils, the structures and functional dynamics of microbial communities in hot deserts remain largely unresolved. The effects of wetting event frequency and intensity on Namib Desert microbial communities from two soils with different water-regime histories were tested over 36 days. A total of 168 soil microcosms received wetting events mimicking fog, light rain and heavy rainfall, with a parallel “dry condition” control. T-RFLP data showed that the different wetting events affected desert microbial community structures, but these effects were attenuated by the effects related to the long-term adaptation of both fungal and bacterial communities to soil origins (i.e. soil water regime histories). The intensity of the water pulses (i.e. the amount of water added) rather than the frequency of wetting events had greatest effect in shaping bacterial and fungal community structures. In contrast to microbial diversity, microbial activities (enzyme activities) showed very little response to the wetting events and were mainly driven by soil origin. This experiment clearly demonstrates the complexity of microbial community responses to wetting events in hyperarid hot desert soil ecosystems and underlines the dynamism of their indigenous microbial communities.

The relationship between extreme weather events and crop losses in central Taiwan

Science.gov (United States)

Lai, Li-Wei

2017-09-01

The frequency of extreme weather events, which cause severe crop losses, is increasing. This study investigates the relationship between crop losses and extreme weather events in central Taiwan from 2003 to 2015 and determines the main factors influencing crop losses. Data regarding the crop loss area and meteorological information were obtained from government agencies. The crops were categorised into the following five groups: `grains', `vegetables', `fruits', `flowers' and `other crops'. The extreme weather events and their synoptic weather patterns were categorised into six and five groups, respectively. The data were analysed using the z score, correlation coefficient and stepwise regression model. The results show that typhoons had the highest frequency of all extreme weather events (58.3%). The largest crop loss area (4.09%) was caused by two typhoons and foehn wind in succession. Extreme wind speed coupled with heavy rainfall is an important factor affecting the losses in the grain and vegetable groups. Extreme wind speed is a common variable that affects the loss of `grains', `vegetables', `fruits' and `flowers'. Consecutive extreme weather events caused greater crop losses than individual events. Crops with long production times suffered greater losses than those with short production times. This suggests that crops with physical structures that can be easily damaged and long production times would benefit from protected cultivation to maintain food security.

Focal mechanisms and inter-event times of low-frequency earthquakes reveal quasi-continuous deformation and triggered slow slip on the deep Alpine Fault

Science.gov (United States)

Baratin, Laura-May; Chamberlain, Calum J.; Townend, John; Savage, Martha K.

2018-02-01

Characterising the seismicity associated with slow deformation in the vicinity of the Alpine Fault may provide constraints on the stresses acting on a major transpressive margin prior to an anticipated great (≥M8) earthquake. Here, we use recently detected tremor and low-frequency earthquakes (LFEs) to examine how slow tectonic deformation is loading the Alpine Fault late in its typical ∼300-yr seismic cycle. We analyse a continuous seismic dataset recorded between 2009 and 2016 using a network of 10-13 short-period seismometers, the Southern Alps Microearthquake Borehole Array. Fourteen primary LFE templates are used in an iterative matched-filter and stacking routine, allowing the detection of similar signals corresponding to LFE families sharing common locations. This yields an 8-yr catalogue containing 10,000 LFEs that are combined for each of the 14 LFE families using phase-weighted stacking to produce signals with the highest possible signal-to-noise ratios. We show that LFEs occur almost continuously during the 8-yr study period and highlight two types of LFE distributions: (1) discrete behaviour with an inter-event time exceeding 2 min; (2) burst-like behaviour with an inter-event time below 2 min. We interpret the discrete events as small-scale frequent deformation on the deep extent of the Alpine Fault and LFE bursts (corresponding in most cases to known episodes of tremor or large regional earthquakes) as brief periods of increased slip activity indicative of slow slip. We compute improved non-linear earthquake locations using a 3-D velocity model. LFEs occur below the seismogenic zone at depths of 17-42 km, on or near the hypothesised deep extent of the Alpine Fault. The first estimates of LFE focal mechanisms associated with continental faulting, in conjunction with recurrence intervals, are consistent with quasi-continuous shear faulting on the deep extent of the Alpine Fault.

The influence of hydrologic residence time on lake carbon cycling dynamics following extreme precipitation events

Science.gov (United States)

Jacob A. Zwart; Stephen D. Sebestyen; Christopher T. Solomon; Stuart E. Jones

2016-01-01

The frequency and magnitude of extreme events are expected to increase in the future, yet little is known about effects of such events on ecosystem structure and function. We examined how extreme precipitation events affect exports of terrestrial dissolved organic carbon (t-DOC) from watersheds to lakes as well as in-lake heterotrophy in three north-temperate lakes....

Station blackout core damage frequency in an advanced nuclear reactor

International Nuclear Information System (INIS)

Carvalho, Luiz Sergio de

2004-01-01

Even though nuclear reactors are provided with protection systems so that they can be automatically shut down in the event of a station blackout, the consequences of this event can be severe. This is because many safety systems that are needed for removing residual heat from the core and for maintaining containment integrity, in the majority of the nuclear power plants, are AC dependent. In order to minimize core damage frequency, advanced reactor concepts are being developed with safety systems that use natural forces. This work shows an improvement in the safety of a small nuclear power reactor provided by a passive core residual heat removal system. Station blackout core melt frequencies, with and without this system, are both calculated. The results are also compared with available data in the literature. (author)

CATEGORIZATION OF EVENT SEQUENCES FOR LICENSE APPLICATION

Energy Technology Data Exchange (ETDEWEB)

G.E. Ragan; P. Mecheret; D. Dexheimer

2005-04-14

The purposes of this analysis are: (1) Categorize (as Category 1, Category 2, or Beyond Category 2) internal event sequences that may occur before permanent closure of the repository at Yucca Mountain. (2) Categorize external event sequences that may occur before permanent closure of the repository at Yucca Mountain. This includes examining DBGM-1 seismic classifications and upgrading to DBGM-2, if appropriate, to ensure Beyond Category 2 categorization. (3) State the design and operational requirements that are invoked to make the categorization assignments valid. (4) Indicate the amount of material put at risk by Category 1 and Category 2 event sequences. (5) Estimate frequencies of Category 1 event sequences at the maximum capacity and receipt rate of the repository. (6) Distinguish occurrences associated with normal operations from event sequences. It is beyond the scope of the analysis to propose design requirements that may be required to control radiological exposure associated with normal operations. (7) Provide a convenient compilation of the results of the analysis in tabular form. The results of this analysis are used as inputs to the consequence analyses in an iterative design process that is depicted in Figure 1. Categorization of event sequences for permanent retrieval of waste from the repository is beyond the scope of this analysis. Cleanup activities that take place after an event sequence and other responses to abnormal events are also beyond the scope of the analysis.

CATEGORIZATION OF EVENT SEQUENCES FOR LICENSE APPLICATION

International Nuclear Information System (INIS)

G.E. Ragan; P. Mecheret; D. Dexheimer

2005-01-01

The purposes of this analysis are: (1) Categorize (as Category 1, Category 2, or Beyond Category 2) internal event sequences that may occur before permanent closure of the repository at Yucca Mountain. (2) Categorize external event sequences that may occur before permanent closure of the repository at Yucca Mountain. This includes examining DBGM-1 seismic classifications and upgrading to DBGM-2, if appropriate, to ensure Beyond Category 2 categorization. (3) State the design and operational requirements that are invoked to make the categorization assignments valid. (4) Indicate the amount of material put at risk by Category 1 and Category 2 event sequences. (5) Estimate frequencies of Category 1 event sequences at the maximum capacity and receipt rate of the repository. (6) Distinguish occurrences associated with normal operations from event sequences. It is beyond the scope of the analysis to propose design requirements that may be required to control radiological exposure associated with normal operations. (7) Provide a convenient compilation of the results of the analysis in tabular form. The results of this analysis are used as inputs to the consequence analyses in an iterative design process that is depicted in Figure 1. Categorization of event sequences for permanent retrieval of waste from the repository is beyond the scope of this analysis. Cleanup activities that take place after an event sequence and other responses to abnormal events are also beyond the scope of the analysis

Dust Storms in North China in 2002: A Case Study of the Low Frequency Oscillation

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

The low frequency oscillation in both hemispheres and its possible role in the dust weather storm events over North China in 2002 are analyzed as a case study. Results show that the Aleutian Low is linked with the Circumpolar Vortex in the Southern Hemisphere on a 30-60-day oscillation, with a weak Circumpolar Vortex tending to deepen the Aleutian Low which may be helpful for the generation of dust storm events.The possible mechanism behind this is the inter-hemispheric interaction of the mean meridional circulation,with the major variability over East Asia. The zonal mean westerly wind at high latitudes of the Southern Hemisphere in the upper level troposphere may lead that of the Northern Hemisphere, which then impacts the local circulation in the Northern Hemisphere. Thus, the low frequency oscillation teleconnection is one possible linkage in the coupling between the Southern Hemisphere circulation and dust events over North China. However, the interannual variation of the low frequency oscillation is unclear.

Spatiotemporal frequency characteristics of cerebral oscillations during the perception of fundamental frequency contour changes in one-syllable intonation.

Science.gov (United States)

Ueno, Sanae; Okumura, Eiichi; Remijn, Gerard B; Yoshimura, Yuko; Kikuchi, Mitsuru; Shitamichi, Kiyomi; Nagao, Kikuko; Mochiduki, Masayuki; Haruta, Yasuhiro; Hayashi, Norio; Munesue, Toshio; Tsubokawa, Tsunehisa; Oi, Manabu; Nakatani, Hideo; Higashida, Haruhiro; Minabe, Yoshio

2012-05-02

Accurate perception of fundamental frequency (F0) contour changes in the human voice is important for understanding a speaker's intonation, and consequently also his/her attitude. In this study, we investigated the neural processes involved in the perception of F0 contour changes in the Japanese one-syllable interjection "ne" in 21 native-Japanese listeners. A passive oddball paradigm was applied in which "ne" with a high falling F0 contour, used when urging a reaction from the listener, was randomly presented as a rare deviant among a frequent "ne" syllable with a flat F0 contour (i.e., meaningless intonation). We applied an adaptive spatial filtering method to the neuromagnetic time course recorded by whole-head magnetoencephalography (MEG) and estimated the spatiotemporal frequency dynamics of event-related cerebral oscillatory changes in the oddball paradigm. Our results demonstrated a significant elevation of beta band event-related desynchronization (ERD) in the right temporal and frontal areas, in time windows from 100 to 300 and from 300 to 500 ms after the onset of deviant stimuli (high falling F0 contour). This is the first study to reveal detailed spatiotemporal frequency characteristics of cerebral oscillations during the perception of intonational (not lexical) F0 contour changes in the human voice. The results further confirmed that the right hemisphere is associated with perception of intonational F0 contour information in the human voice, especially in early time windows. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Lower Hybrid Frequency Range Waves Generated by Ion Polarization Drift Due to Electromagnetic Ion Cyclotron Waves: Analysis of an Event Observed by the Van Allen Probe B

Science.gov (United States)

Khazanov, G. V.; Boardsen, S.; Krivorutsky, E. N.; Engebretson, M. J.; Sibeck, D.; Chen, S.; Breneman, A.

2017-01-01

We analyze a wave event that occurred near noon between 07:03 and 07:08 UT on 23 February 2014 detected by the Van Allen Probes B spacecraft, where waves in the lower hybrid frequency range (LHFR) and electromagnetic ion cyclotron (EMIC) waves are observed to be highly correlated, with Pearson correlation coefficient of approximately 0.86. We assume that the correlation is the result of LHFR wave generation by the ions polarization drift in the electric field of the EMIC waves. To check this assumption the drift velocities of electrons and H+, He+, and O+ ions in the measured EMIC wave electric field were modeled. Then the LHFR wave linear instantaneous growth rates for plasma with these changing drift velocities and different plasma compositions were calculated. The time distribution of these growth rates, their frequency distribution, and the frequency dependence of the ratio of the LHFR wave power spectral density (PSD)parallel and perpendicular to the ambient magnetic eld to the total PSD were found. These characteristics of the growth rates were compared with the corresponding characteristics of the observed LHFR activity. Reasonable agreement between these features and the strong correlation between EMIC and LHFR energy densities support the assumption that the LHFR wave generation can be caused by the ions polarization drift in the electric field of an EMIC wave.

ATWS: a reappraisal. Part III. Frequency of anticipated transients. Interim report

International Nuclear Information System (INIS)

Leverenz, F.L. Jr.; Koren, J.M.; Erdmann, R.C.; Lellouche, G.S.

1978-07-01

The document is Part III of the Institute study of the ATWS question. The frequencies of the various events which have led to a reactor scram are documented from the nuclear power plant records. Some of these events, in the absence of scram, could lead to undesirable system response and are the ''transients of significance'' which comprise the anticipated transients of the ATWS question

Adverse events of modern antifungal drugs during treatment of invasive fungal infections

Directory of Open Access Journals (Sweden)

N. V. Dmitrieva

2014-07-01

Full Text Available Characteristics of adverse events of modern antimycotics by organ systems and comparative frequency between different medicines and their groups are presented. The examples of incompatibility of antifungal drugs with other pharmacological groups are discussed. Records of adverse events and drug compatibility will allow the practitioner to prevent and timely cure possible complications, should they arise.

Adverse events of modern antifungal drugs during treatment of invasive fungal infections

Directory of Open Access Journals (Sweden)

N. V. Dmitrieva

2013-01-01

Full Text Available Characteristics of adverse events of modern antimycotics by organ systems and comparative frequency between different medicines and their groups are presented. The examples of incompatibility of antifungal drugs with other pharmacological groups are discussed. Records of adverse events and drug compatibility will allow the practitioner to prevent and timely cure possible complications, should they arise.

Calibration of semi-stochastic procedure for simulating high-frequency ground motions

Science.gov (United States)

Seyhan, Emel; Stewart, Jonathan P.; Graves, Robert

2013-01-01

Broadband ground motion simulation procedures typically utilize physics-based modeling at low frequencies, coupled with semi-stochastic procedures at high frequencies. The high-frequency procedure considered here combines deterministic Fourier amplitude spectra (dependent on source, path, and site models) with random phase. Previous work showed that high-frequency intensity measures from this simulation methodology attenuate faster with distance and have lower intra-event dispersion than in empirical equations. We address these issues by increasing crustal damping (Q) to reduce distance attenuation bias and by introducing random site-to-site variations to Fourier amplitudes using a lognormal standard deviation ranging from 0.45 for Mw  100 km).

Frequency mixing in boron carbide laser ablation plasmas

Science.gov (United States)

Oujja, M.; Benítez-Cañete, A.; Sanz, M.; Lopez-Quintas, I.; Martín, M.; de Nalda, R.; Castillejo, M.

2015-05-01

Nonlinear frequency mixing induced by a bichromatic field (1064 nm + 532 nm obtained from a Q-switched Nd:YAG laser) in a boron carbide (B4C) plasma generated through laser ablation under vacuum is explored. A UV beam at the frequency of the fourth harmonic of the fundamental frequency (266 nm) was generated. The dependence of the efficiency of the process as function of the intensities of the driving lasers differs from the expected behavior for four-wave mixing, and point toward a six-wave mixing process. The frequency mixing process was strongly favored for parallel polarizations of the two driving beams. Through spatiotemporal mapping, the conditions for maximum efficiency were found for a significant delay from the ablation event (200 ns), when the medium is expected to be a low-ionized plasma. No late components of the harmonic signal were detected, indicating a largely atomized medium.

Dependencies in event trees analyzed by Petri nets

International Nuclear Information System (INIS)

Nývlt, Ondřej; Rausand, Marvin

2012-01-01

This paper discusses how non-marked Petri nets can be used to model and analyze event trees where the pivotal (branching) events are dependent and modeled by fault trees. The dependencies may, for example, be caused by shared utilities, shared components, or general common cause failures that are modeled by beta-factor models. These dependencies are cumbersome to take into account when using standard event-/fault tree modeling techniques, and may lead to significant errors in the calculated end-state probabilities of the event tree if they are not properly analyzed. A new approach is proposed in this paper, where the whole event tree is modeled by a non-marked Petri net and where P-invariants, representing the structural properties of the Petri net, are used to obtain the frequency of each end-state of the event tree with dependencies. The new approach is applied to a real example of an event tree analysis of the Strahov highway tunnel in Prague, Czech Republic, including two types of dependencies (shared Programmable Logic Controllers and Common Cause Failures). - Highlights: ► In this paper, we model and analyze event trees (ET) using Petri nets. ► The pivotal events of the modeled event trees are dependent (e.g., shared PLCs, CCF). ► A new method based on P-invariants to obtain probabilities of end states is proposed. ► Method is shown in the case study of the Stahov tunnel in the Czech Republic.

The rate of adverse events during IV conscious sedation.

Science.gov (United States)

Schwamburger, Nathan T; Hancock, Raymond H; Chong, Chol H; Hartup, Grant R; Vandewalle, Kraig S

2012-01-01

Conscious sedation has become an integral part of dentistry; it is often used to reduce anxiety or fear in some patients during oral surgery, periodontal surgery, implant placement, and general dentistry procedures. The purpose of this study was to evaluate the frequency of adverse events during IV conscious sedation provided by credentialed general dentists and periodontists in the United States Air Force (USAF). Sedation clinical records (Air Force Form 1417) from calendar year 2009 were requested from all USAF bases. A total of 1,468 records were reviewed and 19 adverse events were noted in 17 patients. IV complication (infiltration) was the most common adverse event. The overall adverse event rate was 1.3 per 100 patients treated. The results of this study show that moderate sedation provided by general dentists and periodontists in the USAF has a low incidence of adverse events, and conscious sedation remains a viable option for providers for the reduction of anxiety in select patients.

Selection of mother wavelets for the detection of the oscillation frequencies in power signals of nuclear reactors

International Nuclear Information System (INIS)

Amador G, R.; Castillo D, R.; Ortiz V, J.

2007-01-01

Diverse types of transitory events can lead to oscillations of power in nuclear reactors. In such events, the power monitors provide a signal that contains important characteristics of the transitory one, as the oscillation frequency, tendencies, changes and the instants or periods in those that important events are presented. This characteristics are detected by means of diverse analysis techniques, as Autoregressive methods, Fourier Transform, Fourier Transform in Short Time, Wavelets Transform, among others. Presently work is used the one Wavelets Continuous Transform because it allows to carry out studies of the stationary, quasi-stationary and transitory signals in the Time-scale and Time-scale-spectrum planes. Contrary to other similar works, this work describes a methodology for the selection of the scales and the Wavelet mother to be applied the one Wavelets Continuous Transform, with the objective of detecting to the dominant frequencies of the system. To prove the proposal a broadly well-known real signal of an event of power oscillations it has been used. The obtained results correspond to three families of Wavelets mothers that fulfilled the conditions of scales and central frequency of the proposal. The results show that the value of the certain frequency oscillation in this work is practically the same one reported in other studies with other techniques. (Author)

A semi-automated method for rapid detection of ripple events on interictal voltage discharges in the scalp electroencephalogram.

Science.gov (United States)

Chu, Catherine J; Chan, Arthur; Song, Dan; Staley, Kevin J; Stufflebeam, Steven M; Kramer, Mark A

2017-02-01

High frequency oscillations are emerging as a clinically important indicator of epileptic networks. However, manual detection of these high frequency oscillations is difficult, time consuming, and subjective, especially in the scalp EEG, thus hindering further clinical exploration and application. Semi-automated detection methods augment manual detection by reducing inspection to a subset of time intervals. We propose a new method to detect high frequency oscillations that co-occur with interictal epileptiform discharges. The new method proceeds in two steps. The first step identifies candidate time intervals during which high frequency activity is increased. The second step computes a set of seven features for each candidate interval. These features require that the candidate event contain a high frequency oscillation approximately sinusoidal in shape, with at least three cycles, that co-occurs with a large amplitude discharge. Candidate events that satisfy these features are stored for validation through visual analysis. We evaluate the detector performance in simulation and on ten examples of scalp EEG data, and show that the proposed method successfully detects spike-ripple events, with high positive predictive value, low false positive rate, and high intra-rater reliability. The proposed method is less sensitive than the existing method of visual inspection, but much faster and much more reliable. Accurate and rapid detection of high frequency activity increases the clinical viability of this rhythmic biomarker of epilepsy. The proposed spike-ripple detector rapidly identifies candidate spike-ripple events, thus making clinical analysis of prolonged, multielectrode scalp EEG recordings tractable. Copyright © 2016 Elsevier B.V. All rights reserved.

Automatic Seismic-Event Classification with Convolutional Neural Networks.

Science.gov (United States)

Bueno Rodriguez, A.; Titos Luzón, M.; Garcia Martinez, L.; Benitez, C.; Ibáñez, J. M.

2017-12-01

Active volcanoes exhibit a wide range of seismic signals, providing vast amounts of unlabelled volcano-seismic data that can be analyzed through the lens of artificial intelligence. However, obtaining high-quality labelled data is time-consuming and expensive. Deep neural networks can process data in their raw form, compute high-level features and provide a better representation of the input data distribution. These systems can be deployed to classify seismic data at scale, enhance current early-warning systems and build extensive seismic catalogs. In this research, we aim to classify spectrograms from seven different seismic events registered at "Volcán de Fuego" (Colima, Mexico), during four eruptive periods. Our approach is based on convolutional neural networks (CNNs), a sub-type of deep neural networks that can exploit grid structure from the data. Volcano-seismic signals can be mapped into a grid-like structure using the spectrogram: a representation of the temporal evolution in terms of time and frequency. Spectrograms were computed from the data using Hamming windows with 4 seconds length, 2.5 seconds overlapping and 128 points FFT resolution. Results are compared to deep neural networks, random forest and SVMs. Experiments show that CNNs can exploit temporal and frequency information, attaining a classification accuracy of 93%, similar to deep networks 91% but outperforming SVM and random forest. These results empirically show that CNNs are powerful models to classify a wide range of volcano-seismic signals, and achieve good generalization. Furthermore, volcano-seismic spectrograms contains useful discriminative information for the CNN, as higher layers of the network combine high-level features computed for each frequency band, helping to detect simultaneous events in time. Being at the intersection of deep learning and geophysics, this research enables future studies of how CNNs can be used in volcano monitoring to accurately determine the detection and

Changes in the probability of co-occurring extreme climate events

Science.gov (United States)

Diffenbaugh, N. S.

2017-12-01

Extreme climate events such as floods, droughts, heatwaves, and severe storms exert acute stresses on natural and human systems. When multiple extreme events co-occur, either in space or time, the impacts can be substantially compounded. A diverse set of human interests - including supply chains, agricultural commodities markets, reinsurance, and deployment of humanitarian aid - have historically relied on the rarity of extreme events to provide a geographic hedge against the compounded impacts of co-occuring extremes. However, changes in the frequency of extreme events in recent decades imply that the probability of co-occuring extremes is also changing, and is likely to continue to change in the future in response to additional global warming. This presentation will review the evidence for historical changes in extreme climate events and the response of extreme events to continued global warming, and will provide some perspective on methods for quantifying changes in the probability of co-occurring extremes in the past and future.

Modelling substorm chorus events in terms of dispersive azimuthal drift

Directory of Open Access Journals (Sweden)

A. B. Collier

2004-12-01

Full Text Available The Substorm Chorus Event (SCE is a radio phenomenon observed on the ground after the onset of the substorm expansion phase. It consists of a band of VLF chorus with rising upper and lower cutoff frequencies. These emissions are thought to result from Doppler-shifted cyclotron resonance between whistler mode waves and energetic electrons which drift into a ground station's field of view from an injection site around midnight. The increasing frequency of the emission envelope has been attributed to the combined effects of energy dispersion due to gradient and curvature drifts, and the modification of resonance conditions and variation of the half-gyrofrequency cutoff resulting from the radial component of the ExB drift.

A model is presented which accounts for the observed features of the SCE in terms of the growth rate of whistler mode waves due to anisotropy in the electron distribution. This model provides an explanation for the increasing frequency of the SCE lower cutoff, as well as reproducing the general frequency-time signature of the event. In addition, the results place some restrictions on the injected particle source distribution which might lead to a SCE.

Key words. Space plasma physics (Wave-particle interaction – Magnetospheric physics (Plasma waves and instabilities; Storms and substorms

MURCHISON WIDEFIELD ARRAY LIMITS ON RADIO EMISSION FROM ANTARES NEUTRINO EVENTS

International Nuclear Information System (INIS)

Croft, S.; Kaplan, D. L.; Tingay, S. J.; Murphy, T.; Rowlinson, A.; Bell, M. E.; Adrián-Martínez, S.; Ardid, M.; Ageron, M.; Aubert, J.-J.; Albert, A.; André, M.; Anton, G.; Avgitas, T.; Baret, B.

2016-01-01

We present a search, using the Murchison Widefield Array (MWA), for electromagnetic (EM) counterparts to two candidate high-energy neutrino events detected by the ANTARES neutrino telescope in 2013 November and 2014 March. These events were selected by ANTARES because they are consistent, within 0.°4, with the locations of galaxies within 20 Mpc of Earth. Using MWA archival data at frequencies between 118 and 182 MHz, taken ∼20 days prior to, at the same time as, and up to a year after the neutrino triggers, we look for transient or strongly variable radio sources that are consistent with the neutrino positions. No such counterparts are detected, and we set a 5σ upper limit for low-frequency radio emission of ∼10 37 erg s −1 for progenitors at 20 Mpc. If the neutrino sources are instead not in nearby galaxies, but originate in binary neutron star coalescences, our limits place the progenitors at z ≳ 0.2. While it is possible, due to the high background from atmospheric neutrinos, that neither event is astrophysical, the MWA observations are nevertheless among the first to follow up neutrino candidates in the radio, and illustrate the promise of wide-field instruments like MWA for detecting EM counterparts to such events

MURCHISON WIDEFIELD ARRAY LIMITS ON RADIO EMISSION FROM ANTARES NEUTRINO EVENTS

Energy Technology Data Exchange (ETDEWEB)

Croft, S. [University of California, Berkeley, Astronomy Department, 501 Campbell Hall #3411, Berkeley, CA 94720 (United States); Kaplan, D. L. [Department of Physics, University of Wisconsin-Milwaukee, 1900 East Kenwood Boulevard, Milwaukee, WI 53211 (United States); Tingay, S. J. [International Centre for Radio Astronomy Research, Curtin University, Bentley, WA 6102 (Australia); Murphy, T.; Rowlinson, A. [ARC Centre of Excellence for All-sky Astrophysics (CAASTRO) (Australia); Bell, M. E. [CSIRO Australia Telescope National Facility, P.O. Box 76, Epping, NSW 1710 (Australia); Adrián-Martínez, S.; Ardid, M. [Institut d’Investigació per a la Gestió Integrada de les Zones Costaneres (IGIC)—Universitat Politècnica de València. C/ Paranimf 1, E-46730 Gandia (Spain); Ageron, M.; Aubert, J.-J. [Aix Marseille Université, CNRS/IN2P3, CPPM UMR 7346, F-13288, Marseille (France); Albert, A. [GRPHE—Université de Haute Alsace—Institut universitaire de technologie de Colmar, 34 rue du Grillenbreit BP 50568-68008 Colmar (France); André, M. [Technical University of Catalonia, Laboratory of Applied Bioacoustics, Rambla Exposició, E-08800 Vilanova i la Geltrú, Barcelona (Spain); Anton, G. [Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Str. 1, D-91058 Erlangen (Germany); Avgitas, T.; Baret, B. [APC, Université Paris Diderot, CNRS/IN2P3, CEA/IRFU, Observatoire de Paris, Sorbonne Paris Cité, F-75205 Paris (France); Collaboration: for the MWA Collaboration; for the ANTARES Collaboration; for the TAROT Collaboration; for the ROTSE Collaboration; and others

2016-04-01

We present a search, using the Murchison Widefield Array (MWA), for electromagnetic (EM) counterparts to two candidate high-energy neutrino events detected by the ANTARES neutrino telescope in 2013 November and 2014 March. These events were selected by ANTARES because they are consistent, within 0.°4, with the locations of galaxies within 20 Mpc of Earth. Using MWA archival data at frequencies between 118 and 182 MHz, taken ∼20 days prior to, at the same time as, and up to a year after the neutrino triggers, we look for transient or strongly variable radio sources that are consistent with the neutrino positions. No such counterparts are detected, and we set a 5σ upper limit for low-frequency radio emission of ∼10{sup 37} erg s{sup −1} for progenitors at 20 Mpc. If the neutrino sources are instead not in nearby galaxies, but originate in binary neutron star coalescences, our limits place the progenitors at z ≳ 0.2. While it is possible, due to the high background from atmospheric neutrinos, that neither event is astrophysical, the MWA observations are nevertheless among the first to follow up neutrino candidates in the radio, and illustrate the promise of wide-field instruments like MWA for detecting EM counterparts to such events.

The development of enhanced ripple-fire identification methods using high frequency data from Pinedale

Energy Technology Data Exchange (ETDEWEB)

Carr, D.; Garbin, H.D.

1996-01-01

A technique called ripple fire used in quarry blasts produces modulations in the spectra of these events. The Deployable Seismic Verification System (DSVS) was installed at the Pinedale Seismic Research Facility in Wyoming, an area with a lot of mining activity. DSVS records at frequencies up to 50 Hz and these data provides us with a unique opportunity to determine how well we can discriminate quarry blasts and if there are operational benefits from using high frequency (>20 Hz) data. We have collected a database of 646 events consisting of known earthquakes, known quarry blasts and unknown signals. We have started to calculate preliminary spectrograms if we get the time-independent banding from the quarry blasts, and at what frequencies the banning occurs. We also detail what we hope to accomplish in FY 1996.

Impact of external events on site evaluation: a probabilistic approach

International Nuclear Information System (INIS)

Jaccarino, E.; Giuliani, P.; Zaffiro, C.

1975-01-01

A probabilistic method is proposed for definition of the reference external events of nuclear sites. The external events taken into account are earthquakes, floods and tornadoes. On the basis of the available historical data for each event it is possible to perform statistical analyses to determine the probability of occurrence on site of events of given characteristics. For earthquakes, the method of analysis takes into consideration both the annual frequency of seismic events in Italy and the probabilistic distribution of areas stricken by each event. For floods, the methods of analysis of hydrological data and the basic criteria for the determination of design events are discussed and the general lines of the hydraulic analysis of a nuclear site are shown. For tornadoes, the statistical analysis has been performed for the events which occurred in Italy during the last 40 years; these events have been classified according to an empirical intensity scale. The probability of each reference event should be a function of the potential radiological damage associated with the particular type of plant which must be installed on the site. Thus the reference event could be chosen such that for the whole of the national territory the risk for safety and environmental protection is the same. (author)

Assessment of events involving transport of radioactive materials in France, 1999-2011

International Nuclear Information System (INIS)

2013-01-01

This report presents transport events involving radioactive materials that occurred in France from 1999 to 2011 and entered in the IRSN's database. For each of the 1,304 events recorded, many parameters have been collected and analysed from information listed in the declarations and reports of events sent by users (type of event, purpose, package design, INES level, etc.). The number of events declared in 2010 and 2011 is slightly higher than the average of 100 events per year. The two main reasons for declaration concern errors in transport documentation or labelling and handling mishaps. The new data confirm the downward trend in frequency of package and vehicle contaminations. A short description of outstanding events in 2010 and 2011 is included. This assessment also gives an outline of the actions recommended by IRSN to avoid recurrence of declared events and improve the safety of radioactive material transport. (authors)

Analysis of area events as part of probabilistic safety assessment for Romanian TRIGA SSR 14 MW reactor

International Nuclear Information System (INIS)

Mladin, D.; Stefan, I.

2005-01-01

The international experience has shown that the external events could be an important contributor to plant/ reactor risk. For this reason such events have to be included in the PSA studies. In the context of PSA for nuclear facilities, external events are defined as events originating from outside the plant, but with the potential to create an initiating event at the plant. To support plant safety assessment, PSA can be used to find methods for identification of vulnerable features of the plant and to suggest modifications in order to mitigate the impact of external events or the producing of initiating events. For that purpose, probabilistic assessment of area events concerning fire and flooding risk and impact is necessary. Due to the relatively large power level amongst research reactors, the approach to safety analysis of Romanian 14 MW TRIGA benefits from an ongoing PSA project. In this context, treatment of external events should be considered. The specific tasks proposed for the complete evaluation of area event analysis are: identify the rooms important for facility safety, determine a relative area event risk index for these rooms and a relative area event impact index if the event occurs, evaluate the rooms specific area event frequency, determine the rooms contribution to reactor hazard state frequencies, analyze power supply and room dependencies of safety components (as pumps, motor operated valves). The fire risk analysis methodology is based on Berry's method [1]. This approach provides a systematic procedure to carry out a relative index of different rooms. The factors, which affect the fire probability, are: personal presence in the room, number and type of ignition sources, type and area of combustibles, fuel available in the room, fuel location, and ventilation. The flooding risk analysis is based on the amount of piping in the room. For accuracy of the information regarding piping a facility walk-about is necessary. In case of flooding risk

A computer aided treatment event recognition system in radiation therapy

International Nuclear Information System (INIS)

Xia, Junyi; Mart, Christopher; Bayouth, John

2014-01-01

Purpose: To develop an automated system to safeguard radiation therapy treatments by analyzing electronic treatment records and reporting treatment events. Methods: CATERS (Computer Aided Treatment Event Recognition System) was developed to detect treatment events by retrieving and analyzing electronic treatment records. CATERS is designed to make the treatment monitoring process more efficient by automating the search of the electronic record for possible deviations from physician's intention, such as logical inconsistencies as well as aberrant treatment parameters (e.g., beam energy, dose, table position, prescription change, treatment overrides, etc). Over a 5 month period (July 2012–November 2012), physicists were assisted by the CATERS software in conducting normal weekly chart checks with the aims of (a) determining the relative frequency of particular events in the authors’ clinic and (b) incorporating these checks into the CATERS. During this study period, 491 patients were treated at the University of Iowa Hospitals and Clinics for a total of 7692 fractions. Results: All treatment records from the 5 month analysis period were evaluated using all the checks incorporated into CATERS after the training period. About 553 events were detected as being exceptions, although none of them had significant dosimetric impact on patient treatments. These events included every known event type that was discovered during the trial period. A frequency analysis of the events showed that the top three types of detected events were couch position override (3.2%), extra cone beam imaging (1.85%), and significant couch position deviation (1.31%). The significant couch deviation is defined as the number of treatments where couch vertical exceeded two times standard deviation of all couch verticals, or couch lateral/longitudinal exceeded three times standard deviation of all couch laterals and longitudinals. On average, the application takes about 1 s per patient when

A computer aided treatment event recognition system in radiation therapy

Energy Technology Data Exchange (ETDEWEB)

Xia, Junyi, E-mail: junyi-xia@uiowa.edu; Mart, Christopher [Department of Radiation Oncology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, Iowa 52242 (United States); Bayouth, John [Department of Radiation Oncology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, Iowa 52242 and Department of Human Oncology, University of Wisconsin - Madison, 600 Highland Avenue, K4/B55, Madison, Wisconsin 53792-0600 (United States)

2014-01-15

Purpose: To develop an automated system to safeguard radiation therapy treatments by analyzing electronic treatment records and reporting treatment events. Methods: CATERS (Computer Aided Treatment Event Recognition System) was developed to detect treatment events by retrieving and analyzing electronic treatment records. CATERS is designed to make the treatment monitoring process more efficient by automating the search of the electronic record for possible deviations from physician's intention, such as logical inconsistencies as well as aberrant treatment parameters (e.g., beam energy, dose, table position, prescription change, treatment overrides, etc). Over a 5 month period (July 2012–November 2012), physicists were assisted by the CATERS software in conducting normal weekly chart checks with the aims of (a) determining the relative frequency of particular events in the authors’ clinic and (b) incorporating these checks into the CATERS. During this study period, 491 patients were treated at the University of Iowa Hospitals and Clinics for a total of 7692 fractions. Results: All treatment records from the 5 month analysis period were evaluated using all the checks incorporated into CATERS after the training period. About 553 events were detected as being exceptions, although none of them had significant dosimetric impact on patient treatments. These events included every known event type that was discovered during the trial period. A frequency analysis of the events showed that the top three types of detected events were couch position override (3.2%), extra cone beam imaging (1.85%), and significant couch position deviation (1.31%). The significant couch deviation is defined as the number of treatments where couch vertical exceeded two times standard deviation of all couch verticals, or couch lateral/longitudinal exceeded three times standard deviation of all couch laterals and longitudinals. On average, the application takes about 1 s per patient when

Probabilistic attribution of individual unprecedented extreme events

Science.gov (United States)

Diffenbaugh, N. S.

2016-12-01

The last decade has seen a rapid increase in efforts to understand the influence of global warming on individual extreme climate events. Although trends in the distributions of climate observations have been thoroughly analyzed, rigorously quantifying the contribution of global-scale warming to individual events that are unprecedented in the observed record presents a particular challenge. This paper describes a method for leveraging observations and climate model ensembles to quantify the influence of historical global warming on the severity and probability of unprecedented events. This approach uses formal inferential techniques to quantify four metrics: (1) the contribution of the observed trend to the event magnitude, (2) the contribution of the observed trend to the event probability, (3) the probability of the observed trend in the current climate and a climate without human influence, and (4) the probability of the event magnitude in the current climate and a climate without human influence. Illustrative examples are presented, spanning a range of climate variables, timescales, and regions. These examples illustrate that global warming can influence the severity and probability of unprecedented extremes. In some cases - particularly high temperatures - this change is indicated by changes in the mean. However, changes in probability do not always arise from changes in the mean, suggesting that global warming can alter the frequency with which complex physical conditions co-occur. Because our framework is transparent and highly generalized, it can be readily applied to a range of climate events, regions, and levels of climate forcing.

Effect of parameters in moving average method for event detection enhancement using phase sensitive OTDR

Science.gov (United States)

Kwon, Yong-Seok; Naeem, Khurram; Jeon, Min Yong; Kwon, Il-bum

2017-04-01

We analyze the relations of parameters in moving average method to enhance the event detectability of phase sensitive optical time domain reflectometer (OTDR). If the external events have unique frequency of vibration, then the control parameters of moving average method should be optimized in order to detect these events efficiently. A phase sensitive OTDR was implemented by a pulsed light source, which is composed of a laser diode, a semiconductor optical amplifier, an erbium-doped fiber amplifier, a fiber Bragg grating filter, and a light receiving part, which has a photo-detector and high speed data acquisition system. The moving average method is operated with the control parameters: total number of raw traces, M, number of averaged traces, N, and step size of moving, n. The raw traces are obtained by the phase sensitive OTDR with sound signals generated by a speaker. Using these trace data, the relation of the control parameters is analyzed. In the result, if the event signal has one frequency, then the optimal values of N, n are existed to detect the event efficiently.

On the Frequency Distribution of Neutral Particles from Low-Energy Strong Interactions

Directory of Open Access Journals (Sweden)

Federico Colecchia

2017-01-01

Full Text Available The rejection of the contamination, or background, from low-energy strong interactions at hadron collider experiments is a topic that has received significant attention in the field of particle physics. This article builds on a particle-level view of collision events, in line with recently proposed subtraction methods. While conventional techniques in the field usually concentrate on probability distributions, our study is, to our knowledge, the first attempt at estimating the frequency distribution of background particles across the kinematic space inside individual collision events. In fact, while the probability distribution can generally be estimated given a model of low-energy strong interactions, the corresponding frequency distribution inside a single event typically deviates from the average and cannot be predicted a priori. We present preliminary results in this direction and establish a connection between our technique and the particle weighting methods that have been the subject of recent investigation at the Large Hadron Collider.

Detection of goal events in soccer videos

Science.gov (United States)

Kim, Hyoung-Gook; Roeber, Steffen; Samour, Amjad; Sikora, Thomas

2005-01-01

In this paper, we present an automatic extraction of goal events in soccer videos by using audio track features alone without relying on expensive-to-compute video track features. The extracted goal events can be used for high-level indexing and selective browsing of soccer videos. The detection of soccer video highlights using audio contents comprises three steps: 1) extraction of audio features from a video sequence, 2) event candidate detection of highlight events based on the information provided by the feature extraction Methods and the Hidden Markov Model (HMM), 3) goal event selection to finally determine the video intervals to be included in the summary. For this purpose we compared the performance of the well known Mel-scale Frequency Cepstral Coefficients (MFCC) feature extraction method vs. MPEG-7 Audio Spectrum Projection feature (ASP) extraction method based on three different decomposition methods namely Principal Component Analysis( PCA), Independent Component Analysis (ICA) and Non-Negative Matrix Factorization (NMF). To evaluate our system we collected five soccer game videos from various sources. In total we have seven hours of soccer games consisting of eight gigabytes of data. One of five soccer games is used as the training data (e.g., announcers' excited speech, audience ambient speech noise, audience clapping, environmental sounds). Our goal event detection results are encouraging.

A methodology for the quantitative risk assessment of major accidents triggered by seismic events

International Nuclear Information System (INIS)

Antonioni, Giacomo; Spadoni, Gigliola; Cozzani, Valerio

2007-01-01

A procedure for the quantitative risk assessment of accidents triggered by seismic events in industrial facilities was developed. The starting point of the procedure was the use of available historical data to assess the expected frequencies and the severity of seismic events. Available equipment-dependant failure probability models (vulnerability or fragility curves) were used to assess the damage probability of equipment items due to a seismic event. An analytic procedure was subsequently developed to identify, evaluate the credibility and finally assess the expected consequences of all the possible scenarios that may follow the seismic events. The procedure was implemented in a GIS-based software tool in order to manage the high number of event sequences that are likely to be generated in large industrial facilities. The developed methodology requires a limited amount of additional data with respect to those used in a conventional QRA, and yields with a limited effort a preliminary quantitative assessment of the contribution of the scenarios triggered by earthquakes to the individual and societal risk indexes. The application of the methodology to several case-studies evidenced that the scenarios initiated by seismic events may have a relevant influence on industrial risk, both raising the overall expected frequency of single scenarios and causing specific severe scenarios simultaneously involving several plant units

An estimation of core damage frequency of a pressurized water reactor during midloop operation due to loss of residual heat removal

International Nuclear Information System (INIS)

Chao, C.C.; Chen, C.T.; Lee, M.

1995-01-01

The core damage frequency caused by loss of residual heat removal (RHR) events was assessed during midloop operation of a Westinghouse-designed three-loop pressurized water reactor. The assessment considers two types of outages (refueling and drained maintenance) and uses failure data collected specifically for shutdown condition. Event trees were developed for five categories of loss of RHR events. Human actions to mitigate the loss of RHR events were identified and human error probabilities were quantified using the human cognitive reliability (HCR) and the technique for human error rate prediction (THERP) models. The results showed that the core damage frequency caused by loss of RHR events during midloop operation was 3.4 x 10 -5 per year. The results also showed that the core damage frequency can be reduced significantly by removing a pressurizer safety valve before entering midloop operation. The establishment of reflux cooling, i.e., decay heat removal through the steam generator secondary side, also plays an important role in mitigating the loss of RHR events during midloop operation

An Initiating-Event Analysis for PSA of Hanul Units 3 and 4: Results and Insights

International Nuclear Information System (INIS)

Kim, Dong-San; Park, Jin Hee

2015-01-01

As a part of the PSA, an initiating-event (IE) analysis was newly performed by considering the current state of knowledge and the requirements of the ASME/ANS probabilistic risk assessment (PRA) standard related to IE analysis. This paper describes the methods of, results and some insights from the IE analysis for the PSA of the Hanul units 3 and 4. In this study, as a part of the PSA for the Hanul units 3 and 4, an initiating-event (IE) analysis was newly performed by considering the current state of knowledge and the requirements of the ASME/ANS probabilistic risk assessment (PRA) standard. In comparison with the previous IE analysis, this study performed a more systematic and detailed analysis to identify potential initiating events, and calculated the IE frequencies by using the state-of-the-art methods and the latest data. As a result, not a few IE frequencies are quite different from the previous frequencies, which can change the major accident sequences obtained from the quantification of the PSA model

Moment Magnitudes of Small to Moderate Size Regional Events from Coda in the Middle East

Science.gov (United States)

Gok, R.; Pasyanos, M. E.; Matzel, E.; Mayeda, K. M.; Walter, W. R.

2010-12-01

The uneven distribution of stations and heterogeneous structure of the Middle East makes it difficult to calculate reliable moment magnitudes in the region. Such magnitudes are important for event characterization, and for yield estimation applications. The complex structure of the lithosphere in the region causes significant variation in the recorded amplitude of body and surface waves that travel along different paths. These 2-D effects are most significant for small and moderate magnitude events, which are most observable at periods 4.5) at low frequencies ( < 0.5 Hz). But even using coda waves, high frequency spectra show considerable scatter. Next, we applied tomographic inversion to the geometrical spreading corrected coda amplitudes to calculate 2-D coda Q. Coda Q results agree well with direct Lg and tectonics of the region. We observe low Q in Anatolian and Iranian plateaus and high Q in Arabian Plate. Applying the 2-D correction reduced the inter-station scatter of the higher frequency spectra, allowing us to obtain reliable moment magnitude estimates for smaller events (Mw < 4.5).

Linguistic spatial classifications of event domains in narratives of crime

Directory of Open Access Journals (Sweden)

Blake Stephen Howald

2010-07-01

Full Text Available Structurally, formal definitions of the linguistic narrative minimally require two temporally linked past-time events. The role of space in this definition, based on spatial language indicating where events occur, is considered optional and non-structural. However, based on narratives with a high frequency of spatial language, recent research has questioned this perspective, suggesting that space is more critical than may be readily apparent. Through an analysis of spatially rich serial criminal narratives, it will be demonstrated that spatial information qualitatively varies relative to narrative events. In particular, statistical classifiers in a supervised machine learning task achieve a 90% accuracy in predicting Pre-Crime, Crime, and Post-Crime events based on spatial (and temporal information. Overall, these results suggest a deeper spatial organization of discourse, which not only provides practical event resolution possibilities, but also challenges traditional formal linguistic definitions of narrative.

Estimative of core damage frequency in IPEN'S IEA-R1 research reactor due to the initiating event of loss of coolant caused by large rupture in the pipe of the primary circuit

International Nuclear Information System (INIS)

Hirata, Daniel Massami; Sabundjian, Gaiane; Cabral, Eduardo Lobo Lustosa

2009-01-01

The National Commission of Nuclear Energy (CNEN), which is the Brazilian nuclear regulatory commission, imposes safety and licensing standards in order to ensure that the nuclear power plants operate in a safe way. For licensing a nuclear reactor one of the demands of CNEN is the simulation of some accidents and thermalhydraulic transients considered as design base to verify the integrity of the plant when submitted to adverse conditions. The accidents that must be simulated are those that present large probability to occur or those that can cause more serious consequences. According to the FSAR (Final Safety Analysis Report) the initiating event that can cause the largest damage in the core, of the IEA-R1 research reactor at IPEN-CNEN/SP, is the LOCA (Loss of Coolant Accident). The objective of this paper is estimate the frequency of the IEA-R1 core damage, caused by this initiating event. In this paper we analyze the accident evolution and performance of the systems which should mitigate this event: the Emergency Coolant Core System (ECCS) and the isolated pool system. They will be analyzed by means of the event tree. In this work the reliability of these systems are also quantified using the fault tree. (author)

Rising cyclin-CDK levels order cell cycle events.

Directory of Open Access Journals (Sweden)

Catherine Oikonomou

Full Text Available Diverse mitotic events can be triggered in the correct order and time by a single cyclin-CDK. A single regulator could confer order and timing on multiple events if later events require higher cyclin-CDK than earlier events, so that gradually rising cyclin-CDK levels can sequentially trigger responsive events: the "quantitative model" of ordering.This 'quantitative model' makes predictions for the effect of locking cyclin at fixed levels for a protracted period: at low cyclin levels, early events should occur rapidly, while late events should be slow, defective, or highly variable (depending on threshold mechanism. We titrated the budding yeast mitotic cyclin Clb2 within its endogenous expression range to a stable, fixed level and measured time to occurrence of three mitotic events: growth depolarization, spindle formation, and spindle elongation, as a function of fixed Clb2 level. These events require increasingly more Clb2 according to their normal order of occurrence. Events occur efficiently and with low variability at fixed Clb2 levels similar to those observed when the events normally occur. A second prediction of the model is that increasing the rate of cyclin accumulation should globally advance timing of all events. Moderate (<2-fold overexpression of Clb2 accelerates all events of mitosis, resulting in consistently rapid sequential cell cycles. However, this moderate overexpression also causes a significant frequency of premature mitoses leading to inviability, suggesting that Clb2 expression level is optimized to balance the fitness costs of variability and catastrophe.We conclude that mitotic events are regulated by discrete cyclin-CDK thresholds. These thresholds are sequentially triggered as cyclin increases, yielding reliable order and timing. In many biological processes a graded input must be translated into discrete outputs. In such systems, expression of the central regulator is likely to be tuned to an optimum level, as we

Frequency dependent power fluctuations: a feature of the ESR system or physical?

Directory of Open Access Journals (Sweden)

Y. Ogawa

Full Text Available The k-dependence of the received power in high signal-to-noise ratio (SNR conditions, occurring for naturally enhanced ion-acoustic lines (NEIALs and for real satellites, is investigated by using the EISCAT Svalbard Radar (ESR, where the data are recorded in eight separate channels using different frequencies. For the real satellites we find large variations of the relative powers from event to event, which is probably due to a different number of pulses catching the satellite over the integration period. However, the large power difference remains unexpected in one case. Over short time scale (< 10 s the relative power difference seems to be highly stable. For most NEIAL events the differences between channels are within noise level. In a few cases variations of the relative power well above both the estimated and expected 1-sigma level occur over a signal preintegrated profile. We thus suggest that the frequency dependence of the power in NEIAL events has its origin in the scattering medium itself as the most plausible explanation.

Key words: Ionosphere (auroral ionosphere; plasma waves and instabilities; instruments and techniques

Frequency dependent power fluctuations: a feature of the ESR system or physical?

Directory of Open Access Journals (Sweden)

Y. Ogawa

2000-09-01

Full Text Available The k-dependence of the received power in high signal-to-noise ratio (SNR conditions, occurring for naturally enhanced ion-acoustic lines (NEIALs and for real satellites, is investigated by using the EISCAT Svalbard Radar (ESR, where the data are recorded in eight separate channels using different frequencies. For the real satellites we find large variations of the relative powers from event to event, which is probably due to a different number of pulses catching the satellite over the integration period. However, the large power difference remains unexpected in one case. Over short time scale (< 10 s the relative power difference seems to be highly stable. For most NEIAL events the differences between channels are within noise level. In a few cases variations of the relative power well above both the estimated and expected 1-sigma level occur over a signal preintegrated profile. We thus suggest that the frequency dependence of the power in NEIAL events has its origin in the scattering medium itself as the most plausible explanation.Key words: Ionosphere (auroral ionosphere; plasma waves and instabilities; instruments and techniques

Single-Event Effects in High-Frequency Linear Amplifiers: Experiment and Analysis

Science.gov (United States)

Zeinolabedinzadeh, Saeed; Ying, Hanbin; Fleetwood, Zachary E.; Roche, Nicolas J.-H.; Khachatrian, Ani; McMorrow, Dale; Buchner, Stephen P.; Warner, Jeffrey H.; Paki-Amouzou, Pauline; Cressler, John D.

2017-01-01

The single-event transient (SET) response of two different silicon-germanium (SiGe) X-band (8-12 GHz) low noise amplifier (LNA) topologies is fully investigated in this paper. The two LNAs were designed and implemented in 130nm SiGe HBT BiCMOS process technology. Two-photon absorption (TPA) laser pulses were utilized to induce transients within various devices in these LNAs. Impulse response theory is identified as a useful tool for predicting the settling behavior of the LNAs subjected to heavy ion strikes. Comprehensive device and circuit level modeling and simulations were performed to accurately simulate the behavior of the circuits under ion strikes. The simulations agree well with TPA measurements. The simulation, modeling and analysis presented in this paper can be applied for any other circuit topologies for SET modeling and prediction.

Event streaming in the online system

CERN Document Server

Klous, S; The ATLAS collaboration

2010-01-01

The Large Hadron Collider (LHC), currently in operation at CERN in Geneva, is a circular 27-kilometer-circumference machine, accelerating bunches of protons in opposite directions. The bunches will cross at four different interaction points with a bunch-crossing frequency of 40MHz. ATLAS, the largest LHC experiment, registers the signals induced by particles traversing the detector components on each bunch crossing. When this happens a total of around 1.5MB of data are collected. This results in a data rate of around 60 TB/s flowing out of the detector. Note that the available event storage space is limited to about 6 PB per year. With an operational period of about 20 million seconds per year, this requires a data reduction factor of 200:000 in the trigger and data acquisition (TDAQ) system. Events included in the recording rate budget are already subdivided and organized by ATLAS during data acquisition. So, the TDAQ system does not only take care of data reduction, but also organizes the collected events. ...

Soil erosion under multiple time-varying rainfall events

Science.gov (United States)

Heng, B. C. Peter; Barry, D. Andrew; Jomaa, Seifeddine; Sander, Graham C.

2010-05-01

Soil erosion is a function of many factors and process interactions. An erosion event produces changes in surface soil properties such as texture and hydraulic conductivity. These changes in turn alter the erosion response to subsequent events. Laboratory-scale soil erosion studies have typically focused on single independent rainfall events with constant rainfall intensities. This study investigates the effect of multiple time-varying rainfall events on soil erosion using the EPFL erosion flume. The rainfall simulator comprises ten Veejet nozzles mounted on oscillating bars 3 m above a 6 m × 2 m flume. Spray from the nozzles is applied onto the soil surface in sweeps; rainfall intensity is thus controlled by varying the sweeping frequency. Freshly-prepared soil with a uniform slope was subjected to five rainfall events at daily intervals. In each 3-h event, rainfall intensity was ramped up linearly to a maximum of 60 mm/h and then stepped down to zero. Runoff samples were collected and analysed for particle size distribution (PSD) as well as total sediment concentration. We investigate whether there is a hysteretic relationship between sediment concentration and discharge within each event and how this relationship changes from event to event. Trends in the PSD of the eroded sediment are discussed and correlated with changes in sediment concentration. Close-up imagery of the soil surface following each event highlight changes in surface soil structure with time. This study enhances our understanding of erosion processes in the field, with corresponding implications for soil erosion modelling.

Climate change impacts on the duration and frequency of combined sewer overflows

Science.gov (United States)

Fortier, C.; Mailhot, A.

2012-12-01

Combined sewer overflows (CSO) occur when large rainwater inflow from heavy precipitation exceeds the capacity of urban combined sewage systems. Many American and European cities with old sewage systems see their water quality significantly deteriorate during such events. In the long term, changes in the rainfall regime due to climate change may lead to more severe and more frequent CSO episodes and thus compel cities to review their global water management. The overall objective of this study is to investigate how climate change will impact CSO frequency and duration. Data from rain gauges located nearby 30 overflow outfalls, in southern Quebec, Canada, were used to identify rain events leading to overflows, using CSO monitored data from May to October during the period 2007-2009. For each site, occurrence and duration of CSO events were recorded and linked to a rainfall event. Many rain events features can be used to predict CSO events, such as total depth, duration, average intensity and peak intensity. Results based on Pearson product-moment correlation coefficients and multiple regression analysis show that CSO occurrence is best predicted by total rainfall. A methodology is proposed to calculate the CSO probability of occurrence and duration for each site of interest using rainfall series as input data. Monte Carlo method is then used to estimate CSO frequency. To evaluate the climate change impact on CSO, these relationships are used with simulated data from the Canadian Regional Climate Model to compare the distribution of annual number of CSO events over the 1960-1990 period and the 2070-2100 period.

Synthesis of High-Frequency Ground Motion Using Information Extracted from Low-Frequency Ground Motion

Science.gov (United States)

Iwaki, A.; Fujiwara, H.

2012-12-01

Broadband ground motion computations of scenario earthquakes are often based on hybrid methods that are the combinations of deterministic approach in lower frequency band and stochastic approach in higher frequency band. Typical computation methods for low-frequency and high-frequency (LF and HF, respectively) ground motions are the numerical simulations, such as finite-difference and finite-element methods based on three-dimensional velocity structure model, and the stochastic Green's function method, respectively. In such hybrid methods, LF and HF wave fields are generated through two different methods that are completely independent of each other, and are combined at the matching frequency. However, LF and HF wave fields are essentially not independent as long as they are from the same event. In this study, we focus on the relation among acceleration envelopes at different frequency bands, and attempt to synthesize HF ground motion using the information extracted from LF ground motion, aiming to propose a new method for broad-band strong motion prediction. Our study area is Kanto area, Japan. We use the K-NET and KiK-net surface acceleration data and compute RMS envelope at four frequency bands: 0.5-1.0 Hz, 1.0-2.0 Hz, 2.0-4.0 Hz, .0-8.0 Hz, and 8.0-16.0 Hz. Taking the ratio of the envelopes of adjacent bands, we find that the envelope ratios have stable shapes at each site. The empirical envelope-ratio characteristics are combined with low-frequency envelope of the target earthquake to synthesize HF ground motion. We have applied the method to M5-class earthquakes and a M7 target earthquake that occurred in the vicinity of Kanto area, and successfully reproduced the observed HF ground motion of the target earthquake. The method can be applied to a broad band ground motion simulation for a scenario earthquake by combining numerically-computed low-frequency (~1 Hz) ground motion with the empirical envelope ratio characteristics to generate broadband ground motion

Suitable Method of Overloading for Fast Primary Frequency Control from Offshore Wind Power Plants in Multi-Terminal DC Grid

DEFF Research Database (Denmark)

Sakamuri, Jayachandra N.; Hansen, Anca Daniela; Altin, Müfit

2017-01-01

Increased penetration of offshore wind power plants (OWPPs) demands frequency control services from them. Overloading the wind turbine, for few seconds after the under frequency event, to utilize its kinetic energy seems promising option for fast primary frequency control. Two methods...

Frequency-volume Statistics of Rock Falls: Examples From France, Italy and California

Science.gov (United States)

Dussauge-Peisser, C.; Guzzetti, F.; Wieczorek, G. F.

There is accumulating evidence that the distribution of rock-fall volume exhibits power law (fractal) statistics in different physiographic and geologic environments. We have studied the frequency-volume statistics of rock falls in three areas: Grenoble, France; Umbria, Italy; and Yosemite Valley, California, USA. We present a compari- son of the datasets currently available. For the Grenoble area a catalogue of rock falls between 1248 and 1995 occurred along a 120 km long limestone cliff. The dataset contains information on 105 rock-fall events ranging in size from 3xE-2 to 5xE8 m3. Only the time window 1935-1995 is considered in the study, involving 87 events from 1E-2 to 1E6 m3. The cumulative frequency-volume statistics follow a power-law (frac- tal) relationship with exponent b = -0.4 over the range 50 m3 Yosemite Valley the database contains information on historical (1851-2001) rock falls (122), rock slides (251) and prehistoric rock avalanches (5). For Yosemite, the non-cumulative frequency-volume statistics of rock falls and rock slides are very sim- ilar and correlate well with a power-law (fractal) relation with exponent beta = -1.4, over the range 30 m3 events and earthquake triggered events.

Regional Frequency and Uncertainty Analysis of Extreme Precipitation in Bangladesh

Science.gov (United States)

Mortuza, M. R.; Demissie, Y.; Li, H. Y.

2014-12-01

Increased frequency of extreme precipitations, especially those with multiday durations, are responsible for recent urban floods and associated significant losses of lives and infrastructures in Bangladesh. Reliable and routinely updated estimation of the frequency of occurrence of such extreme precipitation events are thus important for developing up-to-date hydraulic structures and stormwater drainage system that can effectively minimize future risk from similar events. In this study, we have updated the intensity-duration-frequency (IDF) curves for Bangladesh using daily precipitation data from 1961 to 2010 and quantified associated uncertainties. Regional frequency analysis based on L-moments is applied on 1-day, 2-day and 5-day annual maximum precipitation series due to its advantages over at-site estimation. The regional frequency approach pools the information from climatologically similar sites to make reliable estimates of quantiles given that the pooling group is homogeneous and of reasonable size. We have used Region of influence (ROI) approach along with homogeneity measure based on L-moments to identify the homogenous pooling groups for each site. Five 3-parameter distributions (i.e., Generalized Logistic, Generalized Extreme value, Generalized Normal, Pearson Type Three, and Generalized Pareto) are used for a thorough selection of appropriate models that fit the sample data. Uncertainties related to the selection of the distributions and historical data are quantified using the Bayesian Model Averaging and Balanced Bootstrap approaches respectively. The results from this study can be used to update the current design and management of hydraulic structures as well as in exploring spatio-temporal variations of extreme precipitation and associated risk.

Review of events at large pool-type irradiators

International Nuclear Information System (INIS)

Trager, E.A. Jr.

1989-03-01

Large pool-type gamma irradiators are used in applications such as the ''cold'' sterilization of medical and pharmaceutical supplies, and recent changes in federal regulations make it possible they will be used extensively in the preservation of foodstuffs. Because of this possible large increase in the use of irradiators, the Office of Nuclear Materials Safety and Safeguards was interested in knowing what events had occurred at irradiators. The event data would be used as background in developing new regulations on irradiators. Therefore, AEOD began a study of the operating experience at large, wet source storage gamma irradiators. The scope of the study was to assess all available operating information on large (≥ 250,000 curie), pool-type irradiators licensed by both the NRC and the Agreement States, and events at foreign facilities. The study found that about 0.12 events have been reported per irradiator-year. Most of these events were precursor events, in that there was no evidence of damage to the radioactive sources or degradation in the level of safety of the facility. Events with more significant impacts had a reported frequency of about 0.01 event per irradiator-year. However, the actual rate of occurrence of events of concern to the staff may be higher because there are few specific reporting requirements for events at irradiators. It is suggested that during development of a regulation for large pool-type irradiators consideration be given to specifying requirements for: reporting breakdowns in access control systems; periodic inspection of the source movement and suspension system; systems to detect source leakage and product contamination; allowable pool leakage; and feedback of information on operational events involving safety-important systems

"MENTAL STRAIN, MORE IMPORTANT THAN STRESSFUL LIFE EVENTS IN MYOCARDIAL INFARCTION"

OpenAIRE

M. Moosavi; M. Eslami; O. Sheikh Bagloo B. Birashk

2004-01-01

Stressful life events may play an important role in coronary heart disease and sudden cardiac death. This study was performed to compare the frequency of stressful events and mental strain in patients with acute myocardial infarction (MI) and normal population. A case-control study was performed on 50 survivors of MI and 50 controls with no evidence of cardiovascular disease, matched by age, gender, education, race, and number of family members. A questionnaire was used to determine the numbe...

Conjunction Assessment Late-Notice High-Interest Event Investigation: Space Weather Aspects

Science.gov (United States)

Pachura, D.; Hejduk, M. D.

2016-01-01

Late-notice events usually driven by large changes in primary (protected) object or secondary object state. Main parameter to represent size of state change is component position difference divided by associated standard deviation (epsilon divided by sigma) from covariance. Investigation determined actual frequency of large state changes, in both individual and combined states. Compared them to theoretically expected frequencies. Found that large changes ( (epsilon divided by sigma) is greater than 3) in individual object states occur much more frequently than theory dictates. Effect is less pronounced in radial components and in events with probability of collision (Pc) greater than 1 (sup -5) (1e-5). Found combined state matched much closer to theoretical expectation, especially for radial and cross-track. In-track is expected to be the most vulnerable to modeling errors, so not surprising that non-compliance largest in this component.

Assessment of the Chile 2010 and Japan 2011 Tsunami Events in the Galapagos Islands

Science.gov (United States)

Renteria, Willington; Lynett, Patrick

2015-04-01

The object of this study is to present an analysis of measurements and observations from the Chile 2010 and Japan 2011 tsunamis, in order to understand the particular response of the Galápagos Islands to the occurrence of these extreme events. There was very limited data measured in the Galápagos during the tsunami events, other than a high-frequency and continuous record of each event logged at the two tidal gauge stations. With this data, a wavelet analysis is performed with the aim of discriminating different patterns in wave periods along the record of observation and to recognize the frequency response of the islands to an incoming tsunami. During both events, a clear and persistent signal is found in the period range of ten to twelve minutes for Baltra tide gauge, and in the range of seventeen to twenty minutes for Santa Cruz tide gauge. Both of these persistent signals are speculated to be a shelf resonant mode particular to the Galápagos Islands and the Galápagos Platform.

N reactor external events probabilistic risk assessment

International Nuclear Information System (INIS)

Baxter, J.T.

1989-01-01

An external events probabilistic risk assessment of the N Reactor has been completed. The methods used are those currently being proposed for external events analysis in NUREG-1150. Results are presented for the external hazards that survived preliminary screening. They are earthquake, fire, and external flood. Core damage frequencies for these hazards are shown to be comparable to those for commercial pressurized water reactors. Dominant fire sequences are described and related to 10 CFR 50, Appendix R design requirements. Potential remedial measures that reduce fire core damage risk are described including modifications to fire protection systems, procedure changes, and addition of new administrative controls. Dominant seismic sequences are described. The effect of non-safety support system dependencies on seismic risk is presented

Analysis and modeling of a hail event consequences on a building portfolio

Science.gov (United States)

Nicolet, Pierrick; Voumard, Jérémie; Choffet, Marc; Demierre, Jonathan; Imhof, Markus; Jaboyedoff, Michel

2014-05-01

North-West Switzerland has been affected by a severe Hail Storm in July 2011, which was especially intense in the Canton of Aargau. The damage cost of this event is around EUR 105 Million only for the Canton of Aargau, which corresponds to half of the mean annual consolidated damage cost of the last 20 years for the 19 Cantons (over 26) with a public insurance. The aim of this project is to benefit from the collected insurance data to better understand and estimate the risk of such event. In a first step, a simple hail event simulator, which has been developed for a previous hail episode, is modified. The geometric properties of the storm is derived from the maximum intensity radar image by means of a set of 2D Gaussians instead of using 1D Gaussians on profiles, as it was the case in the previous version. The tool is then tested on this new event in order to establish its ability to give a fast damage estimation based on the radar image and buildings value and location. The geometrical properties are used in a further step to generate random outcomes with similar characteristics, which are combined with a vulnerability curve and an event frequency to estimate the risk. The vulnerability curve comes from a 2009 event and is improved with data from this event, whereas the frequency for the Canton is estimated from insurance records. In addition to this regional risk analysis, this contribution aims at studying the relation of the buildings orientation with the damage rate. Indeed, it is expected that the orientation of the roof influences the aging of the material by controlling the frequency and amplitude of thaw-freeze cycles, changing then the vulnerability over time. This part is established by calculating the hours of sunshine, which are used to derive the material temperatures. This information is then compared with insurance claims. A last part proposes a model to study the hail impact on a building, by modeling the different equipment on each facade of the

Mediators of the relationship between life events and memory functioning in a community sample of adults

NARCIS (Netherlands)

Korten, N.C.M.; Sliwinski, M.J.; Comijs, H.C.; Smyth, J.M.

2014-01-01

The present study examines the association of frequency and severity of life events with memory functioning in a community sample of adults. We tested the hypothesis that stress-related cognitive interference mediated the effects of recent life events on cognition, in addition to examining the

Decline of Low-Frequency Hearing in People With Ski-Slope Hearing Loss; Implications for Electrode Array Insertion.

Science.gov (United States)

Schuurbiers, Jasper; Dingemanse, Gertjan; Metselaar, Mick

2017-12-01

The decline of low-frequency hearing in people with ski-slope hearing loss varies and might depend on etiology. People with ski-sloping hearing loss might benefit from cochlear implantation with preservation of residual hearing. To reduce the risk of losing low-frequency hearing after implantation, the electrode-array can be inserted partially up to the desired frequency. That, however, obstructs electrical stimulation of lower frequencies. To decide between complete or partial insertion, knowledge regarding the natural decline of low-frequency hearing is helpful. Patients with at least two ski-slope audiograms over time were selected. We calculated progression at lower frequencies for 320 patients. Etiologies for hearing loss were retrieved from medical records. Progression of hearing loss was analyzed separately for patients with uni- and bilateral hearing losses. Relative progression of hearing loss was obtained by comparing progression to a reference group. Average progression of PTA was 1.73 dB/yr and was not significantly different in the bilateral and unilateral group. Etiologies that did not show significantly more progression compared with the reference group could be identified as single or short-lasting pathologic events, whereas long-lasting conditions had significant more progression of PTA. Patients with a ski-slope hearing loss that was caused by a single or short-lasting event have low progression rate and are viable for partial insertion to minimize the risk of damaging residual low-frequency hearing. In the absence of such an event, complete insertion should be considered because faster than normal deterioration of low-frequency hearing over time will probably limit the advantage of preservation of residual hearing.

The frequency dependence of friction in experiment, theory, and observations of low frequency earthquakes

Science.gov (United States)

Thomas, A.; Beeler, N. M.; Burgmann, R.; Shelly, D. R.

2011-12-01

Low frequency earthquakes (LFEs) are small amplitude, short duration events composing tectonic tremor, probably generated by shear slip on asperities downdip of the seismogenic zone. In Parkfield, Shelly and Hardebeck [2010] have identified 88 LFE families, or hypocentral locations, that contain over half a million LFEs since 2001 on a 160-km-long section of the San Andreas fault between 16 and 30 km depth. A number of studies have demonstrated the extreme sensitivity of low frequency earthquakes (LFEs) near Parkfield to stress changes ranging from contingent upon the amplitude and frequency content of the applied stress. We attempt to test this framework by comparing observations of LFEs triggered in response to stresses spanning several orders of magnitude in both frequency and amplitude (e.g. tides, teleseismic surface waves, static stress changes, etc.) to the predicted response of a single degree of freedom slider block model with rate and state dependent strength. The sensitivity of failure time in the friction model as developed in previous studies does not distinguish between shear and normal stresses; laboratory experiments show a more complicated sensitivity of failure time to normal stress change than in the published model. Because the shear and normal tidal stresses at Parkfield have different amplitudes and are not in phase, we have modified the model to include the expected sensitivity to normal stress. Our prior investigations of the response of both regular and low frequency earthquakes to tidal stresses [Thomas et al., 2009; Shelly and Johnson, 2011] are qualitatively consistent with the predictions of the friction model , as both the timing and degree (probability) of correlation are in agreement.

Characterization of a subset of large amplitude noise events in VIRGO science run 1 (VSR1)

International Nuclear Information System (INIS)

Del Prete, M

2009-01-01

We report about a characterization study of a subset of large amplitude noise events present in the main data channel of the VIRGO detector. The main motivation of this study is the identification of auxiliary channels which can be used to define veto procedures. We characterized large amplitude events both in the time and in the frequency domain. We found evidence of coincidences among these and disturbances detected by magnetometer's sensors or inside the main power supply. In some cases the disturbances were produced by events in the VIRGO environment such as lightnings, main power supply glitches and airplane traffic. We have found two auxiliary channels that can be used to veto events generated by main power supply glitches or lightnings. A procedure to clean the main channel based on them has been successfully tested. We have also identified two auxiliary channels which are useful for the identification of events generated by airplane traffic. These can be used to implement a vetoing procedure both in the time and in the frequency domain.

Characterization of a subset of large amplitude noise events in VIRGO science run 1 (VSR1)

Energy Technology Data Exchange (ETDEWEB)

Del Prete, M [Universita di Pisa, Lungarno Pacinotti, 43, 56126 Pisa Instituto Nazionale di Fisica Nucleare sez. di Pisa, ED C polo Fibonacci, Via F Buonarroti 2, 56127, Pisa (Italy)

2009-10-21

We report about a characterization study of a subset of large amplitude noise events present in the main data channel of the VIRGO detector. The main motivation of this study is the identification of auxiliary channels which can be used to define veto procedures. We characterized large amplitude events both in the time and in the frequency domain. We found evidence of coincidences among these and disturbances detected by magnetometer's sensors or inside the main power supply. In some cases the disturbances were produced by events in the VIRGO environment such as lightnings, main power supply glitches and airplane traffic. We have found two auxiliary channels that can be used to veto events generated by main power supply glitches or lightnings. A procedure to clean the main channel based on them has been successfully tested. We have also identified two auxiliary channels which are useful for the identification of events generated by airplane traffic. These can be used to implement a vetoing procedure both in the time and in the frequency domain.

Changes in Extreme Events and the Potential Impacts on National Security

Science.gov (United States)

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.

New method to analyze super-family events observed with emulsion chambers

International Nuclear Information System (INIS)

Amenomori, M.

1997-01-01

The authors have developed a clustering method to analyze family events observed with emulsion chambers at high mountains. The main purpose of this analysis is to estimate the main production height of individual events, angular spread of gamma-rays in each event and so on. These enable them to investigate hadronic interactions at energies over 10 16 eV inaccessible by the present high-energy accelerators. they examined their clustering method using Monte Carlo events, and found that for the family events whose production height is low (within 2-3 km above the observation point in air), their production heights and lateral spreads are well reproduced. They further applied their method to the super-family events (ΣE γ > 1000 TeV) observed with emulsion chambers at Mt. Kanbala (5500 m above sea-level). The results seem to suggest that particle production with large transverse momentum occurs with considerable frequency even in the fragmentation region in the energy region over 10 16 eV

Investigation of frequencies of waves at different traveltimes

International Nuclear Information System (INIS)

Babbel, G.; Engelhard, L.; Schimanowski, C.

1978-03-01

After finishing preparing theoretical work changes of frequency spectra due to traletime and interbeded layers have been investigated using seismic field recordings, synthetic models and modelseismic records. (three layer model). The most important investigations have been done in order to determine the absorption of seismic waves. Engelhard (Braunschweig) and Babbel (Clausthal) demonstrated that classical methods for determination of absorption (amplitude investigations, division of frequency spectra) using real data cannot solve these problems. Theoretical consideration should give good results of the Q-factor in case of wavelets not superimposed by multiple events. The experiences obtained may be seen as the base of further investigations. (orig.) [de

Regularization of Instantaneous Frequency Attribute Computations

Science.gov (United States)

Yedlin, M. J.; Margrave, G. F.; Van Vorst, D. G.; Ben Horin, Y.

2014-12-01

We compare two different methods of computation of a temporally local frequency:1) A stabilized instantaneous frequency using the theory of the analytic signal.2) A temporally variant centroid (or dominant) frequency estimated from a time-frequency decomposition.The first method derives from Taner et al (1979) as modified by Fomel (2007) and utilizes the derivative of the instantaneous phase of the analytic signal. The second method computes the power centroid (Cohen, 1995) of the time-frequency spectrum, obtained using either the Gabor or Stockwell Transform. Common to both methods is the necessity of division by a diagonal matrix, which requires appropriate regularization.We modify Fomel's (2007) method by explicitly penalizing the roughness of the estimate. Following Farquharson and Oldenburg (2004), we employ both the L curve and GCV methods to obtain the smoothest model that fits the data in the L2 norm.Using synthetic data, quarry blast, earthquakes and the DPRK tests, our results suggest that the optimal method depends on the data. One of the main applications for this work is the discrimination between blast events and earthquakesFomel, Sergey. " Local seismic attributes." , Geophysics, 72.3 (2007): A29-A33.Cohen, Leon. " Time frequency analysis theory and applications." USA: Prentice Hall, (1995).Farquharson, Colin G., and Douglas W. Oldenburg. "A comparison of automatic techniques for estimating the regularization parameter in non-linear inverse problems." Geophysical Journal International 156.3 (2004): 411-425.Taner, M. Turhan, Fulton Koehler, and R. E. Sheriff. " Complex seismic trace analysis." Geophysics, 44.6 (1979): 1041-1063.

Epinephrine syringe exchange events in a paediatric cardiovascular ICU: analysing the storm.

Science.gov (United States)

Achuff, Barbara-Jo; Achuff, Jameson C; Park, Hwan H; Moffett, Brady; Acosta, Sebastian; Rusin, Craig G; Checchia, Paul A

2018-03-01

Introduction Haemodynamically unstable patients can experience potentially hazardous changes in vital signs related to the exchange of depleted syringes of epinephrine to full syringes. The purpose was to determine the measured effects of epinephrine syringe exchanges on the magnitude, duration, and frequency of haemodynamic disturbances in the hour after an exchange event (study) relative to the hours before (control). Materials and methods Beat-to-beat vital signs recorded every 2 seconds from bedside monitors for patients admitted to the paediatric cardiovascular ICU of Texas Children's Hospital were collected between 1 January, 2013 and 30 June, 2015. Epinephrine syringe exchanges without dose/flow change were obtained from electronic records. Time, magnitude, and duration of changes in systolic blood pressure and heart rate were characterised using Matlab. Significant haemodynamic events were identified and compared with control data. In all, 1042 syringe exchange events were found and 850 (81.6%) had uncorrupted data for analysis. A total of 744 (87.5%) exchanges had at least 1 associated haemodynamic perturbation including 2958 systolic blood pressure and 1747 heart-rate changes. Heart-rate perturbations occurred 37% before exchange and 63% after exchange, and 37% of systolic blood pressure perturbations happened before syringe exchange, whereas 63% occurred after syringe exchange with significant differences found in systolic blood pressure frequency (pexchange events.

Evaluation of potential severe accidents during low power and shutdown operations at Grand Gulf, Unit 1: Analysis of core damage frequency from internally induced flooding events for Plant Operational State 5 during a refueling outage. Volume 4

International Nuclear Information System (INIS)

Dandini, V.; Staple, B.; Kirk, H.; Whitehead, D.; Forester, J.

1994-07-01

An estimate of the contribution of internal flooding to the mean core damage frequency at the Grand Gulf Nuclear Station was calculated for Plant Operational State 5 during a refueling outage. Pursuant to this objective, flood zones and sources were identified and flood volumes were calculated. Equipment necessary for the maintenance of plant safety was identified and its vulnerability to flooding was determined. Event trees and fault trees were modified or developed as required, and PRA quantification was performed using the IRRAS code. The mean core damage frequency estimate for GGNS during POS 5 was found to be 2.3 E-8 per year

A novel method for inferring RFID tag reader recordings into clinical events.

Science.gov (United States)

Chang, Yung-Ting; Syed-Abdul, Shabbir; Tsai, Chung-You; Li, Yu-Chuan

2011-12-01

Nosocomial infections (NIs) are among the important indicators used for evaluating patients' safety and hospital performance during accreditation of hospitals. NI rate is higher in Intensive Care Units (ICUs) than in the general wards because patients require intense care involving both invasive and non-invasive clinical procedures. The emergence of Superbugs is motivating health providers to enhance infection control measures. Contact behavior between health caregivers and patients is one of the main causes of cross infections. In this technology driven era remote monitoring of patients and caregivers in the hospital setting can be performed reliably, and thus is in demand. Proximity sensing using radio frequency identification (RFID) technology can be helpful in capturing and keeping track on all contact history between health caregivers and patients for example. This study intended to extend the use of proximity sensing of radio frequency identification technology by proposing a model for inferring RFID tag reader recordings into clinical events. The aims of the study are twofold. The first aim is to set up a Contact History Inferential Model (CHIM) between health caregivers and patients. The second is to verify CHIM with real-time observation done at the ICU ward. A pre-study was conducted followed by two study phases. During the pre-study proximity sensing of RFID was tested, and deployment of the RFID in the Clinical Skill Center in one of the medical centers in Taiwan was done. We simulated clinical events and developed CHIM using variables such as duration of time, frequency, and identity (tag) numbers assigned to caregivers. All clinical proximity events are classified into close-in events, contact events and invasive events. During the first phase three observers were recruited to do real time recordings of all clinical events in the Clinical Skill Center with the deployed automated RFID interaction recording system. The observations were used to verify

Measuring the fractal dimension of the seismic source through the high-frequency fall-off of source spectra

International Nuclear Information System (INIS)

Wu, Z.L.; Chen, Y.T.; Kim, S.G.

1995-09-01

Using the Wigner-distribution estimation, the high-frequency fall-off of source spectra was estimated. The technique was applied to the analysis of the source spectra of the July 22, 1994, Vladivostok M6.4 deep-focus earthquake and that of the July 22, 1994, Northern Japan Sea M5.7 deep-focus earthquake. It is shown that the high-frequency fall-off of the source spectra of these two earthquakes may be characterized by two parts. Between the first corner frequency f 1 and the second corner frequency f 2 , the high-frequency fall-off of the source spectra can be represented by f 5.0 : above f 2 , the high-frequency fall-off can be represented by f 1.4 . In the perspective of the fractal geometry of earthquake source, it seems that the deep-focus earthquakes under consideration may be characterized as being composed of some 'sub events'. On the other hand, each sub event has its complex structure. (author). 12 refs, 3 figs, 1 tab

Effect of face fracturing on shear wave coda quality factor estimated from acoustic emission events

CSIR Research Space (South Africa)

Kgarume, T

2013-10-01

Full Text Available by the number of events. It was found that the Qc dependency on frequency follows a power law. For face events, the power law is given by ( ) 99.006.0 ffQ = and ( ) 58.1003.0 ffQ = for fault slip events. Qc derived from face events was found to be lower than... to be n = 0.99, resulting in the relation: ( ) 99.006.0 ffQ = . For fault slip events, n = 1.58, resulting in the relation: ( ) 58.1003.0 ffQ = . The lower degree of dependency suggests that fractures ahead of the stope face tend to reduce...

Emergency Physicians as Good Samaritans: Survey of Frequency, Locations, Supplies and Medications

Directory of Open Access Journals (Sweden)

Taylor W. Burkholder, MD, MPH

2016-01-01

Full Text Available Introduction: Little is known about the frequency and locations in which emergency physicians (EPs are bystanders to an accident or emergency; equally uncertain is which contents of an “emergency kit” may be useful during such events. The aim of this study was to describe the frequency and locations of Good Samaritan acts by EPs and also determine which emergency kit supplies and medications were most commonly used by Good Samaritans. Methods: We conducted an electronic survey among a convenience sample of EPs in Colorado. Results: Respondents reported a median frequency of 2.0 Good Samaritan acts per five years of practice, with the most common locations being sports and entertainment events (25%, road traffic accidents (21%, and wilderness settings (19%. Of those who had acted as Good Samaritans, 86% reported that at least one supply would have been useful during the most recent event, and 66% reported at least one medication would have been useful. The most useful supplies were gloves (54%, dressings (34%, and a stethoscope (20%, while the most useful medications were oxygen (19%, intravenous fluids (17%, and epinephrine (14%. Conclusion: The majority of EPs can expect to provide Good Samaritan care during their careers and would be better prepared by carrying a kit with common supplies and medications where they are most likely to use them.

Late Adverse Events after Enhanced and Unenhanced MRI and CT

DEFF Research Database (Denmark)

Azzouz, Manal; Rømsing, Janne; Thomsen, Henrik S.

2014-01-01

Prospective evaluation of frequency of late and very late adverse events in patients undergoing enhanced or unenhanced magnetic resonance imaging (MRI) or computed tomography (CT). The imaging procedure was performed according to the protocols of the department. All patients were contacted three...... of LAEs was significantly higher in the enhanced MRI (38%) and CT (27%) groups than unenhanced MRI (20%) and CT (16%) groups. The frequency of nausea, dizziness, abdominal pain and diarrhoea was significantly higher in the enhanced MRI group than in the MRI control group, while taste sensation...

Quantification of LOCA core damage frequency based on thermal-hydraulics analysis

International Nuclear Information System (INIS)

Cho, Jaehyun; Park, Jin Hee; Kim, Dong-San; Lim, Ho-Gon

2017-01-01

Highlights: • We quantified the LOCA core damage frequency based on the best-estimated success criteria analysis. • The thermal-hydraulic analysis using MARS code has been applied to Korea Standard Nuclear Power Plants. • Five new event trees with new break size boundaries and new success criteria were developed. • The core damage frequency is 5.80E−07 (/y), which is 12% less than the conventional PSA event trees. - Abstract: A loss-of-coolant accident (LOCA) has always been significantly considered one of the most important initiating events. However, most probabilistic safety assessment models, up to now, have undoubtedly adopted the three groups of LOCA, and even an exact break size boundary that used in WASH-1400 reports was published in 1975. With an awareness of the importance of a realistic PSA for a risk-informed application, several studies have tried to find the realistic thermal-hydraulic behavior of a LOCA, and improve the PSA model. The purpose of this research is to obtain realistic results of the LOCA core damage frequency based on a success criteria analysis using the best-estimate thermal-hydraulics code. To do so, the Korea Standard Nuclear Power Plant (KSNP) was selected for this study. The MARS code was used for a thermal hydraulics analysis and the AIMS code was used for the core damage quantification. One of the major findings in the thermal hydraulics analysis was that the decay power is well removed by only a normal secondary cooling in LOCAs of below 1.4 in and by only a high pressure safety injection in LOCAs of 0.8–9.4 in. Based on the thermal hydraulics results regarding new break size boundaries and new success criteria, five new event trees (ETs) were developed. The core damage frequency of new LOCA ETs is 5.80E−07 (/y), which is 12% less than the conventional PSA ETs. In this research, we obtained not only thermal-hydraulics characteristics for the entire break size of a LOCA in view of the deterministic safety

Quantification of LOCA core damage frequency based on thermal-hydraulics analysis

Energy Technology Data Exchange (ETDEWEB)

Cho, Jaehyun, E-mail: chojh@kaeri.re.kr; Park, Jin Hee; Kim, Dong-San; Lim, Ho-Gon

2017-04-15

Highlights: • We quantified the LOCA core damage frequency based on the best-estimated success criteria analysis. • The thermal-hydraulic analysis using MARS code has been applied to Korea Standard Nuclear Power Plants. • Five new event trees with new break size boundaries and new success criteria were developed. • The core damage frequency is 5.80E−07 (/y), which is 12% less than the conventional PSA event trees. - Abstract: A loss-of-coolant accident (LOCA) has always been significantly considered one of the most important initiating events. However, most probabilistic safety assessment models, up to now, have undoubtedly adopted the three groups of LOCA, and even an exact break size boundary that used in WASH-1400 reports was published in 1975. With an awareness of the importance of a realistic PSA for a risk-informed application, several studies have tried to find the realistic thermal-hydraulic behavior of a LOCA, and improve the PSA model. The purpose of this research is to obtain realistic results of the LOCA core damage frequency based on a success criteria analysis using the best-estimate thermal-hydraulics code. To do so, the Korea Standard Nuclear Power Plant (KSNP) was selected for this study. The MARS code was used for a thermal hydraulics analysis and the AIMS code was used for the core damage quantification. One of the major findings in the thermal hydraulics analysis was that the decay power is well removed by only a normal secondary cooling in LOCAs of below 1.4 in and by only a high pressure safety injection in LOCAs of 0.8–9.4 in. Based on the thermal hydraulics results regarding new break size boundaries and new success criteria, five new event trees (ETs) were developed. The core damage frequency of new LOCA ETs is 5.80E−07 (/y), which is 12% less than the conventional PSA ETs. In this research, we obtained not only thermal-hydraulics characteristics for the entire break size of a LOCA in view of the deterministic safety

Invited Article: Visualisation of extreme value events in optical communications

Science.gov (United States)

Derevyanko, Stanislav; Redyuk, Alexey; Vergeles, Sergey; Turitsyn, Sergei

2018-06-01

Fluctuations of a temporal signal propagating along long-haul transoceanic scale fiber links can be visualised in the spatio-temporal domain drawing visual analogy with ocean waves. Substantial overlapping of information symbols or use of multi-frequency signals leads to strong statistical deviations of local peak power from an average signal power level. We consider long-haul optical communication systems from this unusual angle, treating them as physical systems with a huge number of random statistical events, including extreme value fluctuations that potentially might affect the quality of data transmission. We apply the well-established concepts of adaptive wavefront shaping used in imaging through turbid medium to detect the detrimental phase modulated sequences in optical communications that can cause extreme power outages (rare optical waves of ultra-high amplitude) during propagation down the ultra-long fiber line. We illustrate the concept by a theoretical analysis of rare events of high-intensity fluctuations—optical freak waves, taking as an example an increasingly popular optical frequency division multiplexing data format where the problem of high peak to average power ratio is the most acute. We also show how such short living extreme value spikes in the optical data streams are affected by nonlinearity and demonstrate the negative impact of such events on the system performance.

Human based roots of failures in nuclear events investigations

Energy Technology Data Exchange (ETDEWEB)

Ziedelis, Stanislovas; Noel, Marc; Strucic, Miodrag [Commission of the European Communities, Petten (Netherlands). European Clearinghouse on Operational Experience Feedback for Nuclear Power Plants

2012-10-15

This paper aims for improvement of quality of the event investigations in the nuclear industry through analysis of the existing practices, identifying and removing the existing Human and Organizational Factors (HOF) and management related barriers. It presents the essential results of several studies performed by the European Clearinghouse on Operational Experience. Outcomes of studies are based on survey of currently existing event investigation practices typical for nuclear industry of 12 European countries, as well as on insights from analysis of numerous event investigation reports. System of operational experience feedback from information based on event investigation results is not enough effective to prevent and even to decrease frequency of recurring events due to existing methodological, HOF-related and/or knowledge management related constraints. Besides that, several latent root causes of unsuccessful event investigation are related to weaknesses in safety culture of personnel and managers. These weaknesses include focus on costs or schedule, political manipulation, arrogance, ignorance, entitlement and/or autocracy. Upgrades in safety culture of organization's personnel and its senior management especially seem to be an effective way to improvement. Increasing of competencies, capabilities and level of independency of event investigation teams, elaboration of comprehensive software, ensuring of positive approach, adequate support and impartiality of management could also facilitate for improvement of quality of the event investigations. (orig.)

Human based roots of failures in nuclear events investigations

International Nuclear Information System (INIS)

Ziedelis, Stanislovas; Noel, Marc; Strucic, Miodrag

2012-01-01

This paper aims for improvement of quality of the event investigations in the nuclear industry through analysis of the existing practices, identifying and removing the existing Human and Organizational Factors (HOF) and management related barriers. It presents the essential results of several studies performed by the European Clearinghouse on Operational Experience. Outcomes of studies are based on survey of currently existing event investigation practices typical for nuclear industry of 12 European countries, as well as on insights from analysis of numerous event investigation reports. System of operational experience feedback from information based on event investigation results is not enough effective to prevent and even to decrease frequency of recurring events due to existing methodological, HOF-related and/or knowledge management related constraints. Besides that, several latent root causes of unsuccessful event investigation are related to weaknesses in safety culture of personnel and managers. These weaknesses include focus on costs or schedule, political manipulation, arrogance, ignorance, entitlement and/or autocracy. Upgrades in safety culture of organization's personnel and its senior management especially seem to be an effective way to improvement. Increasing of competencies, capabilities and level of independency of event investigation teams, elaboration of comprehensive software, ensuring of positive approach, adequate support and impartiality of management could also facilitate for improvement of quality of the event investigations. (orig.)

Research frontiers in climate change: Effects of extreme meteorological events on ecosystems

International Nuclear Information System (INIS)

Jentsch, A.; Jentsch, A.; Beierkuhnlein, C.

2008-01-01

Climate change will increase the recurrence of extreme weather events such as drought and heavy rainfall. Evidence suggests that modifications in extreme weather events pose stronger threats to ecosystem functioning than global trends and shifts in average conditions. As ecosystem functioning is connected with ecological services, this has far-reaching effects on societies in the 21. century. Here, we: (i) present the rationale for the increasing frequency and magnitude of extreme weather events in the near future; (ii) discuss recent findings on meteorological extremes and summarize their effects on ecosystems and (iii) identify gaps in current ecological climate change research. (authors)

Analysis of core damage frequency: Peach Bottom, Unit 2 internal events

International Nuclear Information System (INIS)

Kolaczkowski, A.M.; Cramond, W.R.; Sype, T.T.; Maloney, K.J.; Wheeler, T.A.; Daniel, S.L.

1989-08-01

This document contains the appendices for the accident sequence analysis of internally initiated events for the Peach Bottom, Unit 2 Nuclear Power Plant. This is one of the five plant analyses conducted as part of the NUREG-1150 effort for the Nuclear Regulatory Commission. The work performed and described here is an extensive reanalysis of that published in October 1986 as NUREG/CR-4550, Volume 4. It addresses comments from numerous reviewers and significant changes to the plant systems and procedures made since the first report. The uncertainty analysis and presentation of results are also much improved, and considerable effort was expended on an improved analysis of loss of offsite power. The content and detail of this report is directed toward PRA practitioners who need to know how the work was done and the details for use in further studies. 58 refs., 58 figs., 52 tabs

Caplacizumab reduces the frequency of major thromboembolic events, exacerbations and death in patients with acquired thrombotic thrombocytopenic purpura.

Science.gov (United States)

Peyvandi, F; Scully, M; Kremer Hovinga, J A; Knöbl, P; Cataland, S; De Beuf, K; Callewaert, F; De Winter, H; Zeldin, R K

2017-07-01

Essentials Acquired thrombotic thrombocytopenic purpura (aTTP) is linked with significant morbidity/mortality. Caplacizumab's effect on major thromboembolic (TE) events, exacerbations and death was studied. Fewer caplacizumab-treated patients had a major TE event, an exacerbation, or died versus placebo. Caplacizumab has the potential to reduce the acute morbidity and mortality associated with aTTP. Background Acquired thrombotic thrombocytopenic purpura (aTTP) is a life-threatening autoimmune thrombotic microangiopathy. In spite of treatment with plasma exchange and immunosuppression, patients remain at risk for thrombotic complications, exacerbations, and death. In the phase II TITAN study, treatment with caplacizumab, an anti-von Willebrand factor Nanobody ® was shown to reduce the time to confirmed platelet count normalization and exacerbations during treatment. Objective The clinical benefit of caplacizumab was further investigated in a post hoc analysis of the incidence of major thromboembolic events and exacerbations during the study drug treatment period and thrombotic thrombocytopenic purpura-related death during the study. Methods The Standardized Medical Dictionary for Regulatory Activities (MedDRA) Query (SMQ) for 'embolic and thrombotic events' was run to investigate the occurrence of major thromboembolic events and exacerbations in the safety population of the TITAN study, which consisted of 72 patients, of whom 35 received caplacizumab and 37 received placebo. Results Four events (one pulmonary embolism and three aTTP exacerbations) were reported in four patients in the caplacizumab group, and 20 such events were reported in 14 patients in the placebo group (two acute myocardial infarctions, one ischemic stroke, one hemorrhagic stroke, one pulmonary embolism, one deep vein thrombosis, one venous thrombosis, and 13 aTTP exacerbations). Two of the placebo-treated patients died from aTTP during the study. Conclusion In total, 11.4% of caplacizumab

Spacecraft-to-Earth Communications for Juno and Mars Science Laboratory Critical Events

Science.gov (United States)

Soriano, Melissa; Finley, Susan; Jongeling, Andre; Fort, David; Goodhart, Charles; Rogstad, David; Navarro, Robert

2012-01-01

Deep Space communications typically utilize closed loop receivers and Binary Phase Shift Keying (BPSK) or Quadrature Phase Shift Keying (QPSK). Critical spacecraft events include orbit insertion and entry, descent, and landing.---Low gain antennas--> low signal -to-noise-ratio.---High dynamics such as parachute deployment or spin --> Doppler shift. During critical events, open loop receivers and Multiple Frequency Shift Keying (MFSK) used. Entry, Descent, Landing (EDL) Data Analysis (EDA) system detects tones in real-time.

Sparse frequencies data inversion and the role of multi-scattered energy

KAUST Repository

Alkhalifah, Tariq Ali

2017-01-01

time to inject more energy of those frequencies at a reduced cost. Such additional energy is necessary to the recording of more multi-scattered events. The objective of this new paradigm is a high resolution model of the Earth.

What a Shame: Increased Rates of OMS Resident Burnout May Be Related to the Frequency of Shamed Events During Training.

Science.gov (United States)

Shapiro, Michael C; Rao, Sowmya R; Dean, Jason; Salama, Andrew R

2017-03-01

Shame is an ineffective tool in residency education that often results in depression, isolation, and worse patient care. This study aimed to assess burnout, depersonalization, and personal achievement levels in current oral and maxillofacial surgery (OMS) residents, to assess the prevalence of the use of shame in OMS residency training, and to determine whether there is a relation between shame exposure and resident burnout, depersonalization, and personal achievement levels. An anonymous 20-question cross-sectional survey was developed incorporating the Maslach Burnout Index and a previously validated shame questionnaire and sent to all OMS program directors affiliated with the American Association of Oral and Maxillofacial Surgeons for distribution among their respective residents in 2016. Univariate analyses were used to determine the distribution of the predictor (shame) and outcome (burnout) by gender and by frequency of shaming events. Multivariable logistic regression analysis was used to assess the relation of shame to burnout. A 2-sided P value less than .05 was considered statistically significant. Two hundred seventeen responses were received; 82% of respondents were men (n = 178), 95% were 25 to 34 years old (n = 206), and 58% (n = 126) were enrolled in a 4-year program. Frequently shamed residents were more likely to have depression (58 vs 22%; P < .0001), isolation (55 vs 22%; P < .0001), and poor job performance (50 vs 30%; P < .0001). Residents who were frequently shamed were more likely to experience moderate to severe burnout (odds ratio = 4.6; 95% confidence interval, 2.1-10.0; P < .001) and severe depersonalization (odds ratio = 5.1; 95% confidence interval, 2.1-12.0; P < .0001) than residents who had never or infrequently been shamed. There is a clear relation between the number of shame events and burnout and depersonalization levels. It is important to understand the negative impact that the experience of shame has on residents

The potential impacts of climate variability and change on health impacts of extreme weather events in the United States.

Science.gov (United States)

Greenough, G; McGeehin, M; Bernard, S M; Trtanj, J; Riad, J; Engelberg, D

2001-05-01

Extreme weather events such as precipitation extremes and severe storms cause hundreds of deaths and injuries annually in the United States. Climate change may alter the frequency, timing, intensity, and duration of these events. Increases in heavy precipitation have occurred over the past century. Future climate scenarios show likely increases in the frequency of extreme precipitation events, including precipitation during hurricanes, raising the risk of floods. Frequencies of tornadoes and hurricanes cannot reliably be projected. Injury and death are the direct health impacts most often associated with natural disasters. Secondary effects, mediated by changes in ecologic systems and public health infrastructure, also occur. The health impacts of extreme weather events hinge on the vulnerabilities and recovery capacities of the natural environment and the local population. Relevant variables include building codes, warning systems, disaster policies, evacuation plans, and relief efforts. There are many federal, state, and local government agencies and nongovernmental organizations involved in planning for and responding to natural disasters in the United States. Future research on health impacts of extreme weather events should focus on improving climate models to project any trends in regional extreme events and as a result improve public health preparedness and mitigation. Epidemiologic studies of health effects beyond the direct impacts of disaster will provide a more accurate measure of the full health impacts and will assist in planning and resource allocation.

Future frequencies of extreme weather events in the National Wildlife Refuges of the conterminous U.S.

Science.gov (United States)

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

2016-01-01

Climate change is a major challenge for managers of protected areas world-wide, and managers need information about future climate conditions within protected areas. Prior studies of climate change effects in protected areas have largely focused on average climatic conditions. However, extreme weather may have stronger effects on wildlife populations and habitats than changes in averages. Our goal was to quantify future changes in the frequency of extreme heat, drought, and false springs, during the avian breeding season, in 415 National Wildlife Refuges in the conterminous United States. We analyzed spatially detailed data on extreme weather frequencies during the historical period (1950–2005) and under different scenarios of future climate change by mid- and late-21st century. We found that all wildlife refuges will likely experience substantial changes in the frequencies of extreme weather, but the types of projected changes differed among refuges. Extreme heat is projected to increase dramatically in all wildlife refuges, whereas changes in droughts and false springs are projected to increase or decrease on a regional basis. Half of all wildlife refuges are projected to see increases in frequency (> 20% higher than the current rate) in at least two types of weather extremes by mid-century. Wildlife refuges in the Southwest and Pacific Southwest are projected to exhibit the fastest rates of change, and may deserve extra attention. Climate change adaptation strategies in protected areas, such as the U.S. wildlife refuges, may need to seriously consider future changes in extreme weather, including the considerable spatial variation of these changes.

The use of historical information for regional frequency analysis of extreme skew surge

Science.gov (United States)

Frau, Roberto; Andreewsky, Marc; Bernardara, Pietro

2018-03-01

The design of effective coastal protections requires an adequate estimation of the annual occurrence probability of rare events associated with a return period up to 103 years. Regional frequency analysis (RFA) has been proven to be an applicable way to estimate extreme events by sorting regional data into large and spatially distributed datasets. Nowadays, historical data are available to provide new insight on past event estimation. The utilisation of historical information would increase the precision and the reliability of regional extreme's quantile estimation. However, historical data are from significant extreme events that are not recorded by tide gauge. They usually look like isolated data and they are different from continuous data from systematic measurements of tide gauges. This makes the definition of the duration of our observations period complicated. However, the duration of the observation period is crucial for the frequency estimation of extreme occurrences. For this reason, we introduced here the concept of credible duration. The proposed RFA method (hereinafter referenced as FAB, from the name of the authors) allows the use of historical data together with systematic data, which is a result of the use of the credible duration concept.

Cardiovascular Events in Cancer Patients Treated with Highly or Moderately Emetogenic Chemotherapy: Results from a Population-Based Study

International Nuclear Information System (INIS)

Vo, T. T.; Nelson, J. J.

2012-01-01

Studies on cardiovascular safety in cancer patients treated with highly or moderately emetogenic chemotherapy (HEC or MEC), who may have taken the antiemetic, aprepitant, have been limited to clinical trials and postmarketing spontaneous reports. Our study explored background rates of cardiovascular disease (CVD) events among HEC- or MEC-treated cancer patients in a population-based setting to contextualize events seen in a new drug development program and to determine at a high level whether rates differed by aprepitant usage. Medical and pharmacy claims data from the 2005-2007 IMPACT National Benchmark Database were classified into emetogenic chemotherapy categories and CVD outcomes. Among 5827 HEC/MEC-treated patients, frequencies were highest for hypertension (16-21%) and composites of venous (7-12%) and arterial thromboembolic events (4-7%). Aprepitant users generally did not experience higher frequencies of events compared to nonusers. Our study serves as a useful benchmark of background CVD event rates in a population-based setting of cancer patients.

High frequency and large deposition of acid fog on high elevation forest.

Science.gov (United States)

Igawa, Manabu; Matsumura, Ko; Okochi, Hiroshi

2002-01-01

We have collected and analyzed fogwater on the mountainside of Mt. Oyama (1252 m) in the Tanzawa Mountains of Japan and observed the fog event frequency from the base of the mountain with a video camera. The fog event frequency increased with elevation and was observed to be present 46% of the year at the summit. The water deposition via throughfall increased with elevation because of the increase in fogwater interception and was about twice that via rain at the summit, where the air pollutant deposition via throughfall was several times that via rainwater. The dry deposition and the deposition via fogwater were dominant factors in the total ion deposition at high elevation sites. In a fog event, nitric acid, the major acid component on the mountain, is formed during the transport of the air mass from the base of the mountain along the mountainside, where gases including nitric acid deposit and are scavenged by fogwater. Therefore, high acidity caused by nitric acid and relatively low ion strength are observed in the fogwater at high elevation sites.

Mean importance measures for groups of events in fault trees

International Nuclear Information System (INIS)

Haskin, F.E.; Huang, Min

1994-01-01

The method of moments is applied to precisely determine the mean values of three importance measures: risk reduction, partial derivative, and variance reduction. Variance reduction calculations, in particular, are significantly improved by eliminating the imprecision associated with Monte Carlo estimates. The three importance measures are extended to permit analyses of the relative importance of groups of basic and initiating events. The partial derivative importance measure is extended by assessing the contribution of a group of events to the gradient of the top event frequency. The group importance measures are quantified for the overall fuel damage equation and for 14 dominant accident sequences from an independent probabilistic safety assessment of the K Production Reactor. This application demonstrates both the utility and the versatility of the group importance measures

Mean importance measures for groups of events in fault trees

Energy Technology Data Exchange (ETDEWEB)

Haskin, F.E.; Huang, Min [New Mexico Univ., Albuquerque, NM (United States). Dept. of Chemical and Nuclear Engineering; Sasser, M.K.; Stack, D.W. [Los Alamos National Lab., NM (United States)

1993-10-12

The method of moments is applied to precisely determine the mean values of three importance measures: risk reduction, partial derivative, and variance reduction. Variance reduction calculations, in particular, are significantly improved by eliminating the imprecision associated with Monte Carlo estimates. The three importance measures are extended to permit analyses of the relative importance of groups of basic and initiating events. The partial derivative importance measure is extended by assessing the contribution of a group of events to the gradient of the top event frequency. The group importance measures are quantified for the overall fuel damage equation and for 14 dominant accident sequences from an independent probabilistic safety assessment of the K Production Reactor. This application demonstrates both the utility and the versatility of the group importance measures.

Mean importance measures for groups of events in fault trees

International Nuclear Information System (INIS)

Haskin, F.E.; Huang, Min

1993-01-01

The method of moments is applied to precisely determine the mean values of three importance measures: risk reduction, partial derivative, and variance reduction. Variance reduction calculations, in particular, are significantly improved by eliminating the imprecision associated with Monte Carlo estimates. The three importance measures are extended to permit analyses of the relative importance of groups of basic and initiating events. The partial derivative importance measure is extended by assessing the contribution of a group of events to the gradient of the top event frequency. The group importance measures are quantified for the overall fuel damage equation and for 14 dominant accident sequences from an independent probabilistic safety assessment of the K Production Reactor. This application demonstrates both the utility and the versatility of the group importance measures

Exposure to extreme heat and precipitation events associated with increased risk of hospitalization for asthma in Maryland, U.S.A.

Science.gov (United States)

Soneja, Sutyajeet; Jiang, Chengsheng; Fisher, Jared; Upperman, Crystal Romeo; Mitchell, Clifford; Sapkota, Amir

2016-04-27

Several studies have investigated the association between asthma exacerbations and exposures to ambient temperature and precipitation. However, limited data exists regarding how extreme events, projected to grow in frequency, intensity, and duration in the future in response to our changing climate, will impact the risk of hospitalization for asthma. The objective of our study was to quantify the association between frequency of extreme heat and precipitation events and increased risk of hospitalization for asthma in Maryland between 2000 and 2012. We used a time-stratified case-crossover design to examine the association between exposure to extreme heat and precipitation events and risk of hospitalization for asthma (ICD-9 code 493, n = 115,923). Occurrence of extreme heat events in Maryland increased the risk of same day hospitalization for asthma (lag 0) by 3 % (Odds Ratio (OR): 1.03, 95 % Confidence Interval (CI): 1.00, 1.07), with a considerably higher risk observed for extreme heat events that occur during summer months (OR: 1.23, 95 % CI: 1.15, 1.33). Likewise, summertime extreme precipitation events increased the risk of hospitalization for asthma by 11 % in Maryland (OR: 1.11, 95 % CI: 1.06, 1.17). Across age groups, increase in risk for asthma hospitalization from exposure to extreme heat event during the summer months was most pronounced among youth and adults, while those related to extreme precipitation event was highest among ≤4 year olds. Exposure to extreme heat and extreme precipitation events, particularly during summertime, is associated with increased risk of hospitalization for asthma in Maryland. Our results suggest that projected increases in frequency of extreme heat and precipitation event will have significant impact on public health.

Random and externally controlled occurrences of Dansgaard–Oeschger events

Directory of Open Access Journals (Sweden)

J. Lohmann

2018-05-01

Full Text Available Dansgaard–Oeschger (DO events constitute the most pronounced mode of centennial to millennial climate variability of the last glacial period. Since their discovery, many decades of research have been devoted to understand the origin and nature of these rapid climate shifts. In recent years, a number of studies have appeared that report emergence of DO-type variability in fully coupled general circulation models via different mechanisms. These mechanisms result in the occurrence of DO events at varying degrees of regularity, ranging from periodic to random. When examining the full sequence of DO events as captured in the North Greenland Ice Core Project (NGRIP ice core record, one can observe high irregularity in the timing of individual events at any stage within the last glacial period. In addition to the prevailing irregularity, certain properties of the DO event sequence, such as the average event frequency or the relative distribution of cold versus warm periods, appear to be changing throughout the glacial. By using statistical hypothesis tests on simple event models, we investigate whether the observed event sequence may have been generated by stationary random processes or rather was strongly modulated by external factors. We find that the sequence of DO warming events is consistent with a stationary random process, whereas dividing the event sequence into warming and cooling events leads to inconsistency with two independent event processes. As we include external forcing, we find a particularly good fit to the observed DO sequence in a model where the average residence time in warm periods are controlled by global ice volume and cold periods by boreal summer insolation.

Random and externally controlled occurrences of Dansgaard-Oeschger events

Science.gov (United States)

Lohmann, Johannes; Ditlevsen, Peter D.

2018-05-01

Dansgaard-Oeschger (DO) events constitute the most pronounced mode of centennial to millennial climate variability of the last glacial period. Since their discovery, many decades of research have been devoted to understand the origin and nature of these rapid climate shifts. In recent years, a number of studies have appeared that report emergence of DO-type variability in fully coupled general circulation models via different mechanisms. These mechanisms result in the occurrence of DO events at varying degrees of regularity, ranging from periodic to random. When examining the full sequence of DO events as captured in the North Greenland Ice Core Project (NGRIP) ice core record, one can observe high irregularity in the timing of individual events at any stage within the last glacial period. In addition to the prevailing irregularity, certain properties of the DO event sequence, such as the average event frequency or the relative distribution of cold versus warm periods, appear to be changing throughout the glacial. By using statistical hypothesis tests on simple event models, we investigate whether the observed event sequence may have been generated by stationary random processes or rather was strongly modulated by external factors. We find that the sequence of DO warming events is consistent with a stationary random process, whereas dividing the event sequence into warming and cooling events leads to inconsistency with two independent event processes. As we include external forcing, we find a particularly good fit to the observed DO sequence in a model where the average residence time in warm periods are controlled by global ice volume and cold periods by boreal summer insolation.

Extreme wildfire events are linked to global-change-type droughts in the northern Mediterranean

Science.gov (United States)

Ruffault, Julien; Curt, Thomas; Martin-StPaul, Nicolas K.; Moron, Vincent; Trigo, Ricardo M.

2018-03-01

Increasing drought conditions under global warming are expected to alter the frequency and distribution of large and high-intensity wildfires. However, our understanding of the impact of increasing drought on extreme wildfires events remains incomplete. Here, we analyzed the weather conditions associated with the extreme wildfires events that occurred in Mediterranean France during the exceptionally dry summers of 2003 and 2016. We identified that these fires were related to two distinct shifts in the fire weather space towards fire weather conditions that had not been explored before and resulting from specific interactions between different types of drought and different fire weather types. In 2016, a long-lasting press drought intensified wind-driven fires. In 2003, a hot drought combining a heat wave with a press drought intensified heat-induced fires. Our findings highlight that increasing drought conditions projected by climate change scenarios might affect the dryness of fuel compartments and lead to a higher frequency of extremes wildfires events.

Perioperative adverse airway events in cleft lip and palate repair ...

African Journals Online (AJOL)

Background: Airway-related problems account for the majority of anaesthetic morbidity in paediatric anaesthesia, but more so for cleft lip and palate repair. The aim of this study was to assess the frequency, pattern, management and outcome of adverse airway events during the perioperative period in cleft lip and palate ...

Construction and Quantification of the One Top model of the Fire Events PSA

International Nuclear Information System (INIS)

Kang, Dae Il; Lee, Yoon Hwan; Han, Sang Hoon

2008-01-01

KAERI constructed the one top model of the fire events PSA for Ulchin Unit 3 and 4 by using the 'mapping technique'. The mapping technique was developed for the construction and quantification of external events PSA models with a one top model for an internal events PSA. With 'AIMS', the mapping technique can be implemented by the construction of mapping tables. The mapping tables include fire rooms, fire ignition frequency, related initiating events, fire transfer events, and the internal PSA basic events affected by a fire. The constructed one top fire PSA model is based on previously conducted fire PSA results for Ulchin Unit 3 and 4. In this paper, we introduce the construction procedure and quantification results of the one top model of the fire events PSA by using the mapping technique. As the one top model of the fire events PSA developed in this study is based on the previous study, we also introduce the previous fire PSA approach focused on quantification

Traumatic-event headaches

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Haas David C

2004-10-01

Full Text Available Abstract Background Chronic headaches from head trauma and whiplash injury are well-known and common, but chronic headaches from other sorts of physical traumas are not recognized. Methods Specific information was obtained from the medical records of 15 consecutive patients with chronic headaches related to physically injurious traumatic events that did not include either head trauma or whiplash injury. The events and the physical injuries produced by them were noted. The headaches' development, characteristics, duration, frequency, and accompaniments were recorded, as were the patients' use of pain-alleviative drugs. From this latter information, the headaches were classified by the diagnostic criteria of the International Headache Society as though they were naturally-occurring headaches. The presence of other post-traumatic symptoms and litigation were also recorded. Results The intervals between the events and the onset of the headaches resembled those between head traumas or whiplash injuries and their subsequent headaches. The headaches themselves were, as a group, similar to those after head trauma and whiplash injury. Thirteen of the patients had chronic tension-type headache, two had migraine. The sustained bodily injuries were trivial or unidentifiable in nine patients. Fabrication of symptoms for financial remuneration was not evident in these patients of whom seven were not even seeking payments of any kind. Conclusions This study suggests that these hitherto unrecognized post-traumatic headaches constitute a class of headaches characterized by a relation to traumatic events affecting the body but not including head or whiplash traumas. The bodily injuries per se can be discounted as the cause of the headaches. So can fabrication of symptoms for financial remuneration. Altered mental states, not systematically evaluated here, were a possible cause of the headaches. The overall resemblance of these headaches to the headaches after

Frequency and seasonality of flash floods in Slovenia

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Trobec Tajan

2017-01-01

Full Text Available The purpose of this paper is to assess and analyse the dynamics of flash flooding events in Slovenia. The paper examines in particular the frequency of flash floods and their seasonal distribution. The methodology is based on the analysis of historical records and modern flood data. The results of a long-term frequency analysis of 138 flash floods that occurred between 1550 and 2015 are presented. Because of the lack of adequate historical flood data prior to 1950 the main analysis is based on data for the periodbetween1951 and2015, while the analysis of data for the period between1550 and1950 is added as a supplement to the main analysis. Analysis of data for the period after 1950 shows that on average 1.3 flash floods occur each year in Slovenia. The linear trend for the number of flash floods is increasing but is not statistically significant. Despite the fact that the majority of Slovenian rivers have one of the peaks in spring and one of the lows in summer, 90% of flash floods actually occur during meteorological summer or autumn - i.e. between June and November, which shows that discharge regimes and flood regimes are not necessarily related. Because of the lack of flood records from the more distant past as well as the large variability of flash flood events in the last several decades, we cannot provide a definitive answer to the question about possible changes in their frequency and seasonality by relying solely on the detected trends. Nevertheless, considering the results of analysis and future climate change scenarios the frequency of flash floods in Slovenia could increase while the period of flash flood occurrence could be extended.

Time–frequency analysis of nonstationary complex magneto-hydro-dynamics in fusion plasma signals using the Choi–Williams distribution

International Nuclear Information System (INIS)

Xu, L.Q.; Hu, L.Q.; Chen, K.Y.; Li, E.Z.

2013-01-01

Highlights: • Choi–Williams distribution yields excellent time–frequency resolution for discrete signal. • CWD method provides clear time–frequency pictures of EAST and HT-7 fast MHD events. • CWD method has advantages to wavelets transform scalogram and the short-time Fourier transform spectrogram. • We discuss about how to choose the windows and free parameter of CWD method. -- Abstract: The Choi–Williams distribution is applied to the time–frequency analysis of signals describing rapid magneto-hydro-dynamic (MHD) modes and events in tokamak plasmas. A comparison is made with Soft X-ray (SXR) signals as well as Mirnov signal that shows the advantages of the Choi–Williams distribution over both continuous wavelets transform scalogram and the short-time Fourier transform spectrogram. Examples of MHD activities in HT-7 and EAST tokamak are shown, namely the onset of coupling tearing modes, high frequency precursors of sawtooth, and low frequency MHD instabilities in edge localized mode (ELM) free in H mode discharge

Distinguishing low frequency oscillations within the 1/f spectral behaviour of electromagnetic brain signals.

Science.gov (United States)

Demanuele, Charmaine; James, Christopher J; Sonuga-Barke, Edmund Js

2007-12-10

It has been acknowledged that the frequency spectrum of measured electromagnetic (EM) brain signals shows a decrease in power with increasing frequency. This spectral behaviour may lead to difficulty in distinguishing event-related peaks from ongoing brain activity in the electro- and magnetoencephalographic (EEG and MEG) signal spectra. This can become an issue especially in the analysis of low frequency oscillations (LFOs) - below 0.5 Hz - which are currently being observed in signal recordings linked with specific pathologies such as epileptic seizures or attention deficit hyperactivity disorder (ADHD), in sleep studies, etc. In this work we propose a simple method that can be used to compensate for this 1/f trend hence achieving spectral normalisation. This method involves filtering the raw measured EM signal through a differentiator prior to further data analysis. Applying the proposed method to various exemplary datasets including very low frequency EEG recordings, epileptic seizure recordings, MEG data and Evoked Response data showed that this compensating procedure provides a flat spectral base onto which event related peaks can be clearly observed. Findings suggest that the proposed filter is a useful tool for the analysis of physiological data especially in revealing very low frequency peaks which may otherwise be obscured by the 1/f spectral activity inherent in EEG/MEG recordings.

Event-by-event jet quenching

Energy Technology Data Exchange (ETDEWEB)

Fries, R.J.; Rodriguez, R.; Ramirez, E.

2010-08-14

High momentum jets and hadrons can be used as probes for the quark gluon plasma (QGP) formed in nuclear collisions at high energies. We investigate the influence of fluctuations in the fireball on jet quenching observables by comparing propagation of light quarks and gluons through averaged, smooth QGP fireballs with event-by-event jet quenching using realistic inhomogeneous fireballs. We find that the transverse momentum and impact parameter dependence of the nuclear modification factor R{sub AA} can be fit well in an event-by-event quenching scenario within experimental errors. However the transport coefficient {cflx q} extracted from fits to the measured nuclear modification factor R{sub AA} in averaged fireballs underestimates the value from event-by-event calculations by up to 50%. On the other hand, after adjusting {cflx q} to fit R{sub AA} in the event-by-event analysis we find residual deviations in the azimuthal asymmetry v{sub 2} and in two-particle correlations, that provide a possible faint signature for a spatial tomography of the fireball. We discuss a correlation function that is a measure for spatial inhomogeneities in a collision and can be constrained from data.

Event-by-event jet quenching

Energy Technology Data Exchange (ETDEWEB)

Rodriguez, R. [Cyclotron Institute and Physics Department, Texas A and M University, College Station, TX 77843 (United States); Fries, R.J., E-mail: rjfries@comp.tamu.ed [Cyclotron Institute and Physics Department, Texas A and M University, College Station, TX 77843 (United States); RIKEN/BNL Research Center, Brookhaven National Laboratory, Upton, NY 11973 (United States); Ramirez, E. [Physics Department, University of Texas El Paso, El Paso, TX 79968 (United States)

2010-09-27

High momentum jets and hadrons can be used as probes for the quark gluon plasma (QGP) formed in nuclear collisions at high energies. We investigate the influence of fluctuations in the fireball on jet quenching observables by comparing propagation of light quarks and gluons through averaged, smooth QGP fireballs with event-by-event jet quenching using realistic inhomogeneous fireballs. We find that the transverse momentum and impact parameter dependence of the nuclear modification factor R{sub AA} can be fit well in an event-by-event quenching scenario within experimental errors. However the transport coefficient q extracted from fits to the measured nuclear modification factor R{sub AA} in averaged fireballs underestimates the value from event-by-event calculations by up to 50%. On the other hand, after adjusting q to fit R{sub AA} in the event-by-event analysis we find residual deviations in the azimuthal asymmetry v{sub 2} and in two-particle correlations, that provide a possible faint signature for a spatial tomography of the fireball. We discuss a correlation function that is a measure for spatial inhomogeneities in a collision and can be constrained from data.

Frequency analysis of urban runoff quality in an urbanizing catchment of Shenzhen, China

Science.gov (United States)

Qin, Huapeng; Tan, Xiaolong; Fu, Guangtao; Zhang, Yingying; Huang, Yuefei

2013-07-01

This paper investigates the frequency distribution of urban runoff quality indicators using a long-term continuous simulation approach and evaluates the impacts of proposed runoff control schemes on runoff quality in an urbanizing catchment in Shenzhen, China. Four different indicators are considered to provide a comprehensive assessment of the potential impacts: total runoff depth, event pollutant load, Event Mean Concentration, and peak concentration during a rainfall event. The results obtained indicate that urban runoff quantity and quality in the catchment have significant variations in rainfall events and a very high rate of non-compliance with surface water quality regulations. Three runoff control schemes with the capacity to intercept an initial runoff depth of 5 mm, 10 mm, and 15 mm are evaluated, respectively, and diminishing marginal benefits are found with increasing interception levels in terms of water quality improvement. The effects of seasonal variation in rainfall events are investigated to provide a better understanding of the performance of the runoff control schemes. The pre-flood season has higher risk of poor water quality than other seasons after runoff control. This study demonstrates that frequency analysis of urban runoff quantity and quality provides a probabilistic evaluation of pollution control measures, and thus helps frame a risk-based decision making for urban runoff quality management in an urbanizing catchment.

Disentangling the Effects of Precipitation Amount and Frequency on the Performance of 14 Grassland Species

Science.gov (United States)

Didiano, Teresa J.; Johnson, Marc T. J.; Duval, Tim P.

2016-01-01

Climate change is causing shifts in the amount and frequency of precipitation in many regions, which is expected to have implications for plant performance. Most research has examined the impacts of the amount of precipitation on plants rather than the effects of both the amount and frequency of precipitation. To understand how climate-driven changes in precipitation can affect grassland plants, we asked: (i) How does the amount and frequency of precipitation affect plant performance? (ii) Do plant functional groups vary in their response to variable precipitation? To answer these questions we grew 14 monocot and eudicot grassland species and conducted a factorial manipulation of the amount (70 vs 90mm/month) and frequency (every 3, 15, or 30 days) of precipitation under rainout shelters. Our results show that both the amount and frequency of precipitation impact plant performance, with larger effects on eudicots than monocots. Above- and below-ground biomass were affected by the amount of precipitation and/or the interaction between the amount and frequency of precipitation. Above-ground biomass increased by 21–30% when the amount of precipitation was increased. When event frequency was decreased from 3 to 15 or 30 days, below-ground biomass generally decreased by 18–34% in the 70 mm treatment, but increased by 33–40% in the 90 mm treatment. Changes in stomatal conductance were largely driven by changes in event frequency. Our results show that it is important to consider changes in both the amount and frequency of precipitation when predicting how plant communities will respond to variable precipitation. PMID:27622497

Evaluating Monitoring Strategies to Detect Precipitation-Induced Microbial Contamination Events in Karstic Springs Used for Drinking Water

Directory of Open Access Journals (Sweden)

Michael D. Besmer

2017-11-01

Full Text Available Monitoring of microbial drinking water quality is a key component for ensuring safety and understanding risk, but conventional monitoring strategies are typically based on low sampling frequencies (e.g., quarterly or monthly. This is of concern because many drinking water sources, such as karstic springs are often subject to changes in bacterial concentrations on much shorter time scales (e.g., hours to days, for example after precipitation events. Microbial contamination events are crucial from a risk assessment perspective and should therefore be targeted by monitoring strategies to establish both the frequency of their occurrence and the magnitude of bacterial peak concentrations. In this study we used monitoring data from two specific karstic springs. We assessed the performance of conventional monitoring based on historical records and tested a number of alternative strategies based on a high-resolution data set of bacterial concentrations in spring water collected with online flow cytometry (FCM. We quantified the effect of increasing sampling frequency and found that for the specific case studied, at least bi-weekly sampling would be needed to detect precipitation events with a probability of >90%. We then proposed an optimized monitoring strategy with three targeted samples per event, triggered by precipitation measurements. This approach is more effective and efficient than simply increasing overall sampling frequency. It would enable the water utility to (1 analyze any relevant event and (2 limit median underestimation of peak concentrations to approximately 10%. We conclude with a generalized perspective on sampling optimization and argue that the assessment of short-term dynamics causing microbial peak loads initially requires increased sampling/analysis efforts, but can be optimized subsequently to account for limited resources. This offers water utilities and public health authorities systematic ways to evaluate and optimize their

High-frequency field-deployable isotope analyzer for hydrological applications

Science.gov (United States)

Elena S.F. Berman; Manish Gupta; Chris Gabrielli; Tina Garland; Jeffrey J. McDonnell

2009-01-01

A high-frequency, field-deployable liquid water isotope analyzer was developed. The instrument was deployed for 4 contiguous weeks in the H. J. Andrews Experimental Forest Long-term Ecological Research site in western Oregon, where it was used for real-time measurement of the isotope ratios of precipitation and stream water during three large storm events. We were able...

Changes in Intense Precipitation Events in West Africa and the central U.S. under Global Warming

Energy Technology Data Exchange (ETDEWEB)

Cook, Kerry H. [Univ. of Texas, Austin, TX (United States); Vizy, Edward [Univ. of Texas, Austin, TX (United States)

2016-02-08

The purpose of the proposed project is to improve our understanding of the physical processes and large-scale connectivity of changes in intense precipitation events (high rainfall rates) under global warming in West Africa and the central U.S., including relationships with low-frequency modes of variability. This is in response to the requested subject area #2 “simulation of climate extremes under a changing climate … to better quantify the frequency, duration, and intensity of extreme events under climate change and elucidate the role of low frequency climate variability in modulating extremes.” We will use a regional climate model and emphasize an understanding of the physical processes that lead to an intensification of rainfall. The project objectives are as follows: 1. Understand the processes responsible for simulated changes in warm-season rainfall intensity and frequency over West Africa and the Central U.S. associated with greenhouse gas-induced global warming 2. Understand the relationship between changes in warm-season rainfall intensity and frequency, which generally occur on regional space scales, and the larger-scale global warming signal by considering modifications of low-frequency modes of variability. 3. Relate changes simulated on regional space scales to global-scale theories of how and why atmospheric moisture levels and rainfall should change as climate warms.