WorldWideScience

Sample records for proxy key re-encapsulation

  1. Diffie-Hellman Key Based Authentication in Proxy Mobile IPv6

    Directory of Open Access Journals (Sweden)

    HyunGon Kim

    2010-01-01

    Full Text Available Wireless communication service providers have been showing strong interest in Proxy Mobile IPv6 for providing network-based IP mobility management. This could be a prominent way to support IP mobility to mobile nodes, because Proxy Mobile IPv6 requires minimal functionalities on the mobile node. While several extensions for Proxy Mobile IPv6 are being developed in the Internet Engineering Task Force, there has been little attentions paid to developing efficient authentication mechanisms. An authentication scheme for a mobility protocol must protect signaling messages against various security threats, e.g., session stealing attack, intercept attack by redirection, replay attack, and key exposure, while minimizing authentication latency. In this paper, we propose a Diffie-Hellman key based authentication scheme that utilizes the low layer signaling to exchange Diffie-Hellman variables and allows mobility service provisioning entities to exchange mobile node's profile and ongoing sessions securely. By utilizing the low layer signaling and context transfer between relevant nodes, the proposed authentication scheme minimizes authentication latency when the mobile node moves across different networks. In addition, thanks to the use of the Diffie-Hellman key agreement, pre-established security associations between mobility service provisioning entities are not required in the proposed authentication scheme so that network scalability in an operationally efficient manner is ensured. To ascertain its feasibility, security analysis and performance analysis are presented.

  2. Couples' joint decision-making: the construction and validation of a key proxy for understanding gender relations in contemporary families

    Directory of Open Access Journals (Sweden)

    Maira Covre-Sussai

    2014-06-01

    Full Text Available Gender relations have become a key dimension in family studies, and understanding gender relations as both determining and resulting from outcome of new family configurations requires the use of specific surveys aimed at the dynamics of couples. Unfortunately, nationally representative surveys of this type are not available for Latin American countries. Nonetheless, the most recent versions of the Demographic and Health Surveys (DHS include a section called "Women's Status and Empowerment", which can provide information about gender relations as well. This study aims at assessing the construct of gender relations in terms of couples' joint decision-making for all five Brazilian geographical regions. To this end, a step-by-step multi-group confirmatory factor analysis (MGCFA was applied in order to verify whether this concept can be compared across Brazilian regions. Results show that the DHS items can be used reliably for measuring couples' joint decision-making and that this construct can be meaningfully compared over the regions. These findings will contribute to further demographic and sociological research on gender relations which can use this concept and other indicators provided by the DHS to identify the causal processes related to it.

  3. Munchausen syndrome by proxy

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/001555.htm Munchausen syndrome by proxy To use the sharing features on this page, please enable JavaScript. Munchausen syndrome by proxy is a mental illness and ...

  4. Here be web proxies

    DEFF Research Database (Denmark)

    Weaver, Nicholas; Kreibich, Christian; Dam, Martin

    2014-01-01

    HTTP proxies serve numerous roles, from performance enhancement to access control to network censorship, but often operate stealthily without explicitly indicating their presence to the communicating endpoints. In this paper we present an analysis of the evidence of proxying manifest in executions...... of the ICSI Netalyzr spanning 646,000 distinct IP addresses ("clients"). To identify proxies we employ a range of detectors at the transport and application layer, and report in detail on the extent to which they allow us to fingerprint and map proxies to their likely intended uses. We also analyze 17...

  5. Jemen - the Proxy War

    Directory of Open Access Journals (Sweden)

    Magdalena El Ghamari

    2015-12-01

    Full Text Available The military operation in Yemen is significant departure from Saudi Arabia's foreign policy tradition and customs. Riyadh has always relied on three strategies to pursue its interests abroad: wealth, establish a global network and muslim education and diplomacy and meadiation. The term "proxy war" has experienced a new popularity in stories on the Middle East. A proxy war is two opposing countries avoiding direct war, and instead supporting combatants that serve their interests. In some occasions, one country is a direct combatant whilst the other supporting its enemy. Various news sources began using the term to describe the conflict in Yemen immediately, as if on cue, after Saudi Arabia launched its bombing campaign against Houthi targets in Yemen on 25 March 2015. This is the reason, why author try to answer for following questions: Is the Yemen Conflict Devolves into Proxy War? and Who's fighting whom in Yemen's proxy war?" Research area includes the problem of proxy war in the Middle East. For sure, the real problem of proxy war must begin with the fact that the United States and its NATO allies opened the floodgates for regional proxy wars by the two major wars for regime change: in Iraq and Libya. Those two destabilising wars provided opportunities and motives for Sunni states across the Middle East to pursue their own sectarian and political power objectives through "proxy war".

  6. Jemen - the Proxy War

    OpenAIRE

    Magdalena El Ghamari

    2015-01-01

    The military operation in Yemen is significant departure from Saudi Arabia's foreign policy tradition and customs. Riyadh has always relied on three strategies to pursue its interests abroad: wealth, establish a global network and muslim education and diplomacy and meadiation. The term "proxy war" has experienced a new popularity in stories on the Middle East. A proxy war is two opposing countries avoiding direct war, and instead supporting combatants that serve their interests. In some occas...

  7. Molecular proxies for paleoclimatology

    Science.gov (United States)

    Eglinton, Timothy I.; Eglinton, Geoffrey

    2008-10-01

    We summarize the applications of molecular proxies in paleoclimatology. Marine molecular records especially are proving to be of value but certain environmentally persistent compounds can also be measured in lake sediments, loess deposits and ice cores. The fundamentals of this approach are the molecular parameters, the compound abundances and carbon, hydrogen, nitrogen and oxygen isotopic contents which can be derived by the analysis of sediment extracts. These afford proxy measures which can be interpreted in terms of the conditions which control climate and also reflect its operation. We discuss two types of proxy; those of terrigenous and those of aquatic origin, and exemplify their application in the study of marine sediments through the medium of ten case studies based in the Atlantic, Mediterranean and Pacific Oceans, and in Antarctica. The studies are mainly for periods in the present, the Holocene and particularly the last glacial/interglacial, but they also include one study from the Cretaceous. The terrigenous proxies, which are measures of continental vegetation, are based on higher plant leaf wax compounds, i.e. long-chain (circa C 30) hydrocarbons, alcohols and acids. They register the relative contributions of C 3 vs. C 4 type plants to the vegetation in the source areas. The two marine proxies are measures of sea surface temperatures (SST). The longer established one, (U 37K') is based on the relative abundances of C 37 alkenones photosynthesized by unicellular algae, members of the Haptophyta. The newest proxy (TEX 86) is based on C 86 glycerol tetraethers (GDGTs) synthesized in the water column by some of the archaeal microbiota, the Crenarchaeota.

  8. A Type-and-Identity-based Proxy Re-Encryption Scheme and its Application in Healthcare

    NARCIS (Netherlands)

    Ibraimi, L.; Tang, Qiang; Hartel, Pieter H.; Jonker, Willem

    2008-01-01

    Proxy re-encryption is a cryptographic primitive developed to delegate the decryption right from one party (the delegator) to another (the delegatee). In a proxy re-encryption scheme, the delegator assigns a key to a proxy to re-encrypt all messages encrypted with his public key such that the

  9. Proxy Smart Card Systems

    OpenAIRE

    Cattaneo, Giuseppe; Faruolo, Pompeo; Palazzo, Vincenzo; Visconti, Ivan

    2010-01-01

    International audience; The established legal value of digital signatures and the growing availability of identity-based digital services are progressively extending the use of smart cards to all citizens, opening new challenging scenarios. Among them, motivated by concrete applications, secure and practical delegation of digital signatures is becoming more and more critical. Unfortunately, secure delegation systems proposed so far (e.g., proxy signatures) include various drawbacks for any pr...

  10. Munchausen syndrome by proxy

    Directory of Open Access Journals (Sweden)

    Jovanović Aleksandar A.

    2005-01-01

    Full Text Available This review deals with bibliography on Munchausen syndrome by proxy (MSbP. The name of this disorder was introduced by English psychiatrist Roy Meadow who pointed to diagnostic difficulties as well as to serious medical and legal connotations of MSbP. MSbP was classified in DSM-IV among criteria sets provided for further study as "factitious disorder by proxy", while in ICD-10, though not explicitly cited, MSbP might be classified as "factitious disorders" F68.1. MSbP is a special form of abuse where the perpetrator induces somatic or mental symptoms of illness in the victim under his/her care and then persistently presents the victims for medical examinations and care. The victim is usually a preschool child and the perpetrator is the child's mother. Motivation for such pathological behavior of perpetrator is considered to be unconscious need to assume sick role by proxy while external incentives such as economic gain are absent. Conceptualization of MSbP development is still in the domain of psychodynamic speculation, its course is chronic and the prognosis is poor considering lack of consistent, efficient and specific treatment. The authors also present the case report of thirty-three year-old mother who had been abusing her nine year-old son both emotionally and physically over the last several years forcing him to, together with her, report to the police, medical and educational institutions that he had been the victim of rape, poisoning and beating by various individuals, especially teaching and medical staff. Mother manifested psychosis and her child presented with impaired cognitive development, emotional problems and conduct disorder.

  11. A statistical proxy for sulphuric acid concentration

    Directory of Open Access Journals (Sweden)

    S. Mikkonen

    2011-11-01

    Full Text Available Gaseous sulphuric acid is a key precursor for new particle formation in the atmosphere. Previous experimental studies have confirmed a strong correlation between the number concentrations of freshly formed particles and the ambient concentrations of sulphuric acid. This study evaluates a body of experimental gas phase sulphuric acid concentrations, as measured by Chemical Ionization Mass Spectrometry (CIMS during six intensive measurement campaigns and one long-term observational period. The campaign datasets were measured in Hyytiälä, Finland, in 2003 and 2007, in San Pietro Capofiume, Italy, in 2009, in Melpitz, Germany, in 2008, in Atlanta, Georgia, USA, in 2002, and in Niwot Ridge, Colorado, USA, in 2007. The long term data were obtained in Hohenpeissenberg, Germany, during 1998 to 2000. The measured time series were used to construct proximity measures ("proxies" for sulphuric acid concentration by using statistical analysis methods. The objective of this study is to find a proxy for sulfuric acid that is valid in as many different atmospheric environments as possible. Our most accurate and universal formulation of the sulphuric acid concentration proxy uses global solar radiation, SO2 concentration, condensation sink and relative humidity as predictor variables, yielding a correlation measure (R of 0.87 between observed concentration and the proxy predictions. Interestingly, the role of the condensation sink in the proxy was only minor, since similarly accurate proxies could be constructed with global solar radiation and SO2 concentration alone. This could be attributed to SO2 being an indicator for anthropogenic pollution, including particulate and gaseous emissions which represent sinks for the OH radical that, in turn, is needed for the formation of sulphuric acid.

  12. Secure Mobile Agent from Leakage-Resilient Proxy Signatures

    Directory of Open Access Journals (Sweden)

    Fei Tang

    2015-01-01

    Full Text Available A mobile agent can sign a message in a remote server on behalf of a customer without exposing its secret key; it can be used not only to search for special products or services, but also to make a contract with a remote server. Hence a mobile agent system can be used for electronic commerce as an important key technology. In order to realize such a system, Lee et al. showed that a secure mobile agent can be constructed using proxy signatures. Intuitively, a proxy signature permits an entity (delegator to delegate its signing right to another entity (proxy to sign some specified messages on behalf of the delegator. However, the proxy signatures are often used in scenarios where the signing is done in an insecure environment, for example, the remote server of a mobile agent system. In such setting, an adversary could launch side-channel attacks to exploit some leakage information about the proxy key or even other secret states. The proxy signatures which are secure in the traditional security models obviously cannot provide such security. Based on this consideration, in this paper, we design a leakage-resilient proxy signature scheme for the secure mobile agent systems.

  13. [Munchausen by proxy syndrome].

    Science.gov (United States)

    Depauw, A; Loas, G; Delhaye, M

    2015-01-01

    The Munchausen syndrome by proxy (MSBP) was first described in 1977 by the English paediatrician Roy Meadow. The MSBP is an extremely complicated diagnosis because of the difficulty in finding the incriminating evidence of its existence and because of the ethical issue it raises for caregivers. Its implications from a medical, psychological and legal point of view raise difficult questions for any professional confronted to it. In this article we will first present the case of a 16-year-old teenager who had been bedridden in hospital for a year, before an atypical form of MSBP was finally diagnosed, after a stay in a child and adolescent psychiatry unit. We will then discuss this case in light of a literature review on the MSBP.

  14. Proxy consent: moral authority misconceived.

    Science.gov (United States)

    Wrigley, A

    2007-09-01

    The Mental Capacity Act 2005 has provided unified scope in the British medical system for proxy consent with regard to medical decisions, in the form of a lasting power of attorney. While the intentions are to increase the autonomous decision making powers of those unable to consent, the author of this paper argues that the whole notion of proxy consent collapses into a paternalistic judgement regarding the other person's best interests and that the new legislation introduces only an advisor, not a proxy with the moral authority to make treatment decisions on behalf of another. The criticism is threefold. First, there is good empirical evidence that people are poor proxy decision makers as regards accurately representing other people's desires and wishes, and this is therefore a pragmatically inadequate method of gaining consent. Second, philosophical theory explaining how we represent other people's thought processes indicates that we are unlikely ever to achieve accurate simulations of others' wishes in making a proxy decision. Third, even if we could accurately simulate other people's beliefs and wishes, the current construction of proxy consent in the Mental Capacity Act means that it has no significant ethical authority to match that of autonomous decision making. Instead, it is governed by a professional, paternalistic, best-interests judgement that undermines the intended role of a proxy decision maker. The author argues in favour of clearly adopting the paternalistic best-interests option and viewing the proxy as solely an advisor to the professional medical team in helping make best-interests judgements.

  15. Private Computing with Untrustworthy Proxies

    NARCIS (Netherlands)

    Gedrojc, B.

    2011-01-01

    The objective of this thesis is to preserve privacy for the user while untrustworthy proxies are involved in the communication and computation i.e. private computing. A basic example of private computing is an access control system (proxy) which grants access (or not) to users based on fingerprints.

  16. Robotic Vehicle Proxy Simulation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Energid Technologies proposes the development of a digital simulation that can replace robotic vehicles in field studies. This proxy simulation will model the...

  17. Qualitative and Quantitative Sentiment Proxies

    DEFF Research Database (Denmark)

    Zhao, Zeyan; Ahmad, Khurshid

    2015-01-01

    Sentiment analysis is a content-analytic investigative framework for researchers, traders and the general public involved in financial markets. This analysis is based on carefully sourced and elaborately constructed proxies for market sentiment and has emerged as a basis for analysing movements...... and trading volumes. The case study we use is a small market index (Danish Stock Exchange Index, OMXC 20, together with prevailing sentiment in Denmark, to evaluate the impact of sentiment on OMXC 20. Furthermore, we introduce a rather novel and quantitative sentiment proxy, that is the use of the index...

  18. Munchausen syndrome by proxy: a case report.

    Science.gov (United States)

    Lieder, Holly S; Irving, Sharon Y; Mauricio, Rizalina; Graf, Jeanine M

    2005-01-01

    Munchausen syndrome by proxy is difficult to diagnose unless healthcare providers are astute to its clinical features and management. A case is presented to educate nurses and advanced practice nurses, of the nursing, medical, legal, and social complexities associated with Munchausen syndrome by proxy. This article also provides a brief review of the definition of Munchausen syndrome by proxy, its epidemiology, common features of the perpetrator, implications for healthcare personnel, and the legal and international ramifications of Munchausen syndrome by proxy.

  19. Shareholder Activism Through the Proxy Process

    NARCIS (Netherlands)

    Renneboog, L.D.R.; Szilagyi, P.G.

    2009-01-01

    This paper provides evidence on the corporate governance role of shareholder-initiated proxy proposals. Previous studies debate over whether activists use proxy proposals to discipline firms or to simply advance their self-serving agendas, and whether proxy proposals are effective at all in

  20. Shareholder Activism through the Proxy Process

    NARCIS (Netherlands)

    Renneboog, L.D.R.; Szilagyi, P.G.

    2009-01-01

    This paper provides evidence on the corporate governance role of shareholderinitiated proxy proposals. Previous studies debate over whether activists use proxy proposals to discipline firms or to simply advance their self-serving agendas, and whether proxy proposals are effective at all in

  1. Time-and-ID-Based Proxy Reencryption Scheme

    Directory of Open Access Journals (Sweden)

    Kambombo Mtonga

    2014-01-01

    Full Text Available Time- and ID-based proxy reencryption scheme is proposed in this paper in which a type-based proxy reencryption enables the delegator to implement fine-grained policies with one key pair without any additional trust on the proxy. However, in some applications, the time within which the data was sampled or collected is very critical. In such applications, for example, healthcare and criminal investigations, the delegatee may be interested in only some of the messages with some types sampled within some time bound instead of the entire subset. Hence, in order to carter for such situations, in this paper, we propose a time-and-identity-based proxy reencryption scheme that takes into account the time within which the data was collected as a factor to consider when categorizing data in addition to its type. Our scheme is based on Boneh and Boyen identity-based scheme (BB-IBE and Matsuo’s proxy reencryption scheme for identity-based encryption (IBE to IBE. We prove that our scheme is semantically secure in the standard model.

  2. Measuring SIP proxy server performance

    CERN Document Server

    Subramanian, Sureshkumar V

    2013-01-01

    Internet Protocol (IP) telephony is an alternative to the traditional Public Switched Telephone Networks (PSTN), and the Session Initiation Protocol (SIP) is quickly becoming a popular signaling protocol for VoIP-based applications. SIP is a peer-to-peer multimedia signaling protocol standardized by the Internet Engineering Task Force (IETF), and it plays a vital role in providing IP telephony services through its use of the SIP Proxy Server (SPS), a software application that provides call routing services by parsing and forwarding all the incoming SIP packets in an IP telephony network.SIP Pr

  3. Novel Quantum Proxy Signature without Entanglement

    Science.gov (United States)

    Xu, Guang-bao

    2015-08-01

    Proxy signature is an important research topic in classic cryptography since it has many application occasions in our real life. But only a few quantum proxy signature schemes have been proposed up to now. In this paper, we propose a quantum proxy signature scheme, which is designed based on quantum one-time pad. Our scheme can be realized easily since it only uses single-particle states. Security analysis shows that it is secure and meets all the properties of a proxy signature, such as verifiability, distinguishability, unforgeability and undeniability.

  4. Munchausen Syndrome by Proxy: Identification and Intervention

    Science.gov (United States)

    Walk, Alexandra; Davies, Susan C.

    2010-01-01

    This article discusses the Munchausen syndrome by proxy (MSBP), also known as "factitious disorder by proxy" (FDBP) and fabricated and/or induced illness, which is a mental illness in which a person lies about the physical or mental well-being of a person he/she is responsible for. Most often the dynamic transpires between a mother and her child.…

  5. On the use of human mobility proxies for modeling epidemics.

    Directory of Open Access Journals (Sweden)

    Michele Tizzoni

    2014-07-01

    Full Text Available Human mobility is a key component of large-scale spatial-transmission models of infectious diseases. Correctly modeling and quantifying human mobility is critical for improving epidemic control, but may be hindered by data incompleteness or unavailability. Here we explore the opportunity of using proxies for individual mobility to describe commuting flows and predict the diffusion of an influenza-like-illness epidemic. We consider three European countries and the corresponding commuting networks at different resolution scales, obtained from (i official census surveys, (ii proxy mobility data extracted from mobile phone call records, and (iii the radiation model calibrated with census data. Metapopulation models defined on these countries and integrating the different mobility layers are compared in terms of epidemic observables. We show that commuting networks from mobile phone data capture the empirical commuting patterns well, accounting for more than 87% of the total fluxes. The distributions of commuting fluxes per link from mobile phones and census sources are similar and highly correlated, however a systematic overestimation of commuting traffic in the mobile phone data is observed. This leads to epidemics that spread faster than on census commuting networks, once the mobile phone commuting network is considered in the epidemic model, however preserving to a high degree the order of infection of newly affected locations. Proxies' calibration affects the arrival times' agreement across different models, and the observed topological and traffic discrepancies among mobility sources alter the resulting epidemic invasion patterns. Results also suggest that proxies perform differently in approximating commuting patterns for disease spread at different resolution scales, with the radiation model showing higher accuracy than mobile phone data when the seed is central in the network, the opposite being observed for peripheral locations. Proxies

  6. On the use of human mobility proxies for modeling epidemics.

    Science.gov (United States)

    Tizzoni, Michele; Bajardi, Paolo; Decuyper, Adeline; Kon Kam King, Guillaume; Schneider, Christian M; Blondel, Vincent; Smoreda, Zbigniew; González, Marta C; Colizza, Vittoria

    2014-07-01

    Human mobility is a key component of large-scale spatial-transmission models of infectious diseases. Correctly modeling and quantifying human mobility is critical for improving epidemic control, but may be hindered by data incompleteness or unavailability. Here we explore the opportunity of using proxies for individual mobility to describe commuting flows and predict the diffusion of an influenza-like-illness epidemic. We consider three European countries and the corresponding commuting networks at different resolution scales, obtained from (i) official census surveys, (ii) proxy mobility data extracted from mobile phone call records, and (iii) the radiation model calibrated with census data. Metapopulation models defined on these countries and integrating the different mobility layers are compared in terms of epidemic observables. We show that commuting networks from mobile phone data capture the empirical commuting patterns well, accounting for more than 87% of the total fluxes. The distributions of commuting fluxes per link from mobile phones and census sources are similar and highly correlated, however a systematic overestimation of commuting traffic in the mobile phone data is observed. This leads to epidemics that spread faster than on census commuting networks, once the mobile phone commuting network is considered in the epidemic model, however preserving to a high degree the order of infection of newly affected locations. Proxies' calibration affects the arrival times' agreement across different models, and the observed topological and traffic discrepancies among mobility sources alter the resulting epidemic invasion patterns. Results also suggest that proxies perform differently in approximating commuting patterns for disease spread at different resolution scales, with the radiation model showing higher accuracy than mobile phone data when the seed is central in the network, the opposite being observed for peripheral locations. Proxies should therefore be

  7. A Lattice-Based Identity-Based Proxy Blind Signature Scheme in the Standard Model

    Directory of Open Access Journals (Sweden)

    Lili Zhang

    2014-01-01

    Full Text Available A proxy blind signature scheme is a special form of blind signature which allowed a designated person called proxy signer to sign on behalf of original signers without knowing the content of the message. It combines the advantages of proxy signature and blind signature. Up to date, most proxy blind signature schemes rely on hard number theory problems, discrete logarithm, and bilinear pairings. Unfortunately, the above underlying number theory problems will be solvable in the postquantum era. Lattice-based cryptography is enjoying great interest these days, due to implementation simplicity and provable security reductions. Moreover, lattice-based cryptography is believed to be hard even for quantum computers. In this paper, we present a new identity-based proxy blind signature scheme from lattices without random oracles. The new scheme is proven to be strongly unforgeable under the standard hardness assumption of the short integer solution problem (SIS and the inhomogeneous small integer solution problem (ISIS. Furthermore, the secret key size and the signature length of our scheme are invariant and much shorter than those of the previous lattice-based proxy blind signature schemes. To the best of our knowledge, our construction is the first short lattice-based identity-based proxy blind signature scheme in the standard model.

  8. New proxy replacement algorithm for multimedia streaming

    Science.gov (United States)

    Wong, Hau Ling; Lo, Kwok-Tung

    2001-11-01

    Proxy servers play an important role in between servers and clients in various multimedia systems on the Internet. Since proxy servers do not have an infinite-capacity cache for keeping all the continuous media data, the challenge for the replacement policy is to determine which streams should be cached or removed from the proxy server. In this paper, a new proxy replacement algorithm, named the Least Popular Used (LPU) caching algorithm, is proposed for layered encoded multimedia streams in the Internet. The LPU method takes both the short-term and long-term popularity of the video into account in determining the replacement policy. Simulation evaluation shows that our proposed scheme achieves better results than some existing methods in term of the cache efficiency and replacement frequency under both static and dynamic access environments.

  9. 78 FR 70987 - Proxy Advisory Firm Roundtable

    Science.gov (United States)

    2013-11-27

    ... of proxy advisory firm use by investment advisers and institutional investors and potential changes... Special Counsel, Division of Investment Management, at 202-551-6700, or Raymond Be, Special Counsel...

  10. A serial Munchausen syndrome by proxy

    National Research Council Canada - National Science Library

    Esra Unal; Volkan Unal; Ali Gul; Mustafa Celtek; Behzat Diken; Ibrahim Balcioglu

    2017-01-01

    Munchausen syndrome by proxy (MSBP) is a form of child abuse that describes children whose parents or caregivers invent illness stories and substantiate the stories by fabricating false physical signs...

  11. Seizures and Munchausen Syndrome by Proxy

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2002-05-01

    Full Text Available The prevalence, morbidity and mortality, diagnosis and management of cases of fabricated seizures and child abuse (Munchausen syndrome by proxy (MSbp are assessed by pediatricians at the University of Wales College of Medicine, Cardiff, UK.

  12. Munchausen Syndrome by Proxy: A Clinical Vignette

    Science.gov (United States)

    Zylstra, Robert G.; Miller, Karl E.; Stephens, Walter E.

    2000-01-01

    Munchausen syndrome by proxy is the act of one person fabricating or inducing an illness in another to meet his or her own emotional needs through the treatment process. The diagnosis is poorly understood and controversial. We report here the case of a 6-year-old boy who presented with possible pneumonia, nausea, vomiting, and diarrhea and whose mother was suspected of Munchausen syndrome by proxy. PMID:15014581

  13. PENGELOLAAN JARINGAN INTERNET DENGAN PROXY WINGATE

    Directory of Open Access Journals (Sweden)

    Titin Winarti

    2005-01-01

    Full Text Available Proxy adalah bagian dari protokol yang berfungsi sebagai link untuk host tunggal atau sebagai link untuk beberapa host antarajaringan dan jaringan lain. Proxy wingate adalah software yang digunakan untuk berbagi koneksi internet melalui satu alamat IPyang terintegrasi ke internet.

  14. Web proxy auto discovery for the WLCG

    CERN Document Server

    Dykstra, D; Blumenfeld, B; De Salvo, A; Dewhurst, A; Verguilov, V

    2017-01-01

    All four of the LHC experiments depend on web proxies (that is, squids) at each grid site to support software distribution by the CernVM FileSystem (CVMFS). CMS and ATLAS also use web proxies for conditions data distributed through the Frontier Distributed Database caching system. ATLAS & CMS each have their own methods for their grid jobs to find out which web proxies to use for Frontier at each site, and CVMFS has a third method. Those diverse methods limit usability and flexibility, particularly for opportunistic use cases, where an experiment’s jobs are run at sites that do not primarily support that experiment. This paper describes a new Worldwide LHC Computing Grid (WLCG) system for discovering the addresses of web proxies. The system is based on an internet standard called Web Proxy Auto Discovery (WPAD). WPAD is in turn based on another standard called Proxy Auto Configuration (PAC). Both the Frontier and CVMFS clients support this standard. The input into the WLCG system comes from squids regis...

  15. Cryptanalysis and Performance Evaluation of Enhanced Threshold Proxy Signature Scheme Based on RSA for Known Signers

    Directory of Open Access Journals (Sweden)

    Raman Kumar

    2013-01-01

    Full Text Available In these days there are plenty of signature schemes such as the threshold proxy signature scheme (Kumar and Verma 2010. The network is a shared medium so that the weakness security attacks such as eavesdropping, replay attack, and modification attack. Thus, we have to establish a common key for encrypting/decrypting our communications over an insecure network. In this scheme, a threshold proxy signature scheme based on RSA, any or more proxy signers can cooperatively generate a proxy signature while or fewer of them cannot do it. The threshold proxy signature scheme uses the RSA cryptosystem to generate the private and the public key of the signers (Rivest et al., 1978. Comparison is done on the basis of time complexity, space complexity, and communication overhead. We compare the performance of four schemes (Hwang et al. (2003, Kuo and Chen (2005, Yong-Jun et al. (2007, and Li et al. (2007, with the performance of a scheme that has been proposed earlier by the authors of this paper. In the proposed scheme, both the combiner and the secret share holder can verify the correctness of the information that they are receiving from each other. Therefore, the enhanced threshold proxy signature scheme is secure and efficient against notorious conspiracy attacks.

  16. Inferring climate variability from skewed proxy records

    Science.gov (United States)

    Emile-Geay, J.; Tingley, M.

    2013-12-01

    Many paleoclimate analyses assume a linear relationship between the proxy and the target climate variable, and that both the climate quantity and the errors follow normal distributions. An ever-increasing number of proxy records, however, are better modeled using distributions that are heavy-tailed, skewed, or otherwise non-normal, on account of the proxies reflecting non-normally distributed climate variables, or having non-linear relationships with a normally distributed climate variable. The analysis of such proxies requires a different set of tools, and this work serves as a cautionary tale on the danger of making conclusions about the underlying climate from applications of classic statistical procedures to heavily skewed proxy records. Inspired by runoff proxies, we consider an idealized proxy characterized by a nonlinear, thresholded relationship with climate, and describe three approaches to using such a record to infer past climate: (i) applying standard methods commonly used in the paleoclimate literature, without considering the non-linearities inherent to the proxy record; (ii) applying a power transform prior to using these standard methods; (iii) constructing a Bayesian model to invert the mechanistic relationship between the climate and the proxy. We find that neglecting the skewness in the proxy leads to erroneous conclusions and often exaggerates changes in climate variability between different time intervals. In contrast, an explicit treatment of the skewness, using either power transforms or a Bayesian inversion of the mechanistic model for the proxy, yields significantly better estimates of past climate variations. We apply these insights in two paleoclimate settings: (1) a classical sedimentary record from Laguna Pallcacocha, Ecuador (Moy et al., 2002). Our results agree with the qualitative aspects of previous analyses of this record, but quantitative departures are evident and hold implications for how such records are interpreted, and

  17. Cooperative Proxy Caching for Wireless Base Stations

    Directory of Open Access Journals (Sweden)

    James Z. Wang

    2007-01-01

    Full Text Available This paper proposes a mobile cache model to facilitate the cooperative proxy caching in wireless base stations. This mobile cache model uses a network cache line to record the caching state information about a web document for effective data search and cache space management. Based on the proposed mobile cache model, a P2P cooperative proxy caching scheme is proposed to use a self-configured and self-managed virtual proxy graph (VPG, independent of the underlying wireless network structure and adaptive to the network and geographic environment changes, to achieve efficient data search, data cache and date replication. Based on demand, the aggregate effect of data caching, searching and replicating actions by individual proxy servers automatically migrates the cached web documents closer to the interested clients. In addition, a cache line migration (CLM strategy is proposed to flow and replicate the heads of network cache lines of web documents associated with a moving mobile host to the new base station during the mobile host handoff. These replicated cache line heads provide direct links to the cached web documents accessed by the moving mobile hosts in the previous base station, thus improving the mobile web caching performance. Performance studies have shown that the proposed P2P cooperative proxy caching schemes significantly outperform existing caching schemes.

  18. A proxy of DICOM services

    Science.gov (United States)

    Ribeiro, Luís S.; Costa, Carlos; Oliveira, José Luís

    2010-03-01

    Diagnostic tools supported by digital medical images have increasingly become an essential aid to medical decisions. However, despite its growing importance, Picture Archiving and Communication Systems (PACS) are typically oriented to support a single healthcare institution, and the sharing of medical data across institutions is still a difficult process. This paper describes a proposal to publish and control Digital Imaging Communications in Medicine (DICOM) services in a wide domain composed of several healthcare institutions. The system creates virtual bridges between intranets enabling the exchange, search and store of the medical data within the wide domain. The service provider publishes the DICOM services following a token-based strategy. The token advertisements are public and known by all system users. However, access to the DICOM service is controlled through a role association between an access key and the service. Furthermore, in medical diagnoses, time is a crucial factor. Therefore, our system is a turnkey solution, capable of exchanging medical data across firewalls and Network Address Translation (NAT), avoiding bureaucratic issues with local network security. Security is also an important concern - in any transmission across different domains, data is encrypted by Transport Layer Security (TLS).

  19. Web Proxy Auto Discovery for the WLCG

    Science.gov (United States)

    Dykstra, D.; Blomer, J.; Blumenfeld, B.; De Salvo, A.; Dewhurst, A.; Verguilov, V.

    2017-10-01

    All four of the LHC experiments depend on web proxies (that is, squids) at each grid site to support software distribution by the CernVM FileSystem (CVMFS). CMS and ATLAS also use web proxies for conditions data distributed through the Frontier Distributed Database caching system. ATLAS & CMS each have their own methods for their grid jobs to find out which web proxies to use for Frontier at each site, and CVMFS has a third method. Those diverse methods limit usability and flexibility, particularly for opportunistic use cases, where an experiment’s jobs are run at sites that do not primarily support that experiment. This paper describes a new Worldwide LHC Computing Grid (WLCG) system for discovering the addresses of web proxies. The system is based on an internet standard called Web Proxy Auto Discovery (WPAD). WPAD is in turn based on another standard called Proxy Auto Configuration (PAC). Both the Frontier and CVMFS clients support this standard. The input into the WLCG system comes from squids registered in the ATLAS Grid Information System (AGIS) and CMS SITECONF files, cross-checked with squids registered by sites in the Grid Configuration Database (GOCDB) and the OSG Information Management (OIM) system, and combined with some exceptions manually configured by people from ATLAS and CMS who operate WLCG Squid monitoring. WPAD servers at CERN respond to http requests from grid nodes all over the world with a PAC file that lists available web proxies, based on IP addresses matched from a database that contains the IP address ranges registered to organizations. Large grid sites are encouraged to supply their own WPAD web servers for more flexibility, to avoid being affected by short term long distance network outages, and to offload the WLCG WPAD servers at CERN. The CERN WPAD servers additionally support requests from jobs running at non-grid sites (particularly for LHC@Home) which they direct to the nearest publicly accessible web proxy servers. The responses

  20. Munchausen Syndrome by Proxy: Medical Diagnostic Criteria.

    Science.gov (United States)

    Rosenberg, Donna Andrea

    2003-01-01

    Medical diagnostic criteria for Munchausen Syndrome by Proxy (a persistent fabrication by one individual of illness in another) are presented. Since the strength of the known facts may vary from case to case, diagnostic criteria are given for a definitive diagnosis, a possible diagnosis, an inconclusive determination, and the definitely excluded…

  1. Munchausen Syndrome by Proxy: Evaluation and Treatment.

    Science.gov (United States)

    Parnell, Teresa F.; Day, Deborah O.

    Munchausen Syndrome by Proxy (MSBP) is characterized by a significant caretaker, usually a mother, deliberately inducing and/or falsely reporting illness in a child. The potentially fatal outcome of undetected MSBP makes the understanding of this syndrome gravely important. Early detection and effective intervention can be accomplished through the…

  2. Munchausen Syndrome by Proxy: Social Work's Role.

    Science.gov (United States)

    Mercer, Susan O.; Perdue, Jeanette D.

    1993-01-01

    Describes Munchausen syndrome by proxy, diagnosis used to describe variation of child abuse whereby parent or adult caregiver fabricates medical history or induces symptoms in child, or both, resulting in unnecessary examinations, treatments, hospitalizations, and even death. Reviews assessment procedures, provides case studies, and describes…

  3. Munchausen Syndrome by Proxy: A Family Affair.

    Science.gov (United States)

    Mehl, Albert L.; And Others

    1990-01-01

    The article reports on a case of Munchausen syndrome by proxy in which chronic illicit insulin was administered to a one-year-old child by her mother. Factitious illnesses continued despite psychiatric intervention. Retrospective review of medical records suggested 30 previous episodes of factitious illness within the family. (DB)

  4. The Syndrome of Munchausen by Proxy.

    Science.gov (United States)

    Jones, David P. H.

    1994-01-01

    This editorial introduces two articles on Munchausen by Proxy syndrome (the induction of an appearance or state of physical ill health in a child, by the caretaker, and the child's subsequent presentation to health professionals for diagnosis and/or treatment). The severity of the caretaker's psychological disturbance and the serious effects on…

  5. Improving Internet Archive Service through Proxy Cache.

    Science.gov (United States)

    Yu, Hsiang-Fu; Chen, Yi-Ming; Wang, Shih-Yong; Tseng, Li-Ming

    2003-01-01

    Discusses file transfer protocol (FTP) servers for downloading archives (files with particular file extensions), and the change to HTTP (Hypertext transfer protocol) with increased Web use. Topics include the Archie server; proxy cache servers; and how to improve the hit rate of archives by a combination of caching and better searching mechanisms.…

  6. Method of Anti-Virus Protection Based on (n, t Threshold Proxy Signature with an Arbitrator

    Directory of Open Access Journals (Sweden)

    E. A. Tolyupa

    2014-01-01

    Full Text Available The article suggests the method of anti-virus protection of mobile devices based on the usage of proxy digital signatures and an (n;t-threshold proxy signature scheme with an arbitrator. The unique feature of the suggested method is in the absence of necessity to install anti-virus software in a mobile device. It will be enough only to have the software verifying digital signatures and the Internet. The method is used on the base of public keys infrastructure /PKI/, thus minimizing implementation expenses.

  7. An inter-bank E-payment protocol based on quantum proxy blind signature

    Science.gov (United States)

    Wen, Xiaojun; Chen, Yongzhi; Fang, Junbin

    2013-01-01

    Security and anonymity are essential to E-payment systems. However, with the increasing computing power, existing E-payment systems will gradually become insecure. In this paper, we propose an inter-bank E-payment system which is based on quantum proxy blind signature. Adopting the techniques of quantum key distribution, one-time pad and quantum proxy blind signature, our quantum E-payment system could protect user's anonymity as the traditional E-payment systems do, and also have unconditional security which the classical E-payment systems cannot provide. Furthermore, compared with the existing quantum E-payment systems, the proposed system could support inter-bank transactions.

  8. An E-payment Protocol Based on Quantum Multi-proxy Blind Signature

    Science.gov (United States)

    Shao, Ai-Xia; Zhang, Jian-Zhong; Xie, Shu-Cui

    2017-04-01

    Based on quantum multi-proxy blind signature, a new E-payment protocol is proposed in this paper. Adopting the techniques of quantum key distribution, one-time pad and quantum proxy blind signature, our E-payment protocol could protect user's anonymity as the traditional E-payment systems do, and also have unconditional security which the classical E-payment systems cannot provide. Additionally, the quantum operation can be transmitted successfully with the probability 1, which can make the protocol reliable and practical.

  9. Attribute-based proxy re-encryption with keyword search.

    Directory of Open Access Journals (Sweden)

    Yanfeng Shi

    Full Text Available Keyword search on encrypted data allows one to issue the search token and conduct search operations on encrypted data while still preserving keyword privacy. In the present paper, we consider the keyword search problem further and introduce a novel notion called attribute-based proxy re-encryption with keyword search (ABRKS, which introduces a promising feature: In addition to supporting keyword search on encrypted data, it enables data owners to delegate the keyword search capability to some other data users complying with the specific access control policy. To be specific, ABRKS allows (i the data owner to outsource his encrypted data to the cloud and then ask the cloud to conduct keyword search on outsourced encrypted data with the given search token, and (ii the data owner to delegate other data users keyword search capability in the fine-grained access control manner through allowing the cloud to re-encrypted stored encrypted data with a re-encrypted data (embedding with some form of access control policy. We formalize the syntax and security definitions for ABRKS, and propose two concrete constructions for ABRKS: key-policy ABRKS and ciphertext-policy ABRKS. In the nutshell, our constructions can be treated as the integration of technologies in the fields of attribute-based cryptography and proxy re-encryption cryptography.

  10. Legal requirements governing proxy voting in Denmark

    DEFF Research Database (Denmark)

    Werlauff, Erik

    2008-01-01

    The requirements in Danish company law concerning proxy voting in companies whose shares have been accepted for listing on a regulated market have been successively tightened in recent years, and corporate governance principles have also led to the introduction of several requirements concerning...... proxy holders. A thorough knowledge of these requirements is important not only for the listed companies but also for their advisers and investors in Denmark and abroad. This article considers these requirements as well as the additional requirements which will derive from Directive 2007....../36 on the exercise of shareholders' rights in listed companies, which must be implemented by 3 August 2009. It is pointed out that companies may provide with advantage in their articles of association for both the existing and the forthcoming requirements at this early stage....

  11. Observable Proxies For 26 Al Enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Fryer, Christopher L [Los Alamos National Laboratory; Young, Patrick A [Los Alamos National Laboratory; Ellinger, Carola I [ASU; Arnett, William D [UNIV ARIZONA

    2008-01-01

    We consider the cospatial production of elements in supernova explosions to find observationally detectable proxies for enhancement of {sup 26}Al in supernova ejecta and stellar systems. Using four progenitors we explore a range of 1D explosions at different energies and an asymmetric 3D explosion. We find that the most reliable indicator of the presence of {sup 26}Al in unmixed ejecta is a very low S/Si ratio ({approx} 0.05). Production of N in O/S/Si-rich regions is also indicative. The biologically important element P is produced at its highest abundance in the same regions. Proxies should be detectable in supernova ejecta with high spatial resolution multi wavelength observations, but the small absolute abundance of material injected into a proto-planetary disk makes detection unlikely in existing or forming stellar/planetary systems.

  12. Non-destructive foraminiferal paleoclimatic proxies: A brief insight

    Digital Repository Service at National Institute of Oceanography (India)

    Saraswat, R.

    Non-Destructive Foraminiferal Paleoclimatic Proxies: A Brief Insight The knowledge of past climate can help us to understand imminent climatic changes. Oceans are the vast archives of past climate. Various indirect techniques termed as proxies...

  13. Implementasi Proxy Server Dengan Linux Clear OS 5.2

    OpenAIRE

    Setiadi, Aprian

    2013-01-01

    Tugas Akhir ini membahas mengenai cara untuk membangun sebuah proxy server dalam jaringan LAN. Jaringan LAN yang dibangun menggunakan arsitektur topologi star dengan menjadikan komputer server sebagai Gateway Server dan Proxy Server, sehingga tidak membutuhkan perangkat tambahan Router yang berfungsi sebagai Gateway Server. Proxy Server yang yang dibangun menggunakan metode Transparent Mode, sehingga pada komputer klien tidak perlu mengkonfigurasi port proxy server pada Web Browser. Hasil ya...

  14. 12 CFR 7.2002 - Director or attorney as proxy.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Director or attorney as proxy. 7.2002 Section 7... OPERATIONS Corporate Practices § 7.2002 Director or attorney as proxy. Any person or group of persons, except the bank's officers, clerks, tellers, or bookkeepers, may be designated to act as proxy. The bank's...

  15. Physicians' Involvement with the New York State Health Care Proxy

    Science.gov (United States)

    Heyman, Janna C.; Sealy, Yvette M.

    2011-01-01

    This study examined physicians' attitude, involvement, and perceived barriers with the health care proxy. A cross sectional, correlational design was used to survey practicing physicians (N = 70). Physicians had positive attitudes toward the health care proxy and indicated that the most significant barriers to health care proxy completion were…

  16. Proxy Graph: Visual Quality Metrics of Big Graph Sampling.

    Science.gov (United States)

    Nguyen, Quan Hoang; Hong, Seok-Hee; Eades, Peter; Meidiana, Amyra

    2017-06-01

    Data sampling has been extensively studied for large scale graph mining. Many analyses and tasks become more efficient when performed on graph samples of much smaller size. The use of proxy objects is common in software engineering for analysis and interaction with heavy objects or systems. In this paper, we coin the term 'proxy graph' and empirically investigate how well a proxy graph visualization can represent a big graph. Our investigation focuses on proxy graphs obtained by sampling; this is one of the most common proxy approaches. Despite the plethora of data sampling studies, this is the first evaluation of sampling in the context of graph visualization. For an objective evaluation, we propose a new family of quality metrics for visual quality of proxy graphs. Our experiments cover popular sampling techniques. Our experimental results lead to guidelines for using sampling-based proxy graphs in visualization.

  17. Adaptability in CORBA: The Mobile Proxy Approach

    DEFF Research Database (Denmark)

    Aziz, B.; Jensen, Christian D.

    2000-01-01

    are inherently open, heterogeneous, and dynamic environments integrating a wide range of platforms, operating systems and applications from a number of different sources. In this paper, we propose to use mobile proxies to provide adaptability in distributed applications integrated using the CORBA technology......Adaptability is one of the most important challenges in modern distributed systems. It may be defined as the ease with which a software application satisfies the different system constraints and the requirements of users and other applications. Adaptability is needed because distributed systems...

  18. Source-specific diatom lipid biomarkers as proxies for Arctic and Antarctic sea ice

    Science.gov (United States)

    Belt, Simon

    2016-04-01

    Sea ice plays a key role in controlling global climate due its influence over heat and gas exchange between the oceans and the atmosphere. In addition, sea ice exerts a strong influence over the absorption of incoming radiation at the ocean surface as a result of its high reflectivity or albedo. Driven, in part, by the recent dramatic changes to sea ice cover in both the Arctic and the Antarctic, the development of proxies for sea ice has received growing attention over the last 10 years or so. Amongst these, some so-called highly branched isoprenoid (HBI) lipid biomarkers have attracted considerable interest, not least, because they are derived from certain diatoms that reside and bloom within the sea ice matrix itself, thus providing a more direct indication of sea ice presence compared with some other proxies. The signature HBI sea proxies are a mono-unsaturated HBI (IP25) for the Arctic and a di-unsaturated HBI (C25:2) for the Antarctic, with different source organisms for each. Although the variability in sedimentary abundances of IP25 and C25:2 in Arctic and Antarctic sediments generally reflect the corresponding changes in sea ice conditions, a more complete picture of reconstructing sea ice conditions likely requires a multi-proxy approach involving, for example, other lipid biomarkers that serve as proxy measures of nearby open water conditions or sea surface temperature. By adoption of such an approach, a research strategy aimed at improving estimates of sea ice concentrations or better definitions of sea ice conditions (e.g. marginal ice zone, polynyas, permanent ice cover) represents the next stage in lipid-based sea ice proxy development. This presentation will focus on recent developments and future plans that involve a multi-proxy approach to improving sea ice reconstruction. An understanding of sources, ecology and environmental fate of various HBIs and other diatom lipids will likely be key in shaping the future direction of lipid-based sea ice

  19. Munchausen syndrome by proxy: ongoing clinical challenges.

    Science.gov (United States)

    Squires, Janet E; Squires, Robert H

    2010-09-01

    In 1977, Roy Meadow, a pediatric nephrologist, first described a condition he subsequently coined Munchausen syndrome by proxy. The classic form involves a parent or other caregiver who inflicts injury or induces illness in a child, deceive the treating physician with fictitious or exaggerated information, and perpetrate the trick for months or years. A related form of pathology is more insidious and more common but also damaging. It involves parents who fabricate or exaggerate symptoms of illness in children, causing overly aggressive medical evaluations and interventions. The common thread is that the treating physician plays a role in inflicting the abuse upon the child. Failure to recognize the problem is common because the condition is often not included in the differential diagnosis of challenging or confusing clinical problems. We believe that a heightened "self-awareness" of the physician's role in Munchausen syndrome by proxy will prevent or reduce the morbidity and mortality associated with this diagnosis. In addition, we believe contemporary developments within the modern health care system likely facilitate this condition.

  20. Workflows for intelligent monitoring using proxy services.

    Science.gov (United States)

    Rüping, Stefan; Wegener, Dennis; Sfakianakis, Stelios; Sengstag, Thierry

    2009-01-01

    Grid technologies have proven to be very successful in the area of eScience, and in particular in healthcare applications. But while the applicability of workflow enacting tools for biomedical research has long since been proven, the practical adoption into regular clinical research has some additional challenges in grid context. In this paper, we investigate the case of data monitoring, and how to seamlessly implement the step between a one-time proof-of-concept workflow and high-performance on-line monitoring of data streams, as exemplified by the case of long-running clinical trials. We will present an approach based on proxy services that allows executing single-run workflows repeatedly with little overhead.

  1. Salmon: Robust Proxy Distribution for Censorship Circumvention

    Directory of Open Access Journals (Sweden)

    Douglas Frederick

    2016-10-01

    Full Text Available Many governments block their citizens’ access to much of the Internet. Simple workarounds are unreliable; censors quickly discover and patch them. Previously proposed robust approaches either have non-trivial obstacles to deployment, or rely on low-performance covert channels that cannot support typical Internet usage such as streaming video. We present Salmon, an incrementally deployable system designed to resist a censor with the resources of the “Great Firewall” of China. Salmon relies on a network of volunteers in uncensored countries to run proxy servers. Although any member of the public can become a user, Salmon protects the bulk of its servers from being discovered and blocked by the censor via an algorithm for quickly identifying malicious users. The algorithm entails identifying some users as especially trustworthy or suspicious, based on their actions. We impede Sybil attacks by requiring either an unobtrusive check of a social network account, or a referral from a trustworthy user.

  2. Development of six PROMIS pediatrics proxy-report item banks

    Directory of Open Access Journals (Sweden)

    Irwin Debra E

    2012-02-01

    Full Text Available Abstract Background Pediatric self-report should be considered the standard for measuring patient reported outcomes (PRO among children. However, circumstances exist when the child is too young, cognitively impaired, or too ill to complete a PRO instrument and a proxy-report is needed. This paper describes the development process including the proxy cognitive interviews and large-field-test survey methods and sample characteristics employed to produce item parameters for the Patient Reported Outcomes Measurement Information System (PROMIS pediatric proxy-report item banks. Methods The PROMIS pediatric self-report items were converted into proxy-report items before undergoing cognitive interviews. These items covered six domains (physical function, emotional distress, social peer relationships, fatigue, pain interference, and asthma impact. Caregivers (n = 25 of children ages of 5 and 17 years provided qualitative feedback on proxy-report items to assess any major issues with these items. From May 2008 to March 2009, the large-scale survey enrolled children ages 8-17 years to complete the self-report version and caregivers to complete the proxy-report version of the survey (n = 1548 dyads. Caregivers of children ages 5 to 7 years completed the proxy report survey (n = 432. In addition, caregivers completed other proxy instruments, PedsQL™ 4.0 Generic Core Scales Parent Proxy-Report version, PedsQL™ Asthma Module Parent Proxy-Report version, and KIDSCREEN Parent-Proxy-52. Results Item content was well understood by proxies and did not require item revisions but some proxies clearly noted that determining an answer on behalf of their child was difficult for some items. Dyads and caregivers of children ages 5-17 years old were enrolled in the large-scale testing. The majority were female (85%, married (70%, Caucasian (64% and had at least a high school education (94%. Approximately 50% had children with a chronic health condition, primarily

  3. Optical Proxies for Terrestrial Dissolved Organic Matter in Estuaries and Coastal Waters

    Directory of Open Access Journals (Sweden)

    Christopher L. Osburn

    2016-01-01

    Full Text Available Optical proxies, especially DOM fluorescence, were used to track terrestrial DOM fluxes through estuaries and coastal waters by comparing models developed for several coastal ecosystems. Key to using optical properties is validating and calibrating them with chemical measurements, such as lignin-derived phenols - a proxy to quantify terrestrial DOM. Utilizing parallel factor analysis (PARAFAC, and comparing models statistically using the OpenFluor database (http://www.openfluor.org we have found common, ubiquitous fluorescing components which correlate most strongly with lignin phenol concentrations in several estuarine and coastal environments. Optical proxies for lignin were computed for the following regions: Mackenzie River Estuary, Atchafalaya River Estuary, Charleston Harbor, Chesapeake Bay, and Neuse River Estuary. The slope of linear regression models relating CDOM absorption at 350 nm (a350 to DOC and to lignin, varied 5 to 10 fold among systems. Where seasonal observations were available from a region, there were distinct seasonal differences in equation parameters for these optical proxies. Despite variability, overall models using single linear regression were developed that related dissolved organic carbon (DOC concentration to CDOM (DOC = 40×a350+138; R2 = 0.77; N = 130 and lignin (Σ8 to CDOM (Σ8 = 2.03×a350-0.5; R2 = 0.87; N = 130. This wide variability suggested that local or regional optical models should be developed for predicting terrestrial DOM flux into coastal oceans and taken into account when upscaling to remote sensing observations and calibrations.

  4. Proxy-produced ethnographic work: what are the problems, issues, and dilemmas arising from proxy ethnography?

    DEFF Research Database (Denmark)

    Martinussen, Marie Louise; Højbjerg, Karin; Tamborg, Andreas Lindenskov

    2018-01-01

    and positions arising from such a setup between the teacher/researcher and the proxy ethnographer/student are found to have implications for the ethnographies produced. This article’s main focus is to show how these relations and positions have not distorted the ethnographic work and the ethnographies but......This article addresses the implications of research-student cooperation in the production of empirical material. For the student to replace the experienced researcher and work under the researcher’s supervision, we call such work proxy-produced ethnographic work. The specific relations...... the research process. These ethnographic distortions will be generated and described within a framework drawn primarily on the work of sociologist Pierre Bourdieu....

  5. Key Nutrients.

    Science.gov (United States)

    Federal Extension Service (USDA), Washington, DC.

    Lessons written to help trainer agents prepare aides for work with families in the Food and Nutrition Program are presented in this booklet. The key nutrients discussed in the 10 lessons are protein, carbohydrates, fat, calcium, iron, iodine, and Vitamins A, B, C, and D. the format of each lesson is as follows: Purpose, Presentation, Application…

  6. Attacks on One Designated Verifier Proxy Signature Scheme

    Directory of Open Access Journals (Sweden)

    Baoyuan Kang

    2012-01-01

    Full Text Available In a designated verifier proxy signature scheme, there are three participants, namely, the original signer, the proxy signer, and the designated verifier. The original signer delegates his or her signing right to the proxy signer, then the proxy signer can generate valid signature on behalf of the original signer. But only the designated verifier can verify the proxy signature. Several designated verifier proxy signature schemes have been proposed. However, most of them were proven secure in the random oracle model, which has received a lot of criticism since the security proofs in the random oracle model are not sound with respect to the standard model. Recently, by employing Water's hashing technique, Yu et al. proposed a new construction of designated verifier proxy signature. They claimed that the new construction is the first designated verifier proxy signature, whose security does not rely on the random oracles. But, in this paper, we will show some attacks on Yu et al.'s scheme. So, their scheme is not secure.

  7. Factitious Disorder by Proxy in Educational Settings: A Review

    Science.gov (United States)

    Frye, Ellen M.; Feldman, Marc D.

    2012-01-01

    Factitious disorder by proxy (FDP), historically known as Munchausen syndrome by proxy, is a diagnosis applied to parents and other caregivers who intentionally feign, exaggerate, and/or induce illness or injury in a child to get attention from health professionals and others. A review of the recent literature and our experience as consultants…

  8. A quantum proxy group signature scheme based on an entangled five-qubit state

    Science.gov (United States)

    Wang, Meiling; Ma, Wenping; Wang, Lili; Yin, Xunru

    2015-09-01

    A quantum proxy group signature (QPGS) scheme based on controlled teleportation is presented, by using the entangled five-qubit quantum state functions as quantum channel. The scheme uses the physical characteristics of quantum mechanics to implement delegation, signature and verification. The security of the scheme is guaranteed by the entanglement correlations of the entangled five-qubit state, the secret keys based on the quantum key distribution (QKD) and the one-time pad algorithm, all of which have been proven to be unconditionally secure and the signature anonymity.

  9. Perbandingan proxy pada linux dan windows untuk mempercepat browsing website

    Directory of Open Access Journals (Sweden)

    Dafwen Toresa

    2017-05-01

    Full Text Available AbstrakPada saat ini sangat banyak organisasi, baik pendidikan, pemerintahan,  maupun perusahaan swasta berusaha membatasi akses para pengguna ke internet dengan alasan bandwidth yang dimiliki mulai terasa lambat ketika para penggunanya mulai banyak yang melakukan browsing ke internet. Mempercepat akses browsing menjadi perhatian utama dengan memanfaatkan teknologi Proxy server. Penggunaan proxy server perlu mempertimbangkan sistem operasi pada server dan tool yang digunakan belum diketahui performansi terbaiknya pada sistem operasi apa.  Untuk itu dirasa perlu untuk menganalisis performan Proxy server pada sistem operasi berbeda yaitu Sistem Operasi Linux dengan tools Squid  dan Sistem Operasi Windows dengan tool Winroute. Kajian ini dilakukan untuk mengetahui perbandingan kecepatan browsing dari komputer pengguna (client. Browser yang digunakan di komputer pengguna adalah Mozilla Firefox. Penelitian ini menggunakan 2 komputer klien dengan pengujian masing-masingnya 5 kali pengujian pengaksesan/browsing web yang dituju melalui proxy server. Dari hasil pengujian yang dilakukan, diperoleh kesimpulan bahwa penerapan proxy server di sistem operasi linux dengan tools squid lebih cepat browsing dari klien menggunakan web browser yang sama dan komputer klien yang berbeda dari pada proxy server sistem operasi windows dengan tools winroute.  Kata kunci: Proxy, Bandwidth, Browsing, Squid, Winroute AbstractAt this time very many organizations, both education, government, and private companies try to limit the access of users to the internet on the grounds that the bandwidth owned began to feel slow when the users began to do a lot of browsing to the internet. Speed up browsing access is a major concern by utilizing Proxy server technology. The use of proxy servers need to consider the operating system on the server and the tool used is not yet known the best performance on what operating system. For that it is necessary to analyze Performance Proxy

  10. Proxy Perspectives about End-of-Life Care for Person’s with Cancer

    Science.gov (United States)

    Bakitas, Marie; Ahles, Tim A.; Skalla, Karen; Brokaw, Frances C.; Byock, Ira; Hanscom, Brett; Lyons, Kathleen Doyle; Hegel, Mark T.

    2013-01-01

    Background Each year more than one-half million people die from cancer in the United States. Despite progress in increasing access to palliative oncology services, end-of-life care still needs improvement. Measuring the quality of the end-of-life experience is difficult due to patient debility and reduced consciousness as death approaches. Family proxies have been proposed as valuable informants regarding the quality of end-of-life care. This paper describes family proxy perspectives on care at the end of life in patients who died from advanced cancer Methods In the context of a novel outpatient palliative care demonstration project, 125 family proxy respondents completed a structured survey by phone 3–6 months following patients’ death from breast, lung, or gastrointestinal cancer. Four key quality of care indicators were measured: decision-making and physician communication, location of death, hospice involvement, and end-of-life symptoms. Results Proxies reported that 80% of patients completed advance directives and about half of them were helpful in guiding care; communication with physicians about end-of-life treatment wishes occurred in 67%, but less than half actually made a plan with the physician to ensure that their wishes were followed; the majority died in their location of choice, most often at home; over half had hospice involvement for an average of 41.8 days prior to death; and during the last week of life the majority of patients experienced troublesome physical and emotional symptoms. Conclusions Measurement of proxy perspectives is feasible and these results provide actionable data for areas of improvement in palliative oncology care. PMID:18306393

  11. Proxy perspectives regarding end-of-life care for persons with cancer.

    Science.gov (United States)

    Bakitas, Marie; Ahles, Tim A; Skalla, Karen; Brokaw, Frances C; Byock, Ira; Hanscom, Brett; Lyons, Kathleen Doyle; Hegel, Mark T

    2008-04-15

    Each year, greater than a half million people die of cancer in the U.S. Despite progress in increasing access to palliative oncology services, end-of-life care still needs improvement. Measuring the quality of the end-of-life experience is difficult because of patient debility and reduced consciousness as death approaches. Family proxies have been proposed as valuable informants regarding the quality of end-of-life care. This article describes family proxy perspectives concerning care at the end of life in patients who died of advanced cancer. In the context of a novel outpatient palliative care demonstration project, 125 family proxy respondents completed a structured survey by telephone 3 months to 6 months after the patient's death from breast, lung, or gastrointestinal cancer. Four key quality of care indicators were measured: decision-making and physician communication, location of death, hospice involvement, and end-of-life symptoms. Proxies reported that 78% to 81% of patients completed at least 1 form of advance directive and approximately half of them were helpful in guiding care. Communication with physicians regarding end-of-life treatment wishes occurred in 67% of cases, but only 57% of the patients actually made a plan with their physician to ensure that their wishes were followed. The majority of patients died in their location of choice, most often at home, and greater than half had hospice involvement for an average of 41.8 days before death. During the last week of life, the majority of patients experienced troublesome physical and emotional symptoms. Measurement of proxy perspectives is feasible as an indicator of the quality of end-of-life care, and the results of the current study provide actionable data for areas of improvement in palliative oncology care.

  12. Proxy SDN Controller for Wireless Networks

    Directory of Open Access Journals (Sweden)

    Won-Suk Kim

    2016-01-01

    Full Text Available Management of wireless networks as well as wired networks by using software-defined networking (SDN has been highlighted continually. However, control features of a wireless network differ from those of a wired network in several aspects. In this study, we identify the various inefficient points when controlling and managing wireless networks by using SDN and propose SDN-based control architecture called Proxcon to resolve these problems. Proxcon introduces the concept of a proxy SDN controller (PSC for the wireless network control, and the PSC entrusted with the role of a main controller performs control operations and provides the latest network state for a network administrator. To address the control inefficiency, Proxcon supports offloaded SDN operations for controlling wireless networks by utilizing the PSC, such as local control by each PSC, hybrid control utilizing the PSC and the main controller, and locally cooperative control utilizing the PSCs. The proposed architecture and the newly supported control operations can enhance scalability and response time when the logically centralized control plane responds to the various wireless network events. Through actual experiments, we verified that the proposed architecture could address the various control issues such as scalability, response time, and control overhead.

  13. Lithium in Brachiopods - proxy for seawater evolution?

    Science.gov (United States)

    Gaspers, Natalie; Magna, Tomas; Tomasovych, Adam; Henkel, Daniela

    2017-04-01

    Marine biogenic carbonates have the potential to serve as a proxy for evolution of seawater chemistry. In order to compile a record of the past and recent δ7Li in the oceans, foraminifera shells, scleractinian corals and belemnites have been used. However, only a foraminifera-based record appears to more accurately reflect the Li isotope composition of ocean water. At present, this record is available for the Cenozoic with implications for major events during this period of time, including K/T event [1]. A record for the entire Phanerozoic has not yet been obtained. In order to extend this record to the more distant past, Li elemental/isotope systematics of brachiopods were investigated because these marine animals were already present in Early Cambrian oceans and because they are less sensitive to diagenesis-induced modifications due to their shell mineralogy (low-Mg calcite). The preliminary data indicates a species-, temperature- and salinity-independent behavior of Li isotopes in brachiopod shells. Also, no vital effects have been observed for different shell parts. The consistent offset of -4‰ relative to modern seawater is in accordance with experimental data [2]. Further data are now being collected for Cenozoic specimens to more rigorously test brachiopods as possible archives of past seawater in comparison to the existing foraminiferal records. [1] Misra & Froelich (2012) Science 335, 818-823 [2] Marriott et al. (2004) Chem Geol 212, 5-15

  14. Deciphering dynamical proxy responses from lake sediments

    Science.gov (United States)

    Ramisch, Arne; Tjallingii, Rik; Hartmann, Kai; Brauer, Achim; Diekmann, Bernhard; Haberzettl, Torsten; Kasper, Thomas; Ahlborn, Marieke

    2017-04-01

    Lakes form a reliable archive of paleoenvironmental change in the terrestrial realm. Non-destructive XRF scans provide high-resolution records of element concentrations that are commonly related to past environmental change. However, XRF records of lake sediments enclose paleoenvironmental information that originates from multiple lake external and internal forcing. The variety of environmental forcing factors can complicate a direct identification of single mechanisms like climatic change from XRF or other proxy records. Here we present XRF records from several Asian lake archives, which indicate asynchronous variations of similar geochemical records since the late glacial/early Holocene. All XRF time series are characterized by damped harmonic oscillations of relative element concentrations through time. The asynchronous variations can be expressed by the frequency and the rate of damping of theses oscillations that differ between the lakes. We argue that the oscillatory behavior is a result of a feedback between the physical removal and dissolution of mineral phases in catchment soils and their subsequent enrichment and deposition within the lake. We present a numerical model, which accurately simulates major Holocene variations in the element concentration of lake records and discuss implications for the reconstruction of environmental signals from lake sediments.

  15. Proxies and consent discussions for dementia research.

    Science.gov (United States)

    Sugarman, Jeremy; Roter, Debra; Cain, Carole; Wallace, Roberta; Schmechel, Don; Welsh-Bohmer, Kathleen A

    2007-04-01

    To better understand the nature of informed consent encounters for research involving patients with dementia that requires proxy consent. Audiotaping of informed-consent encounters for a study of genetic markers for sporadic Alzheimer's disease. Outpatients at an Alzheimer's disease research center. Patients with dementia and their companions. Audiotapes were analyzed to characterize communication style and coverage of the standard elements of informed consent and, using the Roter Interaction Analysis System, to capture the dynamics of three-way interaction between the patient, their companion, and the physician investigator. Of 26 informed consent encounters, all involved a patient, a companion, and a physician. Patients had a mean Mini-Mental State Examination (MMSE) score of 21.8. For patients, 49% of their interactions involved agreement and approval (positive statements), 16% psychosocial information, 7% biomedical information, 7% asking questions, and 7% expressing emotion. Companion interactions involved 37% positive statements and 19% biomedical information. Physician interactions involved emotional expressiveness (30%) and positive statements (19%). Discussion length was positively related to MMSE score (Spearman rho=0.45; Pinformed consent was fairly comprehensive and had no relationship to patients' MMSE scores. These data should inform policies regarding the ethically appropriate ways of conducting research with cognitively impaired adults. For example, patients in this study were more silent than their companions and the physician, but when patients spoke, they primarily agreed with what was said. Although this might first seem to signal assent, such an interpretation should be made with caution for persons with dementia. In addition, previous work on informed consent has focused on its cognitive aspects, but these data reveal that the emotional and social dimensions warrant attention.

  16. Application and Network-Cognizant Proxies - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Antonio Ortega; Daniel C. Lee

    2003-03-24

    OAK B264 Application and Network-Cognizant Proxies - Final Report. Current networks show increasing heterogeneity both in terms of their bandwidths/delays and the applications they are required to support. This is a trend that is likely to intensify in the future, as real-time services, such as video, become more widely available and networking access over wireless links becomes more widespread. For this reason they propose that application-specific proxies, intermediate network nodes that broker the interactions between server and client, will become an increasingly important network element. These proxies will allow adaptation to changes in network characteristics without requiring a direct intervention of either server or client. Moreover, it will be possible to locate these proxies strategically at those points where a mismatch occurs between subdomains (for example, a proxy could be placed so as to act as a bridge between a reliable network domain and an unreliable one). This design philosophy favors scalability in the sense that the basic network infrastructure can remain unchanged while new functionality can be added to proxies, as required by the applications. While proxies can perform numerous generic functions, such as caching or security, they concentrate here on media-specific, and in particular video-specific, tasks. The goal of this project was to demonstrate that application- and network-specific knowledge at a proxy can improve overall performance especially under changing network conditions. They summarize below the work performed to address these issues. Particular effort was spent in studying caching techniques and on video classification to enable DiffServ delivery. other work included analysis of traffic characteristics, optimized media scheduling, coding techniques based on multiple description coding, and use of proxies to reduce computation costs. This work covered much of what was originally proposed but with a necessarily reduced scope.

  17. Optimizing TCP Performance over UMTS with Split TCP Proxy

    DEFF Research Database (Denmark)

    Hu, Liang; Dittmann, Lars

    2009-01-01

    Abstract: The TCP performance over UMTS network is challenged by the large delay bandwidth product. Large delay bandwidth product is mainly caused by the latency from the link layer ARQ retransmissions and diversity technique at physical layer which are used to cope with radio transmission errors...... scenario (e.g.64 kbps). Besides, the split TCP proxy brings more performance gain for downloading large files than downloading small ones. To the end, for the configuration of the split proxy, an aggressive initial TCP congestion window size (e.g. 10 MSS) at proxy is particularly useful for radio links...

  18. Cryptanalytic Performance Appraisal of Improved CCH2 Proxy Multisignature Scheme

    Directory of Open Access Journals (Sweden)

    Raman Kumar

    2014-01-01

    Full Text Available Many of the signature schemes are proposed in which the t out of n threshold schemes are deployed, but they still lack the property of security. In this paper, we have discussed implementation of improved CCH1 and improved CCH2 proxy multisignature scheme based on elliptic curve cryptosystem. We have represented time complexity, space complexity, and computational overhead of improved CCH1 and CCH2 proxy multisignature schemes. We have presented cryptanalysis of improved CCH2 proxy multisignature scheme and showed that improved CCH2 scheme suffered from various attacks, that is, forgery attack and framing attack.

  19. Web proxy cache replacement strategies simulation, implementation, and performance evaluation

    CERN Document Server

    ElAarag, Hala; Cobb, Jake

    2013-01-01

    This work presents a study of cache replacement strategies designed for static web content. Proxy servers can improve performance by caching static web content such as cascading style sheets, java script source files, and large files such as images. This topic is particularly important in wireless ad hoc networks, in which mobile devices act as proxy servers for a group of other mobile devices. Opening chapters present an introduction to web requests and the characteristics of web objects, web proxy servers and Squid, and artificial neural networks. This is followed by a comprehensive review o

  20. Munchausen syndrome by proxy presenting as hearing loss.

    Science.gov (United States)

    Ashraf, N; Thevasagayam, M S

    2014-06-01

    To review the diagnosis of Munchausen syndrome by proxy, a factitious disorder, in which symptoms are induced or feigned, usually in a child, by the caregiver. The involved caregiver seeks to gain attention or sympathy and often has a psychological need to maintain the sick role. We highlight the diagnostic difficulties and factors that may help with diagnosis in an otolaryngology setting. We present the case of Munchausen syndrome by proxy presenting with hearing loss in a five-year old boy, who was diagnosed eight years after his initial presentation. A literature review of Munchausen syndrome by proxy cases presenting with ENT symptoms is provided. Munchausen syndrome by proxy is a diagnosis that otolaryngologists should be aware of, particularly where recurrent or persistent illnesses in children, especially those involving otological symptoms, are refractory to the usual treatments.

  1. Munchausen Syndrome by Proxy: Unusual Manifestations and Disturbing Sequelae.

    Science.gov (United States)

    Porter, Gerald E.; And Others

    1994-01-01

    This study documents previously unreported findings in cases of Munchausen Syndrome by Proxy (in which a mother fabricates an illness in her child). In the reported case, esophageal perforation, retrograde intussusception, tooth loss, and bradycardia were found. (Author/DB)

  2. Applicability of a cognitive questionnaire in the elderly and proxy

    Directory of Open Access Journals (Sweden)

    Renata Areza Fegyveres

    Full Text Available Abstract The Informant Questionnaire on Cognitive Decline in the Elderly with the Proxy (IQCODE was developed as a screening tool for cognition alterations. Objectives: 1 To verify the applicability of IQCODE in the elderly with limited schooling, 2 To verify the reliability of the responses supplied by the aged and their proxies. Methods: Individuals of a Community Group were evaluated using the Mini-Mental State Examination (MMSE, IQCODE and Geriatric Depression Scale (GDS. The IQCODE was applied to informants and proxies. Results: We analyzed 44 individuals, aged between 58-82 years (M=66.8, SD=5.97 with mean elderly-schooling level of 3.75, SD=2.82 and 44 proxies aged 44.5 (SD=13.3, with mean schooling level of 8.25 (SD=4.3. The mean GDS was 8.22, SD=4.90 and 13 participants presented a score suggestive of depressive symptoms. The mean elderly IQCODE score was 3.26, SD=0.69 and 3.21, SD=0.65, for proxy responses. There was no statistical difference between these means. On the MMSE, the mean score was 24.20, SD=4.14 and 18 participants presented scores below the cut-off. The IQCODE answers by the elderly in this latter group were more congruent with MMSE than the answers of proxies. Conclusions: The applicability of the IQCODE in a population with little schooling was verified in that the proxy-report was similar to the elderly report. We can affirm that the elderly answers were more accurate than the proxies, as they were closer to MMSE score. The inclusion of a greater number of participants from community-dwelling settings is necessary to confirm the results obtained in this study.

  3. Proxy-rated quality of life in Alzheimer's disease

    DEFF Research Database (Denmark)

    Vogel, Asmus; Bhattacharya, Suvosree; Waldorff, Frans Boch

    2012-01-01

    The study investigated the change in proxy rated quality of life (QoL) of a large cohort of home living patients with Alzheimer's disease (AD) over a period of 36 months.......The study investigated the change in proxy rated quality of life (QoL) of a large cohort of home living patients with Alzheimer's disease (AD) over a period of 36 months....

  4. Biomarker Proxy Calibration Along the AMT Transect: Alkenone Uk37' and δD

    Science.gov (United States)

    Gould, J.; Kienast, M.; Dowd, M.; Schefuß, E.

    2016-12-01

    This study analyzes 60 suspended particulate organic matter (SPOM) samples from an Atlantic Meridional Transect (AMT20), spanning approximately 105° latitude (Southampton to Punta Arenas), for key biomarker proxy signatures: alkenone unsaturation (Uk37') and hydrogen isotopic (δD) composition. The wide range in surface ocean characteristics along the transect offers a unique opportunity to refine our understanding of these proxies. Initial alkenone δD values correlate - to a first order - with water column δD signatures, which in turn parallel salinity values along the AMT20 transect. Other factors that have been shown to influence δD will be discussed as well. The Uk37' data presented are in good agreement with previously published SPOM data, though we offer an alternative regression model to relate Uk37' to sea surface temperatures (SST); the Richards curve (Richards, 1959). This non-linear regression model uniquely accounts for both the fact that the Uk37' index is a proportion, and so must lie between 0 and 1, as well as for an apparent reduction in slope at temperature extremes. The inverse of this relationship allows estimation of SST from a measured Uk37' value with quantitative estimates of uncertainty. Further, we have identified a pronounced seasonal sampling bias in the SPOM dataset analyzed in this and prior studies (e.g. Conte et al. 2006), which may be contributing to a reported offset between surface particulate and core-top Uk37'- SST calibrations for this proxy.

  5. Near coast sedimentary stratigraphy as a proxy for climatic instability

    Science.gov (United States)

    McLivenny, J.

    2009-04-01

    Several studies have indicated a link between climatic deterioration and dune stability (Wilson 2002, Issar 2003, Dawson et al 2004). The frequency and magnitude of storms have been cited as a key variable in the stability of large dune systems. For the stratigraphy of dune systems to act as a regional climatic proxy there must be a good regional relationship between known climatic events and regionally correlated stratigraphic changes. Dunnet Bay in Caithness, Northern Scotland was chosen as a study site to look at the relationship between dune stability and climatic change during the late Holocene in Northern Scotland. Dunnet Bay was chosen for its physical attributes which make it an excellent natural sediment trap. Tucked in between headlands which act as barriers to long-shore transport the predominant movement of sediment there is straight onshore, with only minor amounts being lost to the sea. The immediate back-dune stratigraphy, colloquially known as "links", provided evidence of peat formation and dune stability. Stratigraphy was mapped using traditional field techniques and ground penetrating radar. The cores consisted mostly of massive layers of sand interleaved with peat. Sand layers were dated with optically stimulated luminescence (OSL) and interpreted as reflecting high wind energy regimes transporting sand inland. Peat layers were C14 dated and taken as representing climatic stability. Stratigraphy was mapped using hand auguring, percussion coring, and open sections. Ground penetrating radar was also used to look at the continuity of key layers. OSL dating in two open sections showed dates obtained from the first section (1790 AD ±70, 53 BC ± 100, 300 BC ± 100, 400 BC ± 100) mapped to the top of the second section (1800 AD ± 100, 1500 BC ± 200, 2900 BC ± 300) which was consistent with stratigraphy increasing sediment thickness towards the centre of the bay. The results were consistent with acquired C14 dates from selected peat layers. Taken

  6. A New Proxy Electronic Voting Scheme Achieved by Six-Particle Entangled States

    Science.gov (United States)

    Cao, Hai-Jing; Ding, Li-Yuan; Jiang, Xiu-Li; Li, Peng-Fei

    2017-12-01

    In this paper, we use quantum proxy signature to construct a new secret electronic voting scheme. In our scheme, six particles entangled states function as quantum channels. The voter Alice, the Vote Management Center Bob, the scrutineer Charlie only perform two particles measurements on the Bell bases to realize the electronic voting process. So the scheme reduces the technical difficulty and increases operation efficiency. We use quantum key distribution and one-time pad to guarantee its unconditional security. The significant advantage of our scheme is that transmitted information capacity is twice as much as the capacity of other schemes.

  7. Security analysis and enhanced user authentication in proxy mobile IPv6 networks.

    Directory of Open Access Journals (Sweden)

    Dongwoo Kang

    Full Text Available The Proxy Mobile IPv6 (PMIPv6 is a network-based mobility management protocol that allows a Mobile Node(MN connected to the PMIPv6 domain to move from one network to another without changing the assigned IPv6 address. The user authentication procedure in this protocol is not standardized, but many smartcard based authentication schemes have been proposed. Recently, Alizadeh et al. proposed an authentication scheme for the PMIPv6. However, it could allow an attacker to derive an encryption key that must be securely shared between MN and the Mobile Access Gate(MAG. As a result, outsider adversary can derive MN's identity, password and session key. In this paper, we analyze Alizadeh et al.'s scheme regarding security and propose an enhanced authentication scheme that uses a dynamic identity to satisfy anonymity. Furthermore, we use BAN logic to show that our scheme can successfully generate and communicate with the inter-entity session key.

  8. Security analysis and enhanced user authentication in proxy mobile IPv6 networks.

    Science.gov (United States)

    Kang, Dongwoo; Jung, Jaewook; Lee, Donghoon; Kim, Hyoungshick; Won, Dongho

    2017-01-01

    The Proxy Mobile IPv6 (PMIPv6) is a network-based mobility management protocol that allows a Mobile Node(MN) connected to the PMIPv6 domain to move from one network to another without changing the assigned IPv6 address. The user authentication procedure in this protocol is not standardized, but many smartcard based authentication schemes have been proposed. Recently, Alizadeh et al. proposed an authentication scheme for the PMIPv6. However, it could allow an attacker to derive an encryption key that must be securely shared between MN and the Mobile Access Gate(MAG). As a result, outsider adversary can derive MN's identity, password and session key. In this paper, we analyze Alizadeh et al.'s scheme regarding security and propose an enhanced authentication scheme that uses a dynamic identity to satisfy anonymity. Furthermore, we use BAN logic to show that our scheme can successfully generate and communicate with the inter-entity session key.

  9. Proxy comparisons for Paleogene sea water temperature reconstructions

    Science.gov (United States)

    de Bar, Marijke; de Nooijer, Lennart; Schouten, Stefan; Ziegler, Martin; Sluijs, Appy; Reichart, Gert-Jan

    2017-04-01

    Several studies have reconstructed Paleogene seawater temperatures, using single- or multi-proxy approaches (e.g. Hollis et al., 2012 and references therein), particularly comparing TEX86 with foraminiferal δ18O and Mg/Ca. Whereas trends often agree relatively well, absolute temperatures can differ significantly between proxies, possibly because they are often applied to (extreme) climate events/transitions (e.g. Sluijs et al., 2011), where certain assumptions underlying the temperature proxies may not hold true. A more general long-term multi-proxy temperature reconstruction, is therefore necessary to validate the different proxies and underlying presumed boundary conditions. Here we apply a multi-proxy approach using foraminiferal calcite and organic proxies to generate a low-resolution, long term (80 Myr) paleotemperature record for the Bass River core (New Jersey, North Atlantic). Oxygen (δ18O), clumped isotopes (Δ47) and Mg/Ca of benthic foraminifera, as well as the organic proxies MBT'-CBT, TEX86H, U37K' index and the LDI were determined on the same sediments. The youngest samples of Miocene age are characterized by a high BIT index (>0.8) and fractional abundance of the C32 1,15-diol (>0.6; de Bar et al., 2016) and the absence of foraminifera, all suggesting high continental input and shallow depths. The older sediment layers (˜30 to 90 Ma) display BIT values and C32 1,15-diol fractional abundances global transition from the Cretaceous to Eocene greenhouse world into the icehouse climate. The TEX86H sea surface temperature (SST) record shows a gradual cooling over time of ˜35 to 20 ˚ C, whereas the δ18O-derived bottom water temperatures (BWTs) decrease from ˜20 to 10 ˚ C, and the Mg/Ca and Δ47-derived BWTs decrease from ˜25 to 15 ˚ C. The absolute temperature difference between the δ18O and Δ47, might be explained by local variations in seawater δ18O composition. Similarly, the difference in Mg/Ca- and δ18O-derived BWTs is likely caused by

  10. A new way to proxy levels of infrastructure development

    Directory of Open Access Journals (Sweden)

    Steve Pickering

    2017-01-01

    Full Text Available Researchers in many fields have needed to develop a measure of infrastructure, and many proxies have been used toward this end, such as night light data and the Digital Chart of the World. Yet there are issues in using these methods. This paper presents a new way of proxying infrastructure: analysing the file sizes of map images on the Bing, Google, OpenStreetMap and Sina websites. The paper also demonstrates four ways in which this can be achieved. This approach is by no means perfect and does not solve all of the difficulties presented by other methods. Nevertheless, it does provide a simple and functional alternative proxy for level of infrastructure development.

  11. Munchausen Syndrome By Proxy Admitting with Bloody Urine and Stool

    Directory of Open Access Journals (Sweden)

    Tugba Koca

    2014-02-01

    Full Text Available Munchausen syndrome by Proxy is a severe form of child abuse. Disease symptoms and signs are fabricated or imitated by parents or caregivers The child is usually presented to doctors, persistently. A delay in diagnosis may cause severe negative impact on spiritual, physical, mental and social development of the cases and even death. Symptoms usually disappear in the absence of the perpetrators. The diagnosis is extremely difficult. A 21-month-old boy who had applied to many centers due to bleeding from various parts of the body for last six months, and whose symptoms could not be explained with any physical reason after tests were conducted. Finally he was admitted to our center with bloody urine and stools, and diagnosed Munchausen syndrome by proxy. In cases with recurrent hospital admission in whom no apparent disease is diagnosed, Munchausen syndrome by Proxy should be among the differential diagnosis.

  12. Research on implementation of proxy Arp in IP DSLAM

    Science.gov (United States)

    Cheng, Chuanqing; Wang, Li; Huang, Qiugen

    2005-02-01

    While the ethernet is applied more and more in public network environment and xdsl service become the most common access mode ,IP kenel DSLAM undertakes some functions such as service distribution and convergence ,security management and customer management.Facing the contradiction of the need of port isolation and the shortage of ip address,VLAN aggregation technology is applied in DSLAM.How to implement the communicatio between the two vlan but share the same ip subnet,proxy arp does this. This paper introduces how to implement proxy arp in the DSLAM. TCP/IP communication detail procedure betweent two host ,the relation of VLAN and network segment are discussed. The proxy arp model and its implementation in IP DSLAM is also expatiated in this paper and a conformance tesing is given.

  13. Health anxiety by proxy in women with severe health anxiety

    DEFF Research Database (Denmark)

    Thorgaard, Mette Viller; Frostholm, Lisbeth; Walker, Lynn

    2017-01-01

    Health anxiety (HA) refers to excessive worries and anxiety about harbouring serious illness based on misinterpretation of bodily sensations or changes as signs of serious illness. Severe HA is associated with disability and high health care costs. However, the impact of parental HA on excessive...... concern with their children's health (health anxiety by proxy) is scantly investigated. The aim of this study is to investigate HA by proxy in mothers with severe HA. Fifty mothers with severe HA and two control groups were included, i.e. mothers with rheumatoid arthritis (N = 49) and healthy mothers (N...

  14. Enhanced Collaboration for Space Situational Awareness via Proxy Agents

    Science.gov (United States)

    Picciano, P.; Schurr, N.

    2012-09-01

    The call for dynamic partnerships demanded in the US. Space Policy confronts two formidable challenges. The first is evident in the lack of the adoption of technical innovations that could substantially enhance collaboration. The second category, and perhaps a greater impediment, involves organizational and social constraints that minimize information sharing. Compounding the technical challenges, the organizational barriers to collaboration present a different problem set. There is a culture in the space domain that predisposes most stakeholders to guard their information. Most owner/operators are reluctant to share asset data, whether experiencing an anomaly or just providing status updates. This is unfortunate, because the owner/operators generally have the most accurate and timely data pertaining to their satellite. Comprehensive Space Situational Awareness (SSA) requires the marshaling of disparate mission critical elements. The mission threads reliant on SSA are complex and often require analysis from a diverse team of experts with sophisticated systems and tools that may be dispersed across multiple entities including military, commercial, and public interests. Two significant trends are likely to further perpetuate this state of affairs: 1) the space environment continues to be more congested, contested, and competitive, and 2) further pressures to increase SSA Sharing with a greater number of stakeholders throughout the world. The challenge of delivering the right information to the right people, while protecting national security and privacy interests, is in need of an innovative solution. Our approach, entitled Space Collaboration via an Agent Network (SCAN), enables proxy software agents to represent stakeholders (as individuals and organizations) to enhance collaboration among various agency producers and consumers of space information The SCAN agent network will facilitate collaboration by identifying opportunities to collaborate, as well as optimize

  15. Multi Service Proxy: Mobile Web Traffic Entitlement Point in 4G Core Network

    Directory of Open Access Journals (Sweden)

    Dalibor Uhlir

    2015-05-01

    Full Text Available Core part of state-of-the-art mobile networks is composed of several standard elements like GGSN (Gateway General Packet Radio Service Support Node, SGSN (Serving GPRS Support Node, F5 or MSP (Multi Service Proxy. Each node handles network traffic from a slightly different perspective, and with various goals. In this article we will focus only on the MSP, its key features and especially on related security issues. MSP handles all HTTP traffic in the mobile network and therefore it is a suitable point for the implementation of different optimization functions, e.g. to reduce the volume of data generated by YouTube or similar HTTP-based service. This article will introduce basic features and functions of MSP as well as ways of remote access and security mechanisms of this key element in state-of-the-art mobile networks.

  16. Slices: A shape-proxy based on planar sections

    KAUST Repository

    McCrae, James

    2011-12-01

    Minimalist object representations or shape-proxies that spark and inspire human perception of shape remain an incompletely understood, yet powerful aspect of visual communication. We explore the use of planar sections, i.e., the contours of intersection of planes with a 3D object, for creating shape abstractions, motivated by their popularity in art and engineering. We first perform a user study to show that humans do define consistent and similar planar section proxies for common objects. Interestingly, we observe a strong correlation between user-defined planes and geometric features of objects. Further we show that the problem of finding the minimum set of planes that capture a set of 3D geometric shape features is both NP-hard and not always the proxy a user would pick. Guided by the principles inferred from our user study, we present an algorithm that progressively selects planes to maximize feature coverage, which in turn influence the selection of subsequent planes. The algorithmic framework easily incorporates various shape features, while their relative importance values are computed and validated from the user study data. We use our algorithm to compute planar slices for various objects, validate their utility towards object abstraction using a second user study, and conclude showing the potential applications of the extracted planar slice shape proxies.

  17. Proxy indicators as measure of local economic dispositions in South ...

    African Journals Online (AJOL)

    Even though South Africa is in a more fortunate position with regard to the availability of such data, it also has data gaps, notably with regard to informal economic activities in the rural areas of the country. This exploratory article engages the use of proxy indicators to provide cues as to the state of a local economy.

  18. Proxy indicators as measure of local economic dispositions in South ...

    African Journals Online (AJOL)

    The growth of spare-part sales mirrors the behaviour of the national economy more accurately than used and new vehicles. BER: Retail Survey. (2005-2010). Used vehicles. 0.53. Spare Parts. 0.80. Banking-related proxy indicators. 13. House bonds. 0.43. Although some similarities exist between the national economy and ...

  19. Munchausen Syndrome by Proxy: A Study of Psychopathology.

    Science.gov (United States)

    Bools, Christopher; And Others

    1994-01-01

    This study evaluated 100 mothers with Munchausen Syndrome by Proxy (the fabrication of illness by a mother in her child). Approximately half of the mothers had either smothered or poisoned their child as part of their fabrications. Lifetime psychiatric histories were reported for 47 of the mothers. The most notable psychopathology was personality…

  20. Munchausen Syndrome by Proxy: Mother Fabricates Infant's Hearing Impairment.

    Science.gov (United States)

    Kahn, Gerri; Goldman, Ellen

    1991-01-01

    Case study reports a case of Munchausen Syndrome by Proxy, a form of child abuse in which the mother presents a child for treatment for a condition she herself has invented or created. This case study describes the ways in which a mother obtained a diagnosis of sensorineural hearing loss as well as amplification for her normally hearing infant.…

  1. Munchausen syndrome by adult proxy: a review of the literature.

    Science.gov (United States)

    Burton, M Caroline; Warren, Mark B; Lapid, Maria I; Bostwick, J Michael

    2015-01-01

    Munchausen syndrome by proxy (MSBP), more formally known as factitious disorder imposed on another, is a form of abuse in which a caregiver deliberately produces or feigns illness in a person under his or her care so that the proxy will receive medical care that gratifies the caregiver. Although well documented in the pediatric literature, few cases of MSBP with adult proxies (MSB-AP) have been reported. This study reviews existing literature on MSB-AP to provide a framework for clinicians to recognize this disorder. We searched Ovid MEDLINE, Ovid EMBASE, PubMed, Web of Knowledge, and PsychINFO, supplemented by bibliographic examination. We identified 13 cases of MSB-AP. Perpetrators were caregivers, most (62%) were women, and many worked in healthcare. The age range of the victims was 21 to 82 years. Most were unaware of the abuse, although in 2 cases the victim may have colluded with the perpetrator. Disease fabrication most often resulted from poisoning. MSB-AP should be included in the differential diagnosis of patients presenting with a complex constellation of symptoms without a unifying etiology and an overly involved caregiver with suspected psychological gain. Early identification is necessary so that healthcare providers do not unknowingly perpetuate harm through treatments that satisfy the perpetrator's psychological needs at the proxy's expense. © 2014 Society of Hospital Medicine.

  2. Identifying and Responding to Munchausen Syndrome by Proxy.

    Science.gov (United States)

    Pearl, Peggy T.

    1995-01-01

    Defines Munchausen Syndrome by Proxy in children up to eight years, in which the mother falsifies illness in her child by simulating or producing illness, bringing about frequent hospitalizations, painful tests, potentially harmful treatment, and in extreme cases, death. Describes symptoms and suggested professional actions. (DR)

  3. Munchausen by Proxy Victims in Adulthood: A First Look.

    Science.gov (United States)

    Libow, Judith A.

    1995-01-01

    Childhood experiences and long-term psychological outcomes were investigated with 10 adults, ages 33 through 71, who were self-identified victims of illness fabrication by a parent (Munchausen by Proxy). During childhood they felt unloved and unsafe and had emotional and physical problems. As adults, problems included insecurity, reality-testing…

  4. Munchausen Syndrome by Proxy (MSBP): An Intergenerational Perspective.

    Science.gov (United States)

    Rappaport, Sol R.; Hochstadt, Neil J.

    1993-01-01

    Presents new information about Munchausen Syndrome by Proxy (MSBP), factitious disorder in which caretaker may induce or exaggerate medical illness in his or her child that may lead to illness and even death. Provides psychosocial history of caregiver using intergenerational model. Presents case of MSBP involving three siblings and information…

  5. Shareholder Activism through Proxy Proposals : The European Perspective

    NARCIS (Netherlands)

    Cziraki, P.; Renneboog, L.D.R.; Szilagyi, P.G.

    2009-01-01

    This paper is the first to investigate the corporate governance role of shareholderinitiated proxy proposals in European firms. While proposals in the US are nonbinding even if they pass the shareholder vote, they are legally binding in the UK and most of Continental Europe. Nonetheless, submissions

  6. A comparison of Solar proxy-magnetometry diagnostics

    NARCIS (Netherlands)

    Leenaarts, J.|info:eu-repo/dai/nl/304837946; Rutten, R.J.|info:eu-repo/dai/nl/074143662; Carlsson, M.; Uitenbroek, H.

    2006-01-01

    Aims. We test various proxy-magnetometry diagnostics, i.e., brightness signatures of small-scale magnetic elements, for studying magnetic field structures in the solar photosphere. Methods. Images are numerically synthesized from a 3D solar magneto-convection simulation for, respectively, the G band

  7. Munchausen by Proxy (MBP) Maltreatment: An International Educational Challenge.

    Science.gov (United States)

    Lasher, Louisa J.

    2003-01-01

    This article is an introduction to a special section on Munchausen Syndrome by Proxy (MSBP) as a form of child maltreatment. In MSBP the perpetrator has deliberately induced, fabricated, or exaggerated a physical and/or psychological-behavioral-mental health problem in another. The article stresses the importance of obtaining an MSBP finding of…

  8. SINOMA - a better tool for proxy based reconstructions?

    Science.gov (United States)

    Buras, Allan; Thees, Barnim; Czymzik, Markus; Dräger, Nadine; Kienel, Ulrike; Neugebauer, Ina; Ott, Florian; Scharnweber, Tobias; Simard, Sonia; Slowinski, Michal; Slowinski, Sandra; Tecklenburg, Christina; Zawiska, Izabela; Wilmking, Martin

    2014-05-01

    Our knowledge on past environmental conditions largely relies on reconstructions that are based on linear regressions between proxy variables (e.g. tree-rings, lake sediments, ice cores) covering a comparably long period (centuries to millennia) and environmental parameters (e.g. climate data) of which only rather short measurement series exist (mostly decades). In general, the corresponding measurements are prone to errors. For instance, air temperature records that are to be prolonged by reconstruction from tree-rings are normally not measured in situ, i.e. where the trees used for reconstructions are growing. In contrast, the variation of tree-ring properties which are used as proxies does not only depend on temperature variations but also on other environmental variables and biological effects. However, if regressions are based on noisy data, knowledge on the noise intensity of both predictor and predictand is needed and model parameter estimates (slope and intercept) will be erroneous if information on the noise is not included in their estimation (Kutzbach et al., 2011). Here, we investigate the performance of the new Sequential Iterative Noise Matching Algorithm (SINOMA; Thees et al., 2009; and Thees et al., submitted) on a variety of typical proxy-data of differing temporal resolution (i.e. hourly (dendrometers, piezometers), seasonally (tree-rings), and annually (tree rings and varved lake sediments)). For each of the investigated proxies a number of pseudo-proxy datasets is generated. I.e. to each proxy variable two different noises are added, resulting in two noisy variables that originate from a common signal (the proxy) and of which the respective error noises and the true model parameters (slope and intercept) between both are known. SINOMA is applied to each of these pseudo-proxy datasets and its performance is evaluated against traditional regression techniques. The herewith submitted contribution thus focuses on the applicability of SINOMA rather

  9. Using Experimental Paradigms to Examine Alcohol's Role in Men's Sexual Aggression: Opportunities and Challenges in Proxy Development.

    Science.gov (United States)

    Abbey, Antonia; Wegner, Rhiana

    2015-08-01

    The goals of this article are to review the major findings from alcohol administration studies that use sexual aggression proxies and to encourage additional experimental research that evaluates hypotheses about the role of alcohol in the etiology of men's sexual aggression. Experiments allow participants to be randomly assigned to drink conditions, therefore ensuring that any differences between drinkers and nondrinkers can be attributed to their alcohol consumption. One of the biggest challenges faced by experimental researchers is the identification of valid operationalizations of key constructs. The tension between internal and external validity is particularly problematic for violence researchers because they cannot allow participants to engage in the target behavior in the laboratory. The strengths and limitations associated with written vignettes, audiotapes, videotapes, and confederate proxies for sexual aggression are described. Suggestions are made for future research to broaden the generalizability of the findings from experimental research. © The Author(s) 2015.

  10. Mobile Multicast in Hierarchical Proxy Mobile IPV6

    Science.gov (United States)

    Hafizah Mohd Aman, Azana; Hashim, Aisha Hassan A.; Mustafa, Amin; Abdullah, Khaizuran

    2013-12-01

    Mobile Internet Protocol Version 6 (MIPv6) environments have been developing very rapidly. Many challenges arise with the fast progress of MIPv6 technologies and its environment. Therefore the importance of improving the existing architecture and operations increases. One of the many challenges which need to be addressed is the need for performance improvement to support mobile multicast. Numerous approaches have been proposed to improve mobile multicast performance. This includes Context Transfer Protocol (CXTP), Hierarchical Mobile IPv6 (HMIPv6), Fast Mobile IPv6 (FMIPv6) and Proxy Mobile IPv6 (PMIPv6). This document describes multicast context transfer in hierarchical proxy mobile IPv6 (H-PMIPv6) to provide better multicasting performance in PMIPv6 domain.

  11. How different proxies record precipitation variability over southeastern South America

    Energy Technology Data Exchange (ETDEWEB)

    Chiessi, Cristiano M; Mulitza, Stefan; Paetzold, Juergen; Wefer, Gerold, E-mail: chiessi@uni-bremen.d [MARUM-Center for Marine Environmental Sciences, University of Bremen, Leobener Strasse, 28359 Bremen (Germany)

    2010-03-15

    Detrending natural and anthropogenic components of climate variability is arguably an issue of utmost importance to society. To accomplish this issue, one must rely on a comprehensive understanding of the natural variability of the climate system on a regional level. Here we explore how different proxies (e.g., stalagmite oxygen isotopic composition, pollen percentages, bulk sediment elemental ratios) record Holocene precipitation variability over southeastern South America. We found a general good agreement between the different records both on orbital and centennial time-scales. Dry mid Holocene, and wet late Holocene, Younger Dryas and a period between {approx}9.4 and 8.12 cal kyr BP seem to be pervasive features. Moreover, we show that proxy-specific sensitivity can greatly improve past precipitation reconstructions.

  12. A comparison of proxy performance in coral biodiversity monitoring

    Science.gov (United States)

    Richards, Zoe T.

    2013-03-01

    The productivity and health of coral reef habitat is diminishing worldwide; however, the effect that habitat declines have on coral reef biodiversity is not known. Logistical and financial constraints mean that surveys of hard coral communities rarely collect data at the species level; hence it is important to know if there are proxy metrics that can reliably predict biodiversity. Here, the performances of six proxy metrics are compared using regression analyses on survey data from a location in the northern Great Barrier Reef. Results suggest generic richness is a strong explanatory variable for spatial patterns in species richness (explaining 82 % of the variation when measured on a belt transect). The most commonly used metric of reef health, percentage live coral cover, is not positively or linearly related to hard coral species richness. This result raises doubt as to whether management actions based on such reefscape information will be effective for the conservation of coral biodiversity.

  13. False allegations of abuse and Munchausen syndrome by proxy.

    Science.gov (United States)

    Meadow, R

    1993-01-01

    Fourteen children from seven families are reported for whom false allegations of abuse were made by the mother. Twelve children were alleged to have incurred sexual abuse, one both sexual and physical abuse, and one physical abuse alone. Thirteen of the children had incurred, or were currently victims of, factitious illness abuse invented by the mother. The one child with no history of factitious illness abuse had a sibling who had incurred definite factitious illness abuse. The false allegations of abuse did not occur in the context of parental separation, divorce, or custody disputes concerning the children. They occurred in the context of Munchausen syndrome by proxy abuse. The age of the children, 3 to 9 years, was older than the usual age for Munchausen syndrome by proxy abuse. The mother was the source of the false allegations and was the person who encouraged or taught six of the children to substantiate allegations of sexual abuse. PMID:8503664

  14. Munchausen syndrome and Munchausen syndrome by proxy in dermatology.

    Science.gov (United States)

    Boyd, Alan S; Ritchie, Coleman; Likhari, Sunaina

    2014-08-01

    Patients with Munchausen syndrome purposefully injure themselves, often with the injection of foreign materials, to gain hospital admission and the attention associated with having a difficult-to-identify condition. Munchausen syndrome by proxy occurs when a child's caregiver, typically the mother, injures the child for the same reasons. Cases of Munchausen syndrome and Munchausen syndrome by proxy with primary cutaneous involvement appear to be rarely described in the literature suggesting either that diagnosis is not made readily or that it is, in fact, an uncommon disorder. At the center of both conditions is significant psychological pathology and treatment is difficult as many patients with Munchausen syndrome when confronted with these diagnostic possibilities simply leave the hospital. Little is known about the long-term outcome or prognosis of these patients. Copyright © 2014 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

  15. A case report of Factitious Disorder (Munchausen Syndrome by proxy

    Directory of Open Access Journals (Sweden)

    Mehdi Shirzadifar

    2014-09-01

    Full Text Available Background: In Factitious Disorder by proxy, one person (perpetrator induces the disease in another person, thereby seeking emotional needs during the treatment process Diagnosis of this disorder is very difficult and there is not much consensus over it among experts. Lack of timely diagnosis of this disorder may lead to serious harms in patients. Case presentation: We will introduce a 19 year-old boy with mental retardation and history of multiple admissions to psychiatric, internal, urology and surgery wards. He has a 12 year-old sister and a 4 year-old brother, both with history of multiple admissions to pediatrics and internal wards. The father of family was 48 years old with chronic mental disorder, drug dependency and history of multiple admissions to medical, psychiatry and neurology wards. The mother of this family was diagnosed with munchausen syndrome by proxy.

  16. Munchausen syndrome by proxy: an alarming face of child abuse.

    Science.gov (United States)

    Gehlawat, Pratibha; Gehlawat, Virender Kumar; Singh, Priti; Gupta, Rajiv

    2015-01-01

    Munchausen syndrome by proxy (MSBP) is emerging as a serious form of child abuse. It is an intentional production of illness in another, usually children by mothers, to assume sick role by proxy. It is poorly understood and a controversial diagnosis. Treatment is very difficult. We present a case of 9-year-old boy brought to Pt. B. D. Sharma, PGIMS, Rohtak, a tertiary care hospital in northern India by his father and paternal uncle with complaints of hematemesis since July 2012. He underwent many invasive procedures until the diagnosis of MSBP was finally considered. The examination of the blood sample confirmed the diagnosis. The child was placed under custody of his mother. The case was reported to social services, which incorporated whole family in the management.

  17. The effects of metamorphism on iron mineralogy and the iron speciation redox proxy

    Science.gov (United States)

    Slotznick, Sarah P.; Eiler, John M.; Fischer, Woodward W.

    2018-03-01

    As the most abundant transition metal in the Earth's crust, iron is a key player in the planetary redox budget. Observations of iron minerals in the sedimentary record have been used to describe atmospheric and aqueous redox environments over the evolution of our planet; the most common method applied is iron speciation, a geochemical sequential extraction method in which proportions of different iron minerals are compared to calibrations from modern sediments to determine water-column redox state. Less is known about how this proxy records information through post-depositional processes, including diagenesis and metamorphism. To get insight into this, we examined how the iron mineral groups/pools (silicates, oxides, sulfides, etc.) and paleoredox proxy interpretations can be affected by known metamorphic processes. Well-known metamorphic reactions occurring in sub-chlorite to kyanite rocks are able to move iron between different iron pools along a range of proxy vectors, potentially affecting paleoredox results. To quantify the effect strength of these reactions, we examined mineralogical and geochemical data from two classic localities where Silurian-Devonian shales, sandstones, and carbonates deposited in a marine sedimentary basin with oxygenated seawater (based on global and local biological constraints) have been regionally metamorphosed from lower-greenschist facies to granulite facies: Waits River and Gile Mountain Formations, Vermont, USA and the Waterville and Sangerville-Vassalboro Formations, Maine, USA. Plotting iron speciation ratios determined for samples from these localities revealed apparent paleoredox conditions of the depositional water column spanning the entire range from oxic to ferruginous (anoxic) to euxinic (anoxic and sulfidic). Pyrrhotite formation in samples highlighted problems within the proxy as iron pool assignment required assumptions about metamorphic reactions and pyrrhotite's identification depended on the extraction techniques

  18. Proxy-SU(3) symmetry in heavy deformed nuclei

    Science.gov (United States)

    Bonatsos, Dennis; Assimakis, I. E.; Minkov, N.; Martinou, Andriana; Cakirli, R. B.; Casten, R. F.; Blaum, K.

    2017-06-01

    Background: Microscopic calculations of heavy nuclei face considerable difficulties due to the sizes of the matrices that need to be solved. Various approximation schemes have been invoked, for example by truncating the spaces, imposing seniority limits, or appealing to various symmetry schemes such as pseudo-SU(3). This paper proposes a new symmetry scheme also based on SU(3). This proxy-SU(3) can be applied to well-deformed nuclei, is simple to use, and can yield analytic predictions. Purpose: To present the new scheme and its microscopic motivation, and to test it using a Nilsson model calculation with the original shell model orbits and with the new proxy set. Method: We invoke an approximate, analytic, treatment of the Nilsson model, that allows the above vetting and yet is also transparent in understanding the approximations involved in the new proxy-SU(3). Results: It is found that the new scheme yields a Nilsson diagram for well-deformed nuclei that is very close to the original Nilsson diagram. The specific levels of approximation in the new scheme are also shown, for each major shell. Conclusions: The new proxy-SU(3) scheme is a good approximation to the full set of orbits in a major shell. Being able to replace a complex shell model calculation with a symmetry-based description now opens up the possibility to predict many properties of nuclei analytically and often in a parameter-free way. The new scheme works best for heavier nuclei, precisely where full microscopic calculations are most challenged. Some cases in which the new scheme can be used, often analytically, to make specific predictions, are shown in a subsequent paper.

  19. Law Enforcement Proxies Matter for the Law and Finance Nexus

    OpenAIRE

    Valentin Toci; Iraj Hashi

    2013-01-01

    The paper employs various measures of law enforcement to provide new evidence on the importance of legal institutions for different dimensions of financial development in transition economies. It offers a critical assessment of law enforcement measures employed in recent studies by showing that some proxies for law enforcement in the credit market may not be appropriate. Hence, care should be taken in how the quality of institutions is measured and the context which it represents. An original...

  20. Fingerprinting Reverse Proxies Using Timing Analysis of TCP Flows

    Science.gov (United States)

    2013-09-01

    Address Translation NPS Naval Postgraduate School OTT One-way Transit Time PET Privacy Enhancing Technology PHP Hypertext Preprocessor P2P ] Peer-to...of timing information that can translate into usable intelligence for detecting the use of reverse proxies by a network domain. 1.1 Problem Statement...websites (i.e., Sky News Arabia, Kemalist Gazete, Detroit News), and entertainment industry sites (i.e., HBO GO, LeoVegas Online Casino , FreeRide Games

  1. Marine proxy evidence linking decadal North Pacific and Atlantic climate

    Energy Technology Data Exchange (ETDEWEB)

    Hetzinger, S. [University of Toronto Mississauga, CPS-Department, Mississauga, ON (Canada); Leibniz Institute of Marine Sciences, IFM-GEOMAR, Kiel (Germany); Halfar, J. [University of Toronto Mississauga, CPS-Department, Mississauga, ON (Canada); Mecking, J.V.; Keenlyside, N.S. [Leibniz Institute of Marine Sciences, IFM-GEOMAR, Kiel (Germany); University of Bergen, Geophysical Institute and Bjerknes Centre for Climate Research, Bergen (Norway); Kronz, A. [University of Goettingen, Geowissenschaftliches Zentrum, Goettingen (Germany); Steneck, R.S. [University of Maine, Darling Marine Center, Walpole, ME (United States); Adey, W.H. [Smithsonian Institution, Department of Botany, Washington, DC (United States); Lebednik, P.A. [ARCADIS U.S. Inc., Walnut Creek, CA (United States)

    2012-09-15

    Decadal- to multidecadal variability in the extra-tropical North Pacific is evident in 20th century instrumental records and has significant impacts on Northern Hemisphere climate and marine ecosystems. Several studies have discussed a potential linkage between North Pacific and Atlantic climate on various time scales. On decadal time scales no relationship could be confirmed, potentially due to sparse instrumental observations before 1950. Proxy data are limited and no multi-centennial high-resolution marine geochemical proxy records are available from the subarctic North Pacific. Here we present an annually-resolved record (1818-1967) of Mg/Ca variations from a North Pacific/Bering Sea coralline alga that extends our knowledge in this region beyond available data. It shows for the first time a statistically significant link between decadal fluctuations in sea-level pressure in the North Pacific and North Atlantic. The record is a lagged proxy for decadal-scale variations of the Aleutian Low. It is significantly related to regional sea surface temperature and the North Atlantic Oscillation (NAO) index in late boreal winter on these time scales. Our data show that on decadal time scales a weaker Aleutian Low precedes a negative NAO by several years. This atmospheric link can explain the coherence of decadal North Pacific and Atlantic Multidecadal Variability, as suggested by earlier studies using climate models and limited instrumental data. (orig.)

  2. MUNCHAUSEN SYNDROME BY PROXY IN PEDIATRIC DENTISTRY: MYTH OR REALITY?

    Directory of Open Access Journals (Sweden)

    Veronica PINTILICIUC-ŞERBAN

    2017-06-01

    Full Text Available Background and aims: Munchausen syndrome by proxy is a condition traditionally comprising physical and mental abuse and medical neglect as a form of psychogenic maltreatment of the child, secondary to fabrication of a pediatric illness by the parent or guardian. The aim of our paper is to assess whether such condition occurs in current pediatric dental practice and to evidence certain situations in which the pediatric dentist should suspect this form of child abuse. Problem statement: Munchausen syndrome by proxy in pediatric dentistry may lead to serious chronic disabilities of the abused or neglected child, being one of the causes of treatment failure. Discussion: Prompt detection of such condition should be regarded as one of the duties of the practitioner who should be trained to report the suspected cases to the governmental child protective agencies. This should be regarded as a form of child abuse and neglect, and the responsible caregiver could be held liable when such wrongful actions cause harm or endanger child’s welfare. Conclusion: Munchausen syndrome by proxy should be regarded as a reality in current pediatric dental practice and dental teams should be trained to properly recognize, assess and manage such complex situations.

  3. Short-term indicators. Intensities as a proxy for savings

    Energy Technology Data Exchange (ETDEWEB)

    Boonekamp, P.G.M.; Gerdes, J. [ECN Policy Studies, Petten (Netherlands); Faberi, S. [Institute of Studies for the Integration of Systems ISIS, Rome (Italy)

    2013-12-15

    The ODYSSEE database on energy efficiency indicators (www.odyssee-indicators.org) has been set up to enable the monitoring and evaluation of realised energy efficiency improvements and related energy savings. The database covers the 27 EU countries as well as Norway and Croatia and data are available from 1990 on. This work contributes to the growing need for quantitative monitoring and evaluation of the impacts of energy policies and measures, both at the EU and national level, e.g. due to the Energy Services Directive and the proposed Energy Efficiency Directive. Because the underlying data become available only after some time, the savings figures are not always timely available. This is especially true for the ODEX efficiency indices per sector that rely on a number of indicators. Therefore, there is a need for so-called short-term indicators that become available shortly after the year has passed for which data are needed. The short term indicators do not replace the savings indicators but function as a proxy for the savings in the most recent year. This proxy value is faster available, but will be less accurate than the saving indicators themselves. The short term indicators have to be checked regularly with the ODEX indicators in order to see whether they can function still as a proxy.

  4. A unified proxy for ENSO and PDO variability since 1650

    Directory of Open Access Journals (Sweden)

    S. McGregor

    2010-01-01

    Full Text Available In this manuscript we have attempted to consolidate the common signal in previously defined proxy reconstructions of the El Niño-Southern Oscillation into one individual proxy titled the Unified ENSO Proxy (UEP. While correlating well with the majority of input reconstructions, the UEP provides better representation of observed indices of ENSO, discrete ENSO events and documented historical chronologies of ENSO than any of these input ENSO reconstructions. Further to this, the UEP also provides a means to reconstruct the PDO/IPO multi-decadal variability of the Pacific Ocean as the low-pass filtered UEP displays multi-decadal variability that is consistent with the 20th century variability of the PDO and IPO. The UEP is then used to describe changes in ENSO variability which have occurred since 1650 focusing on changes in ENSOs variance, multi-year ENSO events, PDO-like multi-decadal variability and the effects of volcanic and solar forcing on ENSO. We find that multi-year El Niño events similar to the 1990–1995 event have occurred several times over the last 3 1/2 centuries. Consistent with earlier studies we find that volcanic forcing can induce a statistically significant change in the mean state of ENSO in the year of the eruption and a doubling of the probability of an El Niño (La Niña event occurring in the year of (three years after the eruption.

  5. Evaluating Ground-based Proxies for Solar Irradiance Variation

    Science.gov (United States)

    Oegerle, William (Technical Monitor); Jordan, Stuart

    2003-01-01

    In order to determine what ground-based proxies are best for evaluating solar irradiance variation before the advent of space observations, it is necessary to test these proxies against space observations. We have tested sunspot number, total sunspot area, and sunspot umbral area against the Nimbus-7 measurements of total solar irradiance variation cover the eleven year period 1980-1990. The umbral area yields the best correlation and the total sunspot area yields the poorest. Reasons for expecting the umbral area to yield the best correlation are given, the statistical procedure followed to obtain the results is described, and the value of determining the best proxy is discussed. The latter is based upon the availability of an excellent database from the Greenwich Observatory obtained over the period 1876-1976, which can be used to estimate the total solar irradiance variation before sensitive space observations were available. The ground-based observations used were obtained at the Coimbra Solar Observatory. The analysis was done at Goddard using these data and data from the Nimbus-7 satellite.

  6. Shell architecture: a novel proxy for paleotemperature reconstructions?

    Science.gov (United States)

    Milano, Stefania; Nehrke, Gernot; Wanamaker, Alan D., Jr.; Witbaard, Rob; Schöne, Bernd R.

    2017-04-01

    Mollusk shells are unique high-resolution paleoenvironmental archives. Their geochemical properties, such as oxygen isotope composition (δ18Oshell) and element-to-calcium ratios, are routinely used to estimate past environmental conditions. However, the existing proxies have certain drawbacks that can affect paleoreconstruction robustness. For instance, the estimation of water temperature of brackish and near-shore environments can be biased by the interdependency of δ18Oshell from multiple environmental variables (water temperature and δ18Owater). Likely, the environmental signature can be masked by physiological processes responsible for the incorporation of trace elements into the shell. The present study evaluated the use of shell structural properties as alternative environmental proxies. The sensitivity of shell architecture at µm and nm-scale to the environment was tested. In particular, the relationship between water temperature and microstructure formation was investigated. To enable the detection of potential structural changes, the shells of the marine bivalves Cerastoderma edule and Arctica islandica were analyzed with Scanning Electron Microscopy (SEM), nanoindentation and Confocal Raman Microscopy (CRM). These techniques allow a quantitative approach to the microstructural analysis. Our results show that water temperature induces a clear response in shell microstructure. A significant alteration in the morphometric characteristics and crystallographic orientation of the structural units was observed. Our pilot study suggests that shell architecture records environmental information and it has potential to be used as novel temperature proxy in near-shore and open ocean habitats.

  7. Heinrich event 4 characterized by terrestrial proxies in southwestern Europe

    Directory of Open Access Journals (Sweden)

    J. M. López-García

    2013-05-01

    Full Text Available Heinrich event 4 (H4 is well documented in the North Atlantic Ocean as a cooling event that occurred between 39 and 40 Ka. Deep-sea cores around the Iberian Peninsula coastline have been analysed to characterize the H4 event, but there are no data on the terrestrial response to this event. Here we present for the first time an analysis of terrestrial proxies for characterizing the H4 event, using the small-vertebrate assemblage (comprising small mammals, squamates and amphibians from Terrassa Riera dels Canyars, an archaeo-palaeontological deposit located on the seaboard of the northeastern Iberian Peninsula. This assemblage shows that the H4 event is characterized in northeastern Iberia by harsher and drier terrestrial conditions than today. Our results were compared with other proxies such as pollen, charcoal, phytolith, avifauna and large-mammal data available for this site, as well as with the general H4 event fluctuations and with other sites where H4 and the previous and subsequent Heinrich events (H5 and H3 have been detected in the Mediterranean and Atlantic regions of the Iberian Peninsula. We conclude that the terrestrial proxies follow the same patterns as the climatic and environmental conditions detected by the deep-sea cores at the Iberian margins.

  8. Error characterization for asynchronous computations: Proxy equation approach

    Science.gov (United States)

    Sallai, Gabriella; Mittal, Ankita; Girimaji, Sharath

    2017-11-01

    Numerical techniques for asynchronous fluid flow simulations are currently under development to enable efficient utilization of massively parallel computers. These numerical approaches attempt to accurately solve time evolution of transport equations using spatial information at different time levels. The truncation error of asynchronous methods can be divided into two parts: delay dependent (EA) or asynchronous error and delay independent (ES) or synchronous error. The focus of this study is a specific asynchronous error mitigation technique called proxy-equation approach. The aim of this study is to examine these errors as a function of the characteristic wavelength of the solution. Mitigation of asynchronous effects requires that the asynchronous error be smaller than synchronous truncation error. For a simple convection-diffusion equation, proxy-equation error analysis identifies critical initial wave-number, λc. At smaller wave numbers, synchronous error are larger than asynchronous errors. We examine various approaches to increase the value of λc in order to improve the range of applicability of proxy-equation approach.

  9. Efficient Conditional Proxy Re-encryption with Chosen-Ciphertext Security

    NARCIS (Netherlands)

    Weng, Jiang; Yang, Yanjiang; Tang, Qiang; Deng, Robert H.; Bao, Feng

    Recently, a variant of proxy re-encryption, named conditional proxy re-encryption (C-PRE), has been introduced. Compared with traditional proxy re-encryption, C-PRE enables the delegator to implement fine-grained delegation of decryption rights, and thus is more useful in many applications. In this

  10. 17 CFR 240.14a-16 - Internet availability of proxy materials.

    Science.gov (United States)

    2010-04-01

    ... holder to access and review the proxy materials before voting; (3) The Internet Web site address where... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Internet availability of proxy... Under the Securities Exchange Act of 1934 Regulation 14a: Solicitation of Proxies § 240.14a-16 Internet...

  11. Remote Patron Validation: Posting a Proxy Server at the Digital Doorway.

    Science.gov (United States)

    Webster, Peter

    2002-01-01

    Discussion of remote access to library services focuses on proxy servers as a method for remote access, based on experiences at Saint Mary's University (Halifax). Topics include Internet protocol user validation; browser-directed proxies; server software proxies; vendor alternatives for validating remote users; and Internet security issues. (LRW)

  12. A novel salinity proxy based on Na incorporation into foraminiferal calcite

    NARCIS (Netherlands)

    Wit, J.C.; de Nooijer, L.J.; Wolthers, M.; Reichart, G.J.

    2013-01-01

    Salinity and temperature determine seawater density, and differences in both thereby control global thermohaline circulation. Whereas numerous proxies have been calibrated and applied to reconstruct temperature, a direct and independent proxy for salinity is still missing. Ideally, a new proxy for

  13. Public key encryption supporting plaintext equality test and user-specified authorization

    NARCIS (Netherlands)

    Tang, Qiang

    2012-01-01

    In this paper, we investigate a category of public key encryption schemes that supports plaintext equality test and userspecified authorization. With this new primitive, two users, who possess their own public/private key pairs, can issue token(s) to a proxy to authorize it to perform plaintext

  14. How to combine sparse proxy data and coupled climate models

    Science.gov (United States)

    Paul, André; Schäfer-Neth, Christian

    2005-04-01

    We address the problem of reconstructing a global field from proxy data with sparse spatial sampling such as the MARGO (multi-proxy approach for the reconstruction of the glacial ocean surface) SST (sea-surface temperature) and δ18O c (oxygen-18/oxygen-16 isotope ratio preserved in fossil carbonate shells of planktic foraminifera) data. To this end, we propose to `assimilate' these data into coupled climate models by adjusting some of their parameters and optimizing the fit. In particular, we suggest to combine a forward model and an objective function that quantifies the misfit to the data. Because of their computational efficiency, earth system models of intermediate complexity are particularly well-suited for this purpose. We used one such model (the University of Victoria Earth System Climate Model) and carried out a series of sensitivity experiments by varying a single model parameter through changing the atmospheric CO2 concentration. The unanalyzed World Ocean Atlas SST and the observed sea-ice concentration served as present-day targets. The sparse data coverage as implied by the locations of 756 ocean sediment cores from the MARGO SST database was indeed sufficient to determine the best fit. As anticipated, it turned out to be the 365 ppm experiment. We also found that the 200 ppm experiment came surprisingly close to what is commonly expected for the Last Glacial Maximum ocean circulation. Our strategy has a number of advantages over more traditional mapping methods, e.g., there is no need to force the results of different proxies into a single map, because they can be compared to the model output one at a time, properly taking into account the different seasons of plankton growth or varying depth habitats. It can be extended to more model parameters and even be automated.

  15. Patient-rated versus proxy-rated cognitive and functional measures in older adults

    Science.gov (United States)

    Howland, Molly; Allan, Kevin C; Carlton, Caitlin E; Tatsuoka, Curtis; Smyth, Kathleen A; Sajatovic, Martha

    2017-01-01

    Objectives Patients with cognitive impairment may have difficulty reporting their functional and cognitive abilities, which are important clinical outcomes. Health care proxies may be able to corroborate patient self-reports. Several studies reported discrepancy between patient and proxy ratings, though the literature is sparse on changes over time of these ratings. Our goals in this 12-month study were to compare patient and proxy reports on functioning, cognition, and everyday executive function, and to further elucidate correlates of patient–proxy discrepancy. Methods This was a prospective cohort study of individuals older than 70 years who ranged from having no cognitive impairment to having moderate dementia who had a proxy available to complete instruments at baseline (N=76). Measurements included Alzheimer’s Disease Cooperative Study–Activities of Daily Living Inventory (ADCS-ADLI), Neuro-QOL Executive Function, PROMIS Applied Cognition (PROMIS-Cog), Mini-Mental State Examination (MMSE), and Geriatric Depression Scale. Results Patient- and proxy-rated ADCS-ADLI were correlated at baseline and at 1-year follow-up. Patient and proxy ratings were discrepant on Neuro-QOL Executive Function and PROMIS-Cog. Greater patient–proxy discrepancy on PROMIS-Cog was associated with younger age and less depression, and greater patient–proxy discrepancy on Neuro-QOL Executive Function was associated with less depression and worse cognitive impairment. Patient–proxy discrepancy increased over time for everyday executive function. Changes in proxy-rated but not patient-rated ADCS-ADLI correlated with MMSE changes. Conclusion Patients and proxies generally agree in reporting on activities of daily living. Patient and proxy reports differ in their respective evaluation of cognitive functioning and everyday executive function. Ratings from both sources may be preferred for these two domains, though studies using gold standard measures are necessary. It is important

  16. Tycho 2: A Proxy Application for Kinetic Transport Sweeps

    Energy Technology Data Exchange (ETDEWEB)

    Garrett, Charles Kristopher [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Computer, Computational, and Statistical Sciences Division; Warsa, James S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Computer, Computational, and Statistical Sciences Division

    2016-09-14

    Tycho 2 is a proxy application that implements discrete ordinates (SN) kinetic transport sweeps on unstructured, 3D, tetrahedral meshes. It has been designed to be small and require minimal dependencies to make collaboration and experimentation as easy as possible. Tycho 2 has been released as open source software. The software is currently in a beta release with plans for a stable release (version 1.0) before the end of the year. The code is parallelized via MPI across spatial cells and OpenMP across angles. Currently, several parallelization algorithms are implemented.

  17. Nursing interventions in Münchausen syndrome by proxy.

    Science.gov (United States)

    Volz, A G

    1995-09-01

    1. Münchausen syndrome by proxy is a rare but serious and potentially lethal form of child abuse in which a primary care giver induces or reports factitious symptoms in a child. 2. The child suffers from the caregiver's actions and health care providers unknowingly become accomplices when they provide unnecessary testing and therapies. 3. The child's physical and psychological welfare can be protected through the efforts of the forensic nurse specialist coordinating a multidisciplinary health care team's work to detect the syndrome and intervene early on.

  18. Compliance with treatment in asthma and Munchausen syndrome by proxy.

    Science.gov (United States)

    Godding, V; Kruth, M

    1991-01-01

    Among 1648 asthmatic patients, 17 families (1%) were identified as having Munchausen syndrome by proxy. Ten families did not treat their children's, attacks or refused medical care, and seven exaggerated the severity of symptoms to obtain invasive investigations and treatment. All the families had disturbed psychosocial backgrounds. The abuse consisted mainly of neglect, in that necessary treatment was not given. In some cases a more direct form of abuse was observed, when useless and sometimes harmful investigations and treatment were given. We conclude that medical control of the compliance of both parents and children is necessary in the management of childhood asthma. PMID:1929492

  19. Investigating genetic loci that encode plant-derived paleoclimate proxies

    Science.gov (United States)

    Bender, A. L. D.; Suess, M.; Chitwood, D. H.; Bradley, A. S.

    2016-12-01

    Long chain (>C25) n-alkanes in sediments predominantly derive from terrestrial plant waxes. Hydrogen isotope ratios (δD) of leaf wax hydrocarbons correlate with δDH2O of precipitation and are commonly used as paleoclimate proxies. However, biological variability in the isotopic fractionations between water and plant materials also affects the n-alkane δD values. Correct interpretation of this paleoclimate proxy requires that we resolve genetic and environmental effects. Genetic variability underlying differences in leaf wax structure and isotopic composition can be quantitatively determined through the use of model organisms. Interfertile Solanum sect. Lycopersicon (tomato) species provide an ideal model species complex for this approach. We used a set of 76 precisely defined near-isogenic lines (introgression lines [ILs]) in which small genomic regions from the wild tomato relative Solanum pennellii have been introduced into the genome of the domestic tomato, S. lycopersicum. By characterizing quantitative traits of these ILs (leaf wax structure and isotopic composition), we can resolve the degree to which each trait is regulated by genetic versus environmental factors. We present data from two growth experiments conducted with all 76 ILs. In this study, we quantify leaf wax traits, including δD values, δ13C values, and structural metrics including the methylation index (a variable that describes the ratio of iso­- and anteiso- to n-alkanes). Among ILs, δD values vary by up to 35‰ and 60‰ for C31 and C33 n-alkanes, respectively. Many ILs have methylation indices that are discernably different from the parent domesticated tomato (p < 0.001), which suggests that methylation is a highly polygenic trait. This pattern is similar to the genetics that control leaf shape, another trait commonly used as a paleoclimate proxy. Based on our preliminary analysis, we propose candidate genes that control aspects of plant physiology that affect these quantitative

  20. Comfort with proxy consent to research involving decisionally impaired older adults: do type of proxy and risk-benefit profile matter?

    Science.gov (United States)

    Dubois, Marie-France; Bravo, Gina; Graham, Janice; Wildeman, Sheila; Cohen, Carole; Painter, Karen; Bellemare, Suzanne

    2011-11-01

    Dementia research often requires the participation of people with dementia. Obtaining informed consent is problematic when potential participants lack the capacity to provide it. We investigated comfort with proxy consent to research involving older adults deemed incapable of this decision, and examined if comfort varies with the type of proxy and the study's risk-benefit profile. We surveyed random samples of five relevant groups (older adults, informal caregivers, physicians, researchers in aging, and Research Ethics Board members) from four Canadian provinces. Respondents were presented with scenarios involving four types of proxies (non-assigned, designated in a healthcare advance directive with or without instructions specific to research participation, and court-appointed). Given a series of risk-benefit profiles, respondents indicated whether they were comfortable with proxy consent to research for each scenario. Two percent of the respondents felt proxy consent should never be allowed. In all groups, comfort depended far more on the risk-benefit profile associated with the research scenario than with type of proxy. For research involving little or no risk and potential personal benefits, over 90% of the respondents felt comfortable with substitute consent by a designated or court-appointed proxy while 80% were at ease with a non-assigned proxy. For studies involving serious risks with potentially greater personal benefits, older adults and informal caregivers were less comfortable with proxy consent. A large majority of Canadians are comfortable with proxy consent for low-risk research. Further work is needed to establish what kinds of research are considered to be low risk.

  1. Thermodynamic Proxies to Compensate for Biases in Drug Discovery Methods.

    Science.gov (United States)

    Ekins, Sean; Litterman, Nadia K; Lipinski, Christopher A; Bunin, Barry A

    2016-01-01

    We propose a framework with simple proxies to dissect the relative energy contributions responsible for standard drug discovery binding activity. We explore a rule of thumb using hydrogen-bond donors, hydrogen-bond acceptors and rotatable bonds as relative proxies for the thermodynamic terms. We apply this methodology to several datasets (e.g., multiple small molecules profiled against kinases, Mycobacterium tuberculosis (Mtb) high throughput screening (HTS) and structure based drug design (SBDD) derived compounds, and FDA approved drugs). We found that Mtb active compounds developed through SBDD methods had statistically significantly larger PEnthalpy values than HTS derived compounds, suggesting these compounds had relatively more hydrogen bond donor and hydrogen bond acceptors compared to rotatable bonds. In recent FDA approved medicines we found that compounds identified via target-based approaches had a more balanced enthalpic relationship between these descriptors compared to compounds identified via phenotypic screens As it is common to experimentally optimize directly for total binding energy, these computational methods provide alternative calculations and approaches useful for compound optimization alongside other common metrics in available software and databases.

  2. Simulation of Wake Vortex Radiometric Detection via Jet Exhaust Proxy

    Science.gov (United States)

    Daniels, Taumi S.

    2015-01-01

    This paper describes an analysis of the potential of an airborne hyperspectral imaging IR instrument to infer wake vortices via turbine jet exhaust as a proxy. The goal was to determine the requirements for an imaging spectrometer or radiometer to effectively detect the exhaust plume, and by inference, the location of the wake vortices. The effort examines the gas spectroscopy of the various major constituents of turbine jet exhaust and their contributions to the modeled detectable radiance. Initially, a theoretical analysis of wake vortex proxy detection by thermal radiation was realized in a series of simulations. The first stage used the SLAB plume model to simulate turbine jet exhaust plume characteristics, including exhaust gas transport dynamics and concentrations. The second stage used these plume characteristics as input to the Line By Line Radiative Transfer Model (LBLRTM) to simulate responses from both an imaging IR hyperspectral spectrometer or radiometer. These numerical simulations generated thermal imagery that was compared with previously reported wake vortex temperature data. This research is a continuation of an effort to specify the requirements for an imaging IR spectrometer or radiometer to make wake vortex measurements. Results of the two-stage simulation will be reported, including instrument specifications for wake vortex thermal detection. These results will be compared with previously reported results for IR imaging spectrometer performance.

  3. Solar spectral irradiance datasets: analysis and comparison with proxies

    Science.gov (United States)

    Kretzschmar, M.; Schoell, M.; Dudok de Wit, T.

    2013-12-01

    Solar spectral irradiance (SSI) measurements have been acquired in space since the late 1960's. These data are of extreme importance to assess the variability of the Sun in the last decades as well as to understand how its magnetic activity affects its radiative output, and therefore to constrain the solar variability further in time. However, these data sometimes disagree between themselves or with our expectations deduced from well known observed proxies, and it is hard to disentangle instrumental effects from possible solar behavior. In the context of the european project SOLID (First European comprehensive SOlar Irradiance Data Exploitation) project, which aims at building an SSI composite with time dependent error-bars over the space age, we will show our first results towards the construction of a carefully assessed homogeneous solar spectral irradiance datasets, focussing on the ultraviolet wavelength range, for which more data are available. We will first present the data used, together with methods for gap-filling and outlier removal. Then we will show some results obtained by comparing a single dataset at different times of the mission, as well as results obtained from the comparison of simultaneous datasets and proxies. Finally, we will discuss how these analyses can help us to estimate errors on the solar variability at a particular wavelength.

  4. Late Oligocene to Late Miocene Antarctic Climate Reconstructions Using Molecular and Isotopic Biomarker Proxies

    Science.gov (United States)

    Duncan, B.; Mckay, R. M.; Bendle, J. A.; Naish, T.; Levy, R. H.; Ventura, G. T.; Moossen, H. M.; Krishnan, S.; Pagani, M.

    2015-12-01

    Major climate and environmental changes occurred during late Oligocene to the late Miocene when atmospheric CO2 ranged between 500 and 300ppm, indicating threshold response of Antarctic ice sheets and climate to relatively modest CO2 variations. This implies that the southern high latitudes are highly sensitive to feedbacks associated with changes in global ice sheet and sea-ice extent, as well as terrestrial and marine ecosystems. This study focuses on two key intervals during the evolution of the Antarctic Ice Sheet: (1) The Late Oligocene and the Oligocene/Miocene boundary, when the East Antarctic Ice Sheet expanded close to present day volume following an extended period of inferred warmth. (2) The Mid-Miocene Climate Optimum (MMCO ~17-15 Ma), a period of global warmth and moderately elevated CO2 (350->500 ppm) which was subsequently followed by rapid cooling at 14-13.5 Ma. Reconstructions of climate and ice sheet variability, and thus an understanding of the various feedbacks that occurred during these intervals, are hampered by a lack of temperature and hydroclimate proxy data from the southern high latitudes. We present proxy climate reconstructions using terrestrial and marine organic biomarkers that provide new insights into Antarctica's climate evolution, using Antarctic drill cores and outcrop samples from a range of depositional settings. Bacterial ether-lipids have been analysed to determine terrestrial mean annual temperatures and soil pH (via the methylation and cyclisation indexes of branched tetraethers - MBT and CBT, respectively). Tetraether-lipids of crenarchaeota found in marine sediments sampled from continental shelves around Antarctica have been used to derive sea surface temperatures using the TEX86 index. Compound specific stable isotopes on n-alkanes sourced from terrestrial plants have been analysed to investigate changes in the hydrological and carbon cycles.

  5. Quantum key management

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Richard John; Thrasher, James Thomas; Nordholt, Jane Elizabeth

    2016-11-29

    Innovations for quantum key management harness quantum communications to form a cryptography system within a public key infrastructure framework. In example implementations, the quantum key management innovations combine quantum key distribution and a quantum identification protocol with a Merkle signature scheme (using Winternitz one-time digital signatures or other one-time digital signatures, and Merkle hash trees) to constitute a cryptography system. More generally, the quantum key management innovations combine quantum key distribution and a quantum identification protocol with a hash-based signature scheme. This provides a secure way to identify, authenticate, verify, and exchange secret cryptographic keys. Features of the quantum key management innovations further include secure enrollment of users with a registration authority, as well as credential checking and revocation with a certificate authority, where the registration authority and/or certificate authority can be part of the same system as a trusted authority for quantum key distribution.

  6. Iron content of soils as a precipitation proxy

    Science.gov (United States)

    Dzombak, R.; Sheldon, N. D.

    2016-12-01

    Given that different iron phases form under different precipitation and drainage regimes, soil iron content could be used as a proxy for both volume and seasonality of precipitation. Constraining these factors is important for predicting future precipitation trends, especially for a warmer climate that will likely see more frequent extreme weather events. Specifically, using paleoprecipitation data from periods of higher temperatures and atmospheric CO2 concentrations helps inform models of future `greenhouse' climate. Forty-five modern samples from across the continental United States were analyzed, with MAP ranging from 200 to 1200 mm yr-1 and MAT ranging from 5 to 22°C. Soil types included Alfisols (N=15), Inceptisols (N=8), Mollisols (N=15), and Aridisols (N=7), and ranged from seasonally wet to well-drained. Analytical techniques included combustion-elemental analysis and organic carbon isotope analysis, a sequential iron extraction modified with a sodium hypochlorite step for the extraction of organic matter-bound iron, and the extraction of iron sulfides. The sequential extractions yield five different `pools' of iron found in sediment: crystalline iron oxides (e.g., goethite, hematite), magnetite, carbonate-bound, organic matter-bound, and labile/easily reducible iron minerals (e.g., ferrihydrite). Analysis by ICP-OES yielded a strong relationship between magnetite-bound iron and MAP, and fair relationships between the other iron pools and MAP. Individual soil orders tended to show stronger relationships to the iron pools than all soils analyzed together, potentially indicating the need for separate proxy relationships for each soil order. Pyrite concentrations were well below 1% by weight for these soils, suggesting that none of these soils has a long enough wet season to encourage its formation and that the presence vs. absence of pyrite in paleosols may be a useful proxy for soil moisture state. In contrast to some earlier work, no significant

  7. Carbohydrates and phenols as quantitative molecular vegetation proxies in peats

    Science.gov (United States)

    Kaiser, K.; Benner, R. H.

    2012-12-01

    Vegetation in peatlands is intricately linked to local environmental conditions and climate. Here we use chemical analyses of carbohydrates and phenols to reconstruct paleovegetation in peat cores collected from 56.8°N (SIB04), 58.4°N (SIB06), 63.8°N (G137) and 66.5°N (E113) in the Western Siberian Lowland. Lignin phenols (vanillyl and syringyl phenols) were sensitive biomarkers for vascular plant contributions and provided additional information on the relative contributions of angiosperm and gymnosperm plants. Specific neutral sugar compositions allowed identification of sphagnum mosses, sedges (Cyperaceae) and lichens. Hydroxyphenols released by CuO oxidation were useful tracers of sphagnum moss contributions. The three independent molecular proxies were calibrated with a diverse group of peat-forming plants to yield quantitative estimates (%C) of vascular plant, sphagnum moss and lichen contributions in peat core samples. Correlation analysis indicated the three molecular proxies produced fairly similar results for paleovegetation compositions, generally within the error interval of each approach (≤26%). The lignin-based method generally lead to higher estimates of vascular plant vegetation. Several significant deviations were also observed due to different reactivities of carbohydrate and phenolic polymers during peat decomposition. Rapid vegetation changes on timescales of 50-200 years were observed in the southern cores SIB04 and SIB06 over the last 2000 years. Vanillyl and syringyl phenol ratios indicated these vegetation changes were largely due to varying inputs of angiosperm and gymnosperm plants. The northern permafrost cores G137 and E113 showed a more stable development. Lichens briefly replaced sphagnum mosses and vascular plants in both of these cores. Shifts in vegetation did not correlate well with Northern hemisphere climate variability over the last 2000 years. This suggested that direct climate forcing of peatland dynamics was overridden

  8. Analysis of Forgery Attack on One-Time Proxy Signature and the Improvement

    Science.gov (United States)

    Wang, Tian-Yin; Wei, Zong-Li

    2016-02-01

    In a recent paper, Yang et al. (Quant. Inf. Process. 13(9), 2007-2016, 2014) analyzed the security of one-time proxy signature scheme Wang and Wei (Quant. Inf. Process. 11(2), 455-463, 2012) and pointed out that it cannot satisfy the security requirements of unforgeability and undeniability because an eavesdropper Eve can forge a valid proxy signature on a message chosen by herself. However, we find that the so-called proxy message-signature pair forged by Eve is issued by the proxy signer in fact, and anybody can obtain it as a requester, which means that the forgery attack is not considered as a successful attack. Therefore, the conclusion that this scheme cannot satisfy the security requirements of proxy signature against forging and denying is not appropriate in this sense. Finally, we study the reason for the misunderstanding and clarify the security requirements for proxy signatures.

  9. Group key management

    Energy Technology Data Exchange (ETDEWEB)

    Dunigan, T.; Cao, C.

    1997-08-01

    This report describes an architecture and implementation for doing group key management over a data communications network. The architecture describes a protocol for establishing a shared encryption key among an authenticated and authorized collection of network entities. Group access requires one or more authorization certificates. The implementation includes a simple public key and certificate infrastructure. Multicast is used for some of the key management messages. An application programming interface multiplexes key management and user application messages. An implementation using the new IP security protocols is postulated. The architecture is compared with other group key management proposals, and the performance and the limitations of the implementation are described.

  10. Expanding Assessment of Fear of Falling among Older Adults with an Intellectual Disability: A Pilot Study to Assess the Value of Proxy Responses

    OpenAIRE

    Foran, Sinead

    2014-01-01

    Fear of falling (FOF) has emerged as an important health concern in older adults, yet it has rarely been investigated in people with intellectual disabilities (ID). Valid and reliable measurement approaches are a particular challenge. Scales that have been developed to measure FOF have not been validated for use with older people with ID and are not routinely used with proxy respondents. Method. 63 people comprised purposeful samples of 3 groups, people with ID , their nominated key workers ,...

  11. Understanding north-western Mediterranean climate variability: a multi-proxy and multi-sequence approach based on wavelet analysis.

    Science.gov (United States)

    Azuara, Julien; Lebreton, Vincent; Jalali, Bassem; Sicre, Marie-Alexandrine; Sabatier, Pierre; Dezileau, Laurent; Peyron, Odile; Frigola, Jaime; Combourieu-Nebout, Nathalie

    2017-04-01

    Forcings and physical mechanisms underlying Holocene climate variability still remain poorly understood. Comparison of different paleoclimatic reconstructions using spectral analysis allows to investigate their common periodicities and helps to understand the causes of past climate changes. Wavelet analysis applied on several proxy time series from the Atlantic domain already revealed the first key-issues on the origin of Holocene climate variability. However the differences in duration, resolution and variance between the time-series are important issues for comparing paleoclimatic sequences in the frequency domain. This work compiles 7 paleoclimatic proxy records from 4 time-series from the north-western Mediterranean all ranging from 7000 to 1000 yrs cal BP: -pollen and clay mineral contents from the lagoonal sediment core PB06 recovered in southern France, -Sea Surface Temperatures (SST) derived from alkenones, concentration of terrestrial alkanes and their average chain length (ACL) from core KSGC-31_GolHo-1B recovered in the Gulf of Lion inner-shelf, - δ18O record from speleothems recovered in the Asiul Cave in north-western Spain, -grain size record from the deep basin sediment drift core MD99-2343 north of Minorca island. A comparison of their frequency content is proposed using wavelet analysis and cluster analysis of wavelet power spectra. Common cyclicities are assessed using cross-wavelet analysis. In addition, a new algorithm is used in order to propagate the age model errors within wavelet power spectra. Results are consistents with a non-stationnary Holocene climate variability. The Halstatt cycles (2000-2500 years) depicted in many proxies (ACL, errestrial alkanes and SSTs) demonstrate solar activity influence in the north-western Mediterranean climate. Cluster analysis shows that pollen and ACL proxies, both indicating changes in aridity, are clearly distinct from other proxies and share significant common periodicities around 1000 and 600 years

  12. Law Enforcement Proxies Matter for the Law and Finance Nexus

    Directory of Open Access Journals (Sweden)

    Valentin Toci

    2013-07-01

    Full Text Available The paper employs various measures of law enforcement to provide new evidence on the importance of legal institutions for different dimensions of financial development in transition economies. It offers a critical assessment of law enforcement measures employed in recent studies by showing that some proxies for law enforcement in the credit market may not be appropriate. Hence, care should be taken in how the quality of institutions is measured and the context which it represents. An original approach to measuring law enforcement in the credit market is developed by embodying the legal theory of dispute resolution and assessing this approach by collecting primary data for Kosovo. The findings suggest that Kosovo compares well with countries in the region and other transition economies in terms of the enforcement of creditor rights.

  13. Munchausen Syndrome by proxy: Definition, context, and psychological factors involved

    Directory of Open Access Journals (Sweden)

    Thomas Gomes Gonçalves

    2014-07-01

    Full Text Available The Munchausen syndrome by proxy refers to a pathology characterized by physical and emotional abuse in which the simulation or production of symptoms is directed towards a child, which involves taking him or her to health treatments and unnecessary surgeries. The difficulties in the diagnosis of this form of abuse and the emotional aspects involved highlight the destructive effects in the infancy subjectivity due to the lack of loving capacity protecting and prioritizing the child demands. Psychoanalysis offers a differentiated view, comprehending that the mother attempts to elaborate her own psychic conflicts by the repetition of traumatic experience. There is a necessity of comprehension of the instinct destructivity presented in the maternal unconscious dynamics revealed in the modality of caring which is reflected in violence.

  14. Obesity as a Presentation of Munchausen Syndrome by Proxy.

    Science.gov (United States)

    Nogueira-de-Almeida, Carlos Alberto; de Almeida, Carla Cristina J N; Pereira, Natália Inocêncio; de Souza Filho, Nilton Antonio; de Oliveira, Valmir Aparecido

    2017-04-17

    To describe a case of an obese child whose weight gain was related to the Munchausen Syndrome by proxy (MSP). This is a case report including information regarding the child's clinical history and the mother's behavior. The common features of the syndrome are confronted with the description of the case, seeking to demonstrate the similarities. The description ratifies the diagnosis based on the signs and symptoms presented by the child (<5 years old, frequent contacts with health system, symptoms witnessed only by the mother, confusing findings, not helped by treatments, emotionally distant father) and the attitude of the mother (concerned, interested in procedures, comfortable in the medical setting, higher medical knowledge, hostile when thwarted). The case presented points to a new etiology, the MSP, to be considered within the set of factors currently known to cause and maintain obesity in childhood.

  15. Interactive images: Cuboid proxies for smart image manipulation

    KAUST Repository

    Zheng, Youyi

    2012-07-01

    Images are static and lack important depth information about the underlying 3D scenes. We introduce interactive images in the context of man-made environments wherein objects are simple and regular, share various non-local relations (e.g., coplanarity, parallelism, etc.), and are often repeated. Our interactive framework creates partial scene reconstructions based on cuboid-proxies with minimal user interaction. It subsequently allows a range of intuitive image edits mimicking real-world behavior, which are otherwise difficult to achieve. Effectively, the user simply provides high-level semantic hints, while our system ensures plausible operations by conforming to the extracted non-local relations. We demonstrate our system on a range of real-world images and validate the plausibility of the results using a user study. © 2012 ACM 0730-0301/2012/08-ART99.

  16. Reliability of proxy reports of parental smoking by elementary schoolchildren.

    Science.gov (United States)

    Barnett, T; O'Loughlin, J; Paradis, G; Renaud, L

    1997-08-01

    To investigate the reliability of reports of parental smoking by elementary schoolchildren aged 9-13 years, and to identify the correlates of disagreement between student proxy and parent self-reports. As part of the evaluation of a school-based heart health promotion program, data on parental smoking status were collected from 1240 student-mother pairs and 898 student-father pairs. Agreement for parental smoking status was 93.1% among student-mother pairs and 86.4% among student-father pairs. Among student-mother pairs, reports by students aged 9 years were more likely to disagree with mothers' self-reports than those of older children (odds ratio (OR) = 3.1). Among student-father pairs, the only significant correlate of disagreement was living in a single-parent family headed by the mother (OR = 2.6). Children 10-years or older can provide reliable reports of the smoking status of cohabiting parents.

  17. STRONTIUM DISTRIBUTION IN UPPER DEVONIAN CONODONT ELEMENTS: A PALAEOBIOLOGICAL PROXY

    Directory of Open Access Journals (Sweden)

    ANDREY V. ZHURAVLEV

    2017-04-01

    Full Text Available Conodonts are an extinct group of marine animals possessing debated affinities. The conodont elements are composed of calcium phosphate [apatite (CaF] and collagen-like proteins. Distribution of Sr in the bioapatite of albid, lamellar and paralamellar tissues of some Upper Devonian conodont element crowns from NW Russia was studied by microprobe. The calcium phosphate of the lamellar and paralamellar tissues demonstrates periodical oscillation of Sr contents across the lamellae (0.4-0.5 wt% in the outer part of lamella, and 0.2 wt% in the inner part. The albid tissue contains Sr of less than 0.4 wt%. It is suggested that oscillations of Sr concentrations reflect the periodic growth of the lamellae, and the average Ca/Sr ratio can be a proxy of the growth rate.

  18. One thousand years of fires: Integrating proxy and model data

    Directory of Open Access Journals (Sweden)

    Natalie Marie Kehrwald

    2016-04-01

    Full Text Available The current fires raging across Indonesia are emitting more carbon than the annual fossil fuel emissions of Germany or Japan, and the fires are still consuming vast tracts of rainforest and peatlands. The National Interagency Fire Center (www.nifc.gov notes that 2015 is one worst fire years on record in the U.S., where more than 9 million acres burned -- equivalent to the combined size of Massachusetts and New Jersey. The U.S. and Indonesian fires have already displaced tens of thousands of people, and their impacts on ecosystems are still unclear. In the case of Indonesia, the burning peat is destroying much of the existing soil, with unknown implications for the type of vegetation regrowth. Such large fires result from a combination of fire management practices, increasing anthropogenic land use, and a changing climate. The expected increase in fire activity in the upcoming decades has led to a surge in research trying to understand their causes, the factors that may have influenced similar times of fire activity in the past, and the implications of such fire activity in the future. Multiple types of complementary data provide information on the impacts of current fires and the extent of past fires. The wide array of data encompasses different spatial and temporal resolutions (Figure 1 and includes fire proxy information such as charcoal and tree ring fire scars, observational records, satellite products, modern emissions data, fire models within global land cover and vegetation models, and sociodemographic data for modeling past human land use and ignition frequency. Any single data type is more powerful when combined with another source of information. Merging model and proxy data enables analyses of how fire activity modifies vegetation distribution, air and water quality, and proximity to cities; these analyses in turn support land management decisions relating to conservation and development.

  19. Assessing paleo-biodiversity using low proxy influx.

    Directory of Open Access Journals (Sweden)

    Olivier Blarquez

    Full Text Available We developed an algorithm to improve richness assessment based on paleoecological series, considering sample features such as their temporal resolutions or their volumes. Our new method can be applied to both high- and low-count size proxies, i.e. pollen and plant macroremain records, respectively. While pollen generally abounds in sediments, plant macroremains are generally rare, thus leading to difficulties to compute paleo-biodiversity indices. Our approach uses resampled macroremain influxes that enable the computation of the rarefaction index for the low influx records. The raw counts are resampled to a constant resolution and sample volume by interpolating initial sample ages at a constant time interval using the age∼depth model. Then, the contribution of initial counts and volume to each interpolated sample is determined by calculating a proportion matrix that is in turn used to obtain regularly spaced time series of pollen and macroremain influx. We applied this algorithm to sedimentary data from a subalpine lake situated in the European Alps. The reconstructed total floristic richness at the study site increased gradually when both pollen and macroremain records indicated a decrease in relative abundances of shrubs and an increase in trees from 11,000 to 7,000 cal BP. This points to an ecosystem change that favored trees against shrubs, whereas herb abundance remained stable. Since 6,000 cal BP, local richness decreased based on plant macroremains, while pollen-based richness was stable. The reconstructed richness and evenness are interrelated confirming the difficulty to distinguish these two aspects for the studies in paleo-biodiversity. The present study shows that low-influx bio-proxy records (here macroremains can be used to reconstruct stand diversity and address ecological issues. These developments on macroremain and pollen records may contribute to bridge the gap between paleoecology and biodiversity studies.

  20. Assessing paleo-biodiversity using low proxy influx.

    Science.gov (United States)

    Blarquez, Olivier; Finsinger, Walter; Carcaillet, Christopher

    2013-01-01

    We developed an algorithm to improve richness assessment based on paleoecological series, considering sample features such as their temporal resolutions or their volumes. Our new method can be applied to both high- and low-count size proxies, i.e. pollen and plant macroremain records, respectively. While pollen generally abounds in sediments, plant macroremains are generally rare, thus leading to difficulties to compute paleo-biodiversity indices. Our approach uses resampled macroremain influxes that enable the computation of the rarefaction index for the low influx records. The raw counts are resampled to a constant resolution and sample volume by interpolating initial sample ages at a constant time interval using the age∼depth model. Then, the contribution of initial counts and volume to each interpolated sample is determined by calculating a proportion matrix that is in turn used to obtain regularly spaced time series of pollen and macroremain influx. We applied this algorithm to sedimentary data from a subalpine lake situated in the European Alps. The reconstructed total floristic richness at the study site increased gradually when both pollen and macroremain records indicated a decrease in relative abundances of shrubs and an increase in trees from 11,000 to 7,000 cal BP. This points to an ecosystem change that favored trees against shrubs, whereas herb abundance remained stable. Since 6,000 cal BP, local richness decreased based on plant macroremains, while pollen-based richness was stable. The reconstructed richness and evenness are interrelated confirming the difficulty to distinguish these two aspects for the studies in paleo-biodiversity. The present study shows that low-influx bio-proxy records (here macroremains) can be used to reconstruct stand diversity and address ecological issues. These developments on macroremain and pollen records may contribute to bridge the gap between paleoecology and biodiversity studies.

  1. Intensity modulated neutron radiotherapy optimization by photon proxy.

    Science.gov (United States)

    Snyder, Michael; Hammoud, Ahmad; Bossenberger, Todd; Spink, Robyn; Burmeister, Jay

    2012-08-01

    Introducing intensity modulation into neutron radiotherapy (IMNRT) planning has the potential to mitigate some normal tissue complications seen in past neutron trials. While the hardware to deliver IMNRT plans has been in use for several years, until recently the IMNRT planning process has been cumbersome and of lower fidelity than conventional photon plans. Our in-house planning system used to calculate neutron therapy plans allows beam weight optimization of forward planned segments, but does not provide inverse optimization capabilities. Commercial treatment planning systems provide inverse optimization capabilities, but currently cannot model our neutron beam. We have developed a methodology and software suite to make use of the robust optimization in our commercial planning system while still using our in-house planning system to calculate final neutron dose distributions. Optimized multileaf collimator (MLC) leaf positions for segments designed in the commercial system using a 4 MV photon proxy beam are translated into static neutron ports that can be represented within our in-house treatment planning system. The true neutron dose distribution is calculated in the in-house system and then exported back through the MATLAB software into the commercial treatment planning system for evaluation. The planning process produces optimized IMNRT plans that reduce dose to normal tissue structures as compared to 3D conformal plans using static MLC apertures. The process involves standard planning techniques using a commercially available treatment planning system, and is not significantly more complex than conventional IMRT planning. Using a photon proxy in a commercial optimization algorithm produces IMNRT plans that are more conformal than those previously designed at our center and take much less time to create. The planning process presented here allows for the optimization of IMNRT plans by a commercial treatment planning optimization algorithm, potentially allowing

  2. Proxy-assisted multicasting of video streams over mobile wireless networks

    Science.gov (United States)

    Nguyen, Maggie; Pezeshkmehr, Layla; Moh, Melody

    2005-03-01

    This work addresses the challenge of providing seamless multimedia services to mobile users by proposing a proxy-assisted multicast architecture for delivery of video streams. We propose a hybrid system of streaming proxies, interconnected by an application-layer multicast tree, where each proxy acts as a cluster head to stream out content to its stationary and mobile users. The architecture is based on our previously proposed Enhanced-NICE protocol, which uses an application-layer multicast tree to deliver layered video streams to multiple heterogeneous receivers. We targeted the study on placements of streaming proxies to enable efficient delivery of live and on-demand video, supporting both stationary and mobile users. The simulation results are evaluated and compared with two other baseline scenarios: one with a centralized proxy system serving the entire population and one with mini-proxies each to serve its local users. The simulations are implemented using the J-SIM simulator. The results show that even though proxies in the hybrid scenario experienced a slightly longer delay, they had the lowest drop rate of video content. This finding illustrates the significance of task sharing in multiple proxies. The resulted load balancing among proxies has provided a better video quality delivered to a larger audience.

  3. Analisis Perbandingan Respons Time Squid Proxy Pada Windows Server dan Linux Server

    OpenAIRE

    Sirait, Parulian

    2016-01-01

    In the development of information technology, information is obtained quickly through technology computer network known as the Internet. The use bandwidth for Internet access can be maximized by using a proxy server. One of the proxy server is squid. The use squid as the proxy server need to consider the operating system on the server and have not known its best performance on any operating system yet. For that it is necessary to analyze the performance of squid proxy server on a different op...

  4. Public Key Cryptography.

    Science.gov (United States)

    Tapson, Frank

    1996-01-01

    Describes public key cryptography, also known as RSA, which is a system using two keys, one used to put a message into cipher and another used to decipher the message. Presents examples using small prime numbers. (MKR)

  5. Key Management Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Provides a secure environment to research and develop advanced electronic key management and networked key distribution technologies for the Navy and DoD....

  6. Financial Key Ratios

    OpenAIRE

    Tănase Alin-Eliodor

    2014-01-01

    This article focuses on computing techniques starting from trial balance data regarding financial key ratios. There are presented activity, liquidity, solvency and profitability financial key ratios. It is presented a computing methodology in three steps based on a trial balance.

  7. A Robust on-Demand Path-Key Establishment Framework via Random Key Predistribution for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Wu Weili

    2006-01-01

    Full Text Available Secure communication is a necessity for some wireless sensor network (WSN applications. However, the resource constraints of a sensor render existing cryptographic systems for traditional network systems impractical for a WSN. Random key predistribution scheme has been proposed to overcome these limits. In this scheme, a ring of keys is randomly drawn from a large key pool and assigned to a sensor. Nodes sharing common keys can communicate securely using a shared key, while a path-key is established for those nodes that do not share any common keys. This scheme requires moderate memory and processing power, thus it is considered suitable for WSN applications. However, since the shared key is not exclusively owned by the two end entities, the established path-key may be revealed to other nodes just by eavesdropping. Based on the random-key predistribution scheme, we present a framework that utilizes multiple proxies to secure the path-key establishment. Our scheme is resilient against node capture, collusive attack, and random dropping, while only incurring a small amount of overhead. Furthermore, the scheme ensures that, with high probability, all path-keys are exclusively known by the two end nodes involved in the communication along the path.

  8. Efficient Path Key Establishment for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Emi Garcia

    2008-04-01

    Full Text Available Key predistribution schemes have been proposed as means to overcome wireless sensor network constraints such as limited communication and processing power. Two sensor nodes can establish a secure link with some probability based on the information stored in their memories, though it is not always possible that two sensor nodes may set up a secure link. In this paper, we propose a new approach that elects trusted common nodes called “Proxies” which reside on an existing secure path linking two sensor nodes. These sensor nodes are used to send the generated key which will be divided into parts (nuggets according to the number of elected proxies. Our approach has been assessed against previously developed algorithms, and the results show that our algorithm discovers proxies more quickly which are closer to both end nodes, thus producing shorter path lengths. We have also assessed the impact of our algorithm on the average time to establish a secure link when the transmitter and receiver of the sensor nodes are “ON.” The results show the superiority of our algorithm in this regard. Overall, the proposed algorithm is well suited for wireless sensor networks.

  9. LOCKS AND KEYS SERVICE

    CERN Multimedia

    Locks and Keys Service

    2002-01-01

    The Locks and Keys service (ST/FM) will move from building 55 to building 570 from the 2nd August to the 9th August 2002 included. During this period the service will be closed. Only in case of extreme urgency please call the 164550. Starting from Monday, 12th August, the Locks and Keys Service will continue to follow the activities related to office keys (keys and locks) and will provide the keys for furniture. The service is open from 8h30 to 12h00 and from 13h00 to 17h30. We remind you that your divisional correspondents can help you in the execution of the procedures. We thank you for your comprehension and we remain at your service to help you in solving all the matters related to keys for offices and furniture. Locks and Keys Service - ST Division - FM Group

  10. Do proxies reflect patients' health concerns about urinary incontinence and gait problems?

    Science.gov (United States)

    Higashi, Takahiro; Hays, Ron D; Brown, Julie A; Kamberg, Caren J; Pham, Chau; Reuben, David B; Shekelle, Paul G; Solomon, David H; Young, Roy T; Roth, Carol P; Chang, John T; MacLean, Catherine H; Wenger, Neil S

    2005-01-01

    Background While falls and urinary incontinence are prevalent among older patients, who sometimes rely on proxies to provide their health information, the validity of proxy reports of concern about falls and urinary incontinence remains unknown. Methods Telephone interviews with 43 consecutive patients with falls or fear of falling and/or bothersome urinary incontinence and their proxies chosen by patients as most knowledgeable about their health. The questionnaire included items derived from the Medical Outcomes Study Short Form 12 (SF-12), a scale assessing concerns about urinary incontinence (UI), and a measure of fear of falling, the Falls Efficacy Scale (FES). Scores were estimated using items asking the proxy perspective (6 items from the SF-12, 10 items from a UI scale, and all 10 FES items). Proxy and patient scores were compared using intraclass correlation coefficients (ICC, one-way model). Variables associated with absolute agreement between patients and proxies were explored. Results Patients had a mean age of 81 years (range 75–93) and 67% were female while proxies had a mean age of 70 (range 42–87) and 49% were female. ICCs were 0.63 for the SF-12, 0.52 for the UI scale, and 0.29 for the FES. Proxies tended to understate patients' general health and incontinence concern, but overstate patients' concern about falling. Proxies who lived with patients and those who more often see patients more closely reflected patient FES scores compared to those who lived apart or those who saw patients less often. Internal consistency reliability of proxy responses was 0.62 for the SF-12, 0.86 for the I-QOL, and 0.93 for the FES. In addition, construct validity of the proxy FES scale was supported by greater proxy-perceived fear of falling for patients who received medical care after a fall during the past 12 months (p < .05). Conclusion Caution should be exercised when using proxies as a source of information about older patients' health perceptions. Questions

  11. Do proxies reflect patients' health concerns about urinary incontinence and gait problems?

    Directory of Open Access Journals (Sweden)

    Solomon David H

    2005-11-01

    Full Text Available Abstract Background While falls and urinary incontinence are prevalent among older patients, who sometimes rely on proxies to provide their health information, the validity of proxy reports of concern about falls and urinary incontinence remains unknown. Methods Telephone interviews with 43 consecutive patients with falls or fear of falling and/or bothersome urinary incontinence and their proxies chosen by patients as most knowledgeable about their health. The questionnaire included items derived from the Medical Outcomes Study Short Form 12 (SF-12, a scale assessing concerns about urinary incontinence (UI, and a measure of fear of falling, the Falls Efficacy Scale (FES. Scores were estimated using items asking the proxy perspective (6 items from the SF-12, 10 items from a UI scale, and all 10 FES items. Proxy and patient scores were compared using intraclass correlation coefficients (ICC, one-way model. Variables associated with absolute agreement between patients and proxies were explored. Results Patients had a mean age of 81 years (range 75–93 and 67% were female while proxies had a mean age of 70 (range 42–87 and 49% were female. ICCs were 0.63 for the SF-12, 0.52 for the UI scale, and 0.29 for the FES. Proxies tended to understate patients' general health and incontinence concern, but overstate patients' concern about falling. Proxies who lived with patients and those who more often see patients more closely reflected patient FES scores compared to those who lived apart or those who saw patients less often. Internal consistency reliability of proxy responses was 0.62 for the SF-12, 0.86 for the I-QOL, and 0.93 for the FES. In addition, construct validity of the proxy FES scale was supported by greater proxy-perceived fear of falling for patients who received medical care after a fall during the past 12 months (p Conclusion Caution should be exercised when using proxies as a source of information about older patients' health perceptions

  12. 75 FR 9073 - Amendments to Rules Requiring Internet Availability of Proxy Materials

    Science.gov (United States)

    2010-02-26

    ... an Internet Web site; it is not intended to serve as a stand-alone basis for making a voting decision... Exchange Commission 17 CFR Parts 230 and 240 Amendments to Rules Requiring Internet Availability of Proxy... Rules Requiring Internet Availability of Proxy Materials AGENCY: Securities and Exchange Commission...

  13. Improving age-depth models using sedimentary proxies for accumulation rates in fluvio-lacustrine deposits

    NARCIS (Netherlands)

    Minderhoud, P.S.J.; Cohen, K.M.|info:eu-repo/dai/nl/185633374; Toonen, W.H.J.|info:eu-repo/dai/nl/317725505; Erkens, G.|info:eu-repo/dai/nl/323349382; Hoek, W.Z.|info:eu-repo/dai/nl/163819394

    2017-01-01

    Lacustrine fills, including those of oxbow lakes in river floodplains, often hold valuable sedimentary and biological proxy records of palaeo-environmental change. Precise dating of accumulated sediments at levels throughout these records is crucial for interpretation and correlation of (proxy) data

  14. 47 CFR 51.513 - Proxies for forward-looking economic cost.

    Science.gov (United States)

    2010-10-01

    ... SERVICES (CONTINUED) INTERCONNECTION Pricing of Elements § 51.513 Proxies for forward-looking economic cost... a cost study that complies with the forward-looking economic cost based pricing methodology... rates that apply in separate geographic areas in a state. (c) Proxies for specific elements—(1) Local...

  15. Diagnostic, Explanatory, and Detection Models of Munchausen by Proxy: Extrapolations from Malingering and Deception

    Science.gov (United States)

    Rogers, Richard

    2004-01-01

    Objective: The overriding objective is a critical examination of Munchausen syndrome by proxy (MSBP) and its closely-related alternative, factitious disorder by proxy (FDBP). Beyond issues of diagnostic validity, assessment methods and potential detection strategies are explored. Methods: A painstaking analysis was conducted of the MSBP and FDBP…

  16. Anxiety and worry when coping with cancer treatment: agreement between patient and proxy responses.

    Science.gov (United States)

    Hermont, Ana Paula; Scarpelli, Ana Carolina; Paiva, Saul M; Auad, Sheyla M; Pordeus, Isabela A

    2015-06-01

    Assess agreement between proxy respondents (caregivers) and children/adolescents related to the impact of cancer on children's/adolescents' health-related quality of life, with respect to anxiety and worry issues. A cross-sectional study was conducted among 83 Brazilian children/adolescents, of both genders, diagnosed with cancer, aged 5-18 years and their proxy respondents. Anxiety and worry were assessed through items of the instrument Pediatric Quality of Life Inventory™ Cancer Module Scale. Participants were recruited from the pediatric hematology/oncology centers at two public hospitals. All individuals were receiving medical care. Descriptive statistics were performed as well as a weighted kappa coefficient, Spearman's correlation coefficient, Wilcoxon signed-rank test and Bland-Altman plots. The magnitude of the difference between the mean scores obtained from children/adolescents and that of their proxy respondents was evaluated through effect size. The proxy respondents underestimated the feelings of worry among children (8-12 years) (p anxiety (p children/adolescents to report increasing feelings of worry as they got older. In the 'treatment anxiety' subscale, there was a tendency for proxy respondents to present higher mean scores, revealing that proxy respondents believed the children's/adolescents' treatment anxiety decreased as they aged. Discrepancies between the reports of children/adolescents and their proxy respondents were observed. Children's/adolescents' reports should not be ignored nor replaced by proxy reports; both reports should be analyzed together.

  17. Patient-rated versus proxy-rated cognitive and functional measures in older adults

    Directory of Open Access Journals (Sweden)

    Howland M

    2017-03-01

    Full Text Available Molly Howland,1 Kevin C Allan,1 Caitlin E Carlton,1 Curtis Tatsuoka,2–4 Kathleen A Smyth,3 Martha Sajatovic1,2,4,5 1Case Western Reserve University School of Medicine, 2Neurological and Behavioral Outcomes Center, University Hospitals Case Medical Center, 3Department of Epidemiology and Biostatistics, 4Department of Neurology, 5Department of Psychiatry, Case Western Reserve University School of Medicine, Cleveland, OH, USA Objectives: Patients with cognitive impairment may have difficulty reporting their functional and cognitive abilities, which are important clinical outcomes. Health care proxies may be able to corroborate patient self-reports. Several studies reported discrepancy between patient and proxy ratings, though the literature is sparse on changes over time of these ratings. Our goals in this 12-month study were to compare patient and proxy reports on functioning, cognition, and everyday executive function, and to further elucidate correlates of patient–proxy discrepancy. Methods: This was a prospective cohort study of individuals older than 70 years who ranged from having no cognitive impairment to having moderate dementia who had a proxy available to complete instruments at baseline (N=76. Measurements included Alzheimer’s Disease Cooperative Study–Activities of Daily Living Inventory (ADCS-ADLI, Neuro-QOL Executive Function, PROMIS Applied Cognition (PROMIS-Cog, Mini-Mental State Examination (MMSE, and Geriatric Depression Scale. Results: Patient- and proxy-rated ADCS-ADLI were correlated at baseline and at 1-year follow-up. Patient and proxy ratings were discrepant on Neuro-QOL Executive Function and PROMIS-Cog. Greater patient–proxy discrepancy on PROMIS-Cog was associated with younger age and less depression, and greater patient–proxy discrepancy on Neuro-QOL Executive Function was associated with less depression and worse cognitive impairment. Patient–proxy discrepancy increased over time for everyday executive

  18. Pseudo-proxy evaluation of climate field reconstruction methods of North Atlantic climate based on an annually resolved marine proxy network

    Science.gov (United States)

    Pyrina, Maria; Wagner, Sebastian; Zorita, Eduardo

    2017-10-01

    Two statistical methods are tested to reconstruct the interannual variations in past sea surface temperatures (SSTs) of the North Atlantic (NA) Ocean over the past millennium based on annually resolved and absolutely dated marine proxy records of the bivalve mollusk Arctica islandica. The methods are tested in a pseudo-proxy experiment (PPE) setup using state-of-the-art climate models (CMIP5 Earth system models) and reanalysis data from the COBE2 SST data set. The methods were applied in the virtual reality provided by global climate simulations and reanalysis data to reconstruct the past NA SSTs using pseudo-proxy records that mimic the statistical characteristics and network of Arctica islandica. The multivariate linear regression methods evaluated here are principal component regression and canonical correlation analysis. Differences in the skill of the climate field reconstruction (CFR) are assessed according to different calibration periods and different proxy locations within the NA basin. The choice of the climate model used as a surrogate reality in the PPE has a more profound effect on the CFR skill than the calibration period and the statistical reconstruction method. The differences between the two methods are clearer for the MPI-ESM model due to its higher spatial resolution in the NA basin. The pseudo-proxy results of the CCSM4 model are closer to the pseudo-proxy results based on the reanalysis data set COBE2. Conducting PPEs using noise-contaminated pseudo-proxies instead of noise-free pseudo-proxies is important for the evaluation of the methods, as more spatial differences in the reconstruction skill are revealed. Both methods are appropriate for the reconstruction of the temporal evolution of the NA SSTs, even though they lead to a great loss of variance away from the proxy sites. Under reasonable assumptions about the characteristics of the non-climate noise in the proxy records, our results show that the marine network of Arctica islandica can

  19. Pseudo-proxy evaluation of climate field reconstruction methods of North Atlantic climate based on an annually resolved marine proxy network

    Directory of Open Access Journals (Sweden)

    M. Pyrina

    2017-10-01

    Full Text Available Two statistical methods are tested to reconstruct the interannual variations in past sea surface temperatures (SSTs of the North Atlantic (NA Ocean over the past millennium based on annually resolved and absolutely dated marine proxy records of the bivalve mollusk Arctica islandica. The methods are tested in a pseudo-proxy experiment (PPE setup using state-of-the-art climate models (CMIP5 Earth system models and reanalysis data from the COBE2 SST data set. The methods were applied in the virtual reality provided by global climate simulations and reanalysis data to reconstruct the past NA SSTs using pseudo-proxy records that mimic the statistical characteristics and network of Arctica islandica. The multivariate linear regression methods evaluated here are principal component regression and canonical correlation analysis. Differences in the skill of the climate field reconstruction (CFR are assessed according to different calibration periods and different proxy locations within the NA basin. The choice of the climate model used as a surrogate reality in the PPE has a more profound effect on the CFR skill than the calibration period and the statistical reconstruction method. The differences between the two methods are clearer for the MPI-ESM model due to its higher spatial resolution in the NA basin. The pseudo-proxy results of the CCSM4 model are closer to the pseudo-proxy results based on the reanalysis data set COBE2. Conducting PPEs using noise-contaminated pseudo-proxies instead of noise-free pseudo-proxies is important for the evaluation of the methods, as more spatial differences in the reconstruction skill are revealed. Both methods are appropriate for the reconstruction of the temporal evolution of the NA SSTs, even though they lead to a great loss of variance away from the proxy sites. Under reasonable assumptions about the characteristics of the non-climate noise in the proxy records, our results show that the marine network of Arctica

  20. Health-related quality of life after stroke: reliability of proxy responses

    DEFF Research Database (Denmark)

    Muus, Ingrid; Petzold, Max; Ringsberg, Karin C

    2009-01-01

    A Danish version of the Stroke-Specific Quality of Life Scale (SSQOL-DK) has been developed for self-reporting; it contains 12 physical and psychosocial domains. The purpose of this study was (a) to assess the reliability of the proxy version of the SSQOL-DK and (b) to evaluate the influence...... of frequency of proxy contact on agreement. In all, 143 patients completed the SSQOL-DK 1 to 5 years post-stroke. A patient chosen proxy completed a proxy version of the same questionnaire. The proxy version showed satisfactory internal consistency (Cronbach's alpha = .85-.95). Agreement was generally high...... of the SSQOL-DK appears to be reliable for use with stroke patients up to a few years following a stroke....

  1. Millennial reconstructions: what can we learn from limited proxy data?

    Science.gov (United States)

    Annan, J. D.; Hargreaves, J. C.

    2011-12-01

    Reconstructions of the past millennium can help us to understand recent and future climate change, by placing the recent anthropogenically-forced changes in the context of natural variability. Proxy data prior to the instrumental era are, however, extremely limited, which raises the question of how well we can truly hope to understand the past. Until recently, temperature reconstructions over the past millennium have primarily used statistical regression-based methods, however approaches using data assimilation methodology (in which observational data are blended with dynamical climate models) have shown great potential and are being increasingly adopted. However, rigorous validation of these methods has been somewhat limited. Here we will present the results of some investigations into the performance, and the potential, of data assimilation approaches to estimate the climate state. We use a massive ensemble of the LOVECLIM model to generate precise results which (through being formally optimal) may be considered an upper bound on the performance of more realistic approaches. We show that the limited precision and volume of data places a severe constraint on our ability to reliably reconstruct past climate variability, especially prior to the middle of the last millennium.

  2. Identification of climatic state with limited proxy data

    Directory of Open Access Journals (Sweden)

    J. D. Annan

    2012-07-01

    Full Text Available We investigate the identifiability of the climate by limited proxy data. We test a data assimilation approach through perfect model pseudoproxy experiments, using a simple likelihood-based weighting based on the particle filtering process. Our experimental set-up enables us to create a massive 10 000-member ensemble at modest computational cost, thus enabling us to generate statistically robust results. We find that the method works well when data are sparse and imprecise, but in this case the reconstruction has a rather low accuracy as indicated by residual RMS errors. Conversely, when data are relatively plentiful and accurate, the estimate tracks the target closely, at least when considering the hemispheric mean. However, in this case, our prior ensemble size of 10 000 appears to be inadequate to correctly represent the true posterior, and the regional performance is poor. Using correlations to assess performance gives a more encouraging picture, with significant correlations ranging from about 0.3 when data are sparse to values over 0.7 when data are plentiful, but the residual RMS errors are substantial in all cases. Our results imply that caution is required in interpreting climate reconstructions, especially when considering the regional scale, as skill on this basis is markedly lower than on the large scale of hemispheric mean temperature.

  3. Medieval horse stable; the results of multi proxy interdisciplinary research.

    Science.gov (United States)

    Dejmal, Miroslav; Lisá, Lenka; Fišáková Nývltová, Miriam; Bajer, Aleš; Petr, Libor; Kočár, Petr; Kočárová, Romana; Nejman, Ladislav; Rybníček, Michal; Sůvová, Zdenka; Culp, Randy; Vavrčík, Hanuš

    2014-01-01

    A multi proxy approach was applied in the reconstruction of the architecture of Medieval horse stable architecture, the maintenance practices associated with that structure as well as horse alimentation at the beginning of 13th century in Central Europe. Finally, an interpretation of the local vegetation structure along Morava River, Czech Republic is presented. The investigated stable experienced two construction phases. The infill was well preserved and its composition reflects maintenance practices. The uppermost part of the infill was composed of fresh stabling, which accumulated within a few months at the end of summer. Horses from different backgrounds were kept in the stable and this is reflected in the results of isotope analyses. Horses were fed meadow grasses as well as woody vegetation, millet, oat, and less commonly hemp, wheat and rye. Three possible explanations of stable usage are suggested. The stable was probably used on a temporary basis for horses of workers employed at the castle, courier horses and horses used in battle.

  4. Music Therapy by Proxy: Using Humanised Images in Song

    Directory of Open Access Journals (Sweden)

    Carol Chambers

    2013-07-01

    Full Text Available Developing awareness, exploration and expression of emotionally sensitive issues can be difficult for some clients in music therapy. They may find it hard to express emotion through improvised music and may turn instead to the perceived security of the repetition of known songs.This paper presents the results from a completed research PhD, a qualitative case study based on naturalistic clinical practice, which examined the song choices of one woman in a medium-secure forensic unit over the three-year course of her music therapy. A descriptive narrative account was subjected to analysis according to a modified form of therapeutic narrative analysis (Aldridge and Aldridge 2002, resulting in the abstraction of a series of generative metaphoric images, framed within a chronological series of events. Crucially, these images were found to be humanised figures, yet they were also emotionally decentred or depersonalised. When approached from the philosophical and methodological perspective of behaviourism, which views these as conditioned responses associating music with life experiences as part of a process of developing self-identity, such images can be seen to provide an unspoken voice for the client’s feelings to be expressed in a manner that is personally revealing, socially acceptable, culturally accessible and therapeutically constructive.I assert that using these third-person characters as a form of proxy facilitates mutual reference and experimentation, and places music firmly at the heart of a socially constructed process of music therapy.

  5. A Rare Reason of Hyperinsulinism: Munchausen Syndrome by Proxy.

    Science.gov (United States)

    Akın, Onur; Yeşilkaya, Ediz; Sari, Erkan; Akar, Çağdaş; Başbozkurt, Gökalp; Macit, Enis; Aydin, Ibrahim; Taşlipinar, Abdullah; Gül, Hüsamettin

    2016-01-01

    Hyperinsulinism, one of the most important causes of hypoglycaemia, can be congenital or acquired. Rarely, drug toxicity can be a reason for hyperinsulinism. In the context of Munchausen syndrome by proxy (MSP), toxicity usually occurs in children due to drug administration by a parent or caregiver. A 7-year-old girl was referred to our department due to a hyperglycaemic period and hypoglycaemic episodes. On admission, gliclazide was initiated due to her hyperglycaemia, which we attributed to maturity onset diabetes of the young. However, during follow-up, hypoglycaemic levels were detected. Despite cessation of gliclazide, hypoglycaemic seizures occurred. Even with the medications administered, hypoglycaemia could not be prevented. During follow-up, the mother's affect, characterized by anxiety and interest in her daughter's medical care, appeared discordant with the situation. Due to our suspicion of MSP, we discovered toxic levels of gliclazide in the blood and urine samples which had been sent to the toxicology laboratory to search for hypoglycaemic agents. The patient was isolated, and all medications were stopped. After isolation, her hypoglycaemia disappeared, and she became hyperglycaemic (250 mg/dl). Physicians should consider the possibility of MSP in hyperinsulinaemic patients with discordant laboratory results and clinical symptoms, even if the child's parents display great concern. © 2016 S. Karger AG, Basel.

  6. Munchausen syndrome by proxy mimicking as Gaucher disease.

    Science.gov (United States)

    Al-Owain, Mohammed; Al-Zaidan, Hamad; Al-Hashem, Amal; Kattan, Hoda; Al-Dowaish, Abdullah

    2010-08-01

    Although rare, Munchausen syndrome by proxy (MBP) is a potentially life-threatening form of child abuse. Here, we report a 19-month-old female infant who presented with hepatosplenomegaly, anemia, thrombocytopenia, and recurrent septicemia. She was initially thought to have myelodysplastic syndrome. Further hematological and immunological investigations revealed no cause. beta-Glucosylceramidase enzyme activity on dried blood spot was suggestive of Gaucher disease. However, the enzyme level on cultured skin fibroblast was not consistent with Gaucher disease. The first hint about MBP was the recurrent sepsis with numerous gram negative rods. Furthermore, the mother's behavior and health history raised our suspicion about MBP. The child showed significant improvement after she was separated from the mother for a week. Finally, the mother confessed that she was spitting in local herbs and injecting it into the central line. This is, to our knowledge, the first report of MBP resembling in its presentation Gaucher disease. This case should alert the general and specialized pediatricians about MBP, as it may mimic metabolic diseases like Gaucher disease.

  7. Severe hypernatremia in a hospitalized child: munchausen by proxy.

    Science.gov (United States)

    Su, Erik; Shoykhet, Michael; Bell, Michael J

    2010-10-01

    An 8-week-old infant presented to a referring institution with profuse diarrhea and infectious enteritis for 1 week. He was initially treated for suspected Salmonella spp. sepsis and meningitis, because the organism was found in the stool, but the child's illness progressed, manifested by paroxysmal profuse diarrhea and increased urine output. After several weeks, he suffered a sagittal venous thrombosis and intracranial hemorrhage. Subsequently the child was transferred to a tertiary center for intestinal evaluation. The patient's diarrhea and excessive diuresis resolved, and his sodium normalized soon after transfer. Four days later, however, after his mother arrived, he immediately developed severe hypernatremia (serum sodium concentration [Na(+)] = 214 mEq/L), with resumption of diarrhea and excessive diuresis. A gastric aspirate during the crisis demonstrated an extremely high sodium content, [Na(+)] = 1416 mEq/L, consistent with salt intoxication. Surveillance of the mother revealed that she manipulated the indwelling nasogastric tube; confronted, she admitted to salt administration. This case describes one of the ways that Munchausen syndrome by proxy can manifest with profound neurologic sequelae, and highlights the need for close observation and swift intervention when sufficient cause is present. Copyright © 2010 Elsevier Inc. All rights reserved.

  8. Cognitive-Behavioral Therapy for Body Dysmorphic Disorder by Proxy.

    Science.gov (United States)

    Greenberg, Jennifer L; Mothi, Suraj Sarvode; Wilhelm, Sabine

    2016-07-01

    Body dysmorphic disorder (BDD) is a distressing or impairing preoccupation with a perceived defect in physical appearance. BDD by proxy (BDDBP) is a significant but understudied variant of BDD in which the primary preoccupation involves perceived imperfections of another person. Like BDD, individuals with BDDBP engage in time-consuming rituals to "fix" the other person's appearance or alleviate distress. Avoidance is common and the impact of BDDBP on social functioning is profound. Cognitive-behavioral therapy (CBT) is the best-studied and most promising psychological treatment for BDD, but no studies have examined its generalizability to the BDDBP variant. We tested feasibility, acceptability, and treatment outcome of CBT modified for BDDBP in a sample of 6 adults with primary BDDBP. Treatment was delivered in weekly individual sessions over 12-20weeks. Mean symptom severity (BDDBP-YBOCS) dropped from the moderately severe range at pretreatment to the subclinical range at posttreatment, t(6)=10.7, p<.001, d=3.3. One hundred percent of treatment completers were responders (≥30% reduction in BDDBP-YBOCS). Insight also improved. Treatment gains were maintained at 3-month follow-up. To our knowledge, this represents the first treatment study for BDDBP. Copyright © 2016. Published by Elsevier Ltd.

  9. A brief intervention for preparing ICU families to be proxies: A phase I study.

    Science.gov (United States)

    Turnbull, Alison E; Chessare, Caroline M; Coffin, Rachel K; Needham, Dale M

    2017-01-01

    Family members of critically ill patients report high levels of conflict with clinicians, have poor understanding of prognosis, struggle to make decisions, and experience substantial symptoms of anxiety, depression, and post-traumatic stress regardless of patient survival status. Efficient interventions are needed to prepare these families to act as patient proxies. To assess a brief "patient activation" intervention designed to set expectations and prepare families of adult intensive care unit (ICU) patients to communicate effectively with the clinical team. Phase I study of acceptability and immediate side effects. 122 healthcare proxies of 111 consecutive patients with a stay of ≥24 hours in the Johns Hopkins Hospital Medical ICU (MICU), in Baltimore, Maryland. Reading aloud to proxies from a booklet (Flesch-Kincard reading grade level 3.8) designed with multidisciplinary input including from former MICU proxies. Enrolled proxies had a median age of 51 years old with 83 (68%) female, and 55 (45%) African-American. MICU mortality was 18%, and 37 patients (33%) died in hospital or were discharged to hospice. Among proxies 98% (95% CI: 94% - 100%) agreed or strongly agreed that the intervention was appropriate, 98% (95% CI: 92% - 99%) agreed or strongly agreed that it is important for families to know the information in the booklet, and 54 (44%, 95% CI 35%- 54%) agreed or strongly agreed that parts of the booklet are upsetting. Upset vs. non-upset proxies were not statistically or substantially different in terms of age, sex, education level, race, relation to the patient, or perceived decision-making authority. This patient activation intervention was acceptable and important to nearly all proxies. Frequently, the intervention was simultaneously rated as both acceptable/important and upsetting. Proxies who rated the intervention as upsetting were not identifiable based on readily available proxy or patient characteristics.

  10. A Multi-Component Proxy for OH Variability Measured from Space: Evaluation and Evolution

    Science.gov (United States)

    Murray, L. T.; Fiore, A. M.; Valin, L. C.

    2014-12-01

    Observed changes in the decay rate of methyl chloroform (MCF; CH3CCl3) have been the traditional top-down constraint for variability in tropospheric abundances of the hydroxyl radical (OH), and thereby the oxidative capacity of the atmosphere. However, as atmospheric MCF concentrations approach detection limits following its ban under the Montréal Protocol, it is necessary to identify new proxies for global OH and its variability. We present here a novel proxy for tropospheric OH using convolved observations of total and tropospheric columns of ozone, water vapor, NO2, and CO, available from the Aura and Aqua satellites in the NASA Earth Observing System constellation. Derived from photochemical steady-state assumptions, the satellite proxy generates spatiotemporally coherent monthly percent anomalies in column OH for Oct. 2004 through Sept. 2012. We demonstrate that the temporal evolution of the globally integrated signal is statistically consistent with changes inferred by the MCF decay rate during this period. The magnitude of interannual variability in the satellite OH proxy is smaller than that from MCF, more consistent with global chemical transport models (CTMs). We evaluate the proxy by comparing to 9-year hind-cast simulations of the GEOS-Chem global CTM driven by MERRA reanalysis meteorology at 2° x 2.5° horizontal resolution, and find that the satellite proxy correlates with the airmass-weighted tropospheric monthly mean OH anomalies (R = 0.6; n = 96 months). The satellite proxy and model simulations indicate regional-scale coherent OH anomalies for many regions and seasons; where discrepancies occur, we highlight possible causes. We present a source attribution of the spatial and temporal patterns in the satellite OH proxy, informed by the individual components of the satellite proxy, a series of zero-emission sensitivity simulations with GEOS-Chem, and independent proxies for major modes of climate variability.

  11. A brief intervention for preparing ICU families to be proxies: A phase I study.

    Directory of Open Access Journals (Sweden)

    Alison E Turnbull

    Full Text Available Family members of critically ill patients report high levels of conflict with clinicians, have poor understanding of prognosis, struggle to make decisions, and experience substantial symptoms of anxiety, depression, and post-traumatic stress regardless of patient survival status. Efficient interventions are needed to prepare these families to act as patient proxies.To assess a brief "patient activation" intervention designed to set expectations and prepare families of adult intensive care unit (ICU patients to communicate effectively with the clinical team.Phase I study of acceptability and immediate side effects.122 healthcare proxies of 111 consecutive patients with a stay of ≥24 hours in the Johns Hopkins Hospital Medical ICU (MICU, in Baltimore, Maryland.Reading aloud to proxies from a booklet (Flesch-Kincard reading grade level 3.8 designed with multidisciplinary input including from former MICU proxies.Enrolled proxies had a median age of 51 years old with 83 (68% female, and 55 (45% African-American. MICU mortality was 18%, and 37 patients (33% died in hospital or were discharged to hospice. Among proxies 98% (95% CI: 94% - 100% agreed or strongly agreed that the intervention was appropriate, 98% (95% CI: 92% - 99% agreed or strongly agreed that it is important for families to know the information in the booklet, and 54 (44%, 95% CI 35%- 54% agreed or strongly agreed that parts of the booklet are upsetting. Upset vs. non-upset proxies were not statistically or substantially different in terms of age, sex, education level, race, relation to the patient, or perceived decision-making authority.This patient activation intervention was acceptable and important to nearly all proxies. Frequently, the intervention was simultaneously rated as both acceptable/important and upsetting. Proxies who rated the intervention as upsetting were not identifiable based on readily available proxy or patient characteristics.

  12. Penguin tissue as a proxy for relative krill abundance in East Antarctica during the Holocene.

    Science.gov (United States)

    Huang, Tao; Sun, Liguang; Long, Nanye; Wang, Yuhong; Huang, Wen

    2013-09-30

    Antarctic krill (Euphausia superba) is a key component of the Southern Ocean food web. It supports a large number of upper trophic-level predators, and is also a major fishery resource. Understanding changes in krill abundance has long been a priority for research and conservation in the Southern Ocean. In this study, we performed stable isotope analyses on ancient Adélie penguin tissues and inferred relative krill abundance during the Holocene epoch from paleodiets of Adélie penguin (Pygoscelis adeliae), using inverse of δ¹⁵N (ratio of ¹⁵N/¹⁴N) value as a proxy. We find that variations in krill abundance during the Holocene are in accord with episodes of regional climate changes, showing greater krill abundance in cold periods. Moreover, the low δ¹⁵N values found in modern Adélie penguins indicate relatively high krill availability, which supports the hypothesis of krill surplus in modern ages due to recent hunt for krill-eating seals and whales by humans.

  13. Proxy evidence from Chew Bahir (Ethiopia) that environmental change promoted human dispersal out of Northeast Africa

    Science.gov (United States)

    Viehberg, Finn; Just, Janna; Dean, Jonathan; Asrat, Asfawossen; Claussen, Martin; Franz, Sven-Oliver; Klasen, Nicole; Kleinen, Thomas; Lamb, Henry; Leng, Melanie J.; Ludwig, Patrick; Milodowski, Antoni E.; Rethemeyer, Janet; Schäbitz, Frank; Wagner, Bernd

    2017-04-01

    The Chew Bahir rift between the Main Ethiopian Rift (MER) and the Kenyan Rift and is filled with up to 5 km of sediment. It is a failed rift located within the Miocene-aged Broadly Rifted Zone of Southern Ethiopia marking the transition between the active MER to the north and the Turkana Basin to the south. The study site is in the prominent corridor from the source area of the anatomically modern humans to the Arabian peninsula and Levant. Proxy records from lake sediments drilled in the Chew Bahir basin (Ethiopia), close to the key hominin site of Omo-Kibish, show two distinct hydroclimatic phases. An initial period between 120 to 75 kyr, with highly variable conditions with rapid shifts from very wet to extreme aridity, is coincident with the east 'African megadroughts' period. This is followed by a more stable hydroclimate interval between 62 to 32 kyr, which is then followed by the onset of the Late Glacial maximum and later the North African Humid Period. In between these two distinct climatic periods is a gradual shift to drier conditions with an extreme drought at 62 kyr. We propose that this shift, from more to less variable hydroclimate, may help account for the anatomically modern human dispersal events out of Africa from <62 kyr.

  14. The compact key

    NARCIS (Netherlands)

    NN,

    1966-01-01

    Here is given a sample of a new sort of identification key, recently developed by Dr. P. W. Leenhouts of the Rijksherbarium. Having to sort many specimens of Sapindaceae into genera, he became dissatisfied with the common dichotomous key, which too often does not work when the material is not

  15. Using Experimental Paradigms to Examine Alcohol’s Role in Men’s Sexual Aggression: Opportunities and Challenges in Proxy Development

    Science.gov (United States)

    Abbey, Antonia; Wegner, Rhiana

    2015-01-01

    The goals of this article are to review the major findings from alcohol administration studies that use sexual aggression proxies and to encourage additional experimental research that evaluates hypotheses about the role of alcohol in the etiology of men’s sexual aggression. Experiments allow participants to be randomly assigned to drink conditions, therefore ensuring that any differences between drinkers and nondrinkers can be attributed to their alcohol consumption. One of the biggest challenges faced by experimental researchers is the identification of valid operationalizations of key constructs. The tension between internal and external validity is particularly problematic for violence researchers because they cannot allow participants to engage in the target behavior in the laboratory. The strengths and limitations associated with written vignettes, audiotapes, videotapes, and confederate proxies for sexual aggression are described. Suggestions are made for future research to broaden the generalizability of the findings from experimental research. PMID:26048214

  16. On the visualization of water-related big data: extracting insights from drought proxies' datasets

    Science.gov (United States)

    Diaz, Vitali; Corzo, Gerald; van Lanen, Henny A. J.; Solomatine, Dimitri

    2017-04-01

    Big data is a growing area of science where hydroinformatics can benefit largely. There have been a number of important developments in the area of data science aimed at analysis of large datasets. Such datasets related to water include measurements, simulations, reanalysis, scenario analyses and proxies. By convention, information contained in these databases is referred to a specific time and a space (i.e., longitude/latitude). This work is motivated by the need to extract insights from large water-related datasets, i.e., transforming large amounts of data into useful information that helps to better understand of water-related phenomena, particularly about drought. In this context, data visualization, part of data science, involves techniques to create and to communicate data by encoding it as visual graphical objects. They may help to better understand data and detect trends. Base on existing methods of data analysis and visualization, this work aims to develop tools for visualizing water-related large datasets. These tools were developed taking advantage of existing libraries for data visualization into a group of graphs which include both polar area diagrams (PADs) and radar charts (RDs). In both graphs, time steps are represented by the polar angles and the percentages of area in drought by the radios. For illustration, three large datasets of drought proxies are chosen to identify trends, prone areas and spatio-temporal variability of drought in a set of case studies. The datasets are (1) SPI-TS2p1 (1901-2002, 11.7 GB), (2) SPI-PRECL0p5 (1948-2016, 7.91 GB) and (3) SPEI-baseV2.3 (1901-2013, 15.3 GB). All of them are on a monthly basis and with a spatial resolution of 0.5 degrees. First two were retrieved from the repository of the International Research Institute for Climate and Society (IRI). They are included into the Analyses Standardized Precipitation Index (SPI) project (iridl.ldeo.columbia.edu/SOURCES/.IRI/.Analyses/.SPI/). The third dataset was

  17. On the uncertainties associated with using gridded rainfall data as a proxy for observed

    Directory of Open Access Journals (Sweden)

    C. R. Tozer

    2012-05-01

    Full Text Available Gridded rainfall datasets are used in many hydrological and climatological studies, in Australia and elsewhere, including for hydroclimatic forecasting, climate attribution studies and climate model performance assessments. The attraction of the spatial coverage provided by gridded data is clear, particularly in Australia where the spatial and temporal resolution of the rainfall gauge network is sparse. However, the question that must be asked is whether it is suitable to use gridded data as a proxy for observed point data, given that gridded data is inherently "smoothed" and may not necessarily capture the temporal and spatial variability of Australian rainfall which leads to hydroclimatic extremes (i.e. droughts, floods. This study investigates this question through a statistical analysis of three monthly gridded Australian rainfall datasets – the Bureau of Meteorology (BOM dataset, the Australian Water Availability Project (AWAP and the SILO dataset. The results of the monthly, seasonal and annual comparisons show that not only are the three gridded datasets different relative to each other, there are also marked differences between the gridded rainfall data and the rainfall observed at gauges within the corresponding grids – particularly for extremely wet or extremely dry conditions. Also important is that the differences observed appear to be non-systematic. To demonstrate the hydrological implications of using gridded data as a proxy for gauged data, a rainfall-runoff model is applied to one catchment in South Australia initially using gauged data as the source of rainfall input and then gridded rainfall data. The results indicate a markedly different runoff response associated with each of the different sources of rainfall data. It should be noted that this study does not seek to identify which gridded dataset is the "best" for Australia, as each gridded data source has its pros and cons, as does gauged data. Rather, the intention is

  18. Benthic foraminifera from the Arabian Sea oxygen minimum zone: towards a paleo-oxygenation proxy.

    Science.gov (United States)

    Clemence, Caulle; Meryem, Mojtahid; Karoliina, Koho; Andy, Gooday; Gert-Jan, Reichart; Gerhard, Schmiedl; Frans, Jorissen

    2014-05-01

    Benthic foraminifera from the Arabian Sea oxygen minimum zone: towards a paleo-oxygenation proxy. C. Caulle1, M. Mojtahid1, K. Koho2,3, A. Gooday4, G. J. Reichart2,3, G. Schmiedl5, F. Jorissen1 1UMR CNRS 6112 LPG-BIAF, University of Angers, 2 bd Lavoisier, 49045 Angers Cedex 2Utrecht University, Faculty of Geosciences, Department of Earth Sciences, Budapestlaan 4, 3584 CD Utrecht, The Netherlands 3Royal Netherland Institute for Sea Research (Royal NIOZ), Landsdiep 4, 1797 SZ 't Horntje (Texel) 4Southampton Oceanography Centre, Empress Dock, European Way, Southampton SO14 3ZH, UK 5Department of Geosciences, University of Hamburg, Bundesstraße 55, 20146 Hamburg, Germany The thermohaline circulation oxygenates the deep ocean sediment and therefore enables aerobic life on the sea-floor. In the past, interruption of this deep water formation occurred several times causing hypoxic to anoxic conditions on the sea-floor leading to major ecological turnover. A better understanding of the interaction between climate and bottom water oxygenation is therefore essential in order to predict future oceanic responses. Presently, permanent (stable over decadal timescale) low-oxygen conditions occur naturally at mid-water depths in the northern Indian Ocean (Arabian Sea). Oxygen Minimum Zones (OMZ) are key areas to understand the hypoxic-anoxic events and their impact on the benthic ecosystem. In this context, a good knowledge of the ecology and life cycle adaptations of the benthic foraminiferal assemblages living in these low oxygen areas is essential. A series of multicores were recovered from three transects showing an oxygen gradient across the OMZ: the Murray Ridge, the Oman margin and the Indian margin. The stations located at the same depths showed slightly different oxygen concentrations and large differences in organic matter content. These differences are mainly related to the geographic location in the Arabian Sea. We investigated at these stations live and dead benthic

  19. Geochemical Proxies for Enhanced Process Control of Underground Coal Gasification

    Science.gov (United States)

    Kronimus, A.; Koenen, M.; David, P.; Veld, H.; van Dijk, A.; van Bergen, F.

    2009-04-01

    Underground coal gasification (UCG) represents a strategy targeting at syngas production for fuel or power generation from in-situ coal seams. It is a promising technique for exploiting coal deposits as an energy source at locations not allowing conventional mining under economic conditions. Although the underlying concept has already been suggested in 1868 and has been later on implemented in a number of field trials and even at a commercial scale, UCG is still facing technological barriers, impeding its widespread application. Field UCG operations rely on injection wells enabling the ignition of the target seam and the supply with oxidants (air, O2) inducing combustion (oxidative conditions). The combustion process delivers the enthalpy required for endothermic hydrogen production under reduction prone conditions in some distance to the injection point. The produced hydrogen - usually accompanied by organic and inorganic carbon species, e.g. CH4, CO, and CO2 - can then be retrieved through a production well. In contrast to gasification of mined coal in furnaces, it is difficult to measure the combustion temperature directly during UCG operations. It is already known that geochemical parameters such as the relative production gas composition as well as its stable isotope signature are related to the combustion temperature and, consequently, can be used as temperature proxies. However, so far the general applicability of such relations has not been proven. In order to get corresponding insights with respect to coals of significantly different rank and origin, four powdered coal samples covering maturities ranging from Ro= 0.43% (lignite) to Ro= 3.39% (anthracite) have been gasified in laboratory experiments. The combustion temperature has been varied between 350 and 900 ˚ C, respectively. During gasification, the generated gas has been captured in a cryo-trap, dried and the carbon containing gas components have been catalytically oxidized to CO2. Thereafter, the

  20. A Proxy Outcome Approach for Causal Effect in Observational Studies: A Simulation Study

    Directory of Open Access Journals (Sweden)

    Wenbin Liang

    2014-01-01

    Full Text Available Background. Known and unknown/unmeasured risk factors are the main sources of confounding effects in observational studies and can lead to false observations of elevated protective or hazardous effects. In this study, we investigate an alternative approach of analysis that is operated on field-specific knowledge rather than pure statistical assumptions. Method. The proposed approach introduces a proxy outcome into the estimation system. A proxy outcome possesses the following characteristics: (i the exposure of interest is not a cause for the proxy outcome; (ii causes of the proxy outcome and the study outcome are subsets of a collection of correlated variables. Based on these two conditions, the confounding-effect-driven association between the exposure and proxy outcome can then be measured and used as a proxy estimate for the effects of unknown/unmeasured confounders on the outcome of interest. Performance of this approach is tested by a simulation study, whereby 500 different scenarios are generated, with the causal factors of a proxy outcome and a study outcome being partly overlapped under low-to-moderate correlations. Results. The simulation results demonstrate that the conventional approach only led to a correct conclusion in 21% of the 500 scenarios, as compared to 72.2% for the alternative approach. Conclusion. The proposed method can be applied in observational studies in social science and health research that evaluates the health impact of behaviour and mental health problems.

  1. Simulated airplane headache: a proxy towards identification of underlying mechanisms.

    Science.gov (United States)

    Bui, Sebastian Bao Dinh; Petersen, Torben; Poulsen, Jeppe Nørgaard; Gazerani, Parisa

    2017-12-01

    Airplane Headache (AH) occurs during flights and often appears as an intense, short lasting headache during take-off or landing. Reports are limited on pathological mechanisms underlying the occurrence of this headache. Proper diagnosis and treatments would benefit from identification of potential pathways involved in AH pathogenesis. This study aimed at providing a simulated airplane headache condition as a proxy towards identification of its underlying mechanisms. Fourteen participants including 7 volunteers suffering from AH and 7 healthy matched controls were recruited after meeting the diagnostic and safety criteria based on an approved study protocol. Simulation of AH was achieved by entering a pressure chamber with similar characteristics of an airplane flight. Selected potential biomarkers including salivary prostaglandin E2 (PGE2), cortisol, facial thermo-images, blood pressure, pulse, and saturation pulse oxygen (SPO) were defined and values were collected before, during and after flight simulation in the pressure chamber. Salivary samples were analyzed with ELISA techniques, while data analysis and statistical tests were handled with SPSS version 22.0. All participants in the AH-group experienced a headache attack similar to AH experience during flight. The non-AH-group did not experience any headaches. Our data showed that the values for PGE2, cortisol and SPO were significantly different in the AH-group in comparison with the non-AH-group during the flight simulation in the pressure chamber. The pressure chamber proved useful not only to provoke AH-like attack but also to study potential biomarkers for AH in this study. PGE2, and cortisol levels together with SPO presented dysregulation during the simulated AH-attack in affected individuals compared with healthy controls. Based on these findings we propose to use pressure chamber as a model to induce AH, and thus assess new potential biomarkers for AH in future studies.

  2. Using Resin-Based 3D Printing to Build Geometrically Accurate Proxies of Porous Sedimentary Rocks.

    Science.gov (United States)

    Ishutov, Sergey; Hasiuk, Franciszek J; Jobe, Dawn; Agar, Susan

    2017-09-28

    Three-dimensional (3D) printing is capable of transforming intricate digital models into tangible objects, allowing geoscientists to replicate the geometry of 3D pore networks of sedimentary rocks. We provide a refined method for building scalable pore-network models ("proxies") using stereolithography 3D printing that can be used in repeated flow experiments (e.g., core flooding, permeametry, porosimetry). Typically, this workflow involves two steps, model design and 3D printing. In this study, we explore how the addition of post-processing and validation can reduce uncertainty in the 3D-printed proxy accuracy (difference of proxy geometry from the digital model). Post-processing is a multi-step cleaning of porous proxies involving pressurized ethanol flushing and oven drying. Proxies are validated by: (1) helium porosimetry and (2) digital measurements of porosity from thin-section images of 3D-printed proxies. 3D printer resolution was determined by measuring the smallest open channel in 3D-printed "gap test" wafers. This resolution (400 µm) was insufficient to build porosity of Fontainebleau sandstone (∼13%) from computed tomography data at the sample's natural scale, so proxies were printed at 15-, 23-, and 30-fold magnifications to validate the workflow. Helium porosities of the 3D-printed proxies differed from digital calculations by up to 7% points. Results improved after pressurized flushing with ethanol (e.g., porosity difference reduced to ∼1% point), though uncertainties remain regarding the nature of sub-micron "artifact" pores imparted by the 3D printing process. This study shows the benefits of including post-processing and validation in any workflow to produce porous rock proxies. © 2017, National Ground Water Association.

  3. Keys to the City

    DEFF Research Database (Denmark)

    Monsson, Christian Kjær

    2014-01-01

    Review of: Keys to the City: How Economics, Institutions, Social Interaction, and Politics Shape Development / Michael Storper Princeton University Press, Princeton, NJ, 2013, 288 pp., $39.95/£27.95 (cloth), ISBN 9780691143118......Review of: Keys to the City: How Economics, Institutions, Social Interaction, and Politics Shape Development / Michael Storper Princeton University Press, Princeton, NJ, 2013, 288 pp., $39.95/£27.95 (cloth), ISBN 9780691143118...

  4. An ethical analysis of proxy and waiver of consent in critical care research

    DEFF Research Database (Denmark)

    Berg, Ronan M G; Møller, Kirsten; Rossel, Peter J. Hancke

    2013-01-01

    a substituted judgement by a close relative or friend, based on knowledge of patient's values, preferences, and view of life. For the consent to be genuine, the proxy must be informed of and understand three fundamental aspects of research practice: (1) that participation is voluntary and the consent can......It is a central principle in medical ethics that vulnerable patients are entitled to a degree of protection that reflects their vulnerability. In critical care research, this protection is often established by means of so-called proxy consent. Proxy consent for research participation constitutes...

  5. Apatite: a new redox proxy for silicic magmas?

    Science.gov (United States)

    Miles, Andrew; Graham, Colin; Hawkesworth, Chris; Gillespie, Martin; Bromiley, Geoff; Hinton, Richard

    2015-04-01

    Petrology, 89, 226-38. [2] Miles, A.J., Graham, C.M., Hawkesworth, C.J., Gillespie, M.R., Hinton, R.W., 2014, Mn in apatite: A new redox proxy for silicic magmas?: Geochimica et Cosmochimica Acta v. 132, p. 101-119.

  6. Hygroscopic growth and cloud droplet activation of xanthan gum as a proxy for marine hydrogels

    National Research Council Canada - National Science Library

    Dawson, K. W; Petters, M. D; Meskhidze, N; Petters, S. Suda; Kreidenweis, S. M

    2016-01-01

    .... Here we use xanthan gum (XG)—a bacterial biopolymer—as a proxy for marine hydrogels. Measurements were performed for pure XG particles and mixtures of XG with sodium chloride, calcium nitrate, and calcium carbonate...

  7. Middleware Proxy: A Request-Driven Messaging Broker For High Volume Data Distribution

    CERN Document Server

    Sliwinski, W; Dworak, A

    2014-01-01

    Nowadays, all major infrastructures and data centres (commercial and scientific) make an extensive use of the publish-subscribe messaging paradigm, which helps to decouple the message sender (publisher) from the message receiver (consumer). This paradigm is also heavily used in the CERN Accelerator Control system, in Proxy broker - critical part of the Controls Middleware (CMW) project. Proxy provides the aforementioned publish-subscribe facility and also supports execution of synchronous read and write operations. Moreover, it enables service scalability and dramatically reduces the network resources and overhead (CPU and memory) on publisher machine, required to serve all subscriptions. Proxy was developed in modern C++, using state of the art programming techniques (e.g. Boost) and following recommended software patterns for achieving low-latency and high concurrency. The outstanding performance of the Proxy infrastructure was confirmed during the last 3 years by delivering the high volume of LHC equipment...

  8. Youth proxy efficacy for fruit and vegetable availability varies by gender and socio-economic status.

    Science.gov (United States)

    Geller, Karly S; Dzewaltowski, David A

    2010-06-01

    The current study examined proxy efficacy, which was defined as youth's confidence to influence their parents to provide fruits and vegetables. The overall objective was to examine change in middle-school youth's proxy efficacy over time, and to determine if changes were moderated by gender and socio-economic status. Longitudinal cohort nested within schools. Eight middle schools located in urban, suburban and rural areas of a mid-western US state. Seven hundred and twelve youth followed across their 6th, 7th and 8th grade years. The sample was 51.8 % female, 30.5 % low socio-economic status and 89.5 % Caucasian, non-Hispanic. Males and lower socio-economic status youth were significantly lower in proxy efficacy at each assessment year compared with females and high socio-economic youth, respectively. Proxy efficacy to influence parents to provide fruits and vegetables may be an important construct to target in future interventions.

  9. Multiple water isotope proxy reconstruction of extremely low last glacial temperatures in Eastern Beringia (Western Arctic)

    NARCIS (Netherlands)

    Porter, Trevor J.; Froese, Duane G.; Feakins, Sarah J.; Bindeman, Ilya N.; Mahony, Matthew E.; Pautler, Brent G.; Reichart, Gert-Jan; Sanborn, Paul T.; Simpson, Myrna J.; Weijers, Johan W H

    2016-01-01

    Precipitation isotopes are commonly used for paleothermometry in high latitude regions. Here we present multiple water isotope proxies from the same sedimentary context - perennially frozen loess deposits in the Klondike Goldfields in central Yukon, Canada, representing parts of Marine Isotope

  10. Keys through ARQ

    CERN Document Server

    Latif, Mohamed Abdel; Gamal, Hesham El

    2009-01-01

    This paper develops a novel framework for sharing secret keys using the well-known Automatic Repeat reQuest (ARQ) protocol. The proposed key sharing protocol does not assume any prior knowledge about the channel state information (CSI), but, harnesses the available opportunistic secrecy gains using only the one bit feedback, in the form of ACK/NACK. The distribution of key bits among multiple ARQ epochs, in our approach, allows for mitigating the secrecy outage phenomenon observed in earlier works. We characterize the information theoretic limits of the proposed scheme, under different assumptions on the channel spatial and temporal correlation function, and develop low complexity explicit implementations. Our analysis reveals a novel role of "dumb antennas" in overcoming the negative impact of spatial correlation, between the legitimate and eavesdropper channels, on the achievable secrecy rates. We further develop an adaptive rate allocation policy which achieves higher secrecy rates by exploiting the channe...

  11. A Quantum Proxy Weak Blind Signature Scheme Based on Controlled Quantum Teleportation

    Science.gov (United States)

    Cao, Hai-Jing; Yu, Yao-Feng; Song, Qin; Gao, Lan-Xiang

    2015-04-01

    Proxy blind signature is applied to the electronic paying system, electronic voting system, mobile agent system, security of internet, etc. A quantum proxy weak blind signature scheme is proposed in this paper. It is based on controlled quantum teleportation. Five-qubit entangled state functions as quantum channel. The scheme uses the physical characteristics of quantum mechanics to implement message blinding, so it could guarantee not only the unconditional security of the scheme but also the anonymity of the messages owner.

  12. Human rights of children with intellectual disabilities: comparing self-ratings and proxy ratings.

    Science.gov (United States)

    Huus, K; Granlund, M; Bornman, J; Lygnegård, F

    2015-11-01

    A child rights-based approach to research articulates well with Article 12 of the United Nations Convention on the Rights of the Child (CRC) and highlights the importance and value of including children's own views about aspects that concern them. The aim of this study is to compare children with intellectual disability's own ratings (as self-raters) to those of their primary caregivers (as proxy raters) regarding human rights of children. The study also aims to establish whether there is an inter-rater agreement between the self-raters and proxy raters concerning Maslow's hierarchy of needs. This study is nested in a larger study examining the human rights of children with intellectual disability in South Africa. In total, 162 children with intellectual disability from 11 schools across three provinces and their primary caregivers participated by answering parts of a Children's Rights Questionnaire (CRQ) developed by the researchers based on the United Nation's CRC. We compared the answers for six questions in the questionnaire that were addressed to self-raters (children) and proxy raters (primary caregivers) in the same way. Questions regarding basic needs, such as access to clean water or whether the child had food to eat at home, were answered similarly by self-raters and proxy raters. Larger differences were found when self-raters and proxy raters were asked about whether the child had things or friends to play with at home. Socio-economic variables seemed to affect whether self-raters and proxy raters answered similarly. The results underscore the importance of promoting children's rights to express themselves by considering the opinions of both the children as self-raters and their primary caregivers as proxy raters - not only the latter. The results indicate that it is especially important to include children's own voices when more complex needs are surveyed. Agreement between self- and proxy ratings could be affected by socio-economic circumstances.

  13. Design and implementation of Ad-Hoc collaborative proxying scheme for reducing network energy waste

    OpenAIRE

    Rafiullah Khan; Sarmad Ullah Khan

    2017-01-01

    Network devices are equipped with low power states but they are rarely activated due to their inability of maintaining network connectivity. Recently, Network Connectivity Proxy (NCP) concept has been proposed in literature as an effective mechanism to exploit full potential of low power features on network devices by impersonating their virtual presence. However, the NCP concept faces several open issues and challenges especially related to proxying of TCP connections and majority of daily u...

  14. Similarity, agreement, and assumed similarity in proxy end-of-life decision making.

    Science.gov (United States)

    McDade-Montez, Elizabeth; Watson, David; Beer, Andrew

    2013-12-01

    Medical decisions near the end of life are often made by proxies who can be inaccurate in their judgments of patient preferences. Given that accuracy in surrogate decision making is an important goal in end-of-life decision making, and in light of that previously seen levels of accuracy reflect substantial disagreement, error, or both, this study examined both relationship and individual factors that potentially affect surrogate accuracy. Specifically, this study examined similarity, agreement, and assumed similarity-a process whereby raters use their own traits and preferences to rate another person-in spousal ratings of end-of-life treatment. This study expands on previous research by examining the potential influence of relationship factors and assumed similarity on end-of-life decision making among a sample of newlyweds. Newly married couples (n = 197) completed self and spouse measures of hypothetical end-of-life preferences and scales assessing marital satisfaction, personality, and attitudes. Results indicate a moderate level of similarity on husband and wife self-rated end-of-life treatment preferences (rs = .18-.29) and a moderate level of agreement between self and proxy ratings (rs = .17-.41). The largest correlations were seen between self ratings and proxy ratings (e.g., husband self ratings and husband proxy ratings of wife preferences, rs = .46-.69), reflecting strong assumed similarity in proxy ratings. For wives, similarity with husbands on a few attitudinal variables (i.e., spirituality, moral strictness, and conservatism) influenced proxy accuracy. Recognizing the potential impact of personal preferences on proxy ratings, as well as the potential influence of relationship factors, may help improve proxy accuracy and end-of-life care for patients and families.

  15. Contribution in Adaptating Web Interfaces to any Device on the Fly: The HCI Proxy

    Science.gov (United States)

    Lardon, Jérémy; Fayolle, Jacques; Gravier, Christophe; Ates, Mikaël

    2008-11-01

    Lot of work has been done on the adaptation of UIs. In the particular field of Web UI adaptation, many research projects aim at displaying web content designed for PCs on poorer supports. In this paper, we present previous work in the domain and then our proxy architecture, HCI proxy, to test solutions for the problem of adapting Web UIs for mobile phones, PDA and smartphones but also for TVs through browser-embedding STBs, and this on the fly.

  16. A Quantum Proxy Blind Signature Scheme Based on Genuine Five-Qubit Entangled State

    Science.gov (United States)

    Zeng, Chuan; Zhang, Jian-Zhong; Xie, Shu-Cui

    2017-06-01

    In this paper, a quantum proxy blind signature scheme based on controlled quantum teleportation is proposed. This scheme uses a genuine five-qubit entangled state as quantum channel and adopts the classical Vernam algorithm to blind message. We use the physical characteristics of quantum mechanics to implement delegation, signature and verification. Security analysis shows that our scheme is valid and satisfy the properties of a proxy blind signature, such as blindness, verifiability, unforgeability, undeniability.

  17. The suitability of Mytilus edulis as proxy archive and its response to ocean acidification

    OpenAIRE

    Heinemann, Agnes

    2011-01-01

    Past climate changes can be used as indicators of future scenarios, however past climatic changes can not be directly observed. Therefore, the reconstruction of past abiotic conditions can approximated using chemical or isotopic proxies. These proxies can be measured in natural archives (e.g. bivalve shells and coral skeletons). One aspect of current climate change is the acidification of the oceans, a phenomenon caused by the oceanic uptake of anthropogenic CO2 and a resulting shift in the m...

  18. Proxy-based Video Transmission: Error Resiliency, Resource Allocation, and Dynamic Caching

    OpenAIRE

    Tu, Wei

    2009-01-01

    In this dissertation, several approaches are proposed to improve the quality of video transmission over wired and wireless networks. To improve the robustness of video transmission over error-prone mobile networks, a proxy-based reference picture selection scheme is proposed. In the second part of the dissertation, rate-distortion optimized rate adaptation algorithms are proposed for video applications over congested network nodes. A segment-based proxy caching algorithm for video-on-demand a...

  19. Key World Energy Statistics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    The IEA produced its first handy, pocket-sized summary of key energy data in 1997. This new edition responds to the enormously positive reaction to the book since then. Key World Energy Statistics produced by the IEA contains timely, clearly-presented data on supply, transformation and consumption of all major energy sources. The interested businessman, journalist or student will have at his or her fingertips the annual Canadian production of coal, the electricity consumption in Thailand, the price of diesel oil in Spain and thousands of other useful energy facts. It exists in different formats to suit our readers' requirements.

  20. Applying a family systems lens to proxy decision making in clinical practice and research.

    Science.gov (United States)

    Rolland, John S; Emanuel, Linda L; Torke, Alexia M

    2017-03-01

    When patients are incapacitated and face serious illness, family members must make medical decisions for the patient. Medical decision sciences give only modest attention to the relationships among patients and their family members, including impact that these relationships have on the decision-making process. A review of the literature reveals little effort to systematically apply a theoretical framework to the role of family interactions in proxy decision making. A family systems perspective can provide a useful lens through which to understand the dynamics of proxy decision making. This article considers the mutual impact of family systems on the processes and outcomes of proxy decision making. The article first reviews medical decision science's evolution and focus on proxy decision making and then reviews a family systems approach, giving particular attention to Rolland's Family Systems Illness Model. A case illustrates how clinical practice and how research would benefit from bringing family systems thinking to proxy decisions. We recommend including a family systems approach in medical decision science research and clinical practices around proxy decisions making. We propose that clinical decisions could be less conflicted and less emotionally troubling for families and clinicians if family systems approaches were included. This perspective opens new directions for research and novel approaches to clinical care. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  1. A method of separating local and large scale climate signals in coral proxies

    Science.gov (United States)

    Timm, O.; Ruprecht, E.; Pfeiffer, M.; Dullo, W.

    2003-04-01

    Coral proxies in the tropical and subtropical Indian Ocean show markedly different imprints of local climate factors. The oxygen isotopic composition (d18o) reflects a combination of SST and seawater properties. Both are the response to local effects and large scale climate variations in the oceans and the atmosphere, mainly due to air-sea fluxes. Consequently, an important step to large scale climate reconstructions from coral proxies is the separation of the individual local signal and the teleconnection with large scale climate modes such as the El Nino/Southern Oscillation (ENSO). The aim of this study is to present a method capable of extracting the large scale climate signal recorded in corals. Using multiple linear regression (MLR) techniques we first analyse the partial effects of local SST and precipitation minus evaporation on the coral d18o proxies. In a second step multivariate statistics are applied to the proxies and climate variables in order to distinguish between local signals and large scale variability in the proxies. Three d18o records from the Indian Ocean (Chagos, La Reunion, Seychelles) and the ENSO signal are used as an example demonstration. The method is also applied to Carribean corals (Guadeloupe). Preliminary results for the variability of these proxies and their relation to the North Atlantic Oscillation are given.

  2. Technical Note: Probabilistically constraining proxy age–depth models within a Bayesian hierarchical reconstruction model

    Directory of Open Access Journals (Sweden)

    J. P. Werner

    2015-03-01

    Full Text Available Reconstructions of the late-Holocene climate rely heavily upon proxies that are assumed to be accurately dated by layer counting, such as measurements of tree rings, ice cores, and varved lake sediments. Considerable advances could be achieved if time-uncertain proxies were able to be included within these multiproxy reconstructions, and if time uncertainties were recognized and correctly modeled for proxies commonly treated as free of age model errors. Current approaches for accounting for time uncertainty are generally limited to repeating the reconstruction using each one of an ensemble of age models, thereby inflating the final estimated uncertainty – in effect, each possible age model is given equal weighting. Uncertainties can be reduced by exploiting the inferred space–time covariance structure of the climate to re-weight the possible age models. Here, we demonstrate how Bayesian hierarchical climate reconstruction models can be augmented to account for time-uncertain proxies. Critically, although a priori all age models are given equal probability of being correct, the probabilities associated with the age models are formally updated within the Bayesian framework, thereby reducing uncertainties. Numerical experiments show that updating the age model probabilities decreases uncertainty in the resulting reconstructions, as compared with the current de facto standard of sampling over all age models, provided there is sufficient information from other data sources in the spatial region of the time-uncertain proxy. This approach can readily be generalized to non-layer-counted proxies, such as those derived from marine sediments.

  3. Keyed shear joints

    DEFF Research Database (Denmark)

    Hansen, Klaus

    This report gives a summary of the present information on the behaviour of vertical keyed shear joints in large panel structures. An attemp is made to outline the implications which this information might have on the analysis and design of a complete wall. The publications also gives a short...

  4. Cryptographic Key Management System

    Energy Technology Data Exchange (ETDEWEB)

    No, author

    2014-02-21

    This report summarizes the outcome of U.S. Department of Energy (DOE) contract DE-OE0000543, requesting the design of a Cryptographic Key Management System (CKMS) for the secure management of cryptographic keys for the energy sector infrastructure. Prime contractor Sypris Electronics, in collaboration with Oak Ridge National Laboratories (ORNL), Electric Power Research Institute (EPRI), Valicore Technologies, and Purdue University's Center for Education and Research in Information Assurance and Security (CERIAS) and Smart Meter Integration Laboratory (SMIL), has designed, developed and evaluated the CKMS solution. We provide an overview of the project in Section 3, review the core contributions of all contractors in Section 4, and discuss bene ts to the DOE in Section 5. In Section 6 we describe the technical construction of the CKMS solution, and review its key contributions in Section 6.9. Section 7 describes the evaluation and demonstration of the CKMS solution in different environments. We summarize the key project objectives in Section 8, list publications resulting from the project in Section 9, and conclude with a discussion on commercialization in Section 10 and future work in Section 11.

  5. Locks and Keys Service

    CERN Multimedia

    Claude Ducastel

    The GS-LS-SEM section is pleased to inform you that as from Monday 30 November 2009, the opening hours of the Locks and Keys service will be the following: 08h30 - 12h30 / 13h30 - 16:30, Mondays to Fridays. GS-SEM-LS 73333

  6. Key performance indicators

    NARCIS (Netherlands)

    Zwetsloot, G.I.J.M.

    2014-01-01

    This paper addresses how organisations can use OSH performance indicators. This is an important way to mainstream OSH into business management. Key performance indicators (KPIs) should provide objective data on the OSH situation. It is often said that ‘what gets measured gets managed’. Without

  7. 'Doing good by proxy': human-animal kinship and the 'donation' of canine blood.

    Science.gov (United States)

    Ashall, Vanessa; Hobson-West, Pru

    2017-07-01

    This article demonstrates the relevance of animals to medical sociology by arguing that pet owners' accounts of veterinary decision-making can highlight key sociological themes which are important to both human and animal health. Based on semi-structured interviews, the article argues that interspecies 'kinship' allows for the extension of sociological claims regarding altruism, self-interest and mutuality from human blood donation to companion animal blood 'donation'. Furthermore, this study extends sociological understanding of the human-animal bond by showing how the dog's status as kin meant they were expected to donate blood, and that the act of donation itself represents an important opportunity for family 'display'. However, owners who do not or cannot donate blood themselves describe pet blood donation as an opportunity to lessen associated feelings of guilt or obligation through 'doing good by proxy'. These findings raise critical sociological and ethical questions concerning the risks and benefits of donation, and for how we understand third-party decision making. Finally, the article argues for the close entanglement of human and animal health, and concludes that sociologists of health and medicine should explore the radical possibility that decision-making in healthcare more generally might be influenced by experiences at the veterinary clinic, and vice versa. (A Virtual Abstract of this paper can be viewed at: https://www.youtube.com/channel/UC_979cmCmR9rLrKuD7z0ycA). © 2017 The Authors. Sociology of Health & Illness published by John Wiley & Sons Ltd on behalf of Foundation for SHIL.

  8. Physician Appraisals: Key Challenges

    Directory of Open Access Journals (Sweden)

    Klich Jacek

    2017-06-01

    Full Text Available The main purpose of the article is to identify key criteria being used for physician appraisals and to find how communication skills of physicians are valued in those appraisals. ScienceDirect and EBSCOhost databases were used for this search. The results show that a physician appraisal is underestimated both theoretically and empirically. The particular gap exists with respect to the communication skills of physicians, which are rarely present in medical training syllabi and physician assessments. The article contributes to the theoretical discourse on physician appraisals and points out at the inconsistency between the high status of physicians as a key hospital resource on the one hand and, on the other hand, at inadequate and poorly researched assessment of their performance with a special emphasis on communication skills. The article may inspire health managers to develop and implement up-to-date assessment forms for physicians and good managerial practices in this respect in hospitals and other health care units.

  9. Ancel Keys: a tribute

    Directory of Open Access Journals (Sweden)

    VanItallie Theodore B

    2005-02-01

    Full Text Available Abstract Ancel Keys, Ph.D., who died in November, 2004, at the age of 100, was among the first scientists to recognize that human atherosclerosis is not an inevitable consequence of aging, and that a high-fat diet can be a major risk factor for coronary heart disease. During World War II, he and a group of talented co-workers at the University of Minnesota conducted a large-scale study of experimentally-induced human starvation. The data generated by this study – which was immediately recognized to be a classic – continue to be of inestimable value to nutrition scientists. In his later years, Keys spent more time at his home in Naples, Italy, where he had the opportunity to continue his personal study of the beneficial effects on health and longevity of a Mediterranean diet.

  10. Chapter 06: Identification key

    Science.gov (United States)

    Alex Wiedenhoeft

    2011-01-01

    The key is written to guide you through the identification process in the most efficient and accurate way possible. It presents you with a numbered series of questions and asks you to answer them. The answers you provide will be based on your interpretations of the anatomical characters in your unknown specimen and will lead you to a new set of questions. Each time you...

  11. Mg/Ca and Sr/Ca as novel geochemical proxies for understanding sediment transport processes within coral reefs

    Science.gov (United States)

    Gacutan, J.; Vila-Concejo, A.; Nothdurft, L. D.; Fellowes, T. E.; Cathey, H. E.; Opdyke, B. N.; Harris, D. L.; Hamylton, S.; Carvalho, R. C.; Byrne, M.; Webster, J. M.

    2017-10-01

    Sediment transport is a key driver of reef zonation and biodiversity, where an understanding of sediment dynamics gives insights into past reef processes and allows the prediction of geomorphic responses to changing environmental conditions. However, modal conditions within the back-reef seldom promote sediment transport, hence direct observation is inherently difficult. Large benthic foraminifera (LBF) have previously been employed as 'tracers' to infer sediment transport pathways on coral reefs, as their habitat is largely restricted to the algal flat and post-mortem, their calcium carbonate test is susceptible to sediment transport forces into the back-reef. Foraminiferal test abundance and post-depositional test alteration have been used as proxies for sediment transport, although the resolution of these measures becomes limited by low test abundance and the lack of variation within test alteration. Here we propose the novel use of elemental ratios as a proxy for sediment transport. Two species, Baculogypsina sphaerulata and Calcarina capricornia, were analysed using a taphonomic index within One Tree and Lady Musgrave reefs, Great Barrier Reef (Australia). Inductively coupled plasma-atomic emission spectrometry (ICP-AES) was used to determine Mg/Ca and Sr/Ca and these ratios were compared with taphonomic data. Decreases in test Mg/Ca accompany increases in Sr/Ca in specimens from algal-flat to lagoonal samples in both species, mirroring trends indicated by taphonomic values, therefore indicating a relationship with test alteration. To delineate mechanisms driving changes in elemental ratios, back-scattered electron (BSE) images, elemental mapping and in situ quantitative spot analyses by electron microprobe microanalysis (EPMA) using wavelength dispersive X-ray spectrometers (WDS) were performed on un-altered algal flat and heavily abraded tests for both species. EPMA analyses reveal heterogeneity in Mg/Ca between spines and the test wall, implying the loss of

  12. Tracking fluctuations in the intensity of the eastern tropical north Pacific oxygen minimum zone using a multi-proxy approach

    Science.gov (United States)

    Tems, C.

    2015-12-01

    Naturally occurring oxygen minimum zones (OMZs) are permanent midwater features that are associated with highly productive regions of the ocean, key microbial mediated biogeochemical cycling, and the deposition of organic rich sediments. The intensity of OMZs varies on glacial to interglacial time scales, indicating a relationship between the climate system and the expanse of OMZs, however, high-resolution studies tracking the fluctuations of OMZs on a near annual basis are lacking. In the Gulf of California (Pescadero Slope), the eastern tropical north Pacific OMZ impinges on basin slopes depositing laminated, hemipelagic sediments that record useful proxies of OMZ fluctuations. In an OMZ, low O2 content promotes water column denitrification, imparting an elevated 15N/14N isotopic signature on the residual nitrate in the water column. The elevated 15NO3- is upwelled and incorporated into particulate organic mater (POM) during primary production. The exported POM δ15Nsed then reflects the intensity of the regional OMZ at the time it was deposited. The Pescadero Slope record shows distinct temporal fluctuations in the δ15Nsed with decadal to multi-decadal and centennial cyclicity over the past 1200 years. The record reveals that the OMZ contracts during warmer climatic periods, including the Medieval Climate Optimum and the Industrial Revolution, and expands during cooler climates, specifically the Little Ice Age. The local mechanisms that are influencing fluctuations in the OMZ are investigated through an analysis of productivity proxies, including weight percent organic carbon and weight percent biogenic silica, and indicate OMZ expansion during periods of high productivity. Local productivity is driven by the intensity in the easterly trade winds in the Pacific, and thus the relationship between regional trade wind intensity and fluctuations in the intensity of the OMZ over the past 160 years will be discussed.

  13. Statistical framework for evaluation of climate model simulations by use of climate proxy data from the last millennium – Part 2: A pseudo-proxy study addressing the amplitude of solar forcing

    Directory of Open Access Journals (Sweden)

    A. Hind

    2012-08-01

    Full Text Available The statistical framework of Part 1 (Sundberg et al., 2012, for comparing ensemble simulation surface temperature output with temperature proxy and instrumental records, is implemented in a pseudo-proxy experiment. A set of previously published millennial forced simulations (Max Planck Institute – COSMOS, including both "low" and "high" solar radiative forcing histories together with other important forcings, was used to define "true" target temperatures as well as pseudo-proxy and pseudo-instrumental series. In a global land-only experiment, using annual mean temperatures at a 30-yr time resolution with realistic proxy noise levels, it was found that the low and high solar full-forcing simulations could be distinguished. In an additional experiment, where pseudo-proxies were created to reflect a current set of proxy locations and noise levels, the low and high solar forcing simulations could only be distinguished when the latter served as targets. To improve detectability of the low solar simulations, increasing the signal-to-noise ratio in local temperature proxies was more efficient than increasing the spatial coverage of the proxy network. The experiences gained here will be of guidance when these methods are applied to real proxy and instrumental data, for example when the aim is to distinguish which of the alternative solar forcing histories is most compatible with the observed/reconstructed climate.

  14. Munchausen syndrome by proxy and pediatric nephrology.

    Science.gov (United States)

    Bertulli, Cristina; Cochat, Pierre

    2017-11-01

    Munchausen syndrome by proxy is a persistent fabrication of illness done by a person to another. Renal and urologic forms of this syndrome are not as uncommon as can be thought; a review of all the cases of Munchausen-by-proxy syndrome reveals that 25% of the children had renal or urologic issues. This syndrome can result in a serious diagnostic dilemma for the physicians; knowing this entity can allow early recognition of falsification and limit the physical and psychological damages caused in the victim. In this study, we reviewed the pediatric nephrology cases of Munchausen syndrome by proxy, grouping them through the principal signs of presentation. Copyright © 2017 Société francophone de néphrologie, dialyse et transplantation. Published by Elsevier Masson SAS. All rights reserved.

  15. Toxicological evaluation of two children diagnosed as Munchausen syndrome by proxy.

    Science.gov (United States)

    Türkmen, Zeynep; Ziyalar, Neylan; Tari, Itir; Mercan, Selda; Kayiran, Sinan Mahir; Sener, Dicle; Cengiz, Salih; Akçakaya, Necla

    2012-01-01

    Munchausen syndrome by proxy is a kind of child abuse in which affected children are often hospitalized for long periods and endure repetitive, painful and expensive diagnostic attempts. We present herein two toxicologically confirmed cases of Munchausen syndrome by proxy. Case 1 is a 16-month-old male who had fever, peripheral cyanosis, tremor, and reported cardiac arrest. Symptoms recurred in the hospital when the mother administered fluids. Toxicology detected 3.5 ng/ml mercury (Hg) in the fluid and 9.4 microg Hg/g creatinine in the urine. Case 2 is a 14-year-old female who had irregular blood findings and multiple hospitalizations. Serum analysis detected warfarin. Both mothers were transferred to psychiatric care. Munchausen syndrome by proxy should be suspected when clinical/laboratory findings are negative, illness descriptions are inconsistent, and frequent hospitalization yields no diagnosis. Psychiatric evaluation and toxicological analysis are recommended.

  16. A Quantum Multi-Proxy Weak Blind Signature Scheme Based on Entanglement Swapping

    Science.gov (United States)

    Yan, LiLi; Chang, Yan; Zhang, ShiBin; Han, GuiHua; Sheng, ZhiWei

    2017-02-01

    In this paper, we present a multi-proxy weak blind signature scheme based on quantum entanglement swapping of Bell states. In the scheme, proxy signers can finish the signature instead of original singer with his/her authority. It can be applied to the electronic voting system, electronic paying system, etc. The scheme uses the physical characteristics of quantum mechanics to implement delegation, signature and verification. It could guarantee not only the unconditionally security but also the anonymity of the message owner. The security analysis shows the scheme satisfies the security features of multi-proxy weak signature, singers cannot disavowal his/her signature while the signature cannot be forged by others, and the message owner can be traced.

  17. A new proxy measure for state-level gun ownership in studies of firearm injury prevention.

    Science.gov (United States)

    Siegel, Michael; Ross, Craig S; King, Charles

    2014-06-01

    Since many states are considering gun control laws, researchers need reliable data on rates of gun ownership at the state level. Survey measures of gun ownership in all 50 states, however, are only available for 3 years, and no state-level data have been collected since 2004. Consequently, the National Research Council has declared the development of a valid proxy that can be constructed from accessible, annual, state-level data to be a priority. While such a proxy does exist (the proportion of suicides in a state committed using a gun (FS/S), its correlation with state estimates of gun ownership in recent years is only 0.80. Using state-level data for the years 2001, 2002 and 2004, we developed an improved proxy for state-level gun ownership that uses FS/S (firearm suicides divided by all suicides) and also the per capita number of hunting licenses. We validated this measure using data from surveys of gun ownership conducted in 48 states during 1996 and 1999, and in 21 states during 1995-1998. Adding per capita hunting licenses to the proxy increased its correlation with survey-measured gun ownership from 0.80 to 0.95. The correlations of the new proxy with gun ownership in the two validation studies were 0.95 and 0.97. We conclude that the combination of FS/S and per capita hunting licenses improves substantially upon FS/S alone. This new proxy is easily computed from data that are available annually by state and may be useful for investigating the effect of gun prevalence on firearm-related morbidity and mortality. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  18. Quantifying the magnitude of environmental exposure misclassification when using imprecise address proxies in public health research.

    Science.gov (United States)

    Healy, Martin A; Gilliland, Jason A

    2012-04-01

    In spatial epidemiologic and public health research it is common to use spatially aggregated units such as centroids of postal/zip codes, census tracts, dissemination areas, blocks or block groups as proxies for sample unit locations. Few studies, however, address the potential problems associated with using these units as address proxies. The purpose of this study is to quantify the magnitude of distance errors and accessibility misclassification that result from using several commonly-used address proxies in public health research. The impact of these positional discrepancies for spatial epidemiology is illustrated by examining misclassification of accessibility to several health-related facilities, including hospitals, public recreation spaces, schools, grocery stores, and junk food retailers throughout the City of London and Middlesex County, Ontario, Canada. Positional errors are quantified by multiple neighborhood types, revealing that address proxies are most problematic when used to represent residential locations in small towns and rural areas compared to suburban and urban areas. Findings indicate that the shorter the threshold distance used to measure accessibility between subject population and health-related facility, the greater the proportion of misclassified addresses. Using address proxies based on large aggregated units such as centroids of census tracts or dissemination areas can result in very large positional discrepancies (median errors up to 343 and 2088 m in urban and rural areas, respectively), and therefore should be avoided in spatial epidemiologic research. Even smaller, commonly-used, proxies for residential address such as postal code centroids can have large positional discrepancies (median errors up to 109 and 1363 m in urban and rural areas, respectively), and are prone to misrepresenting accessibility in small towns and rural Canada; therefore, postal codes should only be used with caution in spatial epidemiologic research

  19. Comparing proxy and model estimates of hydroclimate variability and change over the Common Era

    Science.gov (United States)

    Hydro2k Consortium, Pages

    2017-12-01

    Water availability is fundamental to societies and ecosystems, but our understanding of variations in hydroclimate (including extreme events, flooding, and decadal periods of drought) is limited because of a paucity of modern instrumental observations that are distributed unevenly across the globe and only span parts of the 20th and 21st centuries. Such data coverage is insufficient for characterizing hydroclimate and its associated dynamics because of its multidecadal to centennial variability and highly regionalized spatial signature. High-resolution (seasonal to decadal) hydroclimatic proxies that span all or parts of the Common Era (CE) and paleoclimate simulations from climate models are therefore important tools for augmenting our understanding of hydroclimate variability. In particular, the comparison of the two sources of information is critical for addressing the uncertainties and limitations of both while enriching each of their interpretations. We review the principal proxy data available for hydroclimatic reconstructions over the CE and highlight the contemporary understanding of how these proxies are interpreted as hydroclimate indicators. We also review the available last-millennium simulations from fully coupled climate models and discuss several outstanding challenges associated with simulating hydroclimate variability and change over the CE. A specific review of simulated hydroclimatic changes forced by volcanic events is provided, as is a discussion of expected improvements in estimated radiative forcings, models, and their implementation in the future. Our review of hydroclimatic proxies and last-millennium model simulations is used as the basis for articulating a variety of considerations and best practices for how to perform proxy-model comparisons of CE hydroclimate. This discussion provides a framework for how best to evaluate hydroclimate variability and its associated dynamics using these comparisons and how they can better inform

  20. A Case Report of Munchausen Syndrome by Proxy Presenting as Acquired Symptomatic West Syndrome

    Directory of Open Access Journals (Sweden)

    Shridhar Jadhav

    2016-07-01

    Full Text Available Munchausen Syndrome By Proxy (MSBP is an extremely complicated diagnosis because of the difficulty in finding the incriminating evidence of its existence and because of the ethical issue it raises for caregivers. Its implications from a medical, psychological and legal point of view raise difficult questions for any professional confronted to it. We present a case of 8 month female infant who was diagnosed to have Hyperinsulinism causing hypoglycemic brain injury and later developing intractable convulsion with head drops, where EEG was suggestive of West Syndrome, was actually a case of Munchausen syndrome by proxy to start with.

  1. Forgery attack on one-time proxy signature and the improvement

    Science.gov (United States)

    Yang, Chun-Wei; Luo, Yi-Ping; Hwang, Tzonelih

    2014-09-01

    This paper points out that in Wang and Wei's scheme (Quantum Inf Process 11:455-463, 2012), an eavesdropper, Eve, can replace the original message of a proxy signature with a forged one of her choice without being detected by the verifier. Accordingly, one of the security requirements of a quantum signature, i.e., unforgeability, may not be satisfied in their scheme. An improvement is given to avoid this attack, and the comparisons with the existing quantum proxy signature are also demonstrated.

  2. Plant-derived terpenoids as paleovegetation proxies: evaluation of the proxy with Paleocene and Eocene megafloras and plant biomarkers in the Bighorn Basin, USA

    Science.gov (United States)

    Diefendorf, A. F.; Freeman, K. H.; Wing, S. L.

    2012-12-01

    Plant terpenoids (defense compounds synthesized from the 5-carbon building block isoprene) have a long history of use as geochemical plant biomarkers, and potentially can be used to reconstruct changes in the abundances of major land plant groups in rocks and sediments that do not preserve plant megafossils or pollen. Pentacyclic triterpenoids are synthesized almost exclusively by angiosperms whereas conifers produce the tricyclic diterpenoids. Many previous studies have focused on the use of di- to triterpenoid ratios to reconstruct floral changes in the geologic past, however few studies have compared terpenoid-based paleoflora proxies to pollen or megafossils. Prior reconstructions also did not take into account differences in biomarker production between plant functional types, such as deciduous and evergreen plants, which can be quite large. To investigate the use of terpenoids as paleoflora proxies, we examined sediments from the Bighorn Basin (Wyoming, USA) where ancient megafloras have been studied in detail. We analyzed di- and triterpenoid abundances as well as plant leaf waxes (n-alkanes) and other biomarkers in a total of 75 samples from 15 stratigraphic horizons from the late Paleocene (62 Ma) to early Eocene (52.5 Ma). By comparing terpenoid ratios with abundances estimated from plant megafossils, we can evaluate the utility of terpenoids as paleovegetation proxies. In nearly all samples, angiosperm triterpenoids are significantly lower in abundance than conifer diterpenoids. This contrasts with leaf fossil data that indicate paleofloras were dominated by angiosperms in both abundance and diversity. Traditional use of terpenoid paleovegetation proxies would therefore significantly overestimate the abundance of conifers, even when accounting for plant production differences. To determine if this overestimate is related to the loss of angiosperm triterpenoids (rather than enhanced production of diterpenoids in the geologic past), we compared angiosperm

  3. Reconstruction of historic solar magnetic field using proxy data

    Science.gov (United States)

    Lockwood, Mike; Owens, Mathew; Rouillard, Alexis

    2013-04-01

    The reconstruction of the open solar flux from historic geomagnetic activity observations was made possible by the discovery by the Ulysses spacecraft team that the radial component of the heliospheric field is independent of heliographic latitude at all phases of the solar cycle. This allowed understanding of the local heliospheric field near Earth to be converted into a global solar measure. A second key realisation was that some unknown variables that influence geomagnetic activity, such as the orientation of that field, averaged to constant values if sufficiently long (annual) timescales were used. The availability of coincident data on geomagnetic activity and the near-Earth heliospheric field from 3 solar cycles allowed the reconstruction method to be developed. Subsequently, such data has been obtained for a fourth solar cycle and this provides a stringent test of the algorithm because it contained a much weaker solar minimum than had been seen hitherto during the space age. Immediate support for the reconstruction was found in fully-independent data on cosmogenic isotopes stored in terrestrial reservoirs. The reconstruction algorithm has subsequently been improved to make better allowance for the effect of longitudinal solar structure and to exploit the differences between range and hourly mean geomagnetic data to reconstruct both the solar wind speed and the open solar flux. Debate about the validity of the reconstructions was largely centred on the accuracy and intercalibration of the historic geomagnetic data. In this context, the extraordinarily far-reaching work of 1832 by Carl Friedrich Gauss and Wilhelm Weber was vital in allowing the establishment of a global network of well-calibrated geomagnetic observations and this debate has been ended by the addition of data from other stations which support the original data employed. However, we noted a worrying tendency for later scientists to re-calibrate historic data based on their own theories and

  4. Effects of Art Therapy on Distress Levels of Adults with Cancer: A Proxy Pretest Study

    Science.gov (United States)

    Glinzak, Leara

    2016-01-01

    This study identified decreased distress after art therapy in a proxy pretest study with a convenience sample of 73 patients being treated for cancer. Art therapy outcomes from 4 settings (oncology unit, infusion clinic, individual sessions, and open studio) were measured via the self-report Distress Thermometer, which was collected as part of an…

  5. Reducing handover latency in future IP-based wireless networks: Fast Proxy Mobile IPv6

    NARCIS (Netherlands)

    Heijenk, Geert; Bargh, Mortaza S.; Laganier, Julien; Prasad, Anand R.

    2008-01-01

    Current IP-level mobility protocols have difficulties meeting the stringent handover delay requirements of future wireless networks. At the same time they do not give sufficient control to the network to control the handover process. This paper presents an extension to Proxy Mobile IP, which is the

  6. Ethiopia-Eritrea : proxy wars and prospects of peace in the Horn of Africa

    NARCIS (Netherlands)

    Abbink, G.J.

    2003-01-01

    Many inter-State and intra-State conflicts in Africa become more complex by being extended into 'proxy wars', i.e. secondary, often 'low intensity' armed conflicts, pursued in the context of a major power struggle, or outright wars between States carried out by subsidiary or co-opted insurgent

  7. Sources and proxy potential of long chain alkyl diols in lacustrine environments.

    NARCIS (Netherlands)

    Rampen, Sebastiaan W.; Datema, Mariska; Rodrigo-Gámiz, M.; Schouten, Stefan; Reichart, Gert-Jan; Sinninghe Damste, Jaap S.

    2014-01-01

    Long chain 1,13- and 1,15-alkyl diols form the base of a number of recently proposed proxies used for climate reconstruction. However, the sources of these lipids and environmental controls on their distribution are still poorly constrained. We have analyzed the long chain alkyl diol (LCD)

  8. Sources and proxy potential of long chain alkyl diols in lacustrine environments

    NARCIS (Netherlands)

    Rampen, S.; Datema, M.; Rodrigo-Gámiz, M.; Schouten, S.; Reichart, G.-J.; Sinninghe Damsté, J.S.

    2014-01-01

    Long chain 1,13- and 1,15-alkyl diols form the base of a number of recently proposed proxies used for climate reconstruction. However, the sources of these lipids and environmental controls on their distribution are still poorly constrained. We have analyzed the long chain alkyl diol (LCD)

  9. Comparing children's GPS tracks with geospatial proxies for exposure to junk food.

    Science.gov (United States)

    Sadler, Richard C; Gilliland, Jason A

    2015-01-01

    Various geospatial techniques have been employed to estimate children's exposure to environmental cardiometabolic risk factors, including junk food. But many studies uncritically rely on exposure proxies which differ greatly from actual exposure. Misrepresentation of exposure by researchers could lead to poor decisions and ineffective policymaking. This study conducts a GIS-based analysis of GPS tracks--'activity spaces'--and 21 proxies for activity spaces (e.g. buffers, container approaches) for a sample of 526 children (ages 9-14) in London, Ontario, Canada. These measures are combined with a validated food environment database (including fast food and convenience stores) to create a series of junk food exposure estimates and quantify the errors resulting from use of different proxy methods. Results indicate that exposure proxies consistently underestimate exposure to junk foods by as much as 68%. This underestimation is important to policy development because children are exposed to more junk food than estimated using typical methods. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Deuterium values from volcanic glass: A paleoelevation proxy for Oregon's Cascade Range

    Science.gov (United States)

    Carlson, T. B.; Bershaw, J. T.

    2016-12-01

    Hydrated volcanic glass has been used as a proxy to constrain Cenozoic paleoclimate across many of the world's mountain ranges. However, there are concerns that volcanic glass may not preserve the isotopic composition of syndepositional meteoric water. The Cascades are an excellent location to study the validity of hydrated volcanic glass as a paleoenvironmental proxy for several reasons. Moisture is derived from a single oceanic source and falls as orographic precipitation in the Cascades, leading to a characteristic altitude effect, or inverse relationship between elevation and the isotopic composition of meteoric water (δD). In addition, past studies have inferred uplift of the Cascades and an increase in the rain shadow effect since the Eocene through independent methods such as changing fossil assemblages, and other isotopic proxies including carbonates and fossil teeth. In this study, δD values of two hydrated tuff samples are compared: one prior to ( 29 Ma) and one following ( 5 Ma) the onset of High Cascade volcanism. The isotopic composition of these samples are interpreted in the context of modern water across the range to understand the potential of volcanic glass as a proxy for paleoelevation in the Pacific Northwest.

  11. Constructing Proxy Variables to Measure Adult Learners' Time Management Strategies in LMS

    Science.gov (United States)

    Jo, Il-Hyun; Kim, Dongho; Yoon, Meehyun

    2015-01-01

    This study describes the process of constructing proxy variables from recorded log data within a Learning Management System (LMS), which represents adult learners' time management strategies in an online course. Based on previous research, three variables of total login time, login frequency, and regularity of login interval were selected as…

  12. Validity of proxy data obtained by different psychological autopsy information reconstruction techniques.

    Science.gov (United States)

    Fang, L; Zhang, J

    2010-01-01

    Two informants were interviewed for each of 416 living controls (individuals sampled from the normal population) interviewed in a Chinese case-control psychological autopsy study. The validity of proxy data, obtained using seven psychological autopsy information reconstruction techniques (types 1, 2 and A - E), was evaluated, with living controls' self reports used as the gold-standard. Proxy data for reconstruction technique types 1, 2 and D on the Impulsivity Inventory Scale (total impulsivity score) were no different from the living controls' self report gold standard, whereas data for types A and E were smaller than data from living controls. On the 'acceptance or resignation' sub-scale of the avoidance coping dimension of the Moos Coping Response Inventory, information obtained by reconstruction technique types 1 and D was not significantly different from the living controls' self reports, whereas proxy data from types 2, A and E were smaller than those from the living controls. No statistically significant differences were identified for other proxy data obtained by reconstruction technique types 1, 2, A, D and E. These results indicate that using a second informant does not significantly enhance information reconstruction for the target.

  13. 17 CFR 240.14a-4 - Requirements as to proxy.

    Science.gov (United States)

    2010-04-01

    ... persons making the solicitation do not know, a reasonable time before the solicitation, are to be... elected. Provided, however, That nothing in this section 240.14a-4 shall prevent any person soliciting in... authority to vote for nominees named in the registrant's proxy statement, so long as the soliciting party...

  14. The 30 cm radio flux as a solar proxy for thermosphere density modelling

    Directory of Open Access Journals (Sweden)

    Dudok de Wit Thierry

    2017-01-01

    Full Text Available The 10.7 cm radio flux (F10.7 is widely used as a proxy for solar UV forcing of the upper atmosphere. However, radio emissions at other centimetric wavelengths have been routinely monitored since the 1950 s, thereby offering prospects for building proxies that may be better tailored to space weather needs. Here we advocate the 30 cm flux (F30 as a proxy that is more sensitive than F10.7 to longer wavelengths in the UV and show that it improves the response of the thermospheric density to solar forcing, as modelled with DTM (Drag Temperature Model. In particular, the model bias drops on average by 0–20% when replacing F10.7 by F30; it is also more stable (the standard deviation of the bias is 15–40% smaller and the density variation at the the solar rotation period is reproduced with a 35–50% smaller error. We compare F30 to other solar proxies and discuss its assets and limitations.

  15. Proxy documents as a source of measurement error in the Comparative Manifestos Project.

    NARCIS (Netherlands)

    Gemenis, Konstantinos

    2012-01-01

    This paper considers the issue of document type diversity in the Comparative Manifestos Project (CMP). For many years the CMP has been collecting and coding a variety of documents, such as speeches, pamphlets, newspaper articles and leaflets, as manifesto proxies. By using previously unexplored

  16. The Deceit Continues: An Updated Literature Review of Munchausen Syndrome By Proxy.

    Science.gov (United States)

    Sheridan, Mary S.

    2003-01-01

    This updated review of the literature on Munchausen Syndrome by Proxy (MBSP) analyzes 451 cases from 154 medical and psychosocial journal articles. Typical victims were usually 4 years of age or under; 6% were dead, and 7.3% suffered long-term or permanent injury. Twenty-five percent of siblings were dead. Mothers were perpetrators in 76.5% of…

  17. Characteristics of Hospital-Based Munchausen Syndrome by Proxy in Japan

    Science.gov (United States)

    Fujiwara, Takeo; Okuyama, Makiko; Kasahara, Mari; Nakamura, Ayako

    2008-01-01

    Objective: This article explores characteristics of Munchausen Syndrome by Proxy (MSBP) in Japan, a country which provides an egalitarian, low cost, and easy-access health care system. Methods: We sent a questionnaire survey to 11 leading doctors in the child abuse field in Japan, each located in different hospital-based sites. Child abuse doctors…

  18. Beyond Munchausen by Proxy: A Proposed Conceptualization for Cases of Recurring, Unsubstantiated Sexual Abuse Allegations

    Science.gov (United States)

    Lindahl, Mary W.

    2009-01-01

    In the emerging literature, cases involving recurring, unsubstantiated allegations of child sexual abuse have generally been categorized as Munchausen by proxy. Recent scholars have recommended restricting the label to the original conceptualization, involving purposeful deception motivated by psychological needs for medical attention. This leaves…

  19. Web of Deceit: A Literature Review of Munchausen Syndrome by Proxy.

    Science.gov (United States)

    Rosenberg, Donna A.

    1987-01-01

    A literature review and case study provide detailed characteristics of Munchausen syndrome by proxy, a form of child abuse wherein the mother falsifies illness in her child through simulation and/or production of illness, presenting the child for medical care while disclaiming knowledge of its etiology. Guidelines for medical, social service, and…

  20. Repeated False Allegations of Sexual Abuse Presenting to Sheriffs: When Is It Munchausen by Proxy?

    Science.gov (United States)

    Schreier, Herbert A.

    1996-01-01

    In cases of Munchausen Syndrome by Proxy, the perpetrator (generally the mother) simulates or fabricates child abuse in order to maintain an intense relationship with hospital personnel, police personnel, child protection workers, lawyers, or school personnel. A case involving law enforcement agents as a primary "target" illustrates…

  1. Munchausen by Proxy: A Case, Chart Series, and Literature Review of Older Victims

    Science.gov (United States)

    Awadallah, Nida; Vaughan, Aaron; Franco, Kathleen; Munir, Farah; Sharaby, Na'ama; Goldfarb, Johanna

    2005-01-01

    The history of an older child victim of Munchausen by proxy (MBP) is described. He was referred for evaluation after repeated sinus surgeries for recurrent sinus infections believed to be related to a falsified history of an immunodeficiency. The perpetrator was the mother of this 14-year-old victim, consistent with the majority of such cases.…

  2. Concerns about Research and Prevention Strategies in Munchausen Syndrome by Proxy (MSBP) Abuse.

    Science.gov (United States)

    Eminson, Mary; Jureidini, Jon

    2003-01-01

    This article examines three motives for research into Munchausen Syndrome by Proxy child abuse, which are to enhance treatment, to understand the psychopathology of perpetrators, and to find interventions to prevent its occurrence. It argues that only the first justification is valid and proposes that research energy be directed toward…

  3. Parent and Athlete Perceptions of Special Olympics Participation: Utility and Danger of Proxy Responding

    Science.gov (United States)

    Glidden, Laraine Masters; Bamberger, Katharine T.; Draheim, Angela R.; Kersh, Joanne

    2011-01-01

    Participation in athletics has benefits for persons with intellectual disabilities and their parents. Our purposes here were to confirm these benefits and to determine whether reports from athletes and parents were comparable (i.e., to test the validity of proxy responding). We conducted interviews with 34 Special Olympics sailing/kayaking…

  4. Care for Sick Children as a Proxy for Gender Equality in the Family

    Science.gov (United States)

    Eriksson, Rickard; Nermo, Magnus

    2010-01-01

    Swedish parents are entitled to government paid benefits to take care of sick children. In this paper we show that the gender distribution of paid care for sick children is a good proxy for the gender division of household work. Using two examples we show that registry data on care for sick children is a useful data source for studies on gender…

  5. The effect of chemical pretreatment of sediment upon foraminiferal-based proxies

    NARCIS (Netherlands)

    Feldmeijer, W.; Metcalfe, B.; Scussolini, P.; Arthur, K.L.

    2013-01-01

    Paleoceanographic studies routinely combine different foraminiferal proxies (i.e., weight, abundance, trace metal, and stable isotope measurements) into a cohesive narrative. The application of chemical treatment to disaggregate ocean sediments in the most efficient way to isolate the fossils of

  6. Proxy records of Holocene storm events in coastal barrier systems: Storm-wave induced markers

    Science.gov (United States)

    Goslin, Jérôme; Clemmensen, Lars B.

    2017-10-01

    Extreme storm events in the coastal zone are one of the main forcing agents of short-term coastal system behavior. As such, storms represent a major threat to human activities concentrated along the coasts worldwide. In order to better understand the frequency of extreme events like storms, climate science must rely on longer-time records than the century-scale records of instrumental weather data. Proxy records of storm-wave or storm-wind induced activity in coastal barrier systems deposits have been widely used worldwide in recent years to document past storm events during the last millennia. This review provides a detailed state-of-the-art compilation of the proxies available from coastal barrier systems to reconstruct Holocene storm chronologies (paleotempestology). The present paper aims (I) to describe the erosional and depositional processes caused by storm-wave action in barrier and back-barrier systems (i.e. beach ridges, storm scarps and washover deposits), (ii) to understand how storm records can be extracted from barrier and back-barrier sedimentary bodies using stratigraphical, sedimentological, micro-paleontological and geochemical proxies and (iii) to show how to obtain chronological control on past storm events recorded in the sedimentary successions. The challenges that paleotempestology studies still face in the reconstruction of representative and reliable storm-chronologies using these various proxies are discussed, and future research prospects are outlined.

  7. Multi-proxy summer and winter precipitation reconstruction for southern Africa over the last 200 years

    NARCIS (Netherlands)

    Neukom, R.; Nash, D.J.; Endfield, G.H.; Grab, S.W; Grove, C.A.; Kelso, C.; Vogel, C.H.; Zinke, J.

    2014-01-01

    This study presents the first consolidation of palaeoclimate proxy records from multiple archives to develop statistical rainfall reconstructions for southern Africa covering the last two centuries. State-of-the-art ensemble reconstructions reveal multi-decadal rainfall variability in the summer and

  8. Phylogenetic patterns are not proxies of community assembly mechanisms (they are far better)

    NARCIS (Netherlands)

    Gerhold, Pille; Cahill, J.F.; Winter, Marten; Bartish, I.V.; Prinzing, Andreas

    2015-01-01

    The subdiscipline of 'community phylogenetics' is rapidly growing and influencing thinking regarding community assembly. In particular, phylogenetic dispersion of co-occurring species within a community is commonly used as a proxy to identify which community assembly processes may have structured

  9. Linking coral river runoff proxies with climate variability, hydrology and land-use in Madagascar catchments

    NARCIS (Netherlands)

    Maina, J.; de Moel, H.; Vermaat, J.E.; Bruggemann, J.H.; Guillaume, M.M.M.; Grove, C.A.; Madin, J.S.; Merz-Kraus, R.; Zinke, J.

    2012-01-01

    Understanding the linkages between coastal watersheds and adjacent coral reefs is expected to lead to better coral reef conservation strategies. Our study aims to examine the main predictors of environmental proxies recorded in near shore corals and therefore how linked near shore reefs are to the

  10. Fluxes, diagenesis, and the variation of proxies in eastern Mediterranean sediments

    NARCIS (Netherlands)

    Santvoort, Petrus Johannes Maria van

    2004-01-01

    In this thesis diagenetic processes in both organic-poor and organic-rich eastern Mediterranean sediments are studied. Furthermore, (present-day) fluxes and the variations in several proxies are discussed. Chapter 2 deals with the aerobic mineralisation of Corg in surface sediments of the deep

  11. Calcium isotopic composition of high-latitude proxy carrier Neogloboquadrina pachyderma (sin.

    Directory of Open Access Journals (Sweden)

    A. Eisenhauer

    2009-01-01

    Full Text Available The accurate reconstruction of sea surface temperature (SST history in climate-sensitive regions (e.g. tropical and polar oceans became a challenging task in palaeoceanographic research. Biogenic shell carbonate SST proxies successfully developed for tropical regions often fail in cool water environments. Their major regional shortcomings and the cryptic diversity now found within the major high latitude proxy carrier Neogloboquadrina pachyderma (sin. highlight an urgent need to explore complementary SST proxies for these cool-water regions. Here we incorporate the genetic component into a calibration study of a new SST proxy for the high latitudes. We found that the calcium isotopic composition (δ44/40Ca of calcite from genotyped net catches and core-top samples of the planktonic foraminifera Neogloboquadrina pachyderma (sin. is related to temperature and unaffected by genetic variations. The temperature sensitivity has been found to be 0.17 (±0.02‰ per 1°C, highlighting its potential for downcore applications in open marine cool-water environments. Our results further indicate that in extreme polar environments, below a critical threshold temperature of 2.0 (±0.5°C associated with salinities below 33.0 (±0.5‰, a prominent shift in biomineralization affects the δ44/40Ca of genotyped and core-top N. pachyderma (sin., becoming insensitive to temperature. These findings highlight the need of more systematic calibration studies on single planktonic foraminiferal species in order to unravel species-specific factors influencing the temperature sensitivity of Ca isotope fractionation and to validate the proxies' applicability.

  12. Calibration, validation and application of foraminiferal carbonate based proxies. Reconstructing temperature, salinity and sea water Mg/Ca

    NARCIS (Netherlands)

    Wit, J.C.

    2012-01-01

    The chemistry of the calcite test of foraminifera is often relating to the environmental conditions under which they lived. These so-called proxy-relations are regularly used as a tool to reconstruct past climates. Accuracy of these proxies is, however, often limited due to uncertainties or absence

  13. Pharmacological and non-pharmacological treatment preferences of healthcare professionals and proxies for challenging behaviors in patients with dementia

    NARCIS (Netherlands)

    Janus, Sarah I; van Manen, Jeannette G; van Til, Janine A; Zuidema, Sytse U; IJzerman, Maarten J.

    BACKGROUND: Prescribing antipsychotics to patients with neuropsychiatric symptoms is a matter of concern. Physicians have to make treatment decisions for patients with dementia together with proxies and/or nurses. However, it is unknown whether physicians, nurses, and proxies' treatment preferences

  14. Proxying UPnP service discovery and access to a non-IP Bluetooth network on a mobile phone

    NARCIS (Netherlands)

    Delphinanto, A.; Koonen, A.M.J.; Peeters, M.E.; Hartog, F.T.H. den

    2007-01-01

    The current service- and device discovery protocols are not platform- and network independent. Therefore, proxy servers will be needed to extend the range of IP-based discovery protocols to non-IP domains. We developed an architecture of a proxy that enables Universal Plug and Play (UPnP) devices

  15. The proxy problem anatomized: Child-parent disagreement in health related quality of life reports of chronically ill adolescents

    NARCIS (Netherlands)

    J.N.T. Sattoe (Jane); A.L. van Staa (AnneLoes); H.A. Moll (Henriëtte)

    2012-01-01

    textabstractBackground: Discrepancy between self-reports and parent-proxy reports of adolescent health-related quality of life (HRQoL) has been repeatedly acknowledged in the literature as the proxy problem. However, little is known about the extent and direction of this discrepancy. The purpose of

  16. Sets, Subsets, and Dichotomous Keys

    Science.gov (United States)

    Cole, E. James

    1973-01-01

    Discusses the procedures that should be observed in constructing a dichotomous key. The keying exercise described was used as a laboratory activity in a biology course for elementary education majors, however it could be used in other courses. (JR)

  17. Key Concepts in Informatics: Algorithm

    Science.gov (United States)

    Szlávi, Péter; Zsakó, László

    2014-01-01

    "The system of key concepts contains the most important key concepts related to the development tasks of knowledge areas and their vertical hierarchy as well as the links of basic key concepts of different knowledge areas." (Vass 2011) One of the most important of these concepts is the algorithm. In everyday life, when learning or…

  18. Secret-key certificates (continued)

    NARCIS (Netherlands)

    S.A. Brands (Stefan)

    1995-01-01

    textabstractA new construction is described for designing secret-key certificate schemes based on signature schemes other than of the Fiat-Shamir type. Also described are practical secret-key certificate issuing protocols that enable the Certification Authority to certify public keys, without being

  19. Light is an active contributor to the vital effects of coral skeleton proxies

    Science.gov (United States)

    Juillet-Leclerc, Anne; Reynaud, Stéphanie; Dissard, Delphine; Tisserand, Guillaume; Ferrier-Pagès, Christine

    2014-09-01

    Symbiotic colonies of the coral Acropora sp. were cultured in a factorial design of three temperatures (21, 25 and 28 °C) and two light intensities (200 and 400 μmol photon m-2 s-1), under constant conditions. A temperature of 25 °C and a light intensity of 200 μmol photon m-2 s-1 was the starting culture condition. Metabolic (photosynthesis, respiration, calcification and surface expansion rate) and geochemical measurements (δ18O, δ13C, Sr/Ca and Mg/Ca) were conducted on 6 colonies for each experimental condition. Metabolic measurements confirmed that respiration, photosynthesis, calcification and surface expansion rate responded to the combined effect of temperature and light. Under each light intensity, mean calcification rate was linearly correlated with mean photosynthetic activity. Geochemical measurements were also influenced by temperature and, to a lesser degree, by light. All geochemical proxies measured on 6 nubbins showed a wide scattering of values, regardless of the environmental condition. Compared to the other proxies, δ18O exhibited a different behavior. It was the only proxy exhibiting temperature tracer behavior. However, while mean values of Sr/Ca, Mg/Ca and δ13C were well correlated, the correlation between the later and mean δ18O differed with light level. This suggests that both skeleton deposition and temperature oxygen fractionation differs according to light intensity. Overall, the effect of light on geochemical values seems to compromise the use of proxy calibrations solely based on temperature influence. Under high light conditions, the great amplitude shown by individual net photosynthesis is directly proportional to the highly variable zooxanthellae density. As light is affecting all of the proxies, we thus assume that the strong geochemical variability observed could be explained by various algae densities, each nubbin responding according to its zooxanthellae amount. Accordingly, we suggest that each symbiosome (the

  20. Secure key storage and distribution

    Science.gov (United States)

    Agrawal, Punit

    2015-06-02

    This disclosure describes a distributed, fault-tolerant security system that enables the secure storage and distribution of private keys. In one implementation, the security system includes a plurality of computing resources that independently store private keys provided by publishers and encrypted using a single security system public key. To protect against malicious activity, the security system private key necessary to decrypt the publication private keys is not stored at any of the computing resources. Rather portions, or shares of the security system private key are stored at each of the computing resources within the security system and multiple security systems must communicate and share partial decryptions in order to decrypt the stored private key.

  1. Holocene moisture and East Asian summer monsoon evolution in the northeastern Tibetan Plateau recorded by Lake Qinghai and its environs: A review of conflicting proxies

    Science.gov (United States)

    Chen, Fahu; Wu, Duo; Chen, Jianhui; Zhou, Aifeng; Yu, Junqing; Shen, Ji; Wang, Sumin; Huang, Xiaozhong

    2016-12-01

    Climatic and environmental changes in the northeastern Tibetan Plateau are controlled by the Asian summer monsoon (ASM) and the westerlies, two key circulation components of the global climate system which directly affect a large human population and associated ecosystems in eastern Asia. During the past few decades, a series of Holocene palaeoclimatic records have been obtained from sediment cores from Lake Qinghai and from various other geological archives in the surrounding area of the northeastern Tibetan Plateau. However, because of uncertainties regarding the sediment chronologies and the climatic significance of the proxies used, the nature of Holocene climatic changes in the region remains unclear and even controversial. Here we review all major classes of the published data from drilled cores from Lake Qinghai, as well as other evidence from lakes and aeolian deposits from surrounding areas, in order to reconstruct changes in moisture patterns and possible summer monsoon evolution in the area during the Holocene. Combining the results of moisture and precipitation proxies such as vegetation history, pollen-based precipitation reconstruction, aeolian activity, lake water depth/lake level changes, salinity and sediment redness, we conclude that moisture and precipitation began to increase in the early Holocene, reached their maximum during the middle Holocene, and decreased during the late Holocene - similar to the pattern of the East Asian summer monsoon (EASM) in northern China. It is clear that the region experienced a relatively dry climate and weak EASM during the early Holocene, as indicated by relatively low tree pollen percentages and fluctuating pollen concentrations; generally low lake levels of Lake Qinghai and the adjacent Lake Hurleg and Lake Toson in the Qaidam Basin; and widely distributed aeolian sand deposition in the Lake Qinghai Basin and the nearby Gonghe Basin to the south, and in the eastern Qaidam Basin to the west. We argue that the

  2. An Anonymous Access Authentication Scheme Based on Proxy Ring Signature for CPS-WMNs

    Directory of Open Access Journals (Sweden)

    Tianhan Gao

    2017-01-01

    Full Text Available Access security and privacy have become a bottleneck for the popularization of future Cyber-Physical System (CPS networks. Furthermore, users’ need for privacy-preserved access during movement procedure is more urgent. To address the anonymous access authentication issue for CPS Wireless Mesh Network (CPS-WMN, a novel anonymous access authentication scheme based on proxy ring signature is proposed. A hierarchical authentication architecture is presented first. The scheme is then achieved from the aspect of intergroup and intragroup anonymous mutual authentication through proxy ring signature mechanism and certificateless signature mechanism, respectively. We present a formal security proof of the proposed protocol with SVO logic. The simulation and performance analysis demonstrate that the proposed scheme owns higher efficiency and adaptability than the typical one.

  3. Proxy-Based IPv6 Neighbor Discovery Scheme for Wireless LAN Based Mesh Networks

    Science.gov (United States)

    Lee, Jihoon; Jeon, Seungwoo; Kim, Jaehoon

    Multi-hop Wireless LAN-based mesh network (WMN) provides high capacity and self-configuring capabilities. Due to data forwarding and path selection based on MAC address, WMN requires additional operations to achieve global connectivity using IPv6 address. The neighbor discovery operation over WLAN mesh networks requires repeated all-node broadcasting and this gives rise to a big burden in the entire mesh networks. In this letter, we propose the proxy neighbor discovery scheme for optimized IPv6 communication over WMN to reduce network overhead and communication latency. Using simulation experiments, we show that the control overhead and communication setup latency can be significantly reduced using the proxy-based neighbor discovery mechanism.

  4. The solar proxy κ1 Cet and the planetary habitability around the young Sun

    Science.gov (United States)

    do Nascimento, J.-D.; Vidotto, A. A.; Petit, P.; Folsom, C.; Porto de Mello, G. F.; Meibom, S.; Abrevaya, X. C.; Ribas, I.; Castro, M.; Marsden, S. C.; Morin, J.; Jeffers, S. V.; Guinan, E.; Bcool Collaboration

    2017-10-01

    Among the solar proxies, κ1 Cet, stands out as potentially having a mass very close to solar and a young age. We report magnetic field measurements and planetary habitability consequences around this star, a proxy of the young Sun when life arose on Earth. Magnetic strength was determined from spectropolarimetric observations and we reconstruct the large-scale surface magnetic field to derive the magnetic environment, stellar winds, and particle flux permeating the interplanetary medium around κ1 Cet. Our results show a closer magnetosphere and mass-loss rate 50 times larger than the current solar wind mass-loss rate when Life arose on Earth, resulting in a larger interaction via space weather disturbances between the stellar wind and a hypothetical young-Earth analogue, potentially affecting the habitability. Interaction of the wind from the young Sun with the planetary ancient magnetic field may have affected the young Earth and its life conditions.

  5. Solar forced Dansgaard-Oeschger events and their phase relation with solar proxies

    DEFF Research Database (Denmark)

    Ditlevsen, Peter; Braun, H.; Chialvo, D. R.

    2008-01-01

    of a highly nonlinear system to quasi-periodic solar forcing plus noise. This hypothesis was challenged as inconsistent with the observed variability in the phase relation between proxies of solar activity and Greenland climate. Here we reject the claim of inconsistency by showing that this phase variability...... is a robust, generic feature of the nonlinear dynamics of DO events, as described by a model. This variability is expected from the fact that the events are threshold crossing events, resulting from a cooperative process between the periodic forcing and the noise. This process produces a fluctuating phase...... relation with the periodic forcing, consistent with proxies of solar activity and Greenland climate. Udgivelsesdato: 25 March...

  6. A study of practical proxy reencryption with a keyword search scheme considering cloud storage structure.

    Science.gov (United States)

    Lee, Sun-Ho; Lee, Im-Yeong

    2014-01-01

    Data outsourcing services have emerged with the increasing use of digital information. They can be used to store data from various devices via networks that are easy to access. Unlike existing removable storage systems, storage outsourcing is available to many users because it has no storage limit and does not require a local storage medium. However, the reliability of storage outsourcing has become an important topic because many users employ it to store large volumes of data. To protect against unethical administrators and attackers, a variety of cryptography systems are used, such as searchable encryption and proxy reencryption. However, existing searchable encryption technology is inconvenient for use in storage outsourcing environments where users upload their data to be shared with others as necessary. In addition, some existing schemes are vulnerable to collusion attacks and have computing cost inefficiencies. In this paper, we analyze existing proxy re-encryption with keyword search.

  7. Surrogate Decision Makers and Proxy Ownership: Challenges of Privacy Management in Health Care Decision Making

    Science.gov (United States)

    Bute, Jennifer J.; Petronio, Sandra; Torke, Alexia M.

    2016-01-01

    This study explored the communicative experiences of surrogates who served as decision makers for patients who were unable to convey health information and choices about treatment options. Drawing on assumptions from communication privacy management theory (Petronio, 2002), 35 surrogates were interviewed to explore how they navigated the role of guardian of patients’ private health information while the patient was hospitalized. This research determined that surrogates are not only guardians and thereby co-owners of the patients’ private health information, they actually served in a “proxy ownership” role. Surrogates described obstacles to both obtaining and sharing private health information about the patient, suggesting that their rights as legitimate co-owners of the patients’ information were not fully acknowledged by the medical teams. Surrogates also described challenges in performing the proxy ownership role when they were not fully aware of the patient's wishes. Theoretical and practical implications of these challenges are discussed. PMID:25175060

  8. A proxy analysis of urban air quality hazards in Bergen, Norway under a changing climate.

    Science.gov (United States)

    Wolf, Tobias; Esau, Igor; Reuder, Joachim

    2014-05-01

    The urban air quality in Bergen, Norway is characterized by clean air throughout most of the year interrupted by short episodes of hazardous pollution levels especially in close proximity to major road-emission sources. These pollution episodes are linked to winter time anti-cyclonic weather conditions with persistent stable temperature stratification (inversions) in the Atmospheric Boundary Layer. Although the pollution episodes are local events, the high pollution episodes are linked to large-scale persistent blockings in the atmospheric circulation. Here we present an atmospheric circulation proxy for the pollution episodes based on the ECMWF ERA-Interim reanalysis. The proxy is based on local 3-hourly instantaneous wind-speeds and directions at the 1000 hPa pressure level, and 1-day running mean temperature deviations at 2 m above ground from the 1-day running mean temperatures averaged over the full ERA-Interim record length. We tuned the thresholds for each quantity to the occurrence of events with an hourly mean NO2 concentration > 150 μg/m3 at a high pollution reference station. A condition on cloud cover had only little effect, sea-level pressure was not applicable. High pollution episodes predicted during typical low traffic days (Sundays, Christmas, New Year) were removed. The final proxy had a detection rate of 82 %, a false alarm rate of 77 % and a correct null prediction rate of 96 %. The high false alarm rate was expected because of the relaxed thresholds chosen in order to include a large fraction of possible states of atmospheric circulation that lead to hazardous air quality. Additionally, the false alarm rate was high because no constraint on the persistence of adverse meteorological conditions was set and because of the high variability of traffic, not always leading to hazardous pollution levels, even if the atmospheric circulation would allow for it. The Scandinavian index, an often used proxy for the occurrence of atmospheric circulation

  9. Self and proxy rating of quality of life in adults with intellectual disabilities: results from the DISQOL study.

    Science.gov (United States)

    Schmidt, Silke; Power, Mick; Green, Ann; Lucas-Carrasco, Ramona; Eser, Erhan; Dragomirecka, Eva; Fleck, Marcello

    2010-01-01

    The aim of this study was to analyze the agreement between self and proxy reports of quality of life (QoL) in people with intellectual disabilities and to examine the factors which contribute to these differences. The study was conducted across six international centres in a sample of 614 adults with intellectual disabilities as well as two different samples of proxies (N=874) including both professional carers and relatives. QoL was assessed with the disability version of the WHOQOL-BREF. In both proxy samples results show a significant moderate association between the persons' QoL-assessment and the assessment of their proxies in all of the five QoL domains. There were significant mean differences in most items which varied in their direction. In general, people with disabilities rated their QoL higher than their proxies except for two items from the physical domain. The factors which most significantly contributed to these differences were proxy knowledge of the person as well as the WHODAS-disability score. Cross-cultural differences in the magnitude of concordance were observed. As a conclusion, the study shows a good agreement between the person-proxy QoL-assessments, and that the factors associated with disagreement are limited in this study. Future studies should elaborate the stability of concordance over time. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  10. Validity of proxy-reported height and weight to derive body mass index in adults participating in Special Olympics.

    Science.gov (United States)

    Dobranowski, Kristin; Lloyd, Meghann; Côté, Pierre; Balogh, Robert

    2017-02-16

    Overweight and obesity are common in adults with intellectual disabilities, which complicates their health. To meet their health needs, individuals with intellectual disability frequently rely on proxies to answer questions on their behalf. In the general population, the use of proxy-reported height and weight to compute body mass index (BMI) has been validated, but not among adults with intellectual disability. The objective of this study was to determine the accuracy of proxy-reported height, weight and derived BMI among adults with intellectual disability. Proxies were asked to report height and weight on behalf of adults with intellectual disability who participate in Special Olympics Ontario; their answers were compared to measured height and weight. Proxies reported height and weight accurately; the sensitivity of proxy reports for classifying individuals with intellectual disability as overweight and/or obese was 84.6%. Proxy reports may be useful when direct measurements of individuals with intellectual disability are not available. © 2017 John Wiley & Sons Ltd.

  11. From Antarctic ice cores to Australia's water resources: Investigating an alternative streamflow proxy

    Science.gov (United States)

    Tozer, Carly; Kiem, Anthony; Vance, Tessa; Roberts, Jason; Curran, Mark; Moy, Andrew

    2017-04-01

    Past research worldwide shows that streamflow reconstructions, developed from paleoclimate proxies, provide a broader view of the range of climate variability possible relative to the comparatively short instrumental flow records on which water resource management plans are currently based. Hence there is a clear need for the development of streamflow reconstructions to allow us to better manage our water resources into the future. In Australia, however, there is a dearth of local high resolution proxies, particularly in catchments of interest, from which to develop streamflow reconstructions. This has led researchers to look beyond catchment boundaries and also Australia's borders to explore the utility of remote proxies for reconstructing Australian streamflow. Here we investigate, for a case study catchment located on Australia's eastern seaboard, the development of a millennial-length, annual streamflow reconstruction based on 1013 years of summer sea salt deposition recorded in ice cores from East Antarctica. The streamflow reconstruction realistically captures interannual to decadal variability in the gauged streamflow over the 1929-2009 calibration period. For the pre-instrumental period (i.e. pre-1900), the streamflow reconstruction shows longer wet and dry epochs than those recorded in the instrumental period. Furthermore, the variation in the distribution of the duration of wet and dry epochs between centuries suggests that water resources management and planning based on the statistics of the last 100 years of data (or less) is problematic. This information can be utilised to generate more realistic flow scenarios that better capture the range of hydroclimatic variability that Australia has experienced. This work emphasises a novel combination of ice core science, paleoclimatology and catchment-scale hydrology that is now being used to develop more robust water resources planning and management. The continuing work to further develop ice core based

  12. The potential of carbonyl sulfide as a proxy for gross primary production at flux tower sites

    Science.gov (United States)

    Blonquist, J. Mark, Jr.

    Seasonal dynamics of atmospheric carbonyl sulfide (OCS) at regional and continental scales and plant OCS exchange at the leaf level have shown a close relationship with those for CO2. CO2 has both sinks and sources within terrestrial ecosystems, but the primary terrestrial exchange for OCS is thought to be leaf uptake, suggesting potential for OCS uptake as a proxy for gross primary production (GPP). The utility of OCS uptake as a GPP proxy in micrometeorological studies of biosphere-atmosphere CO2 exchange was explored by applying theoretical concepts from earlier OCS studies to estimate GPP. Measured net ecosystem exchange (NEE) was partitioned using the ratio of measured vertical mole fraction gradients of OCS and CO2. At the Harvard Forest AmeriFlux site, measured CO2 and OCS vertical gradients were correlated, and were related to NEE and GPP, respectively. Estimates of GPP from OCS-based NEE partitioning were similar to those from established regression techniques, providing evidence that OCS uptake can potentially serve as a GPP proxy. Measured vertical CO 2 mole fraction gradients at five other AmeriFlux sites were used to project anticipated vertical OCS mole fraction gradients to provide indication of potential OCS signal magnitudes at sites where no OCS measurements were made. Projected OCS gradients at sites with short canopies were greater than those in forests, including measured OCS gradients at Harvard Forest, indicating greater potential for OCS uptake as a GPP proxy at these sites. This exploratory study suggests that continued investigation of linkages between OCS and GPP is warranted.

  13. Multi-periodic climate dynamics: spectral analysis of long-term instrumental and proxy temperature records

    OpenAIRE

    H.-J. Lüdecke; A. Hempelmann; Weiss, C. O.

    2012-01-01

    The longest six instrumental temperature records of monthly means reach back maximally to 1757 AD and were recorded in Europe. All six show a V-shape, with temperature drop in the 19th and rise in the 20th century. Proxy temperature time series of Antarctic ice cores show this same characteristic shape, indicating this pattern as a global phenomenon. We used the mean of the 6 instrumental records for analysis by discrete Fourier transformation (DFT), wavelets, and the detrended fluctuati...

  14. Multi-periodic climate dynamics: spectral analysis of long-term instrumental and proxy temperature records

    OpenAIRE

    Lüdecke, H.-J.; A. Hempelmann; Weiss, C. O.

    2013-01-01

    The longest six instrumental temperature records of monthly means reach back maximally to 1757 AD and were recorded in Europe. All six show a V-shape, with temperature drop in the 19th and rise in the 20th century. Proxy temperature time series of Antarctic ice cores show this same characteristic shape, indicating this pattern as a global phenomenon. We used the mean of the six instrumental records for analysis by discrete Fourier transform (DFT), wavelets, and the detren...

  15. Testing Novel pH Proxies through Inorganic Calcite Precipitations and K/Pg Foraminifera

    Science.gov (United States)

    Super, J. R.; Pagani, M.; Wang, Z.

    2013-12-01

    Ocean pH proxies help constrain the carbon system in the paleocean and can be used to infer atmospheric CO2 when coupled with estimates of total alkalinity, aqueous pCO2 or dissolved inorganic carbon. This project investigates two novel pH proxies (cerium abundance and kinetically-controlled oxygen isotopes) through a series of precipitations of inorganic calcite, as well as the previously established boron isotope pH proxy. Precipitations are performed using varied pH and carbonate saturation states that span the range of typical ocean values as well as a 'free drift' that allows pH and saturation state to vary. The light rare earth element cerium speciates, depending on local oxidation-reduction conditions, between the soluble Ce3+ and highly insoluble Ce4+ ions, causing a relative depletion of cerium in ocean water. This project demonstrates how a suite rare earth elements, including cerium, partitions into inorganic calcite and how partitioning varies with changing pH and carbonate saturation state. Oxygen isotope fractionation is primarily controlled by temperature, but this project examines how pH and carbonate saturation state correlate with oxygen isotope values under kinetic conditions during the initial stage of precipitation. The effect of diagenesis on each proxy is simulated by dissolution of precipitated calcite in a pressure vessel. Results from the precipitations are used to inform a record of well-preserved benthic and planktonic foraminifera from DSDP Site 356 that range in age from the K/Pg boundary to the period when the δ13C gradient between the surface and deep ocean returned to pre-event levels. The pH record is used to infer the magnitude and length of the perturbation to the oceanic carbon system following the extinction event, particularly in terms of export productivity.

  16. Distance-based kriging relying on proxy simulations for inverse conditioning

    OpenAIRE

    Ginsbourger, David; Rosspopoff, Bastien; Pirot, Guillaume; Durrande, Nicolas; Renard, Philippe

    2013-01-01

    We consider the problem of rapidly identifying, among a large set of candidate parameter fields, a subset of candidates whose responses computed by accurate forward flow and transport simulation match a reference response curve. In order to keep the number of calls to the flow simulator computationally tractable, a recent distance-based approach relying on fast proxy simulations is revisited, and turned into a non-stationary Kriging method. The covariance kernel is obtained by combining a cla...

  17. Acute kidney injury in a child: A case of Munchausen syndrome by proxy.

    Science.gov (United States)

    Mantan, Mukta; Dhingra, Dhulika; Gupta, Aditi; Sethi, Gulshan Rai

    2015-11-01

    Renal and urologic problems in pediatric condition falsification (PCF) or Munchausen by proxy (MSP) can result in serious diagnostic dilemma. Symptoms of hematuria, pyuria and recurrent urinary tract infections have occasionally been described. However, MSP presenting as azotemia has not been previously reported. We describe the case of an unfortunate boy who had to undergo unnecessary hemodialysis for persistent hyperkalemia and azotemia before a final diagnosis of the falsification of investigations by the parents was made.

  18. Acute kidney injury in a child: A case of Munchausen syndrome by proxy

    Directory of Open Access Journals (Sweden)

    Mukta Mantan

    2015-01-01

    Full Text Available Renal and urologic problems in pediatric condition falsification (PCF or Munchausen by proxy (MSP can result in serious diagnostic dilemma. Symptoms of hematuria, pyuria and recurrent urinary tract infections have occasionally been described. However, MSP presenting as azotemia has not been previously reported. We describe the case of an unfortunate boy who had to undergo unnecessary hemodialysis for persistent hyperkalemia and azotemia before a final diagnosis of the falsification of investigations by the parents was made.

  19. An Improved Quantum Proxy Blind Signature Scheme Based on Genuine Seven-Qubit Entangled State

    Science.gov (United States)

    Yang, Yuan-Yuan; Xie, Shu-Cui; Zhang, Jian-Zhong

    2017-07-01

    An improved quantum proxy blind signature scheme based on controlled teleportation is proposed in this paper. Genuine seven-qubit entangled state functions as quantum channel. We use the physical characteristics of quantum mechanics to implement delegation, signature and verification. Security analysis shows that our scheme is unforgeability, undeniability, blind and unconditionally secure. Meanwhile, we propose a trust party to provide higher security, the trust party is costless.

  20. A novel salinity proxy based on Na incorporation into foraminiferal calcite

    Directory of Open Access Journals (Sweden)

    J. C. Wit

    2013-10-01

    Full Text Available Salinity and temperature determine seawater density, and differences in both thereby control global thermohaline circulation. Whereas numerous proxies have been calibrated and applied to reconstruct temperature, a direct and independent proxy for salinity is still missing. Ideally, a new proxy for salinity should target one of the direct constituents of dissolved salt, such as [Na+] or [Cl−]. This study investigates the impact of salinity on foraminiferal Na/Ca values by laser ablation ICP-MS analyses of specimens of the benthic foraminifer Ammonia tepida cultured at a range of salinities (30.0–38.6. Foraminifera at lower salinities (30.0 and 32.5 added more chambers (10–11 to their test over the course of the culturing experiment than those maintained at higher salinities (36.1, 7–8 chambers, and 38.6, 6–7 chambers, suggesting that growth rates in this species are promoted by lower salinities. The Na/Ca of cultured specimens correlates significantly with seawater salinity (Na/Ca = 0.22S–0.75, R2 = 0.96, p DNa vary between 5.17 and 9.29 mmol mol−1 and 0.12–0.16 × 10−3, which are similar to values from inorganic precipitation experiments. The significant correlation between test size and Na/Ca results from co-variation with salinity. This implies that foraminiferal Na/Ca could serve as a robust and independent proxy for salinity, enabling salinity reconstructions independent of calcitic δ18O.

  1. Corporate Governance Objectives of Labor Union Shareholders: Evidence from Proxy Voting

    OpenAIRE

    Ashwini K. Agrawal

    2012-01-01

    Labor union pension funds have become increasingly vocal in governance matters; however, their motives are subject to fierce debate. I examine the proxy votes of AFL-CIO union funds around an exogenous change in the union representation of workers across firms. AFL-CIO-affiliated shareholders become significantly less opposed to directors once the AFL-CIO labor organization no longer represents a firm's workers. Other institutional investors, including mutual funds and public pension funds, d...

  2. Cryptanalysis of an inter-bank E-payment protocol based on quantum proxy blind signature

    Science.gov (United States)

    Cai, Xiao-Qiu; Wei, Chun-Yan

    2013-04-01

    We analyze the security of an inter-bank E-payment protocol based on quantum proxy blind signature, and find that there is a security leak in the quantum channels of this protocol, which gives a chance for an outside opponent to launch a special denial-of-service attack. Furthermore, we show that the dishonest merchant can succeed to change the purchase information of the customer in this protocol.

  3. A New Quantum Proxy Multi-signature Scheme Using Maximally Entangled Seven-Qubit States

    Science.gov (United States)

    Cao, Hai-Jing; Zhang, Jia-Fu; Liu, Jian; Li, Zeng-You

    2016-02-01

    In this paper, we propose a new secure quantum proxy multi-signature scheme using seven-qubit entangled quantum state as quantum channels, which may have applications in e-payment system, e-government, e-business, etc. This scheme is based on controlled quantum teleportation. The scheme uses the physical characteristics of quantum mechanics to guarantee its anonymity, verifiability, traceability, unforgetability and undeniability.

  4. CAN ACCOUNTING INFORMATION ACT AS A PROXY FOR EX ANTE UNCERTAINTY IN INITIAL PUBLIC OFFERINGS?

    OpenAIRE

    Tatang Ary Gumanti

    2003-01-01

    This paper reviews and summarizes previous works and the rationale for the proposition that accounting information is in fact value relevant in the determination of an initial public offering IPO).Theoretical and empirical evidence has indicated that certain accounting measures can he used as proxies for total firm risk, that is, they could determine the riskiness of a corporation. The literature also advocates that accounting information is relevant in determining the value and thus the risk...

  5. Linking coral river runoff proxies with climate variability, hydrology and land-use in Madagascar catchments.

    Science.gov (United States)

    Maina, Joseph; de Moel, Hans; Vermaat, Jan E; Bruggemann, J Henrich; Guillaume, Mireille M M; Grove, Craig A; Madin, Joshua S; Mertz-Kraus, Regina; Zinke, Jens

    2012-10-01

    Understanding the linkages between coastal watersheds and adjacent coral reefs is expected to lead to better coral reef conservation strategies. Our study aims to examine the main predictors of environmental proxies recorded in near shore corals and therefore how linked near shore reefs are to the catchment physical processes. To achieve these, we developed models to simulate hydrology of two watersheds in Madagascar. We examined relationships between environmental proxies derived from massive Porites spp. coral cores (spectral luminescence and barium/calcium ratios), and corresponding time-series (1950-2006) data of hydrology, climate, land use and human population growth. Results suggest regional differences in the main environmental drivers of reef sedimentation: on annual time-scales, precipitation, river flow and sediment load explained the variability in coral proxies of river discharge for the northeast region, while El Niño-Southern Oscillation (ENSO) and temperature (air and sea surface) were the best predictors in the southwest region. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Exploring foraminiferal Sr/Ca as a new carbonate system proxy

    Science.gov (United States)

    Keul, Nina; Langer, Gerald; Thoms, Silke; de Nooijer, Lennart Jan; Reichart, Gert-Jan; Bijma, Jelle

    2017-04-01

    In present day paleoclimate research one of the most pressing challenges is the reconstruction of atmospheric CO2 concentrations. A variety of proxies for several components of the marine inorganic carbon system have been developed in this context (e.g. B isotopes, B/Ca, U/Ca) to allow reconstruction of past seawater pH, HCO3- and CO32- and thereby facilitate estimates of past atmospheric pCO2. Based on culture experiments using the benthic foraminifera Ammonia sp. we describe a positive correlation between Sr/Ca and the carbonate system, namely DIC/bicarbonate ion concentration. Foraminiferal Sr/Ca ratios provide potentially additional constraints on the carbonate system proxy, because the analysis of foraminiferal carbonate Sr/Ca is straightforward and not easily contaminated. Applying our calibration to a published dataset of paleo-Sr/Ca suggests the validity of Sr/Ca as a carbonate system proxy. Furthermore, we explore how our data can be used to advance conceptual understanding of the foraminiferal biomineralization mechanism.

  7. A Proxy Architecture to Enhance the Performance of WAP 2.0 by Data Compression

    Directory of Open Access Journals (Sweden)

    Yin Zhanping

    2005-01-01

    Full Text Available This paper presents a novel proxy architecture for wireless application protocol (WAP employing an advanced data compression scheme. Though optional in WAP , a proxy can isolate the wireless from the wired domain to prevent error propagations and to eliminate wireless session delays (WSD by enabling long-lived connections between the proxy and wireless terminals. The proposed data compression scheme combines content compression together with robust header compression (ROHC, which minimizes the air-interface traffic data, thus significantly reduces the wireless access time. By using the content compression at the transport layer, it also enables TLS tunneling, which overcomes the end-to-end security problem in WAP 1.x. Performance evaluations show that while WAP 1.x is optimized for narrowband wireless channels, WAP utilizing TCP/IP outperforms WAP 1.x over wideband wireless channels even without compression. The proposed data compression scheme reduces the wireless access time of WAP by over in CDMA2000 1XRTT channels, and in low-speed IS-95 channels, substantially reduces access time to give comparable performance to WAP 1.x. The performance enhancement is mainly contributed by the reply content compression, with ROHC offering further enhancements.

  8. Technical Note: Correcting for signal attenuation from noisy proxy data in climate reconstructions

    Directory of Open Access Journals (Sweden)

    C. M. Ammann

    2010-04-01

    Full Text Available Regression-based climate reconstructions scale one or more noisy proxy records against a (generally short instrumental data series. Based on that relationship, the indirect information is then used to estimate that particular measure of climate back in time. A well-calibrated proxy record(s, if stationary in its relationship to the target, should faithfully preserve the mean amplitude of the climatic variable. However, it is well established in the statistical literature that traditional regression parameter estimation can lead to substantial amplitude attenuation if the predictors carry significant amounts of noise. This issue is known as "Measurement Error" (Fuller, 1987; Carroll et al., 2006. Climate proxies derived from tree-rings, ice cores, lake sediments, etc., are inherently noisy and thus all regression-based reconstructions could suffer from this problem. Some recent applications attempt to ward off amplitude attenuation, but implementations are often complex (Lee et al., 2008 or require additional information, e.g. from climate models (Hegerl et al., 2006, 2007. Here we explain the cause of the problem and propose an easy, generally applicable, data-driven strategy to effectively correct for attenuation (Fuller, 1987; Carroll et al., 2006, even at annual resolution. The impact is illustrated in the context of a Northern Hemisphere mean temperature reconstruction. An inescapable trade-off for achieving an unbiased reconstruction is an increase in variance, but for many climate applications the change in mean is a core interest.

  9. Understanding the milk-to-feed price ratio as a proxy for dairy farm profitability.

    Science.gov (United States)

    Wolf, C A

    2010-10-01

    This research examines the definition, historical pattern, and utility of the milk-to-feed price ratio (MF) as a measure of dairy farm profitability. The MF was generally an acceptable proxy of profitability in an annual sense from 1985 to 2006. The MF was steady at an average of 2.8 from 1985 to 2006 even as average annual milk price in nominal terms increased from $12 to $14/hundredweight. An alternative proxy for profitability is income over feed costs, which is measured in dollars per hundredweight. Comparison with an actual profit measure, rate of return on assets, is used to examine the appropriateness of the proxies. The volatility from 2007 to 2009 resulted in MF being a poor measure of profitability over that period. The implication is that MF is not the preferred measure of profitability when a significant change in the pattern of one or both price series occurs. Income over feed cost is a better measure of profitability in periods of volatility. Copyright © 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  10. A Proxy Architecture to Enhance the Performance of WAP 2.0 by Data Compression

    Directory of Open Access Journals (Sweden)

    Yin Zhanping

    2005-01-01

    Full Text Available This paper presents a novel proxy architecture for wireless application protocol (WAP 2.0 employing an advanced data compression scheme. Though optional in WAP 2.0 , a proxy can isolate the wireless from the wired domain to prevent error propagations and to eliminate wireless session delays (WSD by enabling long-lived connections between the proxy and wireless terminals. The proposed data compression scheme combines content compression together with robust header compression (ROHC, which minimizes the air-interface traffic data, thus significantly reduces the wireless access time. By using the content compression at the transport layer, it also enables TLS tunneling, which overcomes the end-to-end security problem in WAP 1.x. Performance evaluations show that while WAP 1.x is optimized for narrowband wireless channels, WAP 2.0 utilizing TCP/IP outperforms WAP 1.x over wideband wireless channels even without compression. The proposed data compression scheme reduces the wireless access time of WAP 2.0 by over 45% in CDMA2000 1XRTT channels, and in low-speed IS-95 channels, substantially reduces access time to give comparable performance to WAP 1.x. The performance enhancement is mainly contributed by the reply content compression, with ROHC offering further enhancements.

  11. A provably secure identity-based strong designated verifier proxy signature scheme from bilinear pairings

    Directory of Open Access Journals (Sweden)

    SK Hafizul Islam

    2014-01-01

    Full Text Available The proxy signature, a variant of the ordinary digital signature, has been an active research topic in recent years; it has many useful applications, including distributed systems and grid computing. Although many identity-based proxy signature schemes have been proposed in the literature, only a few proposals for identity-based strong designated verifier proxy signature (ID-SDVPS schemes are available. However, it has been found that most of the ID-SDVPS schemes that have been proposed to date are not efficient in terms of computation and security, and a computationally efficient and secured ID-SDVPS scheme using elliptic curve bilinear pairing has been proposed in this paper. The security of the scheme is mainly based on the hardness assumption of CDH and GBDH problems in the random oracle model, which is existentially unforgeable against different types of adversaries. Furthermore, the security of our scheme is simulated in the AVISPA (Automated Validation of Internet Security Protocols and Applications software, a widely used automated internet protocol validation tool, and the simulation results confirm strong security against both active and passive attacks. In addition, because of a high processing capability and supporting additional security features, the scheme is suitable for the environments in which less computational cost with strong security is required.

  12. [A case of Munchausen Syndrome by proxy in the context of folie a famille].

    Science.gov (United States)

    Foto Özdemir, Dilşad; Gökler, Bahar; Evinç, Ş Gülin; Balseven Odabaşı, Aysun

    2013-01-01

    The occurrence of similar psychotic symptoms in two or more people is called shared paranoid disorder. In this disease, the person who exhibits psychotic symptoms first is the "primary patient". The symptoms are contracted by the other people through persuasion. This disorder is seen among people who share the same house or are emotionally bound. In some cases, shared paranoid disorder may include other diagnoses, such as Munchausen Syndrome. This report discusses the case of a six-year-old, sexually abused boy who, when admitted to the hospital at the age of 10, claimed to have been repeatedly sexually harassed by several different people. His family's frequent changes in hospitals, negative perceptions of and accusations against medical staff, and improper methods of responding to harassment led clinicians to a diagnosis of Munchausen by proxy syndrome. In addition, both parents believed the abuse story, suggesting a potential diagnosis of shared psychotic disorder. In the literature, Munchausen by proxy has rarely been reported with symptoms of sexual abuse. The psychotic symptoms were shared by the family, complicating the case. This report emphasizes that psychodynamic evaluations of Munchausen by proxy and shared psychotic disorder may be helpful in understanding underlying factors.

  13. Comparing Sunspot Area and Sunspot Number as Proxies for Long-term Solar Irradiance Variation

    Science.gov (United States)

    Jordan, Stuart D.; Garcia, A. G.; Oegerle, William (Technical Monitor)

    2002-01-01

    Because relevant observations from space began only in 1979 with Nimbus-7, it is impossible to correlate direct measurements of small changes in solar irradiance with terrestrial temperature over a number of solar cycles. Yet there is recent evidence that some feature of solar change over a cycle may have a larger influence on climate than would result from merely introducing the additional amount of heat delivered to Earth's atmosphere at solar minimum. It would be useful to check this possibility over several solar cycles. To do this, we would need a sufficiently reliable proxy for irradiance change that at least survives a test against the space observations. Sunspot area is a fairly straightforward parameter to measure, and is associated with the extent of magnetic activity known to correlate strongly with solar irradiance change. We have tested the use of sunspot area as a long-term proxy for solar irradiance change, using observations made at the Coimbra Solar Observatory, from which we obtain both statistically weighted sunspot numbers and sunspot areas over the period 1980-1992. These are both correlated with solar irradiance values measured from Nimbus-7 spacecraft over the same time period, to see if sunspot area offers affords a strong positive correlation and also a distinct advantage over sunspot number as a useful proxy that can then be compared with terrestrial temperature records. Preliminary results yield a positive correlation of 0.71 for sunspot area, but further tests are being conducted and will be reported.

  14. Bivariate spatial analysis of temperature and precipitation from general circulation models and observation proxies

    KAUST Repository

    Philbin, R.

    2015-05-22

    This study validates the near-surface temperature and precipitation output from decadal runs of eight atmospheric ocean general circulation models (AOGCMs) against observational proxy data from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis temperatures and Global Precipitation Climatology Project (GPCP) precipitation data. We model the joint distribution of these two fields with a parsimonious bivariate Matérn spatial covariance model, accounting for the two fields\\' spatial cross-correlation as well as their own smoothnesses. We fit output from each AOGCM (30-year seasonal averages from 1981 to 2010) to a statistical model on each of 21 land regions. Both variance and smoothness values agree for both fields over all latitude bands except southern mid-latitudes. Our results imply that temperature fields have smaller smoothness coefficients than precipitation fields, while both have decreasing smoothness coefficients with increasing latitude. Models predict fields with smaller smoothness coefficients than observational proxy data for the tropics. The estimated spatial cross-correlations of these two fields, however, are quite different for most GCMs in mid-latitudes. Model correlation estimates agree well with those for observational proxy data for Australia, at high northern latitudes across North America, Europe and Asia, as well as across the Sahara, India, and Southeast Asia, but elsewhere, little consistent agreement exists.

  15. Polar Network Index as a Magnetic Proxy for the Solar Cycle Studies

    Science.gov (United States)

    Priyal, Muthu; Banerjee, Dipankar; Karak, Bidya Binay; Muñoz-Jaramillo, Andrés; Ravindra, B.; Choudhuri, Arnab Rai; Singh, Jagdev

    2014-09-01

    The Sun has a polar magnetic field which oscillates with the 11 yr sunspot cycle. This polar magnetic field is an important component of the dynamo process which operates in the solar convection zone and produces the sunspot cycle. We have direct systematic measurements of the Sun's polar magnetic field only from about the mid-1970s. There are, however, indirect proxies which give us information about this field at earlier times. The Ca-K spectroheliograms taken at the Kodaikanal Solar Observatory during 1904-2007 have now been digitized with 4k × 4k CCD and have higher resolution (~0.86 arcsec) than the other available historical data sets. From these Ca-K spectroheliograms, we have developed a completely new proxy (polar network index, hereafter PNI) for the Sun's polar magnetic field. We calculate PNI from the digitized images using an automated algorithm and calibrate our measured PNI against the polar field as measured by the Wilcox Solar Observatory for the period 1976-1990. This calibration allows us to estimate the polar fields for the earlier period up to 1904. The dynamo calculations performed with this proxy as input data reproduce reasonably well the Sun's magnetic behavior for the past century.

  16. Design and implementation of Ad-Hoc collaborative proxying scheme for reducing network energy waste

    Directory of Open Access Journals (Sweden)

    Rafiullah Khan

    2017-05-01

    Full Text Available Network devices are equipped with low power states but they are rarely activated due to their inability of maintaining network connectivity. Recently, Network Connectivity Proxy (NCP concept has been proposed in literature as an effective mechanism to exploit full potential of low power features on network devices by impersonating their virtual presence. However, the NCP concept faces several open issues and challenges especially related to proxying of TCP connections and majority of daily used proprietary closed-source applications. This paper presents a new approach for reducing network energy waste through intelligent collaboration among daily used devices (e.g., desktop computers, laptops, tablets, smartphones, etc. It guarantees to run applications on only and only one user device that is under active use at that specific moment. To reduce energy waste and allow idle devices to sleep, our approach also takes benefit from a light-weight home gateway proxy with very basic practically realizable functionalities. The proposed system not just reduces energy waste of fixed devices but also enables mobile devices to significantly improve their battery life. Our developed software prototypes allow devices to autonomously and seamlessly collaborate with each other without requiring any configuration or user input. Further, this paper also presents the basic performance evaluation of developed prototypes in real networking environments.

  17. Technical Note: Correcting for signal attenuation from noisy proxy data in climate reconstructions

    KAUST Repository

    Ammann, C. M.

    2010-04-20

    Regression-based climate reconstructions scale one or more noisy proxy records against a (generally) short instrumental data series. Based on that relationship, the indirect information is then used to estimate that particular measure of climate back in time. A well-calibrated proxy record(s), if stationary in its relationship to the target, should faithfully preserve the mean amplitude of the climatic variable. However, it is well established in the statistical literature that traditional regression parameter estimation can lead to substantial amplitude attenuation if the predictors carry significant amounts of noise. This issue is known as "Measurement Error" (Fuller, 1987; Carroll et al., 2006). Climate proxies derived from tree-rings, ice cores, lake sediments, etc., are inherently noisy and thus all regression-based reconstructions could suffer from this problem. Some recent applications attempt to ward off amplitude attenuation, but implementations are often complex (Lee et al., 2008) or require additional information, e.g. from climate models (Hegerl et al., 2006, 2007). Here we explain the cause of the problem and propose an easy, generally applicable, data-driven strategy to effectively correct for attenuation (Fuller, 1987; Carroll et al., 2006), even at annual resolution. The impact is illustrated in the context of a Northern Hemisphere mean temperature reconstruction. An inescapable trade-off for achieving an unbiased reconstruction is an increase in variance, but for many climate applications the change in mean is a core interest.

  18. Hospital stay as a proxy indicator for severe injury in earthquakes: a retrospective analysis.

    Science.gov (United States)

    Zhao, Lu-Ping; Gerdin, Martin; Westman, Lina; Rodriguez-Llanes, Jose Manuel; Wu, Qi; van den Oever, Barbara; Pan, Liang; Albela, Manuel; Chen, Gao; Zhang, De-Sheng; Guha-Sapir, Debarati; von Schreeb, Johan

    2013-01-01

    Earthquakes are the most violent type of natural disasters and injuries are the dominant medical problem in the early phases after earthquakes. However, likely because of poor data availability, high-quality research on injuries after earthquakes is lacking. Length of hospital stay (LOS) has been validated as a proxy indicator for injury severity in high-income settings and could potentially be used in retrospective research of injuries after earthquakes. In this study, we assessed LOS as an adequate proxy indicator for severe injury in trauma survivors of an earthquake. A retrospective analysis was conducted using a database of 1,878 injured patients from the 2008 Wenchuan earthquake. Our primary outcome was severe injury, defined as a composite measure of serious injury or resource use. Secondary outcomes were serious injury and resource use, analysed separately. Non-parametric receiver operating characteristics (ROC) and area under the curve (AUC) analysis was used to test the discriminatory accuracy of LOS when used to identify severe injury. An 0.7earthquake survivors. However, LOS was found to be a proxy for major nonorthopaedic surgery and blood transfusion. These findings can be useful for retrospective research on earthquake-injured patients when detailed hospital records are not available.

  19. P/Ca in Gastropod Shells as a Nutrient Proxy in Tropical Marine Environments

    Science.gov (United States)

    Grossman, E. L.; Tao, K.; Robbins, J.; O'Dea, A.

    2013-12-01

    Nutrient status and its stability play key roles in the maintenance of marine ecosystems, both in modern and ancient oceans. Modern coral reef communities in the Caribbean are being threatened by anthropogenic input of nutrients whereas one to two million years ago, communities in this same region experienced dramatic overturn of corals and mollusks with the uplift of the Central American Isthmus and subsequent reduction of upwelling-derived nutrients. Thus the ability to record past and present nutrient delivery is paramount for understanding the role of environmental change in controlling past and future biodiversity. To test trace element chemistries in gastropod shells as nutrient proxies, we measured the trace element (Mg, Sr, Ba, Mn, Fe, P, and U ) and stable isotopic (δ18O, δ13C) compositions of 11 modern Conus specimens collected from upwelling and non-upwelling regions in the Caribbean and Pacific coasts of Panama. Four Caribbean shells represent non-upwelling conditions, while seven Pacific shells record conditions of seasonal upwelling (Gulf of Panama) or shoaling of the thermocline (Gulf of Chiriquí). Shells were serially sampled around the spire at 2-3 mm intervals, providing roughly monthly resolution. Shallow-dwelling Pacific specimens show large seasonal range in δ18O (>2‰) reflecting upwelling during the dry season and freshening during the rainy season. In contrast, shallow-dwelling Caribbean specimens show small δ18O range (mostly ≤1‰) indicating limited seasonal upwelling and freshening. For trace element analyses, about 100 μg of carbonate powder was dissolved in 2 ml of 2% HNO3 and analyzed on a high resolution, inductively-coupled plasma mass spectrometer (HR-ICP-MS). Among the wide array of trace elements analyzed, only Sr/Ca shows a significant correlation with upwelling intervals, as indicated by high δ18O. This reflects the positive relationship between Sr/Ca and temperature in Conus shells (Sosdian et al., 2006, G3, Q11023

  20. Calcareous nannofossil paleofluxes as proxy for pCO2 during the Aptian

    Science.gov (United States)

    Bottini, Cinzia; Erba, Elisabetta; Tiraboschi, Daniele

    2014-05-01

    The Aptian (~121 to ~113 Ma) has been characterized by super-greenhouse climate and profound environmental perturbations, including the early Aptian Oceanic Anoxic Event (OAE 1) a, an episode of widespread organic matter burial in oxygen-depleted oceans. The OAE 1a is thought to be related to the emplacement of the Ontong Java Plateau which probably introduced in the atmosphere a large amount of CO2 with consequent impact on biota, climate and ocean chemistry. The major perturbation of the carbon cycle is mirrored by the carbon isotopic record which shows a negative shift at the beginning of OAE 1a followed by a positive excursion which persisted also after the event. The aim of this study is to reconstruct variations in biogenic carbonate production of calcareous nannofossils through the Aptian in order to detect if and how it has been affected by high pCO2. Calcareous nannoplankton is an excellent proxy for reconstructing present and paste surface water conditions, being extremely sensitive to changes in physical and chemical conditions of the oceans (pH). Calcareous nannoplankton act both as biological and carbonate pump, thus changes in nannoplankton assemblages affect the organic and inorganic carbon cycles. This makes coccolithophores key-organisms for understanding the biological pump and adsorption of atmospheric CO2 into the oceans. Experiments on living coccolithophores indicates that coccolith type, abundance and degree of mineralization depend on chemical-physical-trophic conditions as well as on pCO2. Production of dwarf/malformed coccoliths has been documented in the geological record through OAE 1a. Here we present quantitative analyses of nannofossil micrite in thin sections, reconstructing nannofossil absolute abundances and calcite paleofluxes in three drill sites: the Cismon core (Northern Italy), Piobbico core (Central Italy) and DSDP Site 463 in the mid-Pacific Mountains. In these sites, nannofossil absolute abundances and paleofluxes show a

  1. Flow hydrodynamics near inlet key of Piano Key Weir (PKW)

    Indian Academy of Sciences (India)

    This paper presents fundamental outcomes from an experimental study on the hydrodynamic performance near inlet key of Piano Key Weir (PKW). Hydrodynamic performance was tested in a circulated open channel that comprised of PKW and sand bed (d50 = 0.25 mm). Instantaneous velocities were measured at 20 cross ...

  2. Key to good fit: body measurement problems specific to key ...

    African Journals Online (AJOL)

    In this manner, key dimensions were identified and defined. The results revealed that, although international descriptions are available for 100% of the key measurements, major problems seem to be experienced with landmarking, and with consensus about the measuring method and about landmarking. If one assumes ...

  3. Assessing 5 years of GOSAT Proxy XCH4 data and associated uncertainties

    Directory of Open Access Journals (Sweden)

    R. J. Parker

    2015-11-01

    Full Text Available We present 5 years of GOSAT XCH4 retrieved using the "proxy" approach. The Proxy XCH4 data are validated against ground-based TCCON observations and are found to be of high quality with a small bias of 4.8 ppb (∼ 0.27 % and a single-sounding precision of 13.4 ppb (∼ 0.74 %. The station-to-station bias (ameasure of the relative accuracy is found to be 4.2 ppb. For the first time the XCH4 / XCO2 ratio component of the Proxy retrieval is validated (bias of 0.014 ppb ppm−1 (∼ 0.30 %, single-sounding precision of 0.033 ppb ppm−1 (∼ 0.72 %. The uncertainty relating to the model XCO2 component of the Proxy XCH4 is assessed through the use of an ensemble of XCO2 models. While each individual XCO2 model is found to agree well with the TCCON validation data (r = 0.94–0.97, it is not possible to select one model as the best from our comparisons. The median XCO2 value of the ensemble has a smaller scatter against TCCON (a standard deviation of 0.92 ppm than any of the individual models whilst maintaining a small bias (0.15 ppm. This model median XCO2 is used to calculate the Proxy XCH4 with the maximum deviation of the ensemble from the median used as an estimate of the uncertainty. We compare this uncertainty to the a posteriori retrieval error (which is assumed to reduce with sqrt(N and find typically that the model XCO2 uncertainty becomes significant during summer months when the a posteriori error is at its lowest due to the increase in signal related to increased summertime reflected sunlight. We assess the significance of these model and retrieval uncertainties on flux inversion by comparing the GOSAT XCH4 against modelled XCH4 from TM5-4DVAR constrained by NOAA surface observations (MACC reanalysis scenario S1-NOAA. We find that for the majority of regions the differences are much larger than the estimated uncertainties. Our findings show that useful information will be provided to the inversions for the majority of regions in addition

  4. Assessing 5 years of GOSAT Proxy XCH4 data and associated uncertainties

    Science.gov (United States)

    Parker, R. J.; Boesch, H.; Byckling, K.; Webb, A. J.; Palmer, P. I.; Feng, L.; Bergamaschi, P.; Chevallier, F.; Notholt, J.; Deutscher, N.; Warneke, T.; Hase, F.; Sussmann, R.; Kawakami, S.; Kivi, R.; Griffith, D. W. T.; Velazco, V.

    2015-11-01

    We present 5 years of GOSAT XCH4 retrieved using the "proxy" approach. The Proxy XCH4 data are validated against ground-based TCCON observations and are found to be of high quality with a small bias of 4.8 ppb (∼ 0.27 %) and a single-sounding precision of 13.4 ppb (∼ 0.74 %). The station-to-station bias (ameasure of the relative accuracy) is found to be 4.2 ppb. For the first time the XCH4 / XCO2 ratio component of the Proxy retrieval is validated (bias of 0.014 ppb ppm-1 (∼ 0.30 %), single-sounding precision of 0.033 ppb ppm-1 (∼ 0.72 %)). The uncertainty relating to the model XCO2 component of the Proxy XCH4 is assessed through the use of an ensemble of XCO2 models. While each individual XCO2 model is found to agree well with the TCCON validation data (r = 0.94-0.97), it is not possible to select one model as the best from our comparisons. The median XCO2 value of the ensemble has a smaller scatter against TCCON (a standard deviation of 0.92 ppm) than any of the individual models whilst maintaining a small bias (0.15 ppm). This model median XCO2 is used to calculate the Proxy XCH4 with the maximum deviation of the ensemble from the median used as an estimate of the uncertainty. We compare this uncertainty to the a posteriori retrieval error (which is assumed to reduce with sqrt(N)) and find typically that the model XCO2 uncertainty becomes significant during summer months when the a posteriori error is at its lowest due to the increase in signal related to increased summertime reflected sunlight. We assess the significance of these model and retrieval uncertainties on flux inversion by comparing the GOSAT XCH4 against modelled XCH4 from TM5-4DVAR constrained by NOAA surface observations (MACC reanalysis scenario S1-NOAA). We find that for the majority of regions the differences are much larger than the estimated uncertainties. Our findings show that useful information will be provided to the inversions for the majority of regions in addition to that

  5. Quick, “Imputation-free” meta-analysis with proxy-SNPs

    Directory of Open Access Journals (Sweden)

    Meesters Christian

    2012-09-01

    Full Text Available Abstract Background Meta-analysis (MA is widely used to pool genome-wide association studies (GWASes in order to a increase the power to detect strong or weak genotype effects or b as a result verification method. As a consequence of differing SNP panels among genotyping chips, imputation is the method of choice within GWAS consortia to avoid losing too many SNPs in a MA. YAMAS (Yet Another Meta Analysis Software, however, enables cross-GWAS conclusions prior to finished and polished imputation runs, which eventually are time-consuming. Results Here we present a fast method to avoid forfeiting SNPs present in only a subset of studies, without relying on imputation. This is accomplished by using reference linkage disequilibrium data from 1,000 Genomes/HapMap projects to find proxy-SNPs together with in-phase alleles for SNPs missing in at least one study. MA is conducted by combining association effect estimates of a SNP and those of its proxy-SNPs. Our algorithm is implemented in the MA software YAMAS. Association results from GWAS analysis applications can be used as input files for MA, tremendously speeding up MA compared to the conventional imputation approach. We show that our proxy algorithm is well-powered and yields valuable ad hoc results, possibly providing an incentive for follow-up studies. We propose our method as a quick screening step prior to imputation-based MA, as well as an additional main approach for studies without available reference data matching the ethnicities of study participants. As a proof of principle, we analyzed six dbGaP Type II Diabetes GWAS and found that the proxy algorithm clearly outperforms naïve MA on the p-value level: for 17 out of 23 we observe an improvement on the p-value level by a factor of more than two, and a maximum improvement by a factor of 2127. Conclusions YAMAS is an efficient and fast meta-analysis program which offers various methods, including conventional MA as well as inserting proxy

  6. Quick, "imputation-free" meta-analysis with proxy-SNPs.

    Science.gov (United States)

    Meesters, Christian; Leber, Markus; Herold, Christine; Angisch, Marina; Mattheisen, Manuel; Drichel, Dmitriy; Lacour, André; Becker, Tim

    2012-09-12

    Meta-analysis (MA) is widely used to pool genome-wide association studies (GWASes) in order to a) increase the power to detect strong or weak genotype effects or b) as a result verification method. As a consequence of differing SNP panels among genotyping chips, imputation is the method of choice within GWAS consortia to avoid losing too many SNPs in a MA. YAMAS (Yet Another Meta Analysis Software), however, enables cross-GWAS conclusions prior to finished and polished imputation runs, which eventually are time-consuming. Here we present a fast method to avoid forfeiting SNPs present in only a subset of studies, without relying on imputation. This is accomplished by using reference linkage disequilibrium data from 1,000 Genomes/HapMap projects to find proxy-SNPs together with in-phase alleles for SNPs missing in at least one study. MA is conducted by combining association effect estimates of a SNP and those of its proxy-SNPs. Our algorithm is implemented in the MA software YAMAS. Association results from GWAS analysis applications can be used as input files for MA, tremendously speeding up MA compared to the conventional imputation approach. We show that our proxy algorithm is well-powered and yields valuable ad hoc results, possibly providing an incentive for follow-up studies. We propose our method as a quick screening step prior to imputation-based MA, as well as an additional main approach for studies without available reference data matching the ethnicities of study participants. As a proof of principle, we analyzed six dbGaP Type II Diabetes GWAS and found that the proxy algorithm clearly outperforms naïve MA on the p-value level: for 17 out of 23 we observe an improvement on the p-value level by a factor of more than two, and a maximum improvement by a factor of 2127. YAMAS is an efficient and fast meta-analysis program which offers various methods, including conventional MA as well as inserting proxy-SNPs for missing markers to avoid unnecessary power loss

  7. Clay minerals as palaeomonsoon proxies: Evaluation and relevance to the late Quaternary records from SE Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Thamban, M.; Rao, V.P.

    Palaeoclimatic studies are largely dependent on the quality of records and a prudent use of environmental proxy indicators. In this study, the factors affecting the detrital clay minerals in marine environment and their utility and reliability...

  8. Servidor proxy caché: comprensión y asimilación tecnológica

    Directory of Open Access Journals (Sweden)

    Carlos E. Gómez

    2012-01-01

    Full Text Available Los proveedores de acceso a Internet usualmente incluyen el concepto de aceleradores de Internet para reducir el tiempo promedio que tarda un navegador en obtener los archivos solicitados. Para los administradores del sistema es difícil elegir la configuración del servidor proxy caché, ya que es necesario decidir los valores que se deben usar en diferentes variables. En este artículo se presenta la forma como se abordó el proceso de comprensión y asimilación tecnológica del servicio de proxy caché, un servicio de alto impacto organizacional. Además, este artículo es producto del proyecto de investigación “Análisis de configuraciones de servidores proxy caché”, en el cual se estudiaron aspectos relevantes del rendimiento de Squid como servidor proxy caché.

  9. Interrelations between Three Proxies of Health Care Need at the Small Area Level: An Urban/Rural Comparison

    National Research Council Canada - National Science Library

    S. Barnett; P. Roderick; D. Martin; I. Diamond; H. Wrigley

    2002-01-01

    ...) and socioeconomic characteristics, and 1991-1996 data on all cause premature mortality. The interrelations between the three widely used proxies of health care need are examined using correlation coefficients and scatterplots...

  10. Simple proxies for estimating the concentrations of monoterpenes and their oxidation products at a boreal forest site

    Directory of Open Access Journals (Sweden)

    J. Kontkanen

    2016-10-01

    Full Text Available The oxidation products of monoterpenes likely have a crucial role in the formation and growth of aerosol particles in boreal forests. However, the continuous measurements of monoterpene concentrations are usually not available on decadal timescales, and the direct measurements of the concentrations of monoterpene oxidation product have so far been scarce. In this study we developed proxies for the concentrations of monoterpenes and their oxidation products at a boreal forest site in Hyytiälä, southern Finland. For deriving the proxies we used the monoterpene concentration measured with a proton transfer reaction mass spectrometer (PTR-MS during 2006–2013. Our proxies for the monoterpene concentration take into account the temperature-controlled emissions from the forest ecosystem, the dilution caused by the mixing within the boundary layer and different oxidation processes. All the versions of our proxies captured the seasonal variation of the monoterpene concentration, the typical proxy-to-measurements ratios being between 0.8 and 1.3 in summer and between 0.6 and 2.6 in winter. In addition, the proxies were able to describe the diurnal variation of the monoterpene concentration rather well, especially in summer months. By utilizing one of the proxies, we calculated the concentration of oxidation products of monoterpenes by considering their production in the oxidation and their loss due to condensation on aerosol particles. The concentration of oxidation products was found to have a clear seasonal cycle, with a maximum in summer and a minimum in winter. The concentration of oxidation products was lowest in the morning or around noon and highest in the evening. In the future, our proxies for the monoterpene concentration and their oxidation products can be used, for example, in the analysis of new particle formation and growth in boreal environments.

  11. A New Proxy Measurement Algorithm with Application to the Estimation of Vertical Ground Reaction Forces Using Wearable Sensors

    Directory of Open Access Journals (Sweden)

    Yuzhu Guo

    2017-09-01

    Full Text Available Measurement of the ground reaction forces (GRF during walking is typically limited to laboratory settings, and only short observations using wearable pressure insoles have been reported so far. In this study, a new proxy measurement method is proposed to estimate the vertical component of the GRF (vGRF from wearable accelerometer signals. The accelerations are used as the proxy variable. An orthogonal forward regression algorithm (OFR is employed to identify the dynamic relationships between the proxy variables and the measured vGRF using pressure-sensing insoles. The obtained model, which represents the connection between the proxy variable and the vGRF, is then used to predict the latter. The results have been validated using pressure insoles data collected from nine healthy individuals under two outdoor walking tasks in non-laboratory settings. The results show that the vGRFs can be reconstructed with high accuracy (with an average prediction error of less than 5.0% using only one wearable sensor mounted at the waist (L5, fifth lumbar vertebra. Proxy measures with different sensor positions are also discussed. Results show that the waist acceleration-based proxy measurement is more stable with less inter-task and inter-subject variability than the proxy measures based on forehead level accelerations. The proposed proxy measure provides a promising low-cost method for monitoring ground reaction forces in real-life settings and introduces a novel generic approach for replacing the direct determination of difficult to measure variables in many applications.

  12. He said, she said: The gender wage gap according to self and proxy reports in the Current Population Survey.

    Science.gov (United States)

    Reynolds, Jeremy; Wenger, Jeffrey B

    2012-03-01

    Roughly half the labor force data in the Current Population Survey (CPS) are provided by proxy respondents, and since 1979, men's reliance on proxies has dropped dramatically while women's reliance on proxies has increased. Few authors, however, have examined how combining these first-hand and second-hand reports may influence our understanding of long-term economic trends. We exploit the outgoing rotation group structure of the CPS by matching individual records one year apart, and we find that self-reported wages are higher than proxy-reported wages even after controlling for all time invariant characteristics. Furthermore, we find that changes in the use of proxy respondents by men and women since 1979 have made current estimates of the gender wage gap larger than they would have been without changes in reporting status. This suggests that the gender wage gap has closed more than previously estimated. We recommend that researchers combine self and proxy responses with great care, especially when analyzing time trends or making gender comparisons. Copyright © 2011 Elsevier Inc. All rights reserved.

  13. DECOY STATE QUANTUM KEY DISTRIBUTION

    Directory of Open Access Journals (Sweden)

    Sellami Ali

    2010-03-01

    Full Text Available Experimental weak + vacuum protocol has been demonstrated using commercial QKD system based on a standard bi-directional ‘Plug & Play’ set-up. By making simple modifications to a commercial quantum key distribution system, decoy state QKD allows us to achieve much better performance than QKD system without decoy state in terms of key generation rate and distance. We demonstrate an unconditionally secure key rate of 6.2931 x 10-4per pulse for a 25 km fiber length.

  14. Spatial Variables as Proxies for Modelling Cognition and Decision-Making in Archaeological Settings: A Theoretical Perspective

    Directory of Open Access Journals (Sweden)

    Thomas G. Whitley

    2004-11-01

    Full Text Available In recent years there has been a flourish of archaeological studies focusing on prehistoric cognition or motivation on the basis of GIS-generated interpretations. These have taken two very different forms on either side of the Atlantic. In the empirically driven positivist community of North American researchers, Cultural Resource Management (CRM projects have created a tendency toward using GIS-based archaeological data in the context of so-called 'predictive modelling', or within typically large-scale interpretations of environmental motivations for settlement. This perspective has its origins in the nature of the North American archaeological record, and the development and dominance of processualism. In contrast, the highly complex European archaeological record and the influence of both post-processualism and landscape forms of archaeology have led to a European focus on using GIS as a tool for reconstructing social and cognitive landscapes. Most frequently this has been in the form of visibility and viewshed analyses of henge-type monuments, hill fortifications and their surrounding landscapes. The disconnect between these two dichotomous traditions suggests on the one hand that North American approaches could benefit from methods that generate a more enriching discussion of agency and social theory, while European approaches could benefit from a less speculative form of epistemological argumentation. These ideas may come together through the use of an enhanced discussion of explanation and causality (in keeping with developments in the history and philosophy of science and key tools such as the use of spatial variables as proxies for cognitive decision-making and social agency.

  15. Multi-proxy paleoenvironmental reconstruction of saline lake carbonates: Paleoclimatic and paleogeographic implications (Priabonian-Rupelian, Issirac Basin, SE France)

    Science.gov (United States)

    Lettéron, Alexandre; Fournier, François; Hamon, Youri; Villier, Loïc; Margerel, Jean-Pierre; Bouche, Alexandre; Feist, Monique; Joseph, Philippe

    2017-08-01

    A 200-m thick carbonate succession has been deposited in shallow-water, saline lake environments during the Priabonian-Rupelian in the Issirac Basin (South-East France). The palaeoenvironmental and palaeogeographic significance of such saline lake carbonates has been characterized on the basis of a multi-proxy analysis including 1) depositional and diagenetic features, 2) biological components (molluscs, ostracods, benthic foraminifers, characean) and 3) carbon, oxygen and strontium stable isotopes. Biological associations are indicative of dominantly shallow (cycles of lake transgression, corresponding to the three main sedimentary units (U1, U2 and U3). Relative lake-level, degree of connectivity with surrounding lakes and climate (dry versus humid) are the three key factors controlling the water composition, carbonate production and depositional environments in the Issirac lake. Although the ASCI (Alès-Issirac-Saint-Chaptes) lacustrine system likely represents an athalassic (inland) lake system evolving through times, the stable isotope composition (C, O and Sr) of carbonates strongly suggests the occurrence of transient connections of the ASCI lake water with water bodies influenced by seawater and/or fed with sulfates deriving from Triassic evaporites. The Issirac Basin may be therefore interpreted as a sill area connecting the ASCI lacustrine system with the Rhône valley (Mormoiron and Valence) saline lake systems during maximum flooding periods. Finally, changes in depositional features, biota and stable isotope composition of carbonates in unit U3 suggest a transition from relatively dry to more humid climate during the uppermost Priabonian or earliest Rupelian.

  16. Key Injury and Violence Data

    Science.gov (United States)

    ... Traumatic Brain Injury Violence Prevention Key Injury and Violence Data Recommend on Facebook Tweet Share Compartir Injuries ... of death among persons 1-44. Injury- and violence-related deaths are only part of the problem ...

  17. Key economic sectors and services

    NARCIS (Netherlands)

    Arent, Douglas J.; Tol, Richard S.J.; Faust, Eberhard; Hella, Joseph P.; Kumar, Surender; Strzepek, Kenneth M.; Tóth, Ferenc L.; Yan, Denghua; Abdulla, Amjad; Kheshgi, Haroon; Xu, He; Ngeh, Julius

    2015-01-01

    Introduction and Context This chapter discusses the implications of climate change on key economic sectors and services, for example, economic activity. Other chapters discuss impacts from a physical, chemical, biological, or social perspective. Economic impacts cannot be isolated; therefore, there

  18. Algorithms for Lightweight Key Exchange.

    Science.gov (United States)

    Alvarez, Rafael; Caballero-Gil, Cándido; Santonja, Juan; Zamora, Antonio

    2017-06-27

    Public-key cryptography is too slow for general purpose encryption, with most applications limiting its use as much as possible. Some secure protocols, especially those that enable forward secrecy, make a much heavier use of public-key cryptography, increasing the demand for lightweight cryptosystems that can be implemented in low powered or mobile devices. This performance requirements are even more significant in critical infrastructure and emergency scenarios where peer-to-peer networks are deployed for increased availability and resiliency. We benchmark several public-key key-exchange algorithms, determining those that are better for the requirements of critical infrastructure and emergency applications and propose a security framework based on these algorithms and study its application to decentralized node or sensor networks.

  19. An entrepreneurial key competencies’ model

    National Research Council Canada - National Science Library

    Arafeh, Labib

    2016-01-01

    ... worldwide.Furthermore, the paper proposes a softcomputing-based entrepreneurial key competencies’ model (SKECM). This tool is capable of predicting/judging the overall quality of entrepreneurial competencies...

  20. Rare earth elements in Holocene reefal microbialites: a new shallow seawater proxy

    Science.gov (United States)

    Webb, Gregory E.; Kamber, Balz S.

    2000-05-01

    The concentration of rare earth elements and yttrium (REE + Y) was determined in Holocene Mg-calcite microbialites from shallow reef framework cavities at Heron Reef, Great Barrier Reef. Shale-normalized REE + Y patterns of 52 microbialite samples show: (1) uniform heavy REE enrichment (Nd SN/Yb SN = 0.236, SD = 0.026); (2) consistent negative Ce and positive La anomalies; (3) marine Y/Ho ratios (56.17, SD = 2.66); and (4) slightly positive Gd anomalies. All of these features are consistent with the geochemistry of well-oxygenated, shallow ambient seawater. REE partition coefficients were calculated relative to shallow Coral Sea seawater. They are uniform (relative SD = 10.2%) across the entire mass range and almost two orders of magnitude higher than those between coral and seawater. Hence, terrigenous detritus-free, modern microbialites are a more reliable proxy for seawater REE chemistry than are skeletal carbonates. Ancient limestones have been considered largely problematic as sources for REE proxies owing to perceived problems with diagenesis, partly on the basis of relatively high REE concentrations in some limestones compared to modern skeletal carbonates. However, high REE concentrations in modern microbialites suggest that ancient limestones with relatively high REE concentrations, if not contaminated by terrigenous detritus, may reflect original seawater chemistry. Terrigenous contamination, if present, is readily detectable on the basis of co-occurring trace element concentrations (Sc, Hf, Th) and Y/Ho ratio. Hence, ancient, particularly reefal, limestones may provide reliable seawater REE proxies. The occurrence of microbialites in clean limestones as old as 3.5 Ga suggests the possibility of reconstructing shallow marine REE chemistry over most of Earth history with important implications for paleogeography and paleoredox studies.

  1. [Self-medication, self-prescription and medicating «by proxy» in paediatrics].

    Science.gov (United States)

    Valenzuela Ortiz, María; Sánchez Ruiz-Cabello, Francisco Javier; Uberos, José; Checa Ros, Ana Fátima; Valenzuela Ortiz, Cristina; Augustín Morales, María Carmen; Muñoz Hoyos, Antonio

    2017-05-01

    Self-prescribing or medicating 'by proxy' is not an autonomous, free and voluntary decision in the case of children. On the contrary, in this case it is based on the subjective interpretation of symptoms made by the mother or by a third person who is legally responsible for the minor. In our opinion, to analyse this situation is of great importance in order to know the determining factors, perceptions, and realities related to this problem. Our proposal is to perform a prospective observational study for analysing maternal and familiar determinant factors related to self-prescribing and self-medicating 'by proxy' in paediatrics. A validated survey was developed to be applied to mothers of children aged 0 to 14 who are users of the Paediatric Emergency Department in a hospital. A total of 1,714 mothers were recruited in a random period of time. This sample included 345 mothers who exclusively self-medicated their children (case group), and 1,369 mothers (control group) who did not meet this requirement. The overall percentage of medicating 'by proxy' was 32.8%. There is a significant association between self-medicating and educational level of the mother, the number of children, and the birth order among siblings. Neither maternal age nor social-occupational level are related to this problem. Most frequently used drugs include antipyretics and 'anticatharrals', usually administered as a monotherapy. Our results seem to indicate that the educational level and the parental experience acquired with previous children could generate the required confidence in parents to choose the medication by themselves. Almost 85% of these drugs come from the 'home first-aid kit.' Copyright © 2016 Asociación Española de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

  2. Impact of prehistoric cooking practices on paleoenvironmental proxies in shell midden constituents

    Science.gov (United States)

    Müller, Peter; Staudigel, Philip; Murray, Sean T.; Westphal, Hildegard; Swart, Peter K.

    2016-04-01

    Paleoenvironmental proxy records such as oxygen isotopes of calcareous skeletal structures like fish otoliths or mollusk shells provide highest-resolution information about environmental conditions experienced by the organism. Accumulations of such skeletal structures by ancient coastal populations in so called "shell midden" deposits provide us with sub-seasonally resolved paleoclimate records covering time spans up to several millennia. Given their high temporal resolution, these deposits are increasingly used for paleoclimate reconstructions and complement our understanding of ancient climate changes. However, gathered as comestibles, most of these skeletal remains were subject to prehistoric cooking methods prior to deposition. The associated alteration of the chemical proxy signatures as well as the subsequent error for paleoenvironmental reconstructions remained almost entirely neglected so far. Here, we present clumped isotope, conventional oxygen and carbon isotopes as well as element:Ca ratios measured in modern bivalve shells after exposing them to different prehistoric cooking methods. Our data show that most cooking methods considerably alter commonly used paleoclimate proxy systems which can lead to substantial misinterpretations of ancient climate conditions. Since the magnitude of chemical alteration is not distinguishable from natural temperature variability in most coastal settings, the alteration of shell midden constituents by prehistoric cooking remains likely unnoticed in most cases. Thus, depending on the cooking method, pre-depositional heating might have introduced considerable errors into previous paleoclimate studies. However, our data also show that clumped isotope thermometry represents a suitable diagnostic tool to detect such pre-depositional cooking events and also allows differentiating between the most commonly applied prehistoric cooking methods.

  3. Geochemical proxies of North American freshwater routing during the Younger Dryas cold event.

    Science.gov (United States)

    Carlson, Anders E; Clark, Peter U; Haley, Brian A; Klinkhammer, Gary P; Simmons, Kathleen; Brook, Edward J; Meissner, Katrin J

    2007-04-17

    The Younger Dryas cold interval represents a time when much of the Northern Hemisphere cooled from approximately 12.9 to 11.5 kiloyears B.P. The cause of this event, which has long been viewed as the canonical example of abrupt climate change, was initially attributed to the routing of freshwater to the St. Lawrence River with an attendant reduction in Atlantic meridional overturning circulation. However, this mechanism has recently been questioned because current proxies and dating techniques have been unable to confirm that eastward routing with an increase in freshwater flux occurred during the Younger Dryas. Here we use new geochemical proxies (DeltaMg/Ca, U/Ca, and (87)Sr/(86)Sr) measured in planktonic foraminifera at the mouth of the St. Lawrence estuary as tracers of freshwater sources to further evaluate this question. Our proxies, combined with planktonic delta(18)O(seawater) and delta(13)C, confirm that routing of runoff from western Canada to the St. Lawrence River occurred at the start of the Younger Dryas, with an attendant increase in freshwater flux of 0.06 +/- 0.02 Sverdrup (1 Sverdrup = 10(6) m(3).s(-1)). This base discharge increase is sufficient to have reduced Atlantic meridional overturning circulation and caused the Younger Dryas cold interval. In addition, our data indicate subsequent fluctuations in the freshwater flux to the St. Lawrence River of approximately 0.06-0.12 Sverdrup, thus explaining the variability in the overturning circulation and climate during the Younger Dryas.

  4. How do roots alter signals of molecular proxies in terrestrial archives?

    Science.gov (United States)

    Wiesenberg, G. L.; Gocke, M. I.

    2016-12-01

    Terrestrial archives such as sediment-paleosol sequences and recent soil profiles have been frequently used for environmental and paleoenvironmental studies. One prominent tool is the use of molecular proxies from the lipid fraction due to their relative persistence and their well known suitability to trace paleoenvironmental developments as well as human activities. However, excavations of sediment-paleosol sequences often reveal the presence of roots or biopores that might have been formed during any later stage of pedogenesis or sediment accumulation, potentially altering the signal of molecular proxies. In the current study, we compile recent soils and paleosols as well as several meter thick sediment-paleosol sequences in order to trace the influence by post-pedogenic/sedimentary root penetration on molecular composition. Therefore, we documented root frequencies during field sampling campaigns and collected root (remains) with their surrounding material to assess the extension of root-derived overprint. While only suberin analysis enables identification of root-derived biomass in the vicinity of living or ancient roots, other biomarkers such as alkanes and fatty acids can derive from the primary vegetation and are commonly assumed to be only aboveground litter-derived. Further, miroorganisms and root-derived biomass contribute to lipid assemblage in soils and sediments. Therefore, their source identification and attribution to root-origin is more difficult, as also promoted degradation in the vicinity of roots can alter the biomarker signal. In the surrounding of visible root remains, we could identify root-derived overprint of up to >8cm distance, whereas this is mainly attributed to finer side roots around visible root remains. Furthermore, alteration can strongly overprint the sedimentary signal due to long-lasting overprint, especially in nutrient-rich horizons, such as paleosols. To enable proper paleoenvironmental reconstructions in terrestrial

  5. Organic molecules in the polar ice: from chemical analysis to environmental proxies

    Science.gov (United States)

    Barbante, Carlo; Zennaro, Piero; Giorio, Chiara; Kehrwald, Natalie; Benton, Alisa K.; Wolff, Eric W.; Kalberer, Markus; Kirchgeorg, Torben; Zangrando, Roberta; Barbaro, Elena; Gambaro, Andrea

    2015-04-01

    The molecular and isotopic compositions of organic matter buried in ice contains information that helps reconstruct past environmental conditions, evaluate histories of climate change, and assess impacts of humans on ecosystems. In recent years novel analytical techniques were developed to quantify molecular compounds in ice cores. As an example, biomass burning markers, including monosaccharide anhydrides, lightweight carboxylic acids, lignin and resin pyrolysis products, black carbon, and charcoal records help in reconstructing past fire activity across seasonal to millennial time scales. Terrestrial biomarkers, such as plant waxes (e.g. long-chain n-alkanes) are also a promising paleo vegetation proxy in ice core studies. Polycyclic aromatic hydrocarbons are ubiquitous pollutants recently detected in ice cores. These hydrocarbons primarily originate from incomplete combustion of organic matter and fossil fuels (e.g. diesel engines, domestic heating, industrial combustion) and therefore can be tracers of past combustion activities. In order to be suitable for paloeclimate purposes, organic molecular markers detected in ice cores should include the following important features. Markers have to be stable under oxidizing atmospheric conditions, and ideally should not react with hydroxyl radicals, during their transport to polar regions. Organic markers must be released in large amounts in order to be detected at remote distances from the sources. Proxies must be specific, in order to differentiate them from other markers with multiple sources. The extraction of glaciochemical information from ice cores is challenging due to the low concentrations of some impurities, thereby demanding rigorous control of external contamination sources and sensitive analytical techniques. Here, we review the analysis and use of organic molecules in ice as proxies of important environmental and climatic processes.

  6. Towards a new proxy of continental atmospheric humidity: the triple oxygen isotopic composition of plant biosilica

    Science.gov (United States)

    Alexandre, A. E.; Pauchet, S.; Landais, A.; Piel, C.; Devidal, S.; Roy, J.; Vallet-Coulomb, C.; Sonzogni, C.; Pasturel, M.; Cornuault, P.; Xin, J.; Mazur, J. C.; Prie, F.; Bentaleb, I.

    2016-12-01

    There is a serious lack of proxy suitable for reconstructing, in a quantitative way, past changes of continental atmospheric humidity. This reduces the possibility to make model-data comparisons necessary for the implementation of climate models. Over the past 10 years, analytical developments have enabled a few laboratories to reach sufficient precision for measuring the triple oxygen isotopes, expressed by the 17O-excess, in water, water vapor, atmospheric oxygen, and minerals. The 17O-excess represents an alternative to d-excess for investigating relative humidity conditions that prevail during water evaporation. The 17O-excess of water results from the increase of kinetic isotopic fractionation at evaporative sites as a function of decreasing relative humidity. This mechanism occurs at large scales, i.e. during seawater evaporation or during plant canopies transpiration. Unlike deuterium-excess, 17O-excess is supposed to be insensitive to temperature and less sensitive than δD and δ18O to equilibrium fractionation during transport and precipitation. Additionally, the 17O-excess is recorded in biogenic minerals less prone to weathering than organic compounds. Here, we calibrate the 17O-excess of plant biosilica as a new air humidity proxy. First, we examined the behavior of the 17O-excess in soil water, leaf water and phytoliths in growth chambers in response to changes in relative humidity. Second, we measured the 17O-excess of soil phytolith assemblages from inter-tropical savannas and forests distributed along humidity transects. Both approaches show similar dependency of phytolith 17O-excess to relative humidity. The results allow to discuss future calibration directions aimed at estimating the precision of the obtained relationship and at quantifying the successive isotopic fractionations in play at the soil-plant-atmosphere interface, to provide a strong proxy of past atmospheric relative humidity.

  7. An Enhanced Multihoming Support Scheme with Proxy Mobile IPv6 for Convergent Networks

    Science.gov (United States)

    Li, Yang; Kum, Dong-Won; Kang, Ju-Eun; Cho, You-Ze

    This paper analyzes the limitations of the multihoming support in the Proxy Mobile IPv6 protocol, then proposes an enhanced multihoming support scheme based on a per-interface address configuration method. The proposed scheme can provide a more flexible multihoming support and also maintain application session continuity during a handoff between two interfaces by using IPv6 extension headers. Plus, flow distribution with filters is also used to realize the advantages of multihoming. Simulation results with the OPNET validate the proposed multihoming support scheme for convergent networks.

  8. Improving age-depth models using sedimentary proxies for accumulation rates in fluvio-lacustrine deposits

    Science.gov (United States)

    Minderhoud, Philip S. J.; Cohen, Kim M.; Toonen, Willem. H. J.; Erkens, Gilles; Hoek, Wim Z.

    2017-04-01

    Lacustrine fills, including those of oxbow lakes in river floodplains, often hold valuable sedimentary and biological proxy records of palaeo-environmental change. Precise dating of accumulated sediments at levels throughout these records is crucial for interpretation and correlation of (proxy) data existing within the fills. Typically, dates are gathered from multiple sampled levels and their results are combined in age-depth models to estimate the ages of events identified between the datings. In this paper, a method of age-depth modelling is presented that varies the vertical accumulation rate of the lake fill based on continuous sedimentary data. In between Bayesian calibrated radiocarbon dates, this produces a modified non-linear age-depth relation based on sedimentology rather than linear or spline interpolation. The method is showcased on a core of an infilled palaeomeander at the floodplain edge of the river Rhine near Rheinberg (Germany). The sequence spans from 4.7 to 2.9 ka cal BP and consists of 5.5 meters of laminated lacustrine, organo-clastic mud, covered by 1 meter of peaty clay. Four radiocarbon dates provide direct dating control, mapping and dating in the wider surroundings provide additional control. The laminated, organo-clastic facies of the oxbow fill contains a record of nearby fluvial-geomorphological activity, including meander reconfiguration events and passage of rare large floods, recognized as fluctuations in coarseness and amount of allochthonous clastic sediment input. Continuous along-core sampling and measurement of loss-on-ignition (LOI) provided a fast way of expressing the variation in clastic sedimentation influx from the nearby river versus autochthonous organic deposition derived from biogenic production in the lake itself. This low-cost sedimentary proxy data feeds into the age-depth modelling. The sedimentology-modelled age-depth relation (re)produces the distinct lithological boundaries in the fill as marked changes in

  9. Munchausen syndrome and Munchausen syndrome by proxy in a student nurse.

    Science.gov (United States)

    Yonge, Olive; Haase, Mary

    2004-01-01

    Most faculty are not prepared for the possibility of encountering Munchausen syndrome (MS) in nursing students and Munchausen syndrome by proxy (MSP) in nursing students' children. When confronted with MS or MSP, their first reaction is often hostility coupled with a sense of betrayal. Given that individuals with this condition are attracted to helping professions, the authors describe both conditions in a case in which a nursing student presented with MS and the student's daughter was a victim of MSP. The focus is on protection of any children and the public, psychiatric treatment for the offender, and assistance for faculty.

  10. A case with unexplained bleeding from multiple sites: munchausen syndrome by proxy.

    Science.gov (United States)

    Tüfekçi, Özlem; Gözmen, Salih; Yılmaz, Şebnem; Hilkay Karapınar, Tuba; Çetin, Benhur; Burak Dursun, Onur; Emiroğlu, Neslihan; Ören, Hale; Irken, Gülersu

    2011-08-01

    Munchausen syndrome by proxy (MBP) is an extreme form of child abuse where children were unnecessarily treated or investigated for medical conditions that were falsified by their caregivers. Here the authors report a 16-year-old female with the complaints of bleeding from multiple and unusual sites, including hemoptysis, hematuria, bloody tears, and bloody nipple discharge, all of which are only witnessed by her mother. Extensive investigation revealed no organic etiologies for bleeding. The diagnosis of MBP was put by a multidisciplinary team. The diagnosis of MBP must be kept in mind in conditions where there is no underlying organic pathology in a bleeding patient.

  11. The role of nonperpetrating fathers in Munchausen syndrome by proxy: a review of the literature.

    Science.gov (United States)

    Morrell, Briyana; Tilley, Donna Scott

    2012-08-01

    Munchausen syndrome by proxy (MSBP) is a psychiatric condition and form of child abuse in which a caregiver, usually a mother, induces illness in a child to gain attention for herself. Because children that are abused by a MSBP perpetrator are likely to be hospitalized multiple times, it is important for the nurse to know warning signs and symptoms of MSBP. Of particular interest is the role of the child's parent that is not involved in the abuse, usually the father. This article presents a review of literature on MSBP, focusing on the role of the nonperpetrating fathers. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. [Fortuitous discovery of intracerebral foreign body leads to the diagnosis of Munchausen syndrome by proxy].

    Science.gov (United States)

    Bouaziz Abed, A; Mustapha, R; Chiha, M

    2011-11-01

    An intracerebral foreign body is a rare situation in childhood. It often occurs accidentally with transorbital or more rarely transnasal penetration. We report the case of a child who had been followed since the age of 2.5 months for chronic vomiting without failure to thrive. The fortuitous discovery at 22 months of age of a 4.5-cm-long sewing needle in his brain probably introduced via the fontanel led us to the diagnosis of Munchausen syndrome by proxy. Copyright © 2011. Published by Elsevier SAS.

  13. Combined effect of carbonate and biotite dissolution in landslides biases silicate weathering proxies

    Science.gov (United States)

    Emberson, R.; Galy, A.; Hovius, N.

    2017-09-01

    Long-term estimates of the dissolution of silicate rock are generally derived from a range of isotopic proxies, such as the radiogenic strontium isotope ratio (87Sr/86Sr), which are preserved in sediment archives. For these systems to fairly represent silicate weathering, the changes in isotopic ratios in terrestrial surface waters should correspond to changes in the overall silicate dissolution. This assumes that the silicate mineral phases that act as sources of a given isotope dissolve at a rate that is proportional to the overall silicate weathering. Bedrock landsliding exhumes large quantities of fresh rock for weathering in transient storage, and rapid weathering in these deposits is controlled primarily by dissolution of the most reactive phases. In this study, we test the hypothesis that preferential weathering of these labile minerals can decouple the dissolution of strontium sources from the actual silicate weathering rates in the rapidly eroding Western Southern Alps (WSA) of New Zealand. We find that rapid dissolution of relatively radiogenic calcite and biotite in landslides leads to high local fluxes in strontium with isotopic ratios that offer no clear discrimination between sources. These higher fluxes of radiogenic strontium are in contrast to silicate weathering rates in landslides that are not systematically elevated. On a mountain belt scale, radiogenic strontium fluxes are not coupled to volumes of recent landslides in large (>100 km2) catchments, but silicate weathering fluxes are. Such decoupling is likely due first to the broad variability in the strontium content of carbonate minerals, and second to the combination of radiogenic strontium released from both biotite and carbonate in recent landslides. This study supports previous work suggesting the limited utility of strontium isotopes as a system to study silicate weathering in the WSA. Crucially however, in settings where bedrock landsliding is a dominant erosive process there is

  14. Mid-late Holocene climate, demography, and cultural dynamics in Iberia: A multi-proxy approach

    Science.gov (United States)

    Lillios, Katina T.; Blanco-González, Antonio; Drake, Brandon Lee; López-Sáez, José Antonio

    2016-03-01

    Despite increasing interest in the relationship between culture transformation and abrupt climate change, their complexities are poorly understood. The local impact of global environmental fluctuations depends on multiple factors, and their effects on societal collapse are often assumed rather than demonstrated. One of the major changes in west European later prehistory was the Copper to Bronze Age transition, contemporaneous with the 4.2 ky cal. BP event. This article offers a multi-dimensional insight into this historical process in the Iberian Peninsula from a multi-proxy and comparative perspective. Three study areas, representative of diverse ecological settings and historical trajectories, are compared. Using radiocarbon dates, 13C discrimination (Δ13C) values on C3 plants, and high-resolution palynological records as palaeoclimatic and palaeodemographic proxies, this study tracks the uneven signals of Holocene climate. The wettest Northwest region features the most stable trend lines, whereas the Southwest exhibits an abrupt decrease in its demographic signals c. 4500 cal. BP, which is then followed by a subsequent rise in the neighbouring Southeast. These lines of evidence suggest the possibility, never previously noted, of demic migration from the Southwest to the Southeast in the Early Bronze Age as a contributing factor to the cultural dynamics of southern Iberia.

  15. Territory occupancy and parental quality as proxies for spatial prioritization of conservation areas.

    Directory of Open Access Journals (Sweden)

    Matthias Tschumi

    Full Text Available In order to maximize their fitness, individuals aim at choosing territories offering the most appropriate combination of resources. As population size fluctuates in time, the frequency of breeding territory occupancy reflects territory quality. We investigated the relationships between the frequency of territory occupancy (2002-2009 vs. habitat characteristics, prey abundance, reproductive success and parental traits in hoopoes Upupa epops L., with the objective to define proxies for the delineation of conservation priority areas. We predicted that the distribution of phenotypes is despotic and sought for phenotypic characteristics expressing dominance. Our findings support the hypothesis of a despotic distribution. Territory selection was non-random: frequently occupied territories were settled earlier in the season and yielded higher annual reproductive success, but the frequency of territory occupancy could not be related to any habitat characteristics. Males found in frequently occupied territories showed traits expressing dominance (i.e. larger body size and mass, and older age. In contrast, morphological traits of females were not related to the frequency of territory occupancy, suggesting that territory selection and maintenance were essentially a male's task. Settlement time in spring, reproductive success achieved in a given territory, as well as phenotypic traits and age of male territory holders reflected territory quality, providing good proxies for assessing priority areas for conservation management.

  16. Is profitability a good proxy for efficiency? Evidence from the subsector of tour operators

    Directory of Open Access Journals (Sweden)

    Hedija Veronika

    2017-12-01

    Full Text Available The goal of the paper is to evaluate the economic efficiency of tour operators in the Czech Republic in the period 2007-2014 using data envelopment analysis (DEA models and prove the link between economic efficiency and profitability and to find out if profitability is a good proxy for economic efficiency. Data was exported from the database Albertina CZ Gold Edition. We calculated the efficiency score using CCR (Charnes, Cooper and Rhodes and BCC (Banker, Charnes and Cooper models based on 3 inputs and 1 output. In the years 2007 to 2010, the efficiency score of almost all the companies was higher than 0.5; however, in years since 2011, we revealed significant differences in the efficiency of individual firms and only about 40 percent of tour operators achieved an efficiency score higher than 0.5. Using Pearson and Spearman correlation coefficients, our findings show that, in the case of the Czech tour operator market, profitability ratios do not correspond with firm efficiency. Profitability ratios are not a good proxy for economic efficiency and should not be used as the only firm criterion of performance.

  17. Surrogate taxa and fossils as reliable proxies of spatial biodiversity patterns in marine benthic communities.

    Science.gov (United States)

    Tyler, Carrie L; Kowalewski, Michał

    2017-03-15

    Rigorous documentation of spatial heterogeneity (β-diversity) in present-day and preindustrial ecosystems is required to assess how marine communities respond to environmental and anthropogenic drivers. However, the overwhelming majority of contemporary and palaeontological assessments have centred on single higher taxa. To evaluate the validity of single taxa as community surrogates and palaeontological proxies, we compared macrobenthic communities and sympatric death assemblages at 52 localities in Onslow Bay (NC, USA). Compositional heterogeneity did not differ significantly across datasets based on live molluscs, live non-molluscs, and all live organisms. Death assemblages were less heterogeneous spatially, likely reflecting homogenization by time-averaging. Nevertheless, live and dead datasets were greater than 80% congruent in pairwise comparisons to the literature estimates of β-diversity in other marine ecosystems, yielded concordant bathymetric gradients, and produced nearly identical ordinations consistently delineating habitats. Congruent estimates from molluscs and non-molluscs suggest that single groups can serve as reliable community proxies. High spatial fidelity of death assemblages supports the emerging paradigm of Conservation Palaeobiology. Integrated analyses of ecological and palaeontological data based on surrogate taxa can quantify anthropogenic changes in marine ecosystems and advance our understanding of spatial and temporal aspects of biodiversity. © 2017 The Author(s).

  18. Conflicts in Africa and Major Powers: Proxy Wars, Zones of Influence or Provocative Instability

    Directory of Open Access Journals (Sweden)

    Jerry Rowlings Tafotie

    2016-12-01

    Full Text Available The article analyses the different nature of conflicts that have occurred in Africa since the end of Cold War. A special attention is given to the role of external factors in the process of conflict evolution and the escalation of violence on the African continent. In effect, this paper demonstrates through a critical examination of the meaning of proxy war as, zone of influence or provocation of instability as a strategy and an analysis of its employment by the United States and China, France etc. in Africa. The new potential confrontation between the United States and China as in Sudan, France in its former coloniesis not only based on a clash of world views about the structure and nature of international relations and security but largely over the control of strategically vital energy resources based in Africa. The authors conclude that this ultimately creates permanent tensions or bitter conflicts between the actors and African populations as a factor that have negative impact on the peace and stability of continent. According to the context of superpower conflict strategies, this paper critically examines, zone of influence, provoking of instability or proxy war as a viable national strategy of nuclear armed great powers in advancing and/or defending their global national interests in a bipolar/multipolar international system.

  19. Planktonic foraminiferal rare earth elements as a potential new aeolian dust proxy

    Science.gov (United States)

    Chou, C.; Liu, Y.; Lo, L.; Wei, K.; Shen, C.

    2012-12-01

    Characteristics of rare earth elements (REEs) have widely been used as important tracers in many fields of earth sciences, including lithosphere research, environmental change, ocean circulation and other natural carbonate materials. Foraminiferal test REE signatures have been suggested to reflect ambient seawater conditions and serve as valuable proxies in the fields of paleoceanography and paleoclimate. Here we present a 60-kyr planktonic foraminifera Globigerinoides ruber (white, 250-300 μm) REE record of a sediment core MD05-2925 (9°20.61'S, 151°27.61'E, water depth 1660 m) from the Solomon Sea. The REE diagram shows two dominant sources of local seawater and nearby terrestrial input. The variability of foraminiferal REE/Ca time series is different from Mg/Ca-inferred sea surface temperature and δ18O records during the past 60-kyr. This inconsistency suggests that planktonic foraminiferal REE content cannot result only from changes in ice volume and temperature. Synchroneity between high planktonic foraminiferal REE content and Antarctic ice core dust amount record implies the same dust sources, probably from Australia or mainland China. Our results suggest that foraminiferal REE can potentially be as a new dust proxy and record dry/humid conditions at the source area.

  20. Territory occupancy and parental quality as proxies for spatial prioritization of conservation areas.

    Science.gov (United States)

    Tschumi, Matthias; Schaub, Michael; Arlettaz, Raphaël

    2014-01-01

    In order to maximize their fitness, individuals aim at choosing territories offering the most appropriate combination of resources. As population size fluctuates in time, the frequency of breeding territory occupancy reflects territory quality. We investigated the relationships between the frequency of territory occupancy (2002-2009) vs. habitat characteristics, prey abundance, reproductive success and parental traits in hoopoes Upupa epops L., with the objective to define proxies for the delineation of conservation priority areas. We predicted that the distribution of phenotypes is despotic and sought for phenotypic characteristics expressing dominance. Our findings support the hypothesis of a despotic distribution. Territory selection was non-random: frequently occupied territories were settled earlier in the season and yielded higher annual reproductive success, but the frequency of territory occupancy could not be related to any habitat characteristics. Males found in frequently occupied territories showed traits expressing dominance (i.e. larger body size and mass, and older age). In contrast, morphological traits of females were not related to the frequency of territory occupancy, suggesting that territory selection and maintenance were essentially a male's task. Settlement time in spring, reproductive success achieved in a given territory, as well as phenotypic traits and age of male territory holders reflected territory quality, providing good proxies for assessing priority areas for conservation management.

  1. Design and Implementation of a Mobile Voting System Using a Novel Oblivious and Proxy Signature

    Directory of Open Access Journals (Sweden)

    Shin-Yan Chiou

    2017-01-01

    Full Text Available Electronic voting systems can make the voting process much more convenient. However, in such systems, if a server signs blank votes before users vote, it may cause undue multivoting. Furthermore, if users vote before the signing of the server, voting information will be leaked to the server and may be compromised. Blind signatures could be used to prevent leaking voting information from the server; however, malicious users could produce noncandidate signatures for illegal usage at that time or in the future. To overcome these problems, this paper proposes a novel oblivious signature scheme with a proxy signature function to satisfy security requirements such as information protection, personal privacy, and message verification and to ensure that no one can cheat other users (including the server. We propose an electronic voting system based on the proposed oblivious and proxy signature scheme and implement this scheme in a smartphone application to allow users to vote securely and conveniently. Security analyses and performance comparisons are provided to show the capability and efficiency of the proposed scheme.

  2. Red is not a proxy signal for female genitalia in humans.

    Directory of Open Access Journals (Sweden)

    Sarah E Johns

    Full Text Available Red is a colour that induces physiological and psychological effects in humans, affecting competitive and sporting success, signalling and enhancing male social dominance. The colour is also associated with increased sexual attractiveness, such that women associated with red objects or contexts are regarded as more desirable. It has been proposed that human males have a biological predisposition towards the colour red such that it is 'sexually salient'. This hypothesis argues that women use the colour red to announce impending ovulation and sexual proceptivity, with this functioning as a proxy signal for genital colour, and that men show increased attraction in consequence. In the first test of this hypothesis, we show that contrary to the hypothesis, heterosexual men did not prefer redder female genitalia and, by extension, that red is not a proxy signal for genital colour. We found a relative preference for pinker genital images with redder genitalia rated significantly less sexually attractive. This effect was independent of raters' prior sexual experience and variation in female genital morphology. Our results refute the hypothesis that men's attraction to red is linked to an implied relationship to genital colour and women's signalling of fertility and sexual proceptivity.

  3. Red is not a proxy signal for female genitalia in humans.

    Science.gov (United States)

    Johns, Sarah E; Hargrave, Lucy A; Newton-Fisher, Nicholas E

    2012-01-01

    Red is a colour that induces physiological and psychological effects in humans, affecting competitive and sporting success, signalling and enhancing male social dominance. The colour is also associated with increased sexual attractiveness, such that women associated with red objects or contexts are regarded as more desirable. It has been proposed that human males have a biological predisposition towards the colour red such that it is 'sexually salient'. This hypothesis argues that women use the colour red to announce impending ovulation and sexual proceptivity, with this functioning as a proxy signal for genital colour, and that men show increased attraction in consequence. In the first test of this hypothesis, we show that contrary to the hypothesis, heterosexual men did not prefer redder female genitalia and, by extension, that red is not a proxy signal for genital colour. We found a relative preference for pinker genital images with redder genitalia rated significantly less sexually attractive. This effect was independent of raters' prior sexual experience and variation in female genital morphology. Our results refute the hypothesis that men's attraction to red is linked to an implied relationship to genital colour and women's signalling of fertility and sexual proceptivity.

  4. Ethical use of covert videoing techniques in detecting Munchausen syndrome by proxy.

    Science.gov (United States)

    Foreman, D M; Farsides, C

    1993-01-01

    Munchausen syndrome by proxy is an especially malignant form of child abuse in which the carer (usually the mother) fabricates or exacerbates illness in the child to obtain medical attention. It can result in serious illness and even death of the child and it is difficult to detect. Some investigators have used video to monitor the carer's interaction with the child without obtaining consent--covert videoing. The technique presents several ethical problems, including exposure of the child to further abuse and a breach of trust between carer, child, and the professionals. Although covert videoing can be justified in restricted circumstances, new abuse procedures under the Children Act now seem to make its use unethical in most cases. Sufficient evidence should mostly be obtained from separation of the child and carer or videoing with consent to enable action to be taken to protect the child under an assessment order. If the new statutory instruments prove ineffective in Munchausen syndrome by proxy covert videoing may need to be re-evaluated. PMID:8401021

  5. 'Munchausen syndrome by proxy' presenting as battered child syndrome: a report of two cases.

    Science.gov (United States)

    Sugandhan, Selvendran; Gupta, Somesh; Khandpur, Sujay; Khanna, Neena; Mehta, Manju; Inna, Prashanth

    2010-06-01

    Child abuse is a major public health crisis and is on the rise. Dermatologists are frequently involved in its evaluation in differentiating abusive injuries from accidental injuries and in excluding pathological conditions that may mimic abuse. Battered child syndrome or physical abuse is not only a common form of child abuse but can also result from a rarer form of child abuse known as Munchausen syndrome by proxy. In this form of abuse, mother, who is the usual perpetrator, induces an illness or abuses the child for her own self-serving psychological needs. We report two cases of battered child syndrome. In both the cases, Psychiatric evaluation was performed on both parents. Observation through one-way mirror was done with the mother and the child alone. Routine hematological and biochemical investigations were done. Diagnosis of Munchausen syndrome by proxy was firmly established in one case and was considered as a possibility in the other. A multidisciplinary team effort is essential in evaluating such cases, and dermatologists should be aware and be well informed about this condition that can be potentially lethal but easily overlooked.

  6. Epidemiology of Munchausen syndrome by proxy, non-accidental poisoning, and non-accidental suffocation.

    Science.gov (United States)

    McClure, R J; Davis, P M; Meadow, S R; Sibert, J R

    1996-01-01

    A two year prospective study was performed to determine the epidemiology of Munchausen syndrome by proxy, non-accidental poisoning, and non-accidental suffocation in the UK and the Republic of Ireland. Cases were notified to the British Paediatric Association Surveillance Unit from September 1992 to August 1994 if a formal case conference had been held for the first time during that period to discuss any of the above conditions. A total of 128 cases were identified: 55 suffered Munchausen syndrome by proxy alone, 15 poisoning, and 15 suffocation; 43 suffered more than one type of abuse. The majority of children were aged under 5 years, the median age being 20 months. On 85% of occasions the perpetrator was the child's mother. In 42% of families with more than one child, a sibling had previously suffered some form of abuse. Eighty five per cent of notifying paediatricians considered the probability of their diagnosis as virtually certain before a case conference was convened. The commonest drugs used to poison were anticonvulsants; opiates were the second commonest. Sixty eight children suffered severe illness of whom eight died. The combined annual incidence of these conditions in children aged under 16 years is at least 0.5/100,000, and for children aged under 1, at least 2.8/100,000. PMID:8813872

  7. A case of Munchausen syndrome by proxy with subsequent suicide of the mother.

    Science.gov (United States)

    Vennemann, B; Perdekamp, M Grosse; Weinmann, W; Faller-Marquardt, M; Pollak, S; Brandis, M

    2006-05-10

    Munchausen syndrome by proxy is a subtle and difficult to diagnose form of child abuse in which the carer (usually the mother) simulates, manipulates or produces symptoms of illness in the victim. In most cases the detrimental effect is caused by applying foreign substances or by airway obstruction. In the presented case a 20-month-old girl developed a spreading soft-tissue infection resistant to treatment on the left upper arm after vaccination, which required a number of surgical interventions. Repeatedly, microorganisms from the intestinal flora were isolated from the wound secretion. After the girl suffered respiratory and circulatory arrest, which required resuscitation measures, chemical toxicological tests revealed not medically prescribed benzodiazepines in serum and urine. When the mother, a trained nurse, was confronted with the allegation to have manipulated the symptoms of the illness she committed suicide. The forensic autopsy of the suicide produced numerous hints suggesting chronic self-damaging behaviour described as Munchausen syndrome. This case shows a number of manipulation forms with the maintenance of a chronic skin and soft tissue infection belonging to the rarer forms of inflicting damage to the child. It also illustrates that confrontation with the allegation of Munchausen syndrome by proxy creates a very stressful emotional situation that may lead to a suicidal act.

  8. Calcium Nodules as a Proxy for Quaternary Paleoclimate Change on China’s Loess Plateau

    Science.gov (United States)

    He, Wenming; He, Hongming; Zhu, Mingyong

    2015-01-01

    Different proxies have been used to investigate Quaternary paleoclimate change. Here, we used weathering of calcium nodules in paleosols on China’s Loess Plateau as a proxy for Quaternary paleoclimate changes to provide an alternative indicator of these changes. Paleosol and carbonate nodules were collected from Luochuan and Lantian counties in Shaanxi Province, China. We found that this approach allowed quantitative reconstruction of temperature, rainfall, soil mineral composition, and the effects of weathering and leaching. The changes in carbonate content in the loess and paleosol sequences were controlled by alternating dry and wet climatic conditions. Nodule formation conditions were directly affected by the leaching and migration of elements. The loess and paleosol sequences developed calcium nodules, and their formation was closely related to the rainfall and leaching characteristics of the paleoclimate. The paleoclimate and soil minerals affected the vegetation types and directly influenced changes in the soil. During formation of the calcium nodules, the surface vegetation evolved slowly, and the number of species and quantity of vegetation both decreased. PMID:26633304

  9. Calcium Nodules as a Proxy for Quaternary Paleoclimate Change on China's Loess Plateau.

    Science.gov (United States)

    He, Wenming; He, Hongming; Zhu, Mingyong

    2015-01-01

    Different proxies have been used to investigate Quaternary paleoclimate change. Here, we used weathering of calcium nodules in paleosols on China's Loess Plateau as a proxy for Quaternary paleoclimate changes to provide an alternative indicator of these changes. Paleosol and carbonate nodules were collected from Luochuan and Lantian counties in Shaanxi Province, China. We found that this approach allowed quantitative reconstruction of temperature, rainfall, soil mineral composition, and the effects of weathering and leaching. The changes in carbonate content in the loess and paleosol sequences were controlled by alternating dry and wet climatic conditions. Nodule formation conditions were directly affected by the leaching and migration of elements. The loess and paleosol sequences developed calcium nodules, and their formation was closely related to the rainfall and leaching characteristics of the paleoclimate. The paleoclimate and soil minerals affected the vegetation types and directly influenced changes in the soil. During formation of the calcium nodules, the surface vegetation evolved slowly, and the number of species and quantity of vegetation both decreased.

  10. Trace element profiles in sediments as proxies of dead zone history; rhenium compared to molybdenum.

    Science.gov (United States)

    Helz, George R; Adelson, Jordan M

    2013-02-05

    Warm-season dead zones-volumes of coastal water containing too little O(2) to support macrofauna-are a growing global menace. Trace elements that are deposited in sediments in response to reducing or sulfidic conditions can provide proxy records for reconstructing dead zone evolution. Based on relative enrichment in reduced vs oxidized marine sediments, Re seems promising as a dead zone proxy. Here, Re is determined by isotope dilution mass spectrometry in sediments underlying the summertime dead zone in Chesapeake Bay. Contrary to expectation, Re becomes only modestly (∼2-fold) elevated during the 20th century and fails to track the historic record of summertime O(2) depletion. Rhenium enrichments are watershed-specific and apparently controlled by anthropogenic sources, not by redox-linked authigenic processes. In contrast, Mo enrichments do track historic O(2) depletion. Three factors cause redox control to override anthropogenic control in the case of Mo: relative to weathering fluxes, anthropogenic Mo fluxes are weaker than Re fluxes; during anoxic periods, Mn refluxing amplifies Mo but not Re concentrations near the sediment surface; and high pore water sulfide-polysulfide promotes Mo fixation in pyrite while promoting formation of organo-Re adducts; the latter are too mobile and reactive to preserve a reliable historic record under seasonally fluctuating redox conditions.

  11. Cost-Effective and Fast Handoff Scheme in Proxy Mobile IPv6 Networks with Multicasting Support

    Directory of Open Access Journals (Sweden)

    Illkyun Im

    2014-01-01

    Full Text Available With recent advancements in wireless communication technologies, mobile multicasting is becoming important, in an effort to use network resources more efficiently. In the past, when various mobile IP-based multicast techniques were proposed, the focus was on the costs needed for network delivery to provide multicast services, as well as on minimizing the multicast handover delay. However, it is fundamentally difficult to resolve the problems of handover delay and tunnel convergence for techniques using MIPv6 (Mobile IPv6, a host-based mobility management protocol. To resolve these problems, the network-based mobility management protocol PMIPv6 (Proxy Mobile IPv6 was standardized. Although performance is improved in PMIPv6 over MIPv6, it still suffers from problems of handover delay and tunnel convergence. To overcome these limitations, a technique called LFH (Low-cost and Fast Handoff is proposed in this paper, for fast and low-cost mobility management with multicasting support in PMIPv6 networks. To reduce the interactions between the complex multicast routing protocol and multicast messages, a simplified proxy method called MLD (Multicast Listener Discovery is implemented and modified. Furthermore, a TCR (Tunnel Combination and Reconstruction algorithm was used in the multicast handover procedure within the LMA (Local Mobility Anchor domain, as well as in the multicast handover procedure between domains, in order to overcome the problem of tunnel convergence. It was found that, compared to other types of multicast techniques, LFH reduces multicast delay, and requires lower cost.

  12. Carbon stable isotopes as a palaeoclimate proxy in vascular plant dominated peatlands

    Science.gov (United States)

    Amesbury, M. J.; Charman, D. J.; Newnham, R. M.; Loader, N. J.; Goodrich, J. P.; Royles, J.; Campbell, D. I.; Roland, T. P.; Gallego-Sala, A.

    2015-09-01

    Carbon stable isotope (δ13C) records from vascular plant dominated peatlands have been used as a palaeoclimate proxy, but a better empirical understanding of fractionation processes in these ecosystems is required. Here, we test the potential of δ13C analysis of ombrotrophic restiad peatlands in New Zealand, dominated by the wire rush (Empodisma spp.), to provide a methodology for developing palaeoclimatic records. We took surface plant samples alongside measurements of water table depth and (micro)climate over spatial (six sites spanning > 10° latitude) and temporal (monthly measurements over 1 year) gradients and analysed the relationships between cellulose δ13C values and environmental parameters. We found strong, significant negative correlations between δ13C and temperature, photosynthetically active radiation and growing degree days above 0 °C. No significant relationships were observed between δ13C and precipitation, relative humidity, soil moisture or water table depth, suggesting no growing season water limitation and a decoupling of the expected link between δ13C in vascular plants and hydrological variables. δ13C of Empodisma spp. roots may therefore provide a valuable temperature proxy in a climatically sensitive region, but further physiological and sub-fossil calibration studies are required to fully understand the observed signal.

  13. Prompt Proxy Mapping of Flood Damaged Rice Fields Using MODIS-Derived Indices

    Directory of Open Access Journals (Sweden)

    Youngjoo Kwak

    2015-11-01

    Full Text Available Flood mapping, particularly hazard and risk mapping, is an imperative process and a fundamental part of emergency response and risk management. This paper aims to produce a flood risk proxy map of damaged rice fields over the whole of Bangladesh, where monsoon river floods are dominant and frequent, affecting over 80% of the total population. This proxy risk map was developed to meet the request of the government on a national level. This study represents a rapid, straightforward methodology for estimating rice-crop damage in flood areas of Bangladesh during the large flood from July to September 2007, despite the lack of primary data. We improved a water detection algorithm to achieve a better discrimination capacity to discern flood areas by using a modified land surface water index (MLSWI. Then, rice fields were estimated utilizing a hybrid rice field map from land-cover classification and MODIS-derived indices, such as the normalized difference vegetation index (NDVI and enhanced vegetation index (EVI. The results showed that the developed method is capable of providing instant, comprehensive, nationwide mapping of flood risks, such as rice field damage. The detected flood areas and damaged rice fields during the 2007 flood were verified by comparing them with the Advanced Land Observing Satellite (ALOS AVNIR-2 images (a 10 m spatial resolution and in situ field survey data with moderate agreement (K = 0.57.

  14. Characterization of Proxy Application Performance on Advanced Architectures. UMT2013, MCB, AMG2013

    Energy Technology Data Exchange (ETDEWEB)

    Howell, Louis H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gunney, Brian T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bhatele, Abhinav [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-09

    Three codes were tested at LLNL as part of a Tri-Lab effort to make detailed assessments of several proxy applications on various advanced architectures, with the eventual goal of extending these assessments to codes of programmatic interest running more realistic simulations. Teams from Sandia and Los Alamos tested proxy apps of their own. The focus in this report is on the LLNL codes UMT2013, MCB, and AMG2013. We present weak and strong MPI scaling results and studies of OpenMP efficiency on a large BG/Q system at LLNL, with comparison against similar tests on an Intel Sandy Bridge TLCC2 system. The hardware counters on BG/Q provide detailed information on many aspects of on-node performance, while information from the mpiP tool gives insight into the reasons for the differing scaling behavior on these two different architectures. Results from three more speculative tests are also included: one that exploits NVRAM as extended memory, one that studies performance under a power bound, and one that illustrates the effects of changing the torus network mapping on BG/Q.

  15. Constraints in the application of the Branched and Isoprenoid Tetraether index as a terrestrial input proxy

    Science.gov (United States)

    Fietz, Susanne; MartíNez-Garcia, Alfredo; Huguet, Carme; Rueda, Gemma; Rosell-Melé, Antoni

    2011-10-01

    Determination of the relative inputs of aquatic autochthonous and terrestrial allochthonous organic matter into marine and lacustrine environments is essential to understanding the global carbon budget. A variety of proxies are used for this purpose, including the Branched and Isoprenoid Tetraether (BIT) index. This is calculated from the concentrations of branched glycerol dialkyl glycerol tetraethers (GDGTs), derived from unidentified terrestrial bacteria, and crenarchaeol, a marker for aquatic mesophile Thaumarchaeota (Crenarchaeota group I). As the index is a ratio, its value depends on both the crenarchaeol aquatic in situ production and the soil-derived branched GDGT input. Therefore, the BIT index reflects not only changes in the input of terrestrial or soil organic matter but also relative variations in aquatic Thaumarchaeota abundance in the water column. In fact, we show that in oceanic and lacustrine settings, the BIT index can be dominated by the aquatic end-member of the ratio. Consequently, the BIT index by itself can be an unreliable proxy to compare the input of terrestrial matter between sites and over time, and we propose that the quantification of branched GDGT fluxes or concentrations may instead be a better indicator of soil terrestrial inputs.

  16. Validation of commercial business lists as a proxy for licensed alcohol outlets.

    Science.gov (United States)

    Carlos, Heather A; Gabrielli, Joy; Sargent, James D

    2017-05-19

    Studies of retail alcohol outlets are restricted to regions due to lack of U.S. national data. Commercial business lists (BL) offer a possible solution, but no data exists to determine if BLs could serve as an adequate proxy for license data. This paper compares geospatial measures of alcohol outlets derived from a commercial BL with license data for a large US state. We validated BL data as a measure of off-premise alcohol outlet density and proximity compared to license data for 5528 randomly selected California residential addresses. We calculated three proximity measures (Euclidean distance, road network travel time and distance) and two density measures (kernel density estimation and the count within a 2-mile radius) for each dataset. The data was acquired in 2015 and processed and analyzed in 2015 and 2016. Correlations and reliabilities between density (correlation 0.98; Cronbach's α 0.97-0.99) and proximity (correlations 0.77-0.86; α 0.87-0.92) measures were high. For proximity, BL data matched license in 55-57% of addresses, overstated distance in 19%, and understated in 24-26%. BL data can serve as a reliable proxy for licensed alcohol outlets, thus extending the work that can be performed in studies on associations between retail alcohol outlets and drinking outcomes.

  17. Sulfur in foraminiferal calcite as a potential proxy for seawater carbonate ion concentration

    Science.gov (United States)

    van Dijk, I.; de Nooijer, L. J.; Boer, W.; Reichart, G.-J.

    2017-07-01

    Sulfur (S) incorporation in foraminiferal shells is hypothesized to change with carbonate ion concentration [CO32-], due to substitution of sulfate for carbonate ions in the calcite crystal lattice. Hence S/Ca values of foraminiferal carbonate shells are expected to reflect sea water carbonate chemistry. To generate a proxy calibration linking the incorporation of S into foraminiferal calcite to carbonate chemistry, we cultured juvenile clones of the larger benthic species Amphistegina gibbosa and Sorites marginalis over a 350-1200 ppm range of pCO2 values, corresponding to a range in [CO32-] of 93 to 211 μmol/kg. We also investigated the potential effect of salinity on S incorporation by culturing juvenile Amphistegina lessonii over a large salinity gradient (25-45). Results show S/CaCALCITE is not impacted by salinity, but increases with increasing pCO2 (and thus decreasing [CO32-] and pH), indicating S incorporation may be used as a proxy for [CO32-]. Higher S incorporation in high-Mg species S. marginalis suggests a superimposed biomineralization effect on the incorporation of S. Microprobe imaging reveals co-occurring banding of Mg and S in Amphistegina lessonii, which is in line with a strong biological control and might explain higher S incorporation in high Mg species. Provided a species-specific calibration is available, foraminiferal S/Ca values might add a valuable new tool for reconstructing past ocean carbonate chemistry.

  18. Parents were accurate proxy reporters of urgent pediatric asthma health services: a retrospective agreement analysis.

    Science.gov (United States)

    Ungar, Wendy J; Davidson-Grimwood, Sara R; Cousins, Martha

    2007-11-01

    To assess agreement between parents' proxy reports of children's respiratory-related health service use and administrative data. A retrospective analysis of statistical agreement between clinical and claims data for reports of physician visits, emergency department (ED) visits, and hospitalizations in 545 asthmatic children recruited from sites in the greater Toronto area was conducted. Health services use data were extracted from the Ontario Health Insurance Plan and Canadian Institute for Health Information databases for each child for the interval coinciding with the proxy report for each health service type. Agreement between administrative data and respondent reports (n=545) was substantial for hospitalizations in the past year (kappa=0.80 [0.74, 0.86]), moderate for ED visits in the past year (kappa=0.60 [0.53, 0.67]), and slight for physician visits (kappa=0.13 [0.00, 0.27]) in the past 6 months. Income, parent's education, and child quality-of-life symptom scores did not affect agreement. Agreement for ED visits was significantly higher (Phealth services utilization.

  19. Phytolith indices as proxies of grass subfamilies on East African tropical mountains

    Science.gov (United States)

    Bremond, Laurent; Alexandre, Anne; Wooller, Matthew J.; Hély, Christelle; Williamson, David; Schäfer, Peter A.; Majule, Amos; Guiot, Joël

    2008-04-01

    The main objective of this paper is to provide researchers that investigate fossil phytolith assemblages and model/data comparisons a new tool for estimating C 3/C 4 grass composition over time. We tested the reliability of modern soil phytolith assemblages and phytolith indices for tracing the dominance of different grass subfamilies and tree cover density. We analyzed modern soil phytolith assemblages from sites over elevation gradients on Mount Kenya (Kenya), Mount Rungwe and around Lake Masoko (southern Tanzania). These data were compared with available botanical data. A phytolith index named Ic, proved to be an effective proxy of the proportions of Pooideae, Arundinoideae and Bambusoideae grasses (mainly C 3 grasses) versus Panicoideae grasses (mainly C 4 grasses), increasing with elevation in East-Africa. When tropical mountains are covered by open habitats (e.g . grasses and shrublands), Ic should be a reliable proxy of the C 3/C 4 grass composition. These results highlight the value of the phytolith index Ic, when interpreting paleo-environmental records from tropical mountains, to: 1) better understand past local and regional C 3/C 4 grass distributions and associated climatic changes and 2) increase the set of C 3/C 4 data available for model/data comparisons.

  20. Calcium Nodules as a Proxy for Quaternary Paleoclimate Change on China's Loess Plateau.

    Directory of Open Access Journals (Sweden)

    Wenming He

    Full Text Available Different proxies have been used to investigate Quaternary paleoclimate change. Here, we used weathering of calcium nodules in paleosols on China's Loess Plateau as a proxy for Quaternary paleoclimate changes to provide an alternative indicator of these changes. Paleosol and carbonate nodules were collected from Luochuan and Lantian counties in Shaanxi Province, China. We found that this approach allowed quantitative reconstruction of temperature, rainfall, soil mineral composition, and the effects of weathering and leaching. The changes in carbonate content in the loess and paleosol sequences were controlled by alternating dry and wet climatic conditions. Nodule formation conditions were directly affected by the leaching and migration of elements. The loess and paleosol sequences developed calcium nodules, and their formation was closely related to the rainfall and leaching characteristics of the paleoclimate. The paleoclimate and soil minerals affected the vegetation types and directly influenced changes in the soil. During formation of the calcium nodules, the surface vegetation evolved slowly, and the number of species and quantity of vegetation both decreased.

  1. Flow hydrodynamics near inlet key of Piano Key Weir (PKW)

    Indian Academy of Sciences (India)

    time fluctuating nature of flows is clearly understood with the help of advanced instrumentation and computing .... validate numerical models concerned with the design and construction of PKW. Acknowledgements ... Erpicum S, Nagel V and Laugier F 2011 Piano Key Weir design study at Raviege dam. Labyrinth and.

  2. A Multi-Proxy Perspective on Climate Variability in the Tropical Pacific over the Last Millennium

    Science.gov (United States)

    Quinn, Terrence; Partin, Jud; Thirumalai, Kaustubh; Hereid, Kelly; Maupin, Chris; Shen, Chuan-Chou; Taylor, Fred

    2014-05-01

    The southwest Pacific is a major source of tropical climate variability through heat and moisture exchanges associated with the Western Pacific Warm Pool (WPWP) and the South Pacific Convergence Zone (SPCZ). These variations are especially significant at the annual, ENSO, and multi-decadal timescales. Climate proxy records from the tropical Pacific must be used to extend records of SST, SSS, and rainfall variations into the pre-instrumental period. We highlight our recent efforts to quantitatively understand tropical climate variability over the last millennium using numerical simulations and climate proxy records (corals and stalagmites), the latter of which overlap with, and extend beyond the instrumental period. We investigate the use of individual foraminiferal analyses (IFA) in assessing past ENSO variability using numerical simulations. The simulation quantifies the sensitivity of IFA to ENSO amplitude and seasonal cycle amplitude (or a combination of both) at different locations in the tropical Pacific. Results indicate that IFA sensitivity towards ENSO is highest at the central equatorial Pacific surface ocean and the eastern equatorial Pacific (EEP) thermocline, whereas sensitivity towards the seasonal cycle is highest at the EEP surface ocean. We investigate tropical surface ocean variability using two recent coral-based climate reconstructions: a 233 yr record from Misima Island, Papua New Guinea (10.6° S, 152.8° E) and a 293 yr record from Olasana Island, Western Province, Solomon Islands (8.2° S, 157.2° E). The PNG coral record of monthly resolved δ18O and Sr/Ca variations spans the interval ~1414-1645. This record indicates that the surface ocean in this region experienced a small change in hydrologic balance with no change in temperature, extended periods of quiescence in El Niño activity, and no change in average amplitudes of El Niño events relative to signals captured in regional modern records. The Solomon coral δ18O record (1716

  3. Key World Energy Statistics 2013

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-08-01

    The IEA produced its first handy, pocket-sized summary of key energy data in 1997 and every year since then it has been more and more successful. Key World Energy Statistics contains timely, clearly-presented data on supply, transformation and consumption of all major energy sources. The interested businessman, journalist or student will have at his or her fingertips the annual Canadian production of coal, the electricity consumption in Thailand, the price of diesel oil in Spain and thousands of other useful energy facts.

  4. Key China Energy Statistics 2011

    Energy Technology Data Exchange (ETDEWEB)

    Levine, Mark [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fridley, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lu, Hongyou [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fino-Chen, Cecilia [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-01-15

    The China Energy Group at Lawrence Berkeley National Laboratory (LBNL) was established in 1988. Over the years the Group has gained recognition as an authoritative source of China energy statistics through the publication of its China Energy Databook (CED). In 2008 the Group published the Seventh Edition of the CED (http://china.lbl.gov/research/chinaenergy-databook). This handbook summarizes key statistics from the CED and is expressly modeled on the International Energy Agency’s “Key World Energy Statistics” series of publications. The handbook contains timely, clearly-presented data on the supply, transformation, and consumption of all major energy sources.

  5. Key China Energy Statistics 2012

    Energy Technology Data Exchange (ETDEWEB)

    Levine, Mark [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fridley, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lu, Hongyou [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fino-Chen, Cecilia [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-05-01

    The China Energy Group at Lawrence Berkeley National Laboratory (LBNL) was established in 1988. Over the years the Group has gained recognition as an authoritative source of China energy statistics through the publication of its China Energy Databook (CED). The Group has published seven editions to date of the CED (http://china.lbl.gov/research/chinaenergy-databook). This handbook summarizes key statistics from the CED and is expressly modeled on the International Energy Agency’s “Key World Energy Statistics” series of publications. The handbook contains timely, clearly-presented data on the supply, transformation, and consumption of all major energy sources.

  6. δ13C signal of earthworm calcite granules: A new proxy for palaeoprecipitation reconstructions during the Last Glacial in western Europe

    Science.gov (United States)

    Prud'homme, Charlotte; Lécuyer, Christophe; Antoine, Pierre; Hatté, Christine; Moine, Olivier; Fourel, François; Amiot, Romain; Martineau, François; Rousseau, Denis-Didier

    2018-01-01

    Quantification of paleoprecipitation during the Last Glacial is a key element to reconstruct palaeoclimates. Recently, fossil calcite granules have been identified in loess sequences with high contents in specific horizons. In this study, we explored for the first time the potential of this new bio-indicator as a climatic proxy for precipitation in western Europe during the Last Glacial. We extracted 30 granules from eleven samples belonging to three tundra gleys and two brown soils from the Nussloch loess sequence previously dated between 50 and 20 ka. Stable carbon isotope measurements were performed on each granule and duplicated. Throughout the studied section, δ13C values range from -15.4 to -10.3‰ for tundra gleys and from -14.9 to -9.5‰ for brown soils. By taking into account the fractionation factor between the carbon ingested by the earthworm and the carbon output of the granules, the δ13C values of these granules reflect the composition of the C3 plant vegetation cover. Thus, we estimated the δ13C of the plants with a mean value of -24.3 ± 0.9‰ for tundra gleys and -24.1 ± 0.9‰ for brown soils, which are in agreement with values obtained from organic matter preserved in sediments. Palaeoprecipitation range over both tundra gley horizons and brown soils were estimated at about 333[159-574] mm/yr by using an empirical relationship determined between present-day plant leaf isotopic discrimination and the mean annual precipitation. This original preliminary study highlights the potential of earthworm calcite granule δ13C measurements as a new proxy for paleoprecipitation during the Last Glacial interstadials in continental environments.

  7. Phanerozoic pCO2 recorded by the plants that used it: refinement, independent validation and multi-proxy comparison of a physiological model.

    Science.gov (United States)

    Franks, P.; Royer, D. L.; Kowalczyk, J.; Milligan, J.

    2016-12-01

    CO2 has been described as the most important greenhouse gas in terms of maintaining a habitable climate on Earth. However, pCO2 has not been constant through time and the resulting variability of its forcing has contributed to periodic swings in global climate between warmer and cooler periods. Reliable prediction of the magnitude and effects of future global warming with increasing pCO2 depends on quantifying climate sensitivity to forcing by pCO2, which can only be measured from the record of pCO2 and temperature in Earth's geological past. This has been difficult because of inherent uncertainties, sometimes unquantifiable, in the reconstruction of pCO2 for past geologic periods. Recently a new CO2 proxy was developed based on the principle that photosynthesis by plants is quantitatively dependent on pCO2 (CO2 being the substrate for photosynthesis), with the record of this relationship preserved in the structure and chemistry of plant fossils (Franks et al., 2014, Geophysical Research Letters, 41: 4685-4694). This method has constrained uncertainty to more moderate bounds and eliminated instances of unbounded uncertainty. Here we describe a refinement to one of the input physiological quantities, the present-day ratio of intercellular to ambient CO2 concentration, ci/ca, which improves model accuracy. We also summarise the key findings of an independent validation and multi proxy comparison of the model using fossil plant material from a floristically diverse early Paleocene site which, at 64.5 Ma, was living 1.5 m.y after the Cretaceous-Paleogene boundary (KPB) mass extinction event. Principal amongst these findings is an upward revision of pCO2 to a median 612 ppm for the early Paleocene, with a corresponding minimum average Earth system sensitivity of 3.8 °C.

  8. Right collaborations is the key

    Indian Academy of Sciences (India)

    First page Back Continue Last page Graphics. Right collaborations is the key. Large-scale production and analysis of stress tolerant transgenics needs active collaborations between plant physiologists, biochemists and geneticists. Collaboration between molecular biologists and biochemists is seen. Active collaboration ...

  9. Key World Energy Statistics 2012

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    Key World Energy Statistics contains timely, clearly-presented data on supply, transformation and consumption of all major energy sources. The interested businessman, journalist or student will have at his or her fingertips the annual Canadian production of coal, the electricity consumption in Thailand, the price of diesel oil in Spain and thousands of other useful energy facts.

  10. Ten Keys to the Portal

    Science.gov (United States)

    Schaffhauser, Dian

    2011-01-01

    Successful web portals help users stay informed, in touch, and up to speed. They are also a telling window into the efficiency of one's institution. To develop a cutting-edge portal takes planning, communication, and research. In this article, the author presents and discusses 10 keys to portal success: (1) make critical info visible; (2) make the…

  11. School Leadership: Some Key Ideas.

    Science.gov (United States)

    Fidler, Brian

    1997-01-01

    Highlights some key ideas and several perspectives on leadership, including: situational leadership; a leadership framework suggested by T.E. Deal and L.G. Bolman; leadership of the chief executive/leading professional; moral leadership; and curricular leadership. Identifies leadership by its contribution to outcomes and its influence on…

  12. Focusing on key development challenges

    International Development Research Centre (IDRC) Digital Library (Canada)

    Strategic Framework to guide our work during 2010–2015. This framework builds on the Centre's strengths ... Focusing on key development challenges. Building on strengths. Meeting tomorrow's ... durable peace, and the inclusion of marginalized groups, particularly women and girls. • Globalization, Growth and Poverty.

  13. Symmetric Key Authentication Services Revisited

    NARCIS (Netherlands)

    Crispo, B.; Popescu, B.C.; Tanenbaum, A.S.

    2004-01-01

    Most of the symmetric key authentication schemes deployed today are based on principles introduced by Needham and Schroeder [15] more than twenty years ago. However, since then, the computing environment has evolved from a LAN-based client-server world to include new paradigms, including wide area

  14. Continuous variable quantum key distribution

    Science.gov (United States)

    Li, Yong-Min; Wang, Xu-Yang; Bai, Zeng-Liang; Liu, Wen-Yuan; Yang, Shen-Shen; Peng, Kun-Chi

    2017-04-01

    Not Available Project supported by the National Natural Science Foundation of China (Grant Nos. 61378010 and 11504219), the Key Project of the Ministry of Science and Technology of China (Grant No. 2016YFA0301403), the Natural Science Foundation of Shanxi Province, China (Grant No. 2014011007-1), and the Program for the Outstanding Innovative Teams of Higher Learning Institutions of Shanxi Province, China.

  15. Data for evaluating the Sr/Ca temperature proxy with in-situ temperature in the western Atlantic coral Siderastrea siderea

    Science.gov (United States)

    Kuffner, Ilsa B.; Roberts, Kelsey E.; Flannery, Jennifer A.; Morrison, Jennifer M.; Richey, Julie

    2016-01-01

    Massive corals are used as environmental recorders throughout the tropics and subtropics to study environmental variability during time periods preceding ocean-observing instrumentation. However, careful testing of paleoproxies is necessary to validate the environmental-proxy record throughout a range of conditions experienced by the recording organisms. As part of the USGS Coral Reef Ecosystems Studies project (http://coastal.er.usgs.gov/crest/), we tested the hypothesis that the coral Siderastrea siderea faithfully records sea-surface temperature (SST) in the Sr/Ca record throughout the subtropical (Florida, USA) seasonal cycle along 350 km of reef tract. Coral samples were analyzed from thirty-nine corals growing in 3 to 4 m depth at Fowey Rocks (Biscayne National Park), Molasses Reef (Florida Keys National Marine Sanctuary, FKNMS), Sombrero Reef (FKNMS), and Pulaski Shoal (Dry Tortugas National Park). Temperatures were recorded with Onset® HOBO® Water Temp Pro V2 (U22-001) data loggers in duplicate at each site. Sr/Ca, Mg/Ca, calcification rate, and select underwater temperature data are provided here. The results of this experiment are interpreted in Kuffner et al. (in review). A larger temperature dataset, including the data provided here, is found in another data release Kuffner (2015), and a larger calcification-rate dataset is interpreted in Kuffner et al. (2013).Kuffner, I.B., K.E. Roberts, J.A. Flannery, J.M. Morrison, and J.N. Richey. In review. Fidelity of the Sr/Ca proxy in recording ocean temperature in the western Atlantic coral Siderastrea siderea.Kuffner, I.B., T.D. Hickey, and J.M. Morrison. 2013. Calcification rates of the massive coral Siderastrea siderea and crustose coralline algae along the Florida Keys (USA) outer-reef tract. Coral Reefs 32:987-997. http://link.springer.com/article/10.1007/s00338-013-1047-8Kuffner, I. B. (2015), Underwater temperature on off-shore coral reefs of the Florida Keys, U.S.A.: U.S. Geological Survey data

  16. Decade to centennial resolution hydrogen isotopic record of climate change from southern New England for the past 16 kyr: proxy validation and multi-proxy comparisons

    Science.gov (United States)

    Huang, Y.; Gao, L.; Hou, J.; Shuman, B. N.; Oswald, W.; Foster, D.

    2009-12-01

    Open system lakes in New England offer excellent archives of precipitation isotopic ratios that yield quantitative paleoclimate information. We have demonstrated previously from a lake sediment transect that hydrogen isotopic ratios of a middle-chain length fatty acid, behenic acid (BA), faithfully record precipitation isotopic ratios. We hypothesized that mid-chain n-alkyl lipids in these small lakes were primarily derived from aquatic plants that record lake water isotopic ratios. To test this hypothesis, we conducted systematic and extensive sampling of both terrestrial and aquatic plants over the past two years at two typical kettle hole lakes, Blood Pond and Rocky Pond, MA, and used a linear algebra approach to delineate percentage inputs of aquatic and terrestrial plant contributions to mid-chain n-alkyl lipids. Our results demonstrate that >92 % of the mid-chain n-alkyl lipids is derived from submerged and floating aquatic macrophytes. Our new data provide a solid basis for the application of behenic hydrogen isotopic ratios as a paleoclimate proxy from small lakes. We will present a decadal to centennial scale 16 kyr record of BA hydrogen isotopic ratios from Blood Pond, and will discuss the results in light of published pollen and lake level data. Overall, our hydrogen isotopic record is fully consistent with regional climate scenarios, including the distinctive warming at B-A events, abrupt cooling at YD event, and transition from glacial to Holcoene climate conditions. However, our high-solution isotopic data provides important new insights concerning abrupt regional climate variability. We demonstrate that the New England climate is exceptionally senstive to AMOC changes and solar forcing and that many of the abrupt climate fluctuations exert major impacts on terrestrial ecosystems, hydrology and lake levels.

  17. Proxy-based reconstruction of erythemal UV doses over Estonia for 1955–2004

    Directory of Open Access Journals (Sweden)

    K. Eerme

    2006-08-01

    Full Text Available A proxy-based reconstruction of the erythemally-weighted UV doses for 1955-2004 has been performed for the Tartu-Tõravere Meteorological Station (58°16' N, 26°28' E, 70 m a.s.l. site. The pyrheliometer-measured daily sum of direct irradiance on partly cloudy and clear days, and the pyranometer-measured daily sum of global irradiance on overcast days were used as the cloudiness influence related proxies. The TOMS ozone data have been used for detecting the daily deviations from the climatic value (averaged annual cycle. In 1998–2004, the biases between the measured and reconstructed daily doses in 55.5% of the cases were within ±10% and in 83.5% of the cases within ±20%, on average. In the summer half-year these amounts were 62% and 88%, respectively. In most years the results for longer intervals did not differ significantly, if no correction was made for the daily deviations of total ozone from its climatic value. The annual and summer half-yearly erythemal doses (contributing, on average, 89% of the annual value agreed within ±2%, except for the years after major volcanic eruptions and one extremely fine weather year (2002. Using the daily relative sunshine duration as a proxy without detailed correction for atmospheric turbidity results in biases of 2–4% in the summer half-yearly dose in the years after major volcanic eruptions and a few other years of high atmospheric turbidity. The year-to-year variations of the summer half-yearly erythemal dose in 1955–2004 were found to be within 92–111% relative to their average value. Exclusion of eight extreme years reduces this range for the remaining to 95–105.5%. Due to the quasi-periodic alternation of wet and dry periods, the interval of cloudy summers 1976–1993 regularly manifests summer half-yearly erythemal dose values lower than the 1955–2004 average. Since 1996/1997 midwinters have been darker than on average.

  18. A multiple-proxy approach to understanding rapid Holocene climate change in Southeast Greenland

    Science.gov (United States)

    Davin, S. H.; Bradley, R. S.; Balascio, N. L.; de Wet, G.

    2012-12-01

    The susceptibility of the Arctic to climate change has made it an excellent workshop for paleoclimatological research. Although there have been previous studies concerning climate variability carried out in the Arctic, there remains a critical dearth of knowledge due the limited number of high-resolution Holocene climate-proxy records available from this region. This gap skews our understanding of observed and predicted climate change, and fuels uncertainty both in the realms of science and policy. This study takes a comprehensive approach to tracking Holocene climate variability in the vicinity of Tasiilaq, Southeast Greenland using a ~5.6 m sediment core from Lower Sermilik Lake. An age-depth model for the core has been established using 8 radiocarbon dates, the oldest of which was taken at 4 m down core and has been been dated to approximately 6.2 kyr BP. The bottom meter of the core below the final radiocarbon date contains a transition from cobbles and coarse sand to organic-rich laminations, indicating the termination of direct glacial influence and therefore likely marking the end of the last glacial period in this region. The remainder of the core is similarly organic-rich, with light-to-dark brown laminations ranging from 0.5 -1 cm in thickness and riddled with turbidites. Using this core in tandem with findings from an on-site assessment of the geomorphic history of the locale we attempt to assess and infer the rapid climatic shifts associated with the Holocene on a sub-centennial scale. Such changes include the termination of the last glacial period, the Mid-Holocene Climatic Optimum, the Neoglacial Period, the Medieval Climatic Optimum, and the Little Ice Age. A multiple proxy approach including magnetic susceptibility, bulk organic geochemistry, elemental profiles acquired by XRF scanning, grain-size, and spectral data will be used to characterize the sediment and infer paleoclimate conditions. Additionally, percent biogenic silica by weight has been

  19. Sources and proxy potential of long chain alkyl diols in lacustrine environments

    Science.gov (United States)

    Rampen, Sebastiaan W.; Datema, Mariska; Rodrigo-Gámiz, Marta; Schouten, Stefan; Reichart, Gert-Jan; Sinninghe Damsté, Jaap S.

    2014-11-01

    Long chain 1,13- and 1,15-alkyl diols form the base of a number of recently proposed proxies used for climate reconstruction. However, the sources of these lipids and environmental controls on their distribution are still poorly constrained. We have analyzed the long chain alkyl diol (LCD) composition of cultures of ten eustigmatophyte species, with three species from different families grown at various temperatures, to identify the effect of species composition and growth temperature on the LCD distribution. The results were compared with the LCD distribution of sixty-two lake surface sediments, and with previously reported LCD distributions from marine environments. The different families within the Eustigmatophyceae show distinct LCD patterns, with the freshwater family Eustigmataceae most closely resembling LCD distributions in both marine and lake environments. Unlike the other two eustigmatophyte families analyzed (Monodopsidaceae and Goniochloridaceae), C28 and C30 1,13-alkyl diols and C30 and C32 1,15-alkyl diols are all relatively abundant in the family Eustigmataceae, while the mono-unsaturated C32 1,15-alkyl diol was below detection limit. In contrast to the marine environment, LCD distributions in lakes did not show a clear relationship with temperature. The Long chain Diol Index (LDI), a proxy previously proposed for sea surface temperature reconstruction, showed a relatively weak correlation (R2 = 0.33) with mean annual air temperature used as an approximation for annual mean surface temperature of the lakes. A much-improved correlation (R2 = 0.74, p-value lipid distributions. The obtained regression model provides good estimates of temperatures for cultures of the family Eustigmataceae, suggesting that algae belonging to this family have an important role as a source for LCDs in lacustrine environments, or, alternatively, that the main sources of LCDs are similarly affected by temperature as the Eustigmataceae. The results suggest that LCDs may have

  20. Thallium Isotopes Tracking Mn-Oxide Burial - A Proxy for Deoxygenation During Oceanic Anoxic Event 2

    Science.gov (United States)

    Ostrander, C.; Owens, J. D.; Nielsen, S.

    2015-12-01

    Thallium (Tl) is proving to be a useful paleoredox proxy given that the Tl isotope composition of seawater is highly dependent on the magnitude of manganese (Mn) oxide burial in the ocean. In turn, Mn oxides require oxygen at the sediment-water interface to precipitate, linking the Tl isotope cycle to ocean oxygenation. Currently, the marine residence time of Tl is ~20kyrs and the Tl isotope composition of seawater is invariant, which suggests Tl isotopes could be a global tracer of marine Mn-oxide burial. Importantly, recent research suggests sediments deposited under a euxinic water column faithfully record the Tl isotope value of the overlying oxic water column (e.g. Black Sea and Cariaco Basin). Therefore, analysis of organic-rich black shales may prove useful in evaluating the seawater Tl isotope composition of past oceans and, hence, large-scale burial of Mn-oxides and the extent of bottom water ocean oxygenation. A logical test for this proxy is during the well-studied Cenomanian-Turonian boundary event termed Oceanic Anoxic Event 2 (OAE-2) at ~94 Ma. It is known that the global extent of anoxia and euxinia increased during this event, however, to what extent global bottom water deoxygenation occured is unconstrained. If deep water deoxygenation occurred, it would be hypothesized that Mn-oxide precipitation would decrease, resulting in a positive Tl isotope excursion during OAE-2. We have analyzed the Tl isotope composition of organic-rich black shales from Site 1258 of the Ocean Drilling Program (ODP) spanning the period before, during, and after OAE-2. Based on Fe redox proxies, the entire section is euxinic and thus no Mn-oxides are present (i.e. no local redox changes). Before the event, Tl isotope compositions are similar or slightly heavier than modern seawater values. Just prior to the onset of OAE-2, a positive shift occurs and is maintained until recovery, slightly before the termination of the event. The shift to heavier values and subsequent

  1. Quantifying the effect of seasonal and vertical habitat tracking on planktonic foraminifera proxies

    Science.gov (United States)

    Jonkers, Lukas; Kučera, Michal

    2017-06-01

    The composition of planktonic foraminiferal (PF) calcite is routinely used to reconstruct climate variability. However, PF ecology leaves a large imprint on the proxy signal: seasonal and vertical habitats of PF species vary spatially, causing variable offsets from annual mean surface conditions recorded by sedimentary assemblages. PF seasonality changes with temperature in a way that minimises the environmental change that individual species experience and it is not unlikely that changes in depth habitat also result from such habitat tracking. While this behaviour could lead to an underestimation of spatial or temporal trends as well as of variability in proxy records, most palaeoceanographic studies are (implicitly) based on the assumption of a constant habitat. Up to now, the effect of habitat tracking on foraminifera proxy records has not yet been formally quantified on a global scale. Here we attempt to characterise this effect on the amplitude of environmental change recorded in sedimentary PF using core top δ18O data from six species. We find that the offset from mean annual near-surface δ18O values varies with temperature, with PF δ18O indicating warmer than mean conditions in colder waters (on average by -0.1 ‰ (equivalent to 0.4 °C) per °C), thus providing a first-order quantification of the degree of underestimation due to habitat tracking. We use an empirical model to estimate the contribution of seasonality to the observed difference between PF and annual mean δ18O and use the residual Δδ18O to assess trends in calcification depth. Our analysis indicates that given an observation-based model parametrisation calcification depth increases with temperature in all species and sensitivity analysis suggests that a temperature-related seasonal habitat adjustment is essential to explain the observed isotope signal. Habitat tracking can thus lead to a significant reduction in the amplitude of recorded environmental change. However, we show that this

  2. Assessing a novel approach to proxy system modeling of speleothem δ18O values

    Science.gov (United States)

    Wong, C. I.; Harman, C. J.; Banner, J.

    2016-12-01

    Assessment of past climate patterns and constraints on the climate processes driving such patterns is enabled by both an expanding network of paleoclimate reconstructions and more and improved simulations of past climate. Paleoclimate-data-model comparisons, however, require the translation of variables simulated by climate models (e.g., precipitation amount and δ18O values) into variables preserved in climate archives (e.g., speleothem δ18O values) using proxy system models. This study presents a new approach for evaluating vadose hydrology and modeling modern cave dripwater δ18O variability, thereby contributing to a component of the proxy system model of the archival of precipitation δ18O by speleothems. We assess the ability of an existing framework, rank StorAge Selection (rSAS) function, to account for variability in dripwater δ18O values in our expanded, decade-long data set from two caves in a semi-arid climate (Texas) and an existing 6.5 year dataset from tropical cave (Borneo). The rSAS approach quantifies the transit time distribution (probability density function of the age of a population of water parcels exiting a system) using functions that represent the way storage (ranked by age) is selected and released to discharge. Importantly, this framework accounts for the effect of antecedent moisture conditions on shifts in flow pathways and connectivity that determine the age distribution of water exiting the system. Initial results suggest that the rSAS approach can better account for dripwater δ18O variability relative to models based on amount weighted precipitation averages that are commonly applied in the interpretation of cave dripwater studies. The use of the rSAS approach is especially advantageous when the monitoring interval is brief relative to water residence time in the system and when drip sites are not dominantly supplied by a single reservoir. With respect to Texas, our expanded monitoring results more robustly demonstrate that cave

  3. Plastic response to a proxy cue of predation risk when direct cues are unreliable.

    Science.gov (United States)

    Miehls, Andrea L J; McAdam, Andrew G; Bourdeau, Paul E; Peacor, Scott D

    2013-10-01

    Responses to proximate cues that directly affect fitness or cues directly released by selective agents are well-documented forms of phenotypic plasticity. For example, to reduce predation risk, prey change phenotype in response to light level (e.g., moon phase) when light affects predation risk from visual predators, and to chemical cues (kairomones) released by predators. Less well understood is the potential for organisms to perceive predation risk through "proxy cues": proximate cues that correlate with, but do not directly affect predation risk. Previous field studies indicate that body and spine length of an invasive cladoceran in Lake Michigan, Bythotrephes longimanus (the spiny water flea), increase during the growing season, coincident with a decrease in clutch size. Although the cause of seasonal trait changes is not known, changes are associated with warmer water temperature and increased predation risk from gape-limited fish (i.e., fish whose ability to consume Bythotrephes is limited by mouth size). Using a laboratory experiment, we found no effect of fish (Perca flavescens) kairomones on Bythotrephes morphology or life history. In contrast, higher water temperature led to longer absolute spine and body length, increased investment in morphological defense of offspring (measured as the ratio of spine-to-body length), and decreased clutch size and age at reproduction. These plastic responses are unlikely to be adaptive to temperature per se, but rather our findings indicate that temperature serves as a proxy cue of fish predation risk. Temperature correlates with risk of gape-limited fish predation due to growth of fish from larval stages incapable of consuming Bythotrephes early in the season, to larger sizes by midseason increasingly capable of consuming Bythotrephes, but limited by gape size to consuming smaller individuals. We argue that for Bythotrephes, temperature is a more reliable cue of predation risk than fish kairomones, because fish

  4. Risk analysis of the proxy life-cycle investments in the second pillar pension scheme in Croatia

    Directory of Open Access Journals (Sweden)

    Renata Kovačević

    2015-03-01

    Full Text Available In this article we analyze the expected risk of pension funds with different risk profiles in the proxy life-cycle model of investments for the 2nd pillar pension scheme in Croatia. The benefits of implementing proxy life-cycle investments, compared to the previous model of mandatory pension funds investments, are clearly visible in the total expected amount of accumulated savings from the risk/return perspective. However, those benefits are partially diminished by the fact that the expected risk of a pension fund with the lowest risk profile is not substantially different from the expected risk of a pension fund with a medium risk profile, due to the lack of diversification. Additionally, we analyze the robustness of the proxy life-cycle model to a sudden and severe market shock, where we determine the presence of risk for those members who choose to switch to a pension fund with a lower risk profile at an unfavorable moment.

  5. [Attachment Quality of Young Children with Mentally Ill Parents on the Example of the Munchausen by Proxy Syndrome].

    Science.gov (United States)

    Ramberg, Axel; Feldkötter, Sinja

    2015-01-01

    One of the most discussed questions in clinical literature concerns the impact of child abuse by mentally ill parents (cf. Mattejat, 1998). It's obvious that most children cannot understand such a parental behaviour and that this lack of understanding along with the lack of knowledge about their parents' emotional disorder results in childrens' fear, disorientation and uncertainty. The consequences are massive interferences in the relationship between parents and children, who could develop an anxious-resistant insecure or even a disorganized/disoriented attachment. But how does a child react, if the behaviour of its parents is ambivalent itself and alternates from abuse to care? Such a parental behaviour is described as the "Munchausen by Proxy Syndrome". This article regards the effects of a "Munchausen by Proxy Syndrome" on the childrens' attachment development. After discussing the basic assumptions about the "Munchhauen by Proxy Syndrome" and the attachment theory we draw conclusions about the syndrome's effect on childrens' attachment behaviour.

  6. Numerical Modelling of Speleothem and Dripwater Chemistry: Interpreting Coupled Trace Element and Isotope Proxies for Climate Reconstructions

    Science.gov (United States)

    Owen, R.; Day, C. C.; Henderson, G. M.

    2016-12-01

    Speleothem palaeoclimate records are widely used but are often difficult to interpret due to the geochemical complexity of the soil-karst-cave system. Commonly analysed proxies (e.g. δ18O, δ13C and Mg/Ca) may be affected by multiple processes along the water flow path from atmospheric moisture source through to the cave drip site. Controls on speleothem chemistry include rainfall and aerosol chemistry, bedrock chemistry, temperature, soil pCO2, the degree of open-system dissolution and prior calcite precipitation. Disentangling the effects of these controls is necessary to fully interpret speleothem palaeoclimate records. To quantify the effects of these processes, we have developed an isotope-enabled numerical model based on the geochemical modelling software PHREEQC. The model calculates dripwater chemistry and isotopes through equilibrium bedrock dissolution and subsequent iterative CO2 degassing and calcite precipitation. This approach allows forward modelling of dripwater and speleothem proxies, both chemical (e.g. Ca concentration, pH, Mg/Ca and Sr/Ca ratios) and isotopic (e.g. δ18O, δ13C, δ44Ca and radiocarbon content), in a unified framework. Potential applications of this model are varied and the model may be readily expanded to include new isotope systems or processes. Here we focus on calculated proxy co-variation due to changes in model parameters. Examples include: - The increase in Ca concentration, decrease in δ13C and increase in radiocarbon content as bedrock dissolution becomes more open-system. - Covariation between δ13C, δ44Ca and trace metal proxies (e.g. Mg/Ca) predicted by changing prior calcite precipitation. - The effect of temperature change on all proxies through the soil-karst-cave system. Separating the impact of soil and karst processes on geochemical proxies allows more quantitative reconstruction of the past environment, and greater understanding in modern cave monitoring studies.

  7. Assessment of scintillation proxy maps for a scintillation study during geomagnetically quiet and disturbed conditions over Uganda

    Science.gov (United States)

    Amabayo, Emirant B.; Jurua, Edward; Cilliers, Pierre J.

    2017-02-01

    The objective of this paper is demonstrate the validity and usefulness of scintillation proxies derived from IGS data, through its comparison with data from dedicated scintillation monitors and its application to GNSS scintillation patterns. The paper presents scintillation patterns developed by using data from the dedicated scintillation monitors of the scintillation network decision aid (SCINDA) network, and proxy maps derived from IGS GPS data for 2011 and 2012 over low latitude stations in Uganda. The amplitude and phase scintillation indicies (S4 and σΦ) were obtained from the Novatel GSV4004B ionospheric scintillation and total electron content (TEC) monitor managed by SCINDA at Makerere (0.340N, 32.570E). The corresponding IGS GPS proxy data were obtained from the receivers at Entebbe (0.040N, 32.440E) and Mbarara (0.600S, 30.740E). The derived amplitude (S4p) and phase (sDPR) scintillation proxy maps were compared with maps of S4 and σΦ during geomagnetic storms (moderate and strong) and geomagnetically quiet conditions. The scintillation patterns using S4 and σΦ and their respective proxies revealed similar diurnal and seasonal patterns of strong scintillation occurrence. The peaks of scintillation occurrence with mean values in the range 0.3 irregularities over Uganda irrespective of the geomagnetic conditions. Therefore, the amplitude and phase scintillation proxies presented here can be used to fill gaps in low-latitude data where there are no data available from dedicated scintillation receivers, irrespective of the geomagnetic conditions.

  8. Impact of spatial proxies on the representation of bottom-up emission inventories: A satellite-based analysis

    Science.gov (United States)

    Geng, Guannan; Zhang, Qiang; Martin, Randall V.; Lin, Jintai; Huo, Hong; Zheng, Bo; Wang, Siwen; He, Kebin

    2017-03-01

    Spatial proxies used in bottom-up emission inventories to derive the spatial distributions of emissions are usually empirical and involve additional levels of uncertainty. Although uncertainties in current emission inventories have been discussed extensively, uncertainties resulting from improper spatial proxies have rarely been evaluated. In this work, we investigate the impact of spatial proxies on the representation of gridded emissions by comparing six gridded NOx emission datasets over China developed from the same magnitude of emissions and different spatial proxies. GEOS-Chem-modeled tropospheric NO2 vertical columns simulated from different gridded emission inventories are compared with satellite-based columns. The results show that differences between modeled and satellite-based NO2 vertical columns are sensitive to the spatial proxies used in the gridded emission inventories. The total population density is less suitable for allocating NOx emissions than nighttime light data because population density tends to allocate more emissions to rural areas. Determining the exact locations of large emission sources could significantly strengthen the correlation between modeled and observed NO2 vertical columns. Using vehicle population and an updated road network for the on-road transport sector could substantially enhance urban emissions and improve the model performance. When further applying industrial gross domestic product (IGDP) values for the industrial sector, modeled NO2 vertical columns could better capture pollution hotspots in urban areas and exhibit the best performance of the six cases compared to satellite-based NO2 vertical columns (slope = 1.01 and R2 = 0. 85). This analysis provides a framework for information from satellite observations to inform bottom-up inventory development. In the future, more effort should be devoted to the representation of spatial proxies to improve spatial patterns in bottom-up emission inventories.

  9. Predicting and mitigating future biodiversity loss using long-term ecological proxies

    Science.gov (United States)

    Fordham, Damien A.; Akçakaya, H. Resit; Alroy, John; Saltré, Frédérik; Wigley, Tom M. L.; Brook, Barry W.

    2016-10-01

    Uses of long-term ecological proxies in strategies for mitigating future biodiversity loss are too limited in scope. Recent advances in geochronological dating, palaeoclimate reconstructions and molecular techniques for inferring population dynamics offer exciting new prospects for using retrospective knowledge to better forecast and manage ecological outcomes in the face of global change. Opportunities include using fossils, genes and computational models to identify ecological traits that caused species to be differentially prone to regional and range-wide extinction, test if threatened-species assessment approaches work and locate habitats that support stable ecosystems in the face of shifting climates. These long-term retrospective analyses will improve efforts to predict the likely effects of future climate and other environmental change on biodiversity, and target conservation management resources most effectively.

  10. Design and Evaluation of a Proxy-Based Monitoring System for OpenFlow Networks.

    Science.gov (United States)

    Taniguchi, Yoshiaki; Tsutsumi, Hiroaki; Iguchi, Nobukazu; Watanabe, Kenzi

    2016-01-01

    Software-Defined Networking (SDN) has attracted attention along with the popularization of cloud environment and server virtualization. In SDN, the control plane and the data plane are decoupled so that the logical topology and routing control can be configured dynamically depending on network conditions. To obtain network conditions precisely, a network monitoring mechanism is necessary. In this paper, we focus on OpenFlow which is a core technology to realize SDN. We propose, design, implement, and evaluate a network monitoring system for OpenFlow networks. Our proposed system acts as a proxy between an OpenFlow controller and OpenFlow switches. Through experimental evaluations, we confirm that our proposed system can capture packets and monitor traffic information depending on administrator's configuration. In addition, we show that our proposed system does not influence significant performance degradation to overall network performance.

  11. Seemingly divergent sea surface temperature proxy records in the central Mediterranean during the last deglaciation

    Directory of Open Access Journals (Sweden)

    M.-A. Sicre

    2013-06-01

    Full Text Available Sea surface temperatures (SSTs were reconstructed over the last 25 000 yr using alkenone paleothermometry and planktonic foraminifera assemblages from two cores of the central Mediterranean Sea: the MD04-2797 core (Siculo–Tunisian channel and the MD90-917 core (South Adriatic Sea. Comparison of the centennial scale structure of the two temperature signals during the last deglaciation period reveals significant differences in timing and amplitude. We suggest that seasonal changes likely account for seemingly proxy record divergences during abrupt transitions from glacial to interglacial climates and for the apparent short duration of the Younger Dryas (YD depicted by the alkenone time series, a feature that has already been stressed in earlier studies on the Mediterranean deglaciation.

  12. Design and Evaluation of a Proxy-Based Monitoring System for OpenFlow Networks

    Directory of Open Access Journals (Sweden)

    Yoshiaki Taniguchi

    2016-01-01

    Full Text Available Software-Defined Networking (SDN has attracted attention along with the popularization of cloud environment and server virtualization. In SDN, the control plane and the data plane are decoupled so that the logical topology and routing control can be configured dynamically depending on network conditions. To obtain network conditions precisely, a network monitoring mechanism is necessary. In this paper, we focus on OpenFlow which is a core technology to realize SDN. We propose, design, implement, and evaluate a network monitoring system for OpenFlow networks. Our proposed system acts as a proxy between an OpenFlow controller and OpenFlow switches. Through experimental evaluations, we confirm that our proposed system can capture packets and monitor traffic information depending on administrator’s configuration. In addition, we show that our proposed system does not influence significant performance degradation to overall network performance.

  13. Climate in Sweden during the past millennium - Evidence from proxy data, instrumental data and model simulations

    Energy Technology Data Exchange (ETDEWEB)

    Moberg, Anders; Gouirand, Isabelle; Schoning, Kristian; Wohlfarth, Barbara [Stockholm Univ. (Sweden). Dept. of Physical Geography and Quaternary Geology; Kjellstroem, Erik; Rummukainen, Markku [Swedish Meteorological and Hydrological Inst., Norrkoeping (Sweden). Rossby Centre; Jong, Rixt de [Lund Univ. (Sweden). Dept. of Quaternary Geology; Linderholm, Hans [Goeteborg Univ. (Sweden). Dept. of Earth Sciences; Zorita, Eduardo [GKSS Research Centre, Geesthacht (Germany)

    2006-12-15

    Knowledge about climatic variations is essential for SKB in its safety assessments of a geological repository for spent nuclear waste. There is therefore a need for information about possible future climatic variations under a range of possible climatic states. However, predictions of future climate in any deterministic sense are still beyond our reach. We can, nevertheless, try to estimate the magnitude of future climate variability and change due to natural forcing factors, by means of inferences drawn from natural climate variability in the past. Indeed, the climate of the future will be shaped by the sum of natural and anthropogenic climate forcing, as well as the internal climate variability. The aim here is to review and analyse the knowledge about Swedish climate variability, essentially during the past millennium. Available climate proxy data and long instrumental records provide empirical information on past climatic changes. We also demonstrate how climate modelling can be used to extend such knowledge. We use output from a global climate model driven with reconstructed radiative forcings (solar, volcanic and greenhouse gas forcing), to provide boundary conditions for a regional climate model. The regional model provides more details of the climate than the global model, and we develop a simulated climate history for Sweden that is complete in time and space and physically consistent. We use output from a regional model simulation for long periods in the last millennium, to study annual mean temperature, precipitation and runoff for the northern and southern parts of Sweden. The simulated data are used to place corresponding instrumental records for the 20th century into a plausible historical perspective. We also use output from the regional model to study how the frequency distribution of the daily temperature, precipitation, runoff and evaporation at Forsmark and Oskarshamn could have varied between unusually warm and cold 30-year periods during the

  14. Pediatric condition falsification (Munchausen syndrome by Proxy) as a continuum of maternal factitious disorder (Munchausen syndrome).

    Science.gov (United States)

    Kucuker, Hudaverdi; Demir, Tevfik; Oral, Resmiye

    2010-12-01

    Pediatric condition falsification (PCF), also known as Munchausen syndrome by Proxy or Medical Child Abuse, is a somewhat rare form of child abuse and neglect. Its association with a history of adult factitious disorder (AFD) or Munchausen syndrome in the perpetrator is also well known. Exogenous insulin injection to cause hypoglycemia both in the context of PCF and AFD has been reported in the literature. However, the coexistence of both conditions via insulin injection in the same family has not been reported in the literature. This paper presents a family, in which the mother was diagnosed with AFD and her three children with PCF perpetrated by their mother via exogenous insulin injection. © 2010 John Wiley & Sons A/S.

  15. Think Again: First Do No Harm: A Case of Munchausen Syndrome by Proxy.

    Science.gov (United States)

    Yalndağ-Öztürk, Nilüfer; Erkek, Nilgün; Şirinoğlu, Melis Bayram

    2015-10-01

    Apparent life-threatening events caused by Munchausen syndrome by proxy (MSP) are rare but difficult to resolve medically. Failure to properly diagnose MSP can lead to further abuse by the caregiver and increase the risk of complications due to long hospital stays and invasive tests. In this paper, we describe our experiences with a baby who ended up being diagnosed with MSP, including our initial failure to find a pathology, delay of MSP diagnosis, our growing suspicion of MSP despite technical setbacks, our actions after we confirmed MSP as the cause of his hospitalizations. We also describe the difficulties of diagnosing MSP compared to more traditional problems and explain a series of precautions and guidelines to help detect it in a timely manner.

  16. Munchausen by proxy syndrome mimicking systemic autoinflammatory disease: case report and review of the literature.

    Science.gov (United States)

    Wittkowski, Helmut; Hinze, Claas; Häfner-Harms, Sigrid; Oji, Vinzenz; Masjosthusmann, Katja; Monninger, Martina; Grenzebach, Ulrike; Foell, Dirk

    2017-04-05

    Systemic autoinflammatory diseases (SAIDs) represent a growing number of monogenic, polygenic or multifactorial disorders that are often difficult to diagnose. Here we report a patient who was initially erroneously diagnosed and treated for SAID. Symptoms consisted of recurrent fever, erythematous and/or blistering skin lesions, angioedema, susceptibility to bleeding, external ear infections and reversible anisocoria in the absence of laboratory evidence of systemic inflammation. After two and a half years of extensive diagnostic work-up and multiple empirical therapies, a final diagnosis of Munchausen by proxy syndrome (MBPS) was established. The diagnosis of SAID needs to be carefully reassessed if measurable systemic inflammation is missing, and MBPS should be included in the differential diagnosis.

  17. The investigation of life-threatening child abuse and Munchausen syndrome by proxy.

    Science.gov (United States)

    Evans, D

    1995-01-01

    The use of covert video surveillance in the investigation of suspected life-threatening child abuse and Munchausen syndrome by proxy raises important ethical questions. That the recently reported provision of this facility in North Staffordshire was not presented to a Local Research Ethics Committee (LREC) for approval as a research exercise raises important questions about the ethical review of research and practice. The case made for avoiding such review is first set out and then examined. The three main premisses which form the basis of the view that LREC approval is not required are identified and tested in turn. The conclusion is that there is an undeniable element of research involved in the procedure and that the welfare of all those subjected to the surveillance would be best protected by the submission of the protocol to an independent committee for ethical assessment. PMID:7776355

  18. Webvise: Browser and Proxy support for open hypermedia structuring mechanisms on the WWW

    DEFF Research Database (Denmark)

    Grønbæk, Kaj; Sloth, Lennard; Ørbæk, Peter

    1999-01-01

    This paper discusses how to augment the World Wide Web with an open hypermedia service (Webvise) that provides structures such as contexts, links, annotations, and guided tours stored in hypermedia databases external to the Web pages. This includes the ability for users collaboratively to create...... Web pages. Support for providing links to/from parts of non-HTML data, such as sound and movie, will be possible via interfaces to plug-ins and Java-based media players. The hypermedia structures are stored in a hypermedia database, developed from the Devise Hypermedia framework, and the service...... be manipulated and used via special Java applets and a pure proxy server solution is provided for users who only need to browse the structures. A user can create and use the external structures as ‘transparency' layers on top of arbitrary Web pages, the user can switch between viewing pages with one or more...

  19. Use of Proton SEE Data as a Proxy for Bounding Heavy-Ion SEE Susceptibility

    Science.gov (United States)

    Ladbury, Raymond L.; Lauenstein, Jean-Marie; Hayes, Kathryn P.

    2015-01-01

    Although heavy-ion single-event effects (SEE) pose serious threats to semiconductor devices in space, many missions face difficulties testing such devices at heavy-ion accelerators. Low-cost missions often find such testing too costly. Even well funded missions face issues testing commercial off the shelf (COTS) due to packaging and integration. Some missions wish to fly COTS systems with little insight into their components. Heavy-ion testing such parts and systems requires access to expensive and hard-to-access ultra-high energy ion accelerators, or significant system modification. To avoid these problems, some have proposed using recoil ions from high-energy protons as a proxy to bound heavy-ion SEE rates.

  20. Near-Earth Asteroids 2006 RH120 AND 2009 BD: Proxies for Maximally Accessible Objects?

    Science.gov (United States)

    Barbee, Brent W.; Chodas, Paul W.

    2015-01-01

    NASA's Near-Earth Object Human Space Flight Accessible Targets Study (NHATS) has identified over 1,400 of the approximately 12,800 currently known near-Earth asteroids (NEAs) as more astrodynamically accessible, round-trip, than Mars. Hundreds of those approximately 1,400 NEAs can be visited round-trip for less change-in-velocity than the lunar surface, and dozens can be visited round-trip for less change-in-velocity than low lunar orbit. How accessible might the millions of undiscovered NEAs be? We probe that question by investigating the hypothesis that NEAs 2006 RH120 and 2009 BD are proxies for the most accessible NEAs we would expect to find, and describing possible future NEA population model studies.

  1. Key drivers of airline loyalty.

    Science.gov (United States)

    Dolnicar, Sara; Grabler, Klaus; Grün, Bettina; Kulnig, Anna

    2011-10-01

    This study investigates drivers of airline loyalty. It contributes to the body of knowledge in the area by investigating loyalty for a number of a priori market segments identified by airline management and by using a method which accounts for the multi-step nature of the airline choice process. The study is based on responses from 687 passengers. Results indicate that, at aggregate level, frequent flyer membership, price, the status of being a national carrier and the reputation of the airline as perceived by friends are the variables which best discriminate between travellers loyal to the airline and those who are not. Differences in drivers of airline loyalty for a number of segments were identified. For example, loyalty programs play a key role for business travellers whereas airline loyalty of leisure travellers is difficult to trace back to single factors. For none of the calculated models satisfaction emerged as a key driver of airline loyalty.

  2. Role of eruption season in reconciling model and proxy responses to tropical volcanism.

    Science.gov (United States)

    Stevenson, Samantha; Fasullo, John T; Otto-Bliesner, Bette L; Tomas, Robert A; Gao, Chaochao

    2017-02-21

    The response of the El Niño/Southern Oscillation (ENSO) to tropical volcanic eruptions has important worldwide implications, but remains poorly constrained. Paleoclimate records suggest an "El Niño-like" warming 1 year following major eruptions [Adams JB, Mann ME, Ammann CM (2003) Nature 426:274-278] and "La Niña-like" cooling within the eruption year [Li J, et al. (2013) Nat Clim Chang 3:822-826]. However, climate models currently cannot capture all these responses. Many eruption characteristics are poorly constrained, which may contribute to uncertainties in model solutions-for example, the season of eruption occurrence is often unknown and assigned arbitrarily. Here we isolate the effect of eruption season using experiments with the Community Earth System Model (CESM), varying the starting month of two large tropical eruptions. The eruption-year atmospheric circulation response is strongly seasonally dependent, with effects on European winter warming, the Intertropical Convergence Zone, and the southeast Asian monsoon. This creates substantial variations in eruption-year hydroclimate patterns, which do sometimes exhibit La Niña-like features as in the proxy record. However, eruption-year equatorial Pacific cooling is not driven by La Niña dynamics, but strictly by transient radiative cooling. In contrast, equatorial warming the following year occurs for all starting months and operates dynamically like El Niño. Proxy reconstructions confirm these results: eruption-year cooling is insignificant, whereas warming in the following year is more robust. This implies that accounting for the event season may be necessary to describe the initial response to volcanic eruptions and that climate models may be more accurately simulating volcanic influences than previously thought.

  3. Implementation of fast handover for proxy mobile IPv6: Resolving out-of-order packets.

    Science.gov (United States)

    Kang, Byungseok; Anh, Khuong Quoc; Choo, Hyunseung

    2017-01-01

    Mobile IP allows for location-independent routing of IP datagrams on the Internet. Mobile IP specifies how a mobile node (MN) registers with its home agent and how the home agent routes datagrams to the MN through the tunnel. Current Mobile IP protocols have difficulties meeting the stringent handover delay requirements of future wireless networks. Fast handover for Proxy Mobile IPv6 (FPMIPv6) is used to resolve handover latency and packet loss problems that occur in the Proxy Mobile IPv6 (PMIPv6) protocol. However, while implementing the FPMIPv6 scheme in a testbed, we encounter the out-of-order packet (OoOP) problem. The cause of this problem is the existence of two paths for data transmitted from a correspondent node (CN) to an MN. Since the problem affects the quality of service (QoS) of the network and the performance of the MN, we propose a new scheme using the last packet marker and packet buffering to solve this problem in FPMIPv6. The new Mobile Access Gateway (MAG) can control and deliver the data transmitted via the old path or the new path to an MN in order, using the last packet marker to notify the end of the data delivery in the old path and the packet buffering for holding the data delivered in the new path. We implement both the proposed scheme and FPMIPv6 in a testbed as a real network environment to demonstrate the correctness, cost effectiveness, and performance of the proposed scheme. A performance evaluation reveals that the proposed scheme can handle the OoOP problem efficiently.

  4. Beers Criteria as a Proxy for Inappropriate Prescribing of Other Medications Among Older Adults

    Science.gov (United States)

    Lund, Brian C; Steinman, Michael A; Chrischilles, Elizabeth A; Kaboli, Peter J

    2014-01-01

    BACKGROUND The Beers criteria are a compilation of medications deemed potentially inappropriate for older adults, and widely used a prescribing quality indicator. OBJECTIVE To determine whether Beers criteria serve as a proxy measure for other forms of inappropriate prescribing, as measured by comprehensive implicit review. METHODS Data for patients 65 years and older were obtained from the VA Enhanced Pharmacy Outpatient Clinic (EPOC) and the Iowa Medicaid Pharmaceutical Case Management (PCM) studies. Comprehensive measurement of prescribing quality was conducted using expert clinician review of medical records according to the Medication Appropriateness Index (MAI). MAI scores attributable to non-Beers medications (non-Beers MAI) were contrasted between patients who did and did not receive a Beers criteria medication. RESULTS Beers criteria medications accounted for 12.9% and 14.0% of total MAI scores in the two studies. Importantly, non-Beers MAI scores were significantly higher in patients receiving a Beers criteria medication in both studies (EPOC: 15.1 vs. 12.4, p = 0.02; PCM: 11.1 vs. 8.7, p = 0.04), after adjusting for important confounding factors. CONCLUSIONS Beers criteria utility extended beyond direct measurement of a limited set of inappropriate prescribing practices by serving as a clinically meaningful proxy for other inappropriate practices. Using prescribing quality indicators to guide interventions should thus identify patients for comprehensive medication review, rather than identifying specific targets for discontinuation. Future research should explore both the quality measurement and the intervention targeting applications of the Beers criteria, particularly when integrated with other indicators. PMID:21972251

  5. Coral proxy record of decadal-scale reduction in base flow from Moloka'i, Hawaii

    Science.gov (United States)

    Prouty, Nancy G.; Jupiter, Stacy D.; Field, Michael E.; McCulloch, Malcolm T.

    2009-01-01

    Groundwater is a major resource in Hawaii and is the principal source of water for municipal, agricultural, and industrial use. With a growing population, a long-term downward trend in rainfall, and the need for proper groundwater management, a better understanding of the hydroclimatological system is essential. Proxy records from corals can supplement long-term observational networks, offering an accessible source of hydrologic and climate information. To develop a qualitative proxy for historic groundwater discharge to coastal waters, a suite of rare earth elements and yttrium (REYs) were analyzed from coral cores collected along the south shore of Moloka'i, Hawaii. The coral REY to calcium (Ca) ratios were evaluated against hydrological parameters, yielding the strongest relationship to base flow. Dissolution of REYs from labradorite and olivine in the basaltic rock aquifers is likely the primary source of coastal ocean REYs. There was a statistically significant downward trend (−40%) in subannually resolved REY/Ca ratios over the last century. This is consistent with long-term records of stream discharge from Moloka'i, which imply a downward trend in base flow since 1913. A decrease in base flow is observed statewide, consistent with the long-term downward trend in annual rainfall over much of the state. With greater demands on freshwater resources, it is appropriate for withdrawal scenarios to consider long-term trends and short-term climate variability. It is possible that coral paleohydrological records can be used to conduct model-data comparisons in groundwater flow models used to simulate changes in groundwater level and coastal discharge.

  6. Alimemazine poisoning as evidence of Munchausen syndrome by proxy: A pediatric case report.

    Science.gov (United States)

    Gomila, Isabel; López-Corominas, Victoria; Pellegrini, Manuela; Quesada, Loreto; Miravet, Elena; Pichini, Simona; Barceló, Bernardino

    2016-09-01

    Munchausen syndrome by proxy (MSBP), also known as fabricated or induced illness in a child by a caretaker, is a form of abuse where a caregiver deliberately produces or feigns illness in a person under his or her care, so that the proxy will receive medical care that gratifies the caregiver. The affected children are often hospitalized for long periods and endure repetitive, painful and expensive diagnostic attempts. We present an analytically confirmed case of MSBP by alimemazine. A 3-year-old boy was brought repetitively to a Pediatric Emergency Department by his mother because he presented limb tremors, dysarthria, obnubilation, and ataxia and generalized tonic-clonic seizures coinciding with intermittent fever. Neither the rest of the physical examination nor the complementary tests showed any significant alterations. MSBP was suspected and a routine systematic toxicological analysis in urine and blood was requested. Alimemazine was detected in all biological samples. The administration of this drug was never mentioned by the mother and the subsequent interview with her corroborated the suspicion of MSBP. Clinically, after separation from the mother, the child's neurological symptoms gradually improved until the complete disappearance of the cerebellar symptoms. Alimemazine was quantified in serum, urine, gastric content and cerebrospinal fluid samples by gas chromatography-mass spectrometry (maximum serum level was 0.42μg/ml). Hair quantification of alimemazine was performed by ultra-performance liquid chromatography-tandem mass spectrometry in different segments of hair. The results confirmed regular substance use during the at least eight last months (8.8, 14.7, 19.7 and 4.6ng/mg hair starting from most proximal segment). This patient represents the first case published with analytical data of alimemazine in blood, urine, gastric content, cerebrospinal fluid and hair, which allowed us to prove an acute and repetitive poisoning with alimemazine as evidence

  7. Implementation of fast handover for proxy mobile IPv6: Resolving out-of-order packets.

    Directory of Open Access Journals (Sweden)

    Byungseok Kang

    Full Text Available Mobile IP allows for location-independent routing of IP datagrams on the Internet. Mobile IP specifies how a mobile node (MN registers with its home agent and how the home agent routes datagrams to the MN through the tunnel. Current Mobile IP protocols have difficulties meeting the stringent handover delay requirements of future wireless networks. Fast handover for Proxy Mobile IPv6 (FPMIPv6 is used to resolve handover latency and packet loss problems that occur in the Proxy Mobile IPv6 (PMIPv6 protocol. However, while implementing the FPMIPv6 scheme in a testbed, we encounter the out-of-order packet (OoOP problem. The cause of this problem is the existence of two paths for data transmitted from a correspondent node (CN to an MN. Since the problem affects the quality of service (QoS of the network and the performance of the MN, we propose a new scheme using the last packet marker and packet buffering to solve this problem in FPMIPv6. The new Mobile Access Gateway (MAG can control and deliver the data transmitted via the old path or the new path to an MN in order, using the last packet marker to notify the end of the data delivery in the old path and the packet buffering for holding the data delivered in the new path. We implement both the proposed scheme and FPMIPv6 in a testbed as a real network environment to demonstrate the correctness, cost effectiveness, and performance of the proposed scheme. A performance evaluation reveals that the proposed scheme can handle the OoOP problem efficiently.

  8. Archaeological evidence of validity of fish populations on unexploited reefs as proxy targets for modern populations.

    Science.gov (United States)

    Longenecker, Ken; Chan, Yvonne L; Toonen, Robert J; Carlon, David B; Hunt, Terry L; Friedlander, Alan M; Demartini, Edward E

    2014-10-01

    Reef-fish management and conservation is hindered by a lack of information on fish populations prior to large-scale contemporary human impacts. As a result, relatively pristine sites are often used as conservation baselines for populations near sites affected by humans. This space-for-time approach can only be validated by sampling assemblages through time. We used archaeological remains to evaluate whether the remote, uninhabited Northwestern Hawaiian Islands (NWHI) might provide a reasonable proxy for a lightly exploited baseline in the Main Hawaiian Islands (MHI). We used molecular and morphological techniques to describe the taxonomic and size composition of the scarine parrotfish catches present in 2 archaeological assemblages from the MHI, compared metrics of these catches with modern estimates of reproductive parameters to evaluate whether catches represented by the archaeological material were consistent with sustainable fishing, and evaluated overlap between size structures represented by the archaeological material and modern survey data from the MHI and the NWHI to assess whether a space-for-time substitution is reasonable. The parrotfish catches represented by archaeological remains were consistent with sustainable fishing because they were dominated by large, mature individuals whose average size remained stable from prehistoric (AD approximately 1400-1700) through historic (AD 1700-1960) periods. The ancient catches were unlike populations in the MHI today. Overlap between the size structure of ancient MHI catches and modern survey data from the NWHI or the MHI was an order of magnitude greater for the NWHI comparison, a result that supports the validity of using the NWHI parrotfish data as a proxy for the MHI before accelerated, heavy human impacts in modern times. © 2014 Society for Conservation Biology.

  9. Reinterpreting climate proxy records from late Quaternary Chinese loess: A detailed OSL investigation

    Science.gov (United States)

    Stevens, Thomas; Thomas, David S. G.; Armitage, Simon J.; Lunn, Hannah R.; Lu, Huayu

    2007-01-01

    Numerous authors have utilised physical properties of Chinese loess and red clay deposits to develop apparently detailed and continuous past climate records from the Miocene into the Holocene. Many of these studies have further suggested that the principal climatic agent responsible for the aeolian emplacement and diagenesis of Chinese loess, the East Asian Monsoon, has fluctuated rapidly on millennial to sub-millennial timescales, in concert with dramatic changes in the North Atlantic (Dansgaard-Oeschger cycles and Heinrich events) and the Western Pacific (El Niño Southern Oscillation). Much of this evidence is based on reconstructions and age models that are tied to assumptions concerning the nature of loess sedimentation and diagenesis, for example, the belief that loess sedimentation can be viewed as essentially continuous. Some authors have however, cast doubt on these assumptions and suggest that the application of radiometric techniques may be required to determine their validity. Recent studies utilising Optically Stimulated Luminescence (OSL) methods have reinforced these doubts and here, OSL dates obtained at 10 cm intervals from three sites along a transect across the Chinese Loess Plateau have been used, in combination with climate proxy evidence, to test the existing assumptions that underpin many palaeoclimatic reconstructions from loess. In this way, the first time-continuous and independently dated late Quaternary climate reconstruction is developed from loess. The data indicate that sedimentation is episodic and that once emplaced, loess is prone to pedogenic disturbance, diagenetic modification and in some cases erosion. The relationships between proxies and sedimentation rates are also assessed and climatic interpretations based on different age models compared. The implications of these findings for reconstructions of climate from loess are explored and comparisons are made between the developed palaeoclimate records and evidence from ice and

  10. Correlating pharmaceutical data with a national health survey as a proxy for estimating rural population health

    Directory of Open Access Journals (Sweden)

    Cossman Ronald E

    2010-09-01

    Full Text Available Abstract Background Chronic disease accounts for nearly three-quarters of US deaths, yet prevalence rates are not consistently reported at the state level and are not available at the sub-state level. This makes it difficult to assess trends in prevalence and impossible to measure sub-state differences. Such county-level differences could inform and direct the delivery of health services to those with the greatest need. Methods We used a database of prescription drugs filled in the US as a proxy for nationwide, county-level prevalence of three top causes of death: heart disease, stroke, and diabetes. We tested whether prescription data are statistically valid proxy measures for prevalence, using the correlation between prescriptions filled at the state level and comparable Behavioral Risk Factor Surveillance System (BRFSS data. We further tested for statistically significant national geographic patterns. Results Fourteen correlations were tested for years in which the BRFSS questions were asked (1999-2003, and all were statistically significant. The correlations at the state level ranged from a low of 0.41 (stroke, 1999 to a high of 0.73 (heart disease, 2003. We also mapped self-reported chronic illnesses along with prescription rates associated with those illnesses. Conclusions County prescription drug rates were shown to be valid measures of sub-state estimates of diagnosed prevalence and could be used to target health resources to counties in need. This methodology could be particularly helpful to rural areas whose prevalence rates cannot be estimated using national surveys. While there are no spatial statistically significant patterns nationally, there are significant variations within states that suggest unmet health needs.

  11. Deciphering Late-Pleistocence landscape evolution: linking proxies by combining pedo-stratigraphy and luminescence dating

    Science.gov (United States)

    Kreutzer, Sebastian; Meszner, Sascha; Faust, Dominik; Fuchs, Markus

    2014-05-01

    Interpreting former landscape evolution asks for understanding the processes that sculpt such landforms by means of deciphering complex systems. For reconstructing terrestrial Quaternary environments based on loess archives this might be considered, at least, as a three step process: (1) Identifying valuable records in appropriate morphological positions in a previously defined research area, (2) analysing the profiles by field work and laboratory methods and finally (3) linking the previously considered pseudo-isolated systems to set up a comprehensive picture. Especially the first and the last step might bring some pitfalls, as it is tempting to specify single records as pseudo-isolated, closed systems. They might be, with regard to their preservation in their specific morphological position, but in fact they are part of a complex, open system. Between 2008 and 2013, Late-Pleistocene loess archives in Saxony have been intensively investigated by field and laboratory methods. Linking pedo- and luminescence dating based chronostratigraphies, a composite profile for the entire Saxonian Loess Region has been established. With this, at least, two-fold approach we tried to avoid misinterpretations that might appear when focussing on one standard profile in an open morphological system. Our contribution focuses on this multi-proxy approach to decipher the Late-Pleistocene landscape evolution in the Saxonian Loess Region. Highlighting the challenges and advantages of combining different methods, we believe that (1) this multi-proxy approach is without alternative, (2) the combination of different profiles may simplify the more complex reality, but it may be a useful generalisation to understand and reveal the stratigraphical significance of the landscape evolution in this region.

  12. Development and Applications of Thallium isotopes: a new proxy tracking the extent of manganese oxide burial

    Science.gov (United States)

    Owens, J. D.; Nielsen, S.; Ostrander, C.; Peterson, L. C.; Anbar, A. D.

    2015-12-01

    Thallium (Tl) isotopes are a new and potential powerful paleoredox proxy with the possibility to track bottom water oxygen conditions based on the burial flux of manganese oxides. Thallium has a residence time of ~20 thousand years, which is long enough to render modern oxic seawater conservative with respect to concentration and isotopes. The isotopic signature of Tl in the global ocean is driven mainly by two outputs (1) adsorption onto manganese oxides and (2) low temperature oceanic crust alteration. Importantly, the isotopic inputs of Tl are all nearly the same value; thus, the isotopic composition and flux of the outputs almost exclusively set the seawater signature. For relatively short term redox events it is reasonable to assume that the dominant isotope fractionation process is associated with manganese oxide precipitation because low temperature alteration is controlled by long-term average ocean crust production rates. We present a broad range of modern samples that span several open ocean profiles combined with water column and sediment profiles from the permanently anoxic basins of the Black Sea and Cariaco Basins. The open ocean shows no variation in depth profiles that encompass most of the major water masses in the Atlantic and Southern Oceans. The anoxic basins, however, reveal Tl isotope signatures closer to their inputs, which is likely due to basinal restriction. The authigenic fraction of organic-rich sediments from the Black Sea and Cariaco Basin capture the Tl isotope value of the overlying water column, which shows that Tl isotopes could be applied as a faithful deep time redox proxy. For the first time, we will present new data showing that Tl isotopes is tracking bottom water ocean oxygenation. We are applying this isotope system to ancient samples, testing the spatial and temporal variability of ocean oxygenation coinciding with major biogeochemical events.

  13. Analisis Perancangan PC (Personal Computer Router Proxy Untuk Menggabungkan Tiga Jalur Koneksi Di Indospeed

    Directory of Open Access Journals (Sweden)

    Bangun Harizal

    2012-05-01

    Full Text Available Router very important for computer network. To get the router can buy a router products but can also design your own using personal computers. Mikrotik is one of the router manufacturer that provides products in the form of hardware or software. If you want to pay less to design a router can use operating system Ubuntu. This operating system is open source and provided free of charge by the manufacturer. If you want to design a router with this OS can make use of personal computers are often used in homes or offices. Merging the performance of both types of routers can also be usedto cover the lack of one another. With the proxy on a local network then the use of bandwidth can be saved. Becausethere are several websites cached and stored therein if the same website is accessed by other users, the router transmits only from the proxy to the computerwhich make the request.

  14. Enhancement web proxy cache performance using Wrapper Feature Selection methods with NB and J48

    Science.gov (United States)

    Mahmoud Al-Qudah, Dua’a.; Funke Olanrewaju, Rashidah; Wong Azman, Amelia

    2017-11-01

    Web proxy cache technique reduces response time by storing a copy of pages between client and server sides. If requested pages are cached in the proxy, there is no need to access the server. Due to the limited size and excessive cost of cache compared to the other storages, cache replacement algorithm is used to determine evict page when the cache is full. On the other hand, the conventional algorithms for replacement such as Least Recently Use (LRU), First in First Out (FIFO), Least Frequently Use (LFU), Randomized Policy etc. may discard important pages just before use. Furthermore, using conventional algorithm cannot be well optimized since it requires some decision to intelligently evict a page before replacement. Hence, most researchers propose an integration among intelligent classifiers and replacement algorithm to improves replacement algorithms performance. This research proposes using automated wrapper feature selection methods to choose the best subset of features that are relevant and influence classifiers prediction accuracy. The result present that using wrapper feature selection methods namely: Best First (BFS), Incremental Wrapper subset selection(IWSS)embedded NB and particle swarm optimization(PSO)reduce number of features and have a good impact on reducing computation time. Using PSO enhance NB classifier accuracy by 1.1%, 0.43% and 0.22% over using NB with all features, using BFS and using IWSS embedded NB respectively. PSO rises J48 accuracy by 0.03%, 1.91 and 0.04% over using J48 classifier with all features, using IWSS-embedded NB and using BFS respectively. While using IWSS embedded NB fastest NB and J48 classifiers much more than BFS and PSO. However, it reduces computation time of NB by 0.1383 and reduce computation time of J48 by 2.998.

  15. Are Quality-Adjusted Life Years a Good Proxy Measure of Individual Capabilities?

    Science.gov (United States)

    Mitchell, Paul Mark; Venkatapuram, Sridhar; Richardson, Jeff; Iezzi, Angelo; Coast, Joanna

    2017-06-01

    There is a debate in the health economics literature concerning the most appropriate way of applying Amartya Sen's capability approach in economic evaluation studies. Some suggest that quality-adjusted life years (QALYs) alone are adequate while others argue that this approach is too narrow and that direct measures of capability wellbeing provide a more extensive application of Sen's paradigm. This paper empirically explores whether QALYs provide a good proxy for individual capabilities. Data is taken from a multinational cross-sectional survey of individuals with seven health conditions (asthma, arthritis, cancer, depression, diabetes, hearing loss, heart disease) and a healthy population. Each individual completed the ICECAP-A measure of capability wellbeing for adults and six health utility instruments that are used to generate QALYs, including EQ-5D and SF-6D. Primary analysis examines how well health utility instruments can explain variation in the ICECAP-A using ordinary least squares regression. The findings show that all seven health conditions have a negative association on overall capability as measured by the ICECAP-A index. Inclusion of health utility instruments into separate regressions improves the predictive power of capability but on average, explains less than half of the variation in capability wellbeing. Individuals with arthritis appear to be less inhibited in terms of capability losses when accounting for health utility, yet those who have depression record significant reductions in capability relative to the healthy population even after accounting for the most commonly used health utility instruments. The study therefore casts doubt on the ability of QALYs to act as a reliable proxy measure of individuals' capability.

  16. The reconstruction of past climate variability in the NW Indian Ocean based on a coral proxy record from the Maldives

    OpenAIRE

    Storz, David

    2010-01-01

    Until now, the NW Indian Ocean was sparsely covered with coral proxy records, and records from the Maldives Archipelago do not exist. The first such coral proxy record from the central Maldives is presented in this study. It originates from a massive Porites lutea (Quoy and Gaimard, 1833) colony that was sampled March 2007 in the lagoon of Rasdhoo Atoll (4°N/ 73°W), which is located in the central Maldives. The record spans a period of 90 yrs and reaches back to 1917 AD with monthly to bimont...

  17. KEY TOPICS IN SPORTS MEDICINE

    OpenAIRE

    Amir Ali Narvani; Panagiotis Thomas; Burce Lynn

    2006-01-01

    Key Topics in Sports Medicine is a single quick reference source for sports and exercise medicine. It presents the essential information from across relevant topic areas, and includes both the core and emerging issues in this rapidly developing field. It covers: 1) Sports injuries, rehabilitation and injury prevention, 2) Exercise physiology, fitness testing and training, 3) Drugs in sport, 4) Exercise and health promotion, 5) Sport and exercise for special and clinical populations, 6) The ps...

  18. Human Resources Key Performance Indicators

    Directory of Open Access Journals (Sweden)

    Gabčanová Iveta

    2012-03-01

    Full Text Available The article brings out a proposed strategy map and respective key performance indicators (KPIs in human resources (HR. The article provides an overview of how HR activities are supported in order to reach the partial goals of HR as defined in the strategic map. Overall the aim of the paper is to show the possibilities of using the modern Balanced Scorecard method in human capital.

  19. The Body: The Key Concepts

    OpenAIRE

    Blackman, Lisa

    2008-01-01

    Questions around 'the body' are central to social theory. Our changing understanding of the body now challenges the ways we conceive power, ideology, subjectivity and social and cultural process. The Body: the key concepts highlights and analyses the debates which make the body central to current sociological, psychological, cultural and feminist thinking. Today, questions around the body are intrinsic to a wide range of debates - from technological developments in media and communications, t...

  20. Disarming the Key Leader Engagement

    Science.gov (United States)

    2010-09-01

    niques and the managed expectation of key leader engagement effects. Effects are not immediate, and we must build them with candor, genuine concern...security agreement for U.S. forces? The agree- ment was understood in theory , but its application generated a litany of ques- tions. However, one...thing was clear: the way ahead would require systematic engagements with Iraqi leaders to leverage their powers of public persuasion. Military

  1. Linking Concurrent Self-Reports and Retrospective Proxy Reports About the Last Year of Life: A Prevailing Picture of Life Satisfaction Decline

    Science.gov (United States)

    Gerstorf, Denis; Ram, Nilam; Schupp, Jürgen; Sprangers, Mirjam A. G.; Wagner, Gert G.

    2014-01-01

    Objective. We examined the extent to which retrospective proxy reports of well-being mirror participant self-reports at 12–24 months before death and how proxy reports of well-being change over the last year of life. We also explored the role of sociodemographic, cognitive, and health factors of both participants and proxies in moderating such associations. Method. We used retrospective proxy ratings obtained in the German Socio-Economic Panel Study (N = 164; age at death = 19–99 years). Results. Results revealed moderate agreement between self- and proxy reports (r = .42), but proxies, on average, overestimated participants’ life satisfaction by two thirds of a scale point on a 0–10 scale (or 0.4 SD). Discrepancies were particularly pronounced when proxies themselves reported low life satisfaction. Over the last year of life, participants were viewed to have experienced declines in life satisfaction (−0.54 SD). Declines were stronger for ill participants and proxies who reported low life satisfaction. Discussion. Results qualify theoretical expectations and empirical results based on self-report data that are typically available 1 or 2 years before death. We discuss that retrospective proxy reports in panel surveys can be used as a hypothesis-generating tool to gather insights into late life. PMID:23766436

  2. Low carbon development. Key issues

    Energy Technology Data Exchange (ETDEWEB)

    Urban, Frauke; Nordensvaard, Johan (eds.)

    2013-03-07

    This comprehensive textbook addresses the interface between international development and climate change in a carbon constrained world. It discusses the key conceptual, empirical and policy-related issues of low carbon development and takes an international and interdisciplinary approach to the subject by drawing on insights from across the natural sciences and social sciences whilst embedding the discussion in a global context. The first part explores the concept of low carbon development and explains the need for low carbon development in a carbon constrained world. The book then discusses the key issues of socio-economic, political and technological nature for low carbon development, exploring topics such as the political economy, social justice, financing and carbon markets, and technologies and innovation for low carbon development. This is followed by key issues for low carbon development in policy and practice, which is presented based on cross-cutting issues such as low carbon energy, forestry, agriculture and transportation. Afterwards, practical case studies are discussed from low carbon development in low income countries in Africa, middle income countries in Asia and Latin America and high income countries in Europe and North America.

  3. Detector decoy quantum key distribution

    Energy Technology Data Exchange (ETDEWEB)

    Moroder, Tobias; Luetkenhaus, Norbert [Quantum Information Theory Group, Institute of Theoretical Physics I, University Erlangen-Nuremberg, Staudtstrasse 7/B2, 91058 Erlangen (Germany); Curty, Marcos [ETSI Telecomunicacion, Department of Signal Theory and Communications, University of Vigo, Campus Universitario, E-36310 Vigo (Spain)], E-mail: tmoroder@iqc.ca

    2009-04-15

    Photon number resolving detectors can enhance the performance of many practical quantum cryptographic setups. In this paper, we employ a simple method to estimate the statistics provided by such a photon number resolving detector using only a threshold detector together with a variable attenuator. This idea is similar in spirit to that of the decoy state technique, and is especially suited to those scenarios where only a few parameters of the photon number statistics of the incoming signals have to be estimated. As an illustration of the potential applicability of the method in quantum communication protocols, we use it to prove security of an entanglement-based quantum key distribution scheme with an untrusted source without the need for a squash model and by solely using this extra idea. In this sense, this detector decoy method can be seen as a different conceptual approach to adapt a single-photon security proof to its physical, full optical implementation. We show that in this scenario, the legitimate users can now even discard the double click events from the raw key data without compromising the security of the scheme, and we present simulations on the performance of the BB84 and the 6-state quantum key distribution protocols.

  4. Key Concepts in Microbial Oceanography

    Science.gov (United States)

    Bruno, B. C.; Achilles, K.; Walker, G.; Weersing, K.; Team, A

    2008-12-01

    The Center for Microbial Oceanography: Research and Education (C-MORE) is a multi-institution Science and Technology Center, established by the National Science Foundation in 2006. C-MORE's research mission is to facilitate a more comprehensive understanding of the diverse assemblages of microorganisms in the sea, ranging from the genetic basis of marine microbial biogeochemistry including the metabolic regulation and environmental controls of gene expression, to the processes that underpin the fluxes of carbon, related bioelements, and energy in the marine environment. The C-MORE education and outreach program is focused on increasing scientific literacy in microbial oceanography among students, educators, and the general public. A first step toward this goal is defining the key concepts that constitute microbial oceanography. After lengthy discussions with scientists and educators, both within and outside C-MORE, we have arrived at six key concepts: 1) Marine microbes are very small and have been around for a long time; 2) Life on Earth could not exist without microbes; 3) Most marine microbes are beneficial; 4) Microbes are everywhere: they are extremely abundant and diverse; 5) Microbes significantly impact our global climate; and 6) There are new discoveries every day in the field of microbial oceanography. A C-MORE-produced brochure on these six key concepts will be distributed at the meeting. Advanced copies may be requested by email or downloaded from the C-MORE web site(http://cmore.soest.hawaii.edu/downloads/MO_key_concepts_hi-res.pdf). This brochure also includes information on career pathways in microbial oceanography, with the aim of broadening participation in the field. C-MORE is eager to work in partnership to incorporate these key concepts into other science literacy publications, particularly those involving ocean and climate literacy. We thank the following contributors and reviewers: P Chisholm, A Dolberry, and A Thompson (MIT); N Lawrence

  5. KeyPathwayMinerWeb

    DEFF Research Database (Denmark)

    List, Markus; Alcaraz, Nicolas; Dissing-Hansen, Martin

    2016-01-01

    such as data integration, input of background knowledge, batch runs for parameter optimization and visualization of extracted pathways. In addition to an intuitive web interface, we also implemented a RESTful API that now enables other online developers to integrate network enrichment as a web service......We present KeyPathwayMinerWeb, the first online platform for de novo pathway enrichment analysis directly in the browser. Given a biological interaction network (e.g. protein-protein interactions) and a series of molecular profiles derived from one or multiple OMICS studies (gene expression...

  6. Key Obama officials leave administration

    Science.gov (United States)

    Showstack, Randy

    2013-01-01

    Secretary of the Interior Ken Salazar is one of the latest members of the Obama administration to announce that he is leaving his position near the start of President Obama's second term in office. Salazar, who has served as interior secretary since January 2009, intends to leave the department by the end of March, the department noted on 16 January. Salazar joins a number of other key officials who are planning to leave the administration. They include Environmental Protection Agency administrator Lisa Jackson, National Oceanic and Atmospheric Administration administrator Jane Lubchenco, and U.S. Geological Survey director Marcia McNutt.

  7. Nephrology key information for internists.

    Science.gov (United States)

    Salim, Sohail Abdul; Medaura, Juan A; Malhotra, Bharat; Garla, Vishnu; Ahuja, Shradha; Lawson, Nicki; Pamarthy, Amaleswari; Sonani, Hardik; Kovvuru, Karthik; Palabindala, Venkataraman

    2017-03-01

    Hospitalists and primary care physicians encounter renal disease daily. Although most cases of acute kidney injury (AKI) are secondary to dehydration and resolve by giving fluids, many cases of AKI are due to not uncommon but unfamiliar causes needing nephrology evaluation. Common indications to consult a nephrologist on an emergency basis include hyperkalemia or volume overload in end stage renal disease patients (ESRD). Other causes of immediate consultation are cresenteric glomerulonephritis / rapidly progressive glomerulonephritis in which renal prognosis of the patient depends on timely intervention. The following evidence-based key information could improve patient care and outcomes. Abbreviations: AKI: Acute kidney injury ESRD: End stage renal disease patients.

  8. Key Note: Living with droughts?

    OpenAIRE

    Erdbrink, C. D.; van Beek, Eelco; van Os, A.G.

    2008-01-01

    The Netherlands Center for River Research (NCR) in its first 10 years of existence has focused its activities on flooding. Climate change might cause that droughts will become as important as or even more important than floods. The dry year 2003 in Europe has shown the huge socio-economic impacts of droughts. New concepts are emerging on how to deal with droughts. This key-note addresses the issues of droughts and scarcity and makes a plea to include more drought research in NCR.

  9. Fibre Optic Communication Key Devices

    CERN Document Server

    Grote, Norbert

    2012-01-01

    The book gives an in-depth description of the key devices of current and next generation fibre optic communication networks. In particular, the book covers devices such as semiconductor lasers, optical amplifiers, modulators, wavelength filters, and detectors but the relevant properties of optical fibres as well. The presentations include the physical principles underlying the various devices, the technologies used for the realization of the different devices, typical performance characteristics and limitations, and development trends towards more advanced components are also illustrated. Thus the scope of the book spans relevant principles, state-of-the-art implementations, the status of current research and expected future components.

  10. Key instrumentation in BWR plants

    Energy Technology Data Exchange (ETDEWEB)

    Laendner, Alexander; Stellwag, Bernhard; Fandrich, Joerg [AREVA NP GmbH, Erlangen (Germany)

    2011-01-15

    This paper describes water chemistry surveillance practices at boiling water reactor (BWR) power plants. The key instrumentation in BWR plants consists of on-line as well as off-line instrumentation. The chemistry monitoring and control parameters are predominantly based on two guidelines, namely the VGB Water Chemistry Guidelines and the EPRI Water Chemistry Guidelines. Control parameters and action levels specified in the VGB guideline are described. Typical sampling locations in BWR plants, chemistry analysis methods and water chemistry data of European BWR plants are summarized. Measurement data confirm the high quality of reactor water of the BWRs in Europe. (orig.)

  11. Key paediatric messages from Amsterdam

    Directory of Open Access Journals (Sweden)

    Jonathan Grigg

    2016-04-01

    Full Text Available The Paediatric Assembly of the European Respiratory Society (ERS maintained its high profile at the 2015 ERS International Congress in Amsterdam. There were symposia on preschool wheeze, respiratory sounds and cystic fibrosis; an educational skills workshop on paediatric respiratory resuscitation; a hot topic session on risk factors and early origins of respiratory diseases; a meet the expert session on paediatric lung function test reference values; and the annual paediatric grand round. In this report the Chairs of the Paediatric Assembly's Groups highlight the key messages from the abstracts presented at the Congress.

  12. Key paediatric messages from Amsterdam

    Science.gov (United States)

    Barben, Jürg; Bohlin, Kajsa; Everard, Mark L.; Hall, Graham; Pijnenburg, Mariëlle; Priftis, Kostas N.; Rusconi, Franca; Midulla, Fabio

    2016-01-01

    The Paediatric Assembly of the European Respiratory Society (ERS) maintained its high profile at the 2015 ERS International Congress in Amsterdam. There were symposia on preschool wheeze, respiratory sounds and cystic fibrosis; an educational skills workshop on paediatric respiratory resuscitation; a hot topic session on risk factors and early origins of respiratory diseases; a meet the expert session on paediatric lung function test reference values; and the annual paediatric grand round. In this report the Chairs of the Paediatric Assembly's Groups highlight the key messages from the abstracts presented at the Congress. PMID:27730186

  13. Public/private key certification authority and key distribution. Draft

    Energy Technology Data Exchange (ETDEWEB)

    Long, J.P.; Christensen, M.J.; Sturtevant, A.P.; Johnston, W.E.

    1995-09-25

    Traditional encryption, which protects messages from prying eyes, has been used for many decades. The present concepts of encryption are built from that heritage. Utilization of modern software-based encryption techniques implies much more than simply converting files to an unreadable form. Ubiquitous use of computers and advances in encryption technology coupled with the use of wide-area networking completely changed the reasons for utilizing encryption technology. The technology demands a new and extensive infrastructure to support these functions. Full understanding of these functions, their utility and value, and the need for an infrastructure, takes extensive exposure to the new paradigm. This paper addresses issues surrounding the establishment and operation of a key management system (i.e., certification authority) that is essential to the successful implementation and wide-spread use of encryption.

  14. n-Alkane distributions as palaeoclimatic proxies in ombrotrophic peat: The role of decomposition and dominant vegetation

    NARCIS (Netherlands)

    Schellekens, J.; Buurman, P.

    2011-01-01

    n-Alkane distributions are frequently used as palaeoclimate proxies in ombrotrophic peat deposits. Although n-alkane distributions differ strongly between plant species, n-alkanes are not species-specific molecules. For a proper interpretation, it is important to understand the different abundances

  15. Quality of Life of Children with Learning Disabilities: A Comparison of Self-Reports and Proxy Reports

    Science.gov (United States)

    Sakiz, Halis; Sart, Zeynep Hande; Börkan, Bengü; Korkmaz, Baris; Babür, Nalan

    2015-01-01

    This study aimed to explore how children with learning disabilities (LD) perceive their quality of life (QoL) and to compare self-reports and proxy reports regarding their QoL. Children with LD, their typically developing peers, their parents and teachers responded to the child, parent, and teacher forms of KINDL® Questionnaire for Measuring…

  16. Investigating Forest Inventory and Analysis-collected tree-ring data from Utah as a proxy for historical climate

    Science.gov (United States)

    R. Justin DeRose; W. Shih-Yu (Simon) Wang; John D. Shaw

    2012-01-01

    Increment cores collected as part of the periodic inventory in the Intermountain West were examined for their potential to represent growth and be a proxy for climate (precipitation) over a large region (Utah). Standardized and crossdated time-series created from pinyon pine (n=249) and Douglas-fir (n=274) increment cores displayed spatiotemporal patterns in growth...

  17. Reconstruction of Antarctic climate change using ice core proxy records from the coastal Dronning Maud Land, East Antarctica

    Digital Repository Service at National Institute of Oceanography (India)

    Thamban, M.; Laluraj, C.M.; Naik, S.S.; Chaturvedi, A.

    with the proxy record of solar activity (sup (10) Be profile from a South Pole ice core), suggesting enhanced NO sub (3) – values during periods of reduced solar activity like the Dalton Minimum (approx. 1790-1830 AD) and Maunder Minimum (approx. 1640- 1710 AD...

  18. Bacterial tetraether membrane lipids in peat and coal: Testing the MBT-CBT temperature proxy for climate reconstruction

    NARCIS (Netherlands)

    Weijers, J.W.H.; Steinmann, P.; Hopmans, E.C.; Schouten, S.; Sinninghe Damsté, J.S.

    2011-01-01

    Peatlands are widespread and important natural archives of environmental change. Here we explore the potential of the recently introduced MBT-CBT proxy (methylation index and cyclisation ratio of branched tetraethers) to estimate past annual mean air temperature (MAT) based on the distribution of

  19. Bacterial tetraether membrane lipids in peat and coal: Testing the MBT-CBT temperature proxy for climate reconstruction

    NARCIS (Netherlands)

    Weijers, J.W.H.; Steinmann, P.; Hopmans, E.C.; Schouten, S.; Sinninghe Damsté, J.S.

    2011-01-01

    Peatlands are widespread and important natural archives of environmental change. Here we explore the potential of the recently introduced MBT–CBT proxy (methylation index and cyclisation ratio of branched tetraethers) to estimate past annual mean air temperature (MAT) based on the distribution of

  20. Perioperative hyperoxia - Long-term impact on cardiovascular complications after abdominal surgery, a post hoc analysis of the PROXI trial

    DEFF Research Database (Denmark)

    Fonnes, Siv; Gogenur, Ismail; Sondergaard, Edith Smed

    2016-01-01

    BACKGROUND: Increased long-term mortality was found in patients exposed to perioperative hyperoxia in the PROXI trial, where patients undergoing laparotomy were randomised to 80% versus 30% oxygen during and after surgery. This post hoc follow-up study assessed the impact of perioperative hyperoxia...

  1. A Proxy Design to Leverage the Interconnection of CoAP Wireless Sensor Networks with Web Applications

    Science.gov (United States)

    Ludovici, Alessandro; Calveras, Anna

    2015-01-01

    In this paper, we present the design of a Constrained Application Protocol (CoAP) proxy able to interconnect Web applications based on Hypertext Transfer Protocol (HTTP) and WebSocket with CoAP based Wireless Sensor Networks. Sensor networks are commonly used to monitor and control physical objects or environments. Smart Cities represent applications of such a nature. Wireless Sensor Networks gather data from their surroundings and send them to a remote application. This data flow may be short or long lived. The traditional HTTP long-polling used by Web applications may not be adequate in long-term communications. To overcome this problem, we include the WebSocket protocol in the design of the CoAP proxy. We evaluate the performance of the CoAP proxy in terms of latency and memory consumption. The tests consider long and short-lived communications. In both cases, we evaluate the performance obtained by the CoAP proxy according to the use of WebSocket and HTTP long-polling. PMID:25585107

  2. Mg/Ca in fossil oyster shells as palaeotemperature proxy, an example from the Palaeogene of Central Asia

    NARCIS (Netherlands)

    Bougeois, L.; De Rafelis, M.; Reichart, G.-J.; de Nooijer, L.J.; Dupont-Nivet, G.

    2016-01-01

    Fossil oyster shells are well-suited to provide palaeotemperature proxies from geologic to seasonal timescalesdue to their ubiquitous occurrence from Triassic to Quaternary sediments, the seasonal nature of their shellgrowth and their relative strong resistance to post-mortemalteration. However, the

  3. Mg/Ca in fossil oyster shells as palaeotemperature proxy, an example from the Palaeogene of Central Asia

    NARCIS (Netherlands)

    Bougeois, Laurie; de Rafélis, Marc; Reichart, Gert-Jan|info:eu-repo/dai/nl/165599081; de Nooijer, Lennart J.|info:eu-repo/dai/nl/337998132; Dupont-Nivet, Guillaume|info:eu-repo/dai/nl/313092559

    2016-01-01

    Fossil oyster shells are well-suited to provide palaeotemperature proxies from geologic to seasonal timescales due to their ubiquitous occurrence from Triassic to Quaternary sediments, the seasonal nature of their shell growth and their relative strong resistance to post-mortem alteration. However,

  4. Comparison of 2010 Census Nonresponse Follow-Up Proxy Responses with Administrative Records Using Census Coverage Measurement Results

    Directory of Open Access Journals (Sweden)

    Mulry Mary H.

    2017-06-01

    Full Text Available The U.S. Census Bureau is currently conducting research on ways to use administrative records to reduce the cost and improve the quality of the 2020 Census Nonresponse Followup (NRFU at addresses that do not self-respond electronically or by mail. Previously, when a NRFU enumerator was unable to contact residents at an address, he/she found a knowledgeable person, such as a neighbor or apartment manager, who could provide the census information for the residents. This was called a proxy response. The Census Bureau’s recent advances in merging federal and third-party databases raise the question: Are proxy responses for NRFU addresses more accurate than the administrative records available for the housing unit? Our study attempts to answer this question by comparing the quality of proxy responses and the administrative records for those housing units in the same timeframe using the results of 2010 Census Coverage Measurement (CCM Program. The assessment of the quality of the proxy responses and the administrative records in the CCM sample of block clusters takes advantage of the extensive fieldwork, processing, and clerical matching conducted for the CCM.

  5. Contrasting variability in foraminiferal and organic paleotemperature proxies in sedimenting particles of the Mozambique Channel (SW Indian Ocean)

    NARCIS (Netherlands)

    Fallet, U.; Ullgren, J.E; Castañeda, I.S.; van Aken, H.M.; Schouten, S.; Ridderinkhof, H.; Brummer, G.J.A.

    2011-01-01

    Accurate sea surface temperature (SST) proxies are important for understanding past ocean and climate systems. Here, we examine material collected from a deep-moored sediment trap in the Mozambique Channel (SW Indian Ocean) to constrain and compare both inorganic (delta O-18, Mg/Ca) and organic

  6. Validation of the European Proxy KIDSCREEN-52 Pilot Test Health-Related Quality of Life Questionnaire: First Results

    NARCIS (Netherlands)

    Robitail, S.; Simeoni, M.-C.; Erhart, M.; Ravens-Sieberer, U.; Bruil, J.; Auquier, P.

    2006-01-01

    Purpose: The KIDSCREEN project aims to develop a European cross-cultural generic self-administered Health-Related Quality of Life (HRQoL) instrument for children and adolescents. Proxy measures HRQoL should be a useful and practical alternative to assess children's HRQoL. The KIDSCREEN pilot study

  7. A proxy design to leverage the interconnection of CoAP Wireless Sensor Networks with Web applications.

    Science.gov (United States)

    Ludovici, Alessandro; Calveras, Anna

    2015-01-09

    In this paper, we present the design of a Constrained Application Protocol (CoAP) proxy able to interconnect Web applications based on Hypertext Transfer Protocol (HTTP) and WebSocket with CoAP based Wireless Sensor Networks. Sensor networks are commonly used to monitor and control physical objects or environments. Smart Cities represent applications of such a nature. Wireless Sensor Networks gather data from their surroundings and send them to a remote application. This data flow may be short or long lived. The traditional HTTP long-polling used by Web applications may not be adequate in long-term communications. To overcome this problem, we include the WebSocket protocol in the design of the CoAP proxy. We evaluate the performance of the CoAP proxy in terms of latency and memory consumption. The tests consider long and short-lived communications. In both cases, we evaluate the performance obtained by the CoAP proxy according to the use of WebSocket and HTTP long-polling.

  8. Fingerprinting of soil organic matter as a proxy for assessing climate and vegetation changes in last interglacial paleosols (Veldwezelt, Belgium)

    NARCIS (Netherlands)

    Vancampenhout, K.; Wouters, K.; Caus, A.; Buurman, P.; Swennen, R.; Deckers, J.

    2008-01-01

    Soil characteristics in palaeosols are an important source of information on past climate and vegetation. Fingerprinting of soil organic matter (SOM) by pyrolysis-GC/MS is assessed as a proxy for palaeo-reconstruction in the complex of humic layers on top of the Rocourt pedosequence in the

  9. A procedure to correct proxy-reported weight in the National Health Interview Survey, 1976–2002

    Directory of Open Access Journals (Sweden)

    Utz Rebecca L

    2009-01-01

    Full Text Available Abstract Background Data from the National Health Interview Survey (NHIS show a larger-than-expected increase in mean BMI between 1996 and 1997. Proxy-reports of height and weight were discontinued as part of the 1997 NHIS redesign, suggesting that the sharp increase between 1996 and 1997 may be artifactual. Methods We merged NHIS data from 1976–2002 into a single database consisting of approximately 1.7 million adults aged 18 and over. The analysis consisted of two parts: First, we estimated the magnitude of BMI differences by reporting status (i.e., self-reported versus proxy-reported height and weight. Second, we developed a procedure to correct biases in BMI introduced by reporting status. Results Our analyses confirmed that proxy-reports of weight tended to be biased downward, with the degree of bias varying by race, sex, and other characteristics. We developed a correction procedure to minimize BMI underestimation associated with proxy-reporting, substantially reducing the larger-than-expected increase found in NHIS data between 1996 and 1997. Conclusion It is imperative that researchers who use reported estimates of height and weight think carefully about flaws in their data and how existing correction procedures might fail to account for them. The development of this particular correction procedure represents an important step toward improving the quality of BMI estimates in a widely used source of epidemiologic data.

  10. Economic valuation of informal care: lessons from the application of the opportunity costs and proxy good methods

    NARCIS (Netherlands)

    van den Berg, Bernard; Brouwer, Werner; van Exel, Job; Koopmanschap, Marc; van den Bos, Geertrudis A. M.; Rutten, Frans

    2006-01-01

    This paper reports the results of the application of the opportunity costs and proxy good methods to determine a monetary value of informal care. We developed a survey in which we asked informal caregivers in The Netherlands to indicate the different types of time forgone (paid work, unpaid work and

  11. Constant Flux Proxies and Pleistocene Sediment Accumulation Rates on the Juan de Fuca Ridge in the Northeast Pacific

    Science.gov (United States)

    Middleton, J. L.; Mukhopadhyay, S.; Langmuir, C. H.; Costa, K.; McManus, J. F.; d'Almeida, M.; Huybers, P. J.; Winckler, G.

    2016-12-01

    Mass accumulation rates of marine sediments are often employed to constrain deposition rates of important proxies such as terrigenous dust, carbonate, and biogenic opal to quantitatively examine variations in continental aridity, atmospheric transport, and biologic productivity across changing climatic conditions. However, deposition rates that are estimated using traditional mass accumulation rates calculated from sediment core age models can be subject to bias from lateral sediment transport and limited age model resolution. Constant flux proxies, such as extraterrestrial helium-3 (3HeET) and excess thorium-230 (230ThXS), can be used to calculate vertical sediment accumulation rates that are independent of age model uncertainties and the effects of lateral sediment transport. While a short half-life limits analyses of 230ThXS to the past 500 ka, 3HeET is stable and could be used to constrain sedimentary fluxes during much of the Cenozoic. Despite the vast paleoceanographic potential of constant flux proxies, few studies have directly compared the behavior of 230ThXS and 3HeET using measurements from the same samples. Sediment grain size fractionation and local scavenging effects may differentially bias one or both proxy systems and complicate the interpretation of 230ThXS or 3HeET data. We will present a new record of vertical sediment accumulation rates spanning the past 600 ka in the Northeast Pacific constrained using analyses of both 3HeET and 230ThXS in two sediment cores from cruise AT26-19 on the Juan de Fuca Ridge. Such a record allows for intercomparison of both constant flux proxies in the mid-ocean ridge environment and examination of sedimentary behavior across multiple glacial cycles. The 230ThXS-derived accumulation rates typically range from 0.5 to 2 g cm-2 ka-1 over the past 450 ka, with periods of maximum deposition coinciding with glacial maxima. Preliminary results of samples analyzed with both 3HeET and 230ThXS indicate relative consistency

  12. The conceptualization and measurement of cognitive reserve using common proxy indicators: Testing some tenable reflective and formative models.

    Science.gov (United States)

    Ikanga, Jean; Hill, Elizabeth M; MacDonald, Douglas A

    2017-02-01

    The examination of cognitive reserve (CR) literature reveals a lack of consensus regarding conceptualization and pervasive problems with its measurement. This study aimed at examining the conceptual nature of CR through the analysis of reflective and formative models using eight proxies commonly employed in the CR literature. We hypothesized that all CR proxies would significantly contribute to a one-factor reflective model and that educational and occupational attainment would produce the strongest loadings on a single CR factor. The sample consisted of 149 participants (82 male/67 female), with 18.1 average years of education and ages of 45-99 years. Participants were assessed for eight proxies of CR (parent socioeconomic status, intellectual functioning, level of education, health literacy, occupational prestige, life leisure activities, physical activities, and spiritual and religious activities). Primary statistical analyses consisted of confirmatory factor analysis (CFA) to test reflective models and structural equation modeling (SEM) to evaluate multiple indicators multiple causes (MIMIC) models. CFA did not produce compelling support for a unitary CR construct when using all eight of our CR proxy variables in a reflective model but fairly cogent evidence for a one-factor model with four variable proxies. A second three-factor reflective model based upon an exploratory principal components analysis of the eight proxies was tested using CFA. Though all eight indicators significantly loaded on their assigned factors, evidence in support of overall model fit was mixed. Based upon the results involving the three-factor reflective model, two alternative formative models were developed and evaluated. While some support was obtained for both, the model in which the formative influences were specified as latent variables appeared to best account for the contributions of all eight proxies to the CR construct. While the findings provide partial support for our

  13. Tales from the South (and West) Pacific in the Common Era: A Climate Proxy Perspective (Invited)

    Science.gov (United States)

    Quinn, T. M.; Taylor, F. W.; Partin, J. W.; Maupin, C. R.; Hereid, K. A.; Gorman, M. K.

    2010-12-01

    The southwest Pacific is a major source of tropical climate variability through heat and moisture exchanges associated with the Western Pacific Warm Pool (WPWP) and the South Pacific Convergence Zone (SPCZ). These variations are especially significant at the annual, interannual (El Niño-Southern Oscillation, ENSO), and multi-decadal timescales. Gridded SST data products are available in the pre-satellite era in this region for the past ~130 years, although data density is a significant issue for the older half of these records. Time series of salinity (SSS) and rainfall from this region are exceedingly rare. Thus, climate proxy records must be used to reconstruct SST, SSS, and rainfall variations in the Common Era (CE) in the tropical Pacific. The analytical laboratory for paleoclimate studies at UT has focused its research efforts into producing climate proxy time series from southwest tropical Pacific using modern and fossil corals, and speleothems. Our most recent results are summarized in this presentation, although much of this work is still in progress. Coral climate records have been generated from Sabine Bank, Vanuatu (16°S, 166°E) and Misima Island, Papua New Guinea (10.6°S, 152.8°E). The Vanuatu coral record of monthly resolved Sr/Ca variations extends back to the late 18th century. All strong ENSO warm phase events of the 20th century observed in the instrumental record are also observed in the coral record. We note that several ENSO warm phase events in the 19th century portion of the coral record are comparable in size to that recorded in response to the 1982/1983 and 1997/1998 events. The Misima coral record of monthly resolved δ18O and Sr/Ca variations spans the interval ~1414-1645 CE — the heart of the Little Ice Age. Amplitude modulation of interannual variability is observed in this LIA record, much like what is observed during the relatively quiescent period of 1920-1950 in the 20th century instrumental and proxy records of ENSO. However

  14. Improved spectral comparisons of paleoclimate models and observations via proxy system modeling: Implications for multi-decadal variability

    Science.gov (United States)

    Dee, S. G.; Parsons, L. A.; Loope, G. R.; Overpeck, J. T.; Ault, T. R.; Emile-Geay, J.

    2017-10-01

    The spectral characteristics of paleoclimate observations spanning the last millennium suggest the presence of significant low-frequency (multi-decadal to centennial scale) variability in the climate system. Since this low-frequency climate variability is critical for climate predictions on societally-relevant scales, it is essential to establish whether General Circulation models (GCMs) are able to simulate it faithfully. Recent studies find large discrepancies between models and paleoclimate data at low frequencies, prompting concerns surrounding the ability of GCMs to predict long-term, high-magnitude variability under greenhouse forcing (Laepple and Huybers, 2014a, 2014b). However, efforts to ground climate model simulations directly in paleoclimate observations are impeded by fundamental differences between models and the proxy data: proxy systems often record a multivariate and/or nonlinear response to climate, precluding a direct comparison to GCM output. In this paper we bridge this gap via a forward proxy modeling approach, coupled to an isotope-enabled GCM. This allows us to disentangle the various contributions to signals embedded in ice cores, speleothem calcite, coral aragonite, tree-ring width, and tree-ring cellulose. The paper addresses the following questions: (1) do forward-modeled ;pseudoproxies; exhibit variability comparable to proxy data? (2) if not, which processes alter the shape of the spectrum of simulated climate variability, and are these processes broadly distinguishable from climate? We apply our method to representative case studies, and broaden these insights with an analysis of the PAGES2k database (PAGES2K Consortium, 2013). We find that current proxy system models (PSMs) can help resolve model-data discrepancies on interannual to decadal timescales, but cannot account for the mismatch in variance on multi-decadal to centennial timescales. We conclude that, specific to this set of PSMs and isotope-enabled model, the paleoclimate

  15. gLExec and MyProxy integration in the ATLAS/OSG PanDA workload management system

    Science.gov (United States)

    Caballero, J.; Hover, J.; Litmaath, M.; Maeno, T.; Nilsson, P.; Potekhin, M.; Wenaus, T.; Zhao, X.

    2010-04-01

    Worker nodes on the grid exhibit great diversity, making it difficult to offer uniform processing resources. A pilot job architecture, which probes the environment on the remote worker node before pulling down a payload job, can help. Pilot jobs become smart wrappers, preparing an appropriate environment for job execution and providing logging and monitoring capabilities. PanDA (Production and Distributed Analysis), an ATLAS and OSG workload management system, follows this design. However, in the simplest (and most efficient) pilot submission approach of identical pilots carrying the same identifying grid proxy, end-user accounting by the site can only be done with application-level information (PanDA maintains its own end-user accounting), and end-user jobs run with the identity and privileges of the proxy carried by the pilots, which may be seen as a security risk. To address these issues, we have enabled PanDA to use gLExec, a tool provided by EGEE which runs payload jobs under an end-user's identity. End-user proxies are pre-staged in a credential caching service, MyProxy, and the information needed by the pilots to access them is stored in the PanDA DB. gLExec then extracts from the user's proxy the proper identity under which to run. We describe the deployment, installation, and configuration of gLExec, and how PanDA components have been augmented to use it. We describe how difficulties were overcome, and how security risks have been mitigated. Results are presented from OSG and EGEE Grid environments performing ATLAS analysis using PanDA and gLExec.

  16. Validation of Spacecraft Active Cavity Radiometer Total Solar Irradiance (TSI) Long Term Measurement Trends Using Proxy TSI Least Squares Analyses

    Science.gov (United States)

    Lee, Robert Benjamin, III; Wilson, Robert S.

    2003-01-01

    Long-term, incoming total solar irradiance (TSI) measurement trends were validated using proxy TSI values, derived from indices of solar magnetic activity. Spacecraft active cavity radiometers (ACR) are being used to measure longterm TSI variability, which may trigger global climate changes. The TSI, typically referred to as the solar constant, was normalized to the mean earth-sun distance. Studies of spacecraft TSI data sets confirmed the existence of a 0.1 %, long-term TSI variability component within a 10-year period. The 0.1% TSI variability component is clearly present in the spacecraft data sets from the 1984-2004 time frame. Typically, three overlapping spacecraft data sets were used to validate long-term TSI variability trends. However, during the years of 1978-1984, 1989-1991, and 1993-1996, three overlapping spacecraft data sets were not available in order to validate TSI trends. The TSI was found to vary with indices of solar magnetic activity associated with recent 10-year sunspot cycles. Proxy TSI values were derived from least squares analyses of the measured TSI variability with the solar indices of 10.7-cm solar fluxes, and with limb-darked sunspot fluxes. The resulting proxy TSI values were compared to the spacecraft ACR measurements of TSI variability to detect ACR instrument degradation, which may be interpreted as TSI variability. Analyses of ACR measurements and TSI proxies are presented primarily for the 1984-2004, Earth Radiation Budget Experiment (ERBE) ACR solar monitor data set. Differences in proxy and spacecraft measurement data sets suggest the existence of another TSI variability component with an amplitude greater than or equal to 0.5 Wm-2 (0.04%), and with a cycle of 20 years or more.

  17. Luminescence signal profiling: a new proxy for sedimentologically "invisible" marine Mass Transport Deposits (MTDs)

    Science.gov (United States)

    López, Gloria I.; Bialik, Or; Waldmann, Nicolas

    2017-04-01

    When dealing with fine-grained, organic-rich, colour-monotone, underwater marine sediment cores retrieved from the continental shelf or slope, the initial visual impression, upon split-opening the vessels, is often of a "disappointing" homogeneous, monotonous, continuous archive. Only after thorough, micro- to macro-scale, multi-parameter investigations the sediment reveals its treasures, initially by performing some measurements on the intact core itself, hence depicting for the first time its contents, and subsequently by carrying out the destructive, multi-proxy sample-based analyses. Usually, routine Multi-Sensor Core Logger (MSCL) measurements of petrophysical parameters (e.g. magnetic susceptibility, density, P-Wave velocity) on un-split sediment cores are the first undertaken while still on-board in the field or back at the laboratory. Less often done, but equally valuable, are continuous X-Ray and CT scan imaging of the same intact archives. Upon splitting, routine granulometry, micro- and macro-fossil and invertebrate identification, total organic / inorganic carbon content (TOC / TIC), amid other analyses take place. The geochronology component is also established usually by AMS 14C on selected organic-rich units, and less common is Optically Stimulated Luminescence (OSL) dating used on the coarser-grained, siliciclastic layers. A relatively new tool used in Luminescence, the Portable OSL Reader, employed to rapidly assess the luminescence signal of untreated poly-mineral samples to assist with targeted field sampling for full OSL dating, was used for the first time in marine sediment cores as a novel petrophysical characterization tool with astonishing results. In this study, two 2 m-long underwater piston sediment cores recovered from 200 m depths on the continental shelf off-southern Israel, were subjected to pulsed-photon stimulation (PPSL) obtaining favourable luminescence signals along their entire lengths. Astoundingly, luminescence signals were

  18. Holocene seasonal variability inferred from multiple proxy records from Crevice Lake, Yellowstone National Park, USA

    Science.gov (United States)

    Whitlock, Cathy; Dean, Walter E.; Fritz, Sherilyn C.; Stevens, Lora R.; Stone, Jeffery R.; Power, Mitchell J.; Rosenbaum, Joseph R.; Pierce, Kenneth L.; Bracht-Flyr, Brandi B.

    2012-01-01

    A 9400-yr-old record from Crevice Lake, a semi-closed alkaline lake in northern Yellowstone National Park, was analyzed for pollen, charcoal, geochemistry, mineralogy, diatoms, and stable isotopes to develop a nuanced understanding of Holocene environmental history in a region of northern Rocky Mountains that receives both summer and winter precipitation. The limited surface area, conical bathymetry, and deep water (> 31 m) of Crevice Lake create oxygen-deficient conditions in the hypolimnion and preserve annually laminated sediment (varves) for much of the record. Pollen data indicate that the watershed supported a closed Pinus-dominated forest and low fire frequency prior to 8200 cal yr BP, followed by open parkland until 2600 cal yr BP, and open mixed-conifer forest thereafter. Fire activity shifted from infrequent stand-replacing fires initially to frequent surface fires in the middle Holocene and stand-replacing events in recent centuries. Low values of δ18O suggest high winter precipitation in the early Holocene, followed by steadily drier conditions after 8500 cal yr BP. Carbonate-rich sediments before 5000 cal yr BP imply warmer summer conditions than after 5000 cal yr BP. High values of molybdenum (Mo), uranium (U), and sulfur (S) indicate anoxic bottom-waters before 8000 cal yr BP, between 4400 and 3900 cal yr BP, and after 2400 cal yr BP. The diatom record indicates extensive water-column mixing in spring and early summer through much of the Holocene, but a period between 2200 and 800 cal yr BP had strong summer stratification, phosphate limitation, and oxygen-deficient bottom waters. Together, the proxy data suggest wet winters, protracted springs, and warm effectively wet summers in the early Holocene and less snowpack, cool springs, warm dry summers in the middle Holocene. In the late Holocene, the region and lake experienced extreme changes in winter, spring, and summer conditions, with particularly short springs and dry summers and winters during

  19. Improvements of palaeochemotaxonomy as a palaeofloristic proxy using artificial maturation of extant conifers

    Science.gov (United States)

    Lu, Y.; Hautevelle, Y.; Michels, R.

    2012-04-01

    Numerous studies of the molecular composition of terrestrial plants show that many organic compounds have a chemotaxonomic value. This means that these biomolecules are synthesized by a restricted number of taxa and can be used as specific biomarkers. Some of these biomolecules, like terpenoids, are poorly altered and preserved in sediments where they are then transformed into geomolecules. Thus, the distribution of vascular plant biomarkers preserved in sedimentary rocks could serve as proxy for terrestrial palaeoflora assessment. Furthermore, as flora association may reflect climatic conditions, vascular plant biomarkers may also serve as palaeoclimatic proxies. Botanical palaeochemotaxonomy presents some specific attributes compared to palaeobotany and palynology in the reconstruction of palaeofloristic and palaeoclimatic evolutions through geological time : 1) plant biomarkers are more widespread in the stratigraphic record than well preserved plant macrofossils, 2) on the contrary to palynomorphs they can be directly linked to specific plant taxa, 3) biomarkers are readily analyzed by usual organic geochemistry procedures. However, our knowledge in botanical palaeochemotaxonomy, allowing to link geomolecular markers to botanical taxa, is still incomplete. Difficulties are related to 1) extrapolation of information from extant plants to their fossil counterparts, 2) the scarcity of well preserved and identifiable fossils. In order to help fill these gaps, we use an experimental method based on artificial maturation of extant plants by confined pyrolysis (*Hautevelle et al. 2006). This technique allows to simulate conversion of biomolecules into diagenetized compounds. The objective of this study is to clarify the molecular signature of fossil conifer families. 69 species belonging to seven families of extant conifers (Araucariaceae, Cupressaceae, Pinaceae, Podocarpaceae, Sciadopityaceae, Taxaceae and Taxodiaceae) were pyrolyzed. Extractable organic matter is

  20. WOOD CELLULAR DENDROCLIMATOLOGY: TESTING NEW PROXIES IN GREAT BASIN BRISTLECONE PINE

    Directory of Open Access Journals (Sweden)

    Emanuele Ziaco

    2016-10-01

    Full Text Available Dendroclimatic proxies can be generated from the analysis of wood cellular structures, allowing for a more complete understanding of the physiological mechanisms that control the climatic response of tree species. Century-long (1870-2013 time series of anatomical parameters were developed for Great Basin bristlecone pine (Pinus longaeva D.K. Bailey by capturing strongly contrasted microscopic images through a Confocal Laser Scanning Microscope. Environmental information embedded in wood anatomical series was analyzed in comparison with ring-width series using measures of empirical signal strength. Response functions were calculated against monthly climatic variables to evaluate climate sensitivity of cellular features (e.g. lumen area; lumen diameter for the period 1950-2013. Calibration-verification tests were used to determine the potential to generate long climate reconstructions from these anatomical proxies. A total of eight tree-ring parameters (two ring-width and six chronologies of xylem anatomical parameters were analyzed. Synchronous variability among samples varied among tree-ring parameters, usually decreasing from ring width to anatomical features. Cellular parameters linked to plant hydraulic performance (e.g. tracheid lumen area and radial lumen diameter showed empirical signal strength similar to ring-width series, while noise was predominant in chronologies of lumen tangential width and cell-wall thickness. Climatic signals were different between anatomical and ring-width chronologies, revealing a positive and temporally stable correlation of tracheid size (i.e. lumen and cell diameter with monthly (i.e. March and seasonal precipitation. In particular, tracheid lumen diameter emerged as a reliable moisture indicator and was then used to reconstruct total March-August precipitation from 1870 to 2013. Wood anatomy holds great potential to refine and expand dendroclimatic records by allowing estimates of plant physiological

  1. Analysis of the application efficiency of the enzyme preparation Ladozim Proxy in the poultry industry

    Directory of Open Access Journals (Sweden)

    A. G. Hurieva

    2016-09-01

    Full Text Available The necessity has been widely noted of improving the nutritional value of forage mixtures used in the poultry industry through the use of enzyme preparations on the basis of phytase for splitting phytic acid and its salts contained in the feed. This technological approach is relevant in feeding farm animals, particularly poultry, as they are unable to synthesise endogenous phytase. On the base of the Agro-Industrial Complex "Oril-Leader" we researched the influence of the enzyme preparation Ladozim Proxy as a feed component for broiler chickens and laying hens on the growth and biochemical parameters of the birds and their egg-laying capacity. The feed ration consisted of wheat, corn, sunflower meal, extruded soy and protein-vitamin complex Biomix. For the research experimental and control groups of broiler chickens were formed (50 birds in each group and laying hens (20 birds in each group. The experimental feeding period was 35 days for the chickens and 30 days for the hens. The research used physical-chemical methods for determining the content of nitrogen, calcium and phosphorus in the feed, the blood and the excrement of the birds. Statistical data processing was carried out by ANOVA. It was established that the use of Ladozim Proxy in the amount of 60–100 mg/kg feed promotes an increase of the live weight of chickens by 21%. The findings can be explained by an increase of the feed nutrients available for digestion in the gastrointestinal tracts of the poultry due to the hydrolytic action of the enzyme complex added to the phytic-containing components of the feed. The result of these phenomena is also a positive dynamic in assimilation of nitrogen, calcium and phosphorus in the feed by chickens of the experimental group: use of these elements increased by 10–16%. The preparation had no effect on hematological indices of the organisms of the poultry and increased the amount of calcium and phosphorus in the blood. The use of the

  2. Multi-proxy constraints on sapropel formation during the late Pliocene of central Mediterranean (southwest Sicily)

    Science.gov (United States)

    Plancq, Julien; Grossi, Vincent; Pittet, Bernard; Huguet, Carme; Rosell-Melé, Antoni; Mattioli, Emanuela

    2015-06-01

    The late Pliocene (Piacenzian) in the Mediterranean region was punctuated by short-lived episodes of widespread deposition of organic-rich sedimentary layers known as sapropels. The causes of their formation remain a long-standing debate in the science community, and require disentangling the roles of climatic/oceanographic processes that triggered higher primary productivity or enhanced organic matter preservation. The lack of data, especially of sea temperatures at sufficient temporal resolution, is one of the main challenges to solve this debate. Here, we present new organic geochemistry and micropaleontological data from the late Pliocene at Punta Grande/Punta Piccola sections (southwest Sicily) that allow untangling the mechanisms that favored the formation of two sapropel series (noted S and A) in the central Mediterranean area during this period. Sea surface (SSTs) and subsurface temperatures were estimated using three distinct organic geochemical proxies namely the alkenone unsaturation index (UK‧37), the long-chain diol index (LDI) and the tetraether index (TEX86). Reconstructed SSTs are relatively stable throughout the late Pliocene and ∼4 °C higher than modern Mediterranean SSTs, which is consistent with the climatic conditions inferred for this period from paleoclimate modeling. An increase in SST is, however, recorded by UK‧37 and LDI proxies across each sapropel horizon, supporting that the two sapropel series S and A were formed during warmer climate conditions. The comparison of SST data with variations in accumulation rates of total organic carbon and lipid-biomarkers (alkenones, long-chain alkyl diols, archaeal and bacterial tetraethers), and with changes in calcareous nannofossil assemblages, indicates that the studied sapropels might have formed under different environmental conditions. The first series of sapropels (S), deposited between 3.1 and 2.8 Ma, is likely due to a better preservation of organic matter, induced by the development

  3. Origin and applicability of tetraether membrane lipids as temperature proxies in French peri-urban lakes

    Science.gov (United States)

    Mainié, François; Huguet, Arnaud; Breban, Alice; Lacroix, Gérard; Anquetil, Christelle; Derenne, Sylvie

    2015-04-01

    The Ile-de-France region is the most populated area in France, with ca. 12 million inhabitants, i.e. about 20 % of French population. The peri-urban aquatic ecosystems of this region are impacted by a large variety of environmental stressors, and especially high anthropogenic pressures (agricultural, industrial and urban pollutants), leading to the increased eutrophication of these water systems. The Ile-de-France lakes are therefore highly vulnerable ecosystems. Over the last years, several environmental markers have been developed to better understand the functioning of aquatic ecosystems, including the so-called GDGTs (glycerol dialkyl glycerol tetraethers). GDGTs are membrane lipids produced by archaea and some unknown bacteria, which are increasingly used to reconstruct mean annual air and surface water temperature as well as pH. These compounds are ubiquitous in terrestrial and aquatic environments, but their origin and applicability as temperature and pH proxies in lakes, especially highly polluted ones, need further investigation. In this study, GDGTs were analysed in 33 lakes from the Ile-de-France region, representing the diversity of the regional landscape and characterised by different levels of eutrophication. The abundance and distribution of GDGTs in lacustrine sediments and surrounding soils were compared. Bacterial GDGTs were systematically much more abundant in sediments than in soils and displayed different distributions in the two types of environments, showing that they are mainly produced in situ in lakes, in the water column and/or sediment. Similarly, the concentration in archaeal GDGTs was much higher in sediments than in soils and the distribution of these compounds differed between soils and sediments, implying that the predominant archaeal communities are not the same in the two environments. When the lakes are distinguished by their eutrophication level, the latter was shown for the first time to have an impact on the microorganisms

  4. UV-B absorbing compounds in present-day and fossil pollen, spores, cuticles seed coats and wood: evaluation of a proxy for solar UV-B radiation.

    NARCIS (Netherlands)

    Rozema, J.; Blokker, P.; Mayoral Fuertes, M.; Broekman, R.A.

    2009-01-01

    UV-B absorbing compounds (UACs) in present-day and fossil pollen, spores, cuticles, seed coats and wood have been evaluated as a proxy for past UV. This proxy may not only provide information on variation of stratospheric ozone and solar UV in the period preceding and during the Antarctic ozone hole

  5. Reconstruction of late Quaternary marine and terrestrial environmental conditions of Northwest Africa and Southeast Australia : a multiple organic proxy study using marine sediments

    NARCIS (Netherlands)

    Alfama Lopes dos Santos, R.

    2012-01-01

    NW Africa and SE Australia are regions which are particularly vulnerable to climate change. In this thesis, organic proxies are used from marine sediment cores to reconstruct past environmental conditions from these areas. In sediments from NW Africa, the UK'37 showed an efficient proxy for sea

  6. Key Aspects of Wave Energy

    DEFF Research Database (Denmark)

    Margheritini, Lucia; Nørgaard, Jørgen Harck

    2012-01-01

    Diversification of renewable energy sources is fundamental to ensure sustainability. In this contest, wave energy can provide a substantial contribution as soon as the sector breaks into the market. In order to accelerate shift from a technology to a market focus and reduce technical and non...... be used as a breakwater therefore providing a solid structure for harbor protection; the Wave Star can be used as a base for offshore wind and photovoltaic installation in the middle of the sea, realizing an hybrid renewable energy platform. It is the authors´ believe that taking wave energy devices......-technical risks, it is critical to provide comprehensive and reliable information on the technologies without neglecting attractive advantages. It is possible to underline a different key of lecture of wave energy performance by considering efficiency and power production as well as device versatility...

  7. Fibre optic communication key devices

    CERN Document Server

    Grote, Norbert

    2017-01-01

    The book gives an in-depth description of key devices of current and next generation fibre optic communication networks. Devices treated include semiconductor lasers, optical amplifiers, modulators, wavelength filters and other passives, detectors, all-optical switches, but relevant properties of optical fibres and network aspects are included as well. The presentations include the physical principles underlying the various devices, technologies used for their realization, typical performance characteristics and limitations, but development trends towards more advanced components are also illustrated. This new edition of a successful book was expanded and updated extensively. The new edition covers among others lasers for optical communication, optical switches, hybrid integration, monolithic integration and silicon photonics. The main focus is on Indium phosphide-based structures but silicon photonics is included as well. The book covers relevant principles, state-of-the-art implementations, status of curren...

  8. Applied public-key steganography

    Science.gov (United States)

    Guillon, Pierre; Furon, Teddy; Duhamel, Pierre

    2002-04-01

    We consider the problem of hiding information in a steganographic framework, i.e. embedding a binary message within an apparently innocuous content, in order to establish a suspicion-free digital communication channel. The adversary is passive as no intentional attack is foreseen. The only threat is that she discovers the presence of a hidden communication. The main goal of this article is to find if the Scalar Costa Scheme, a recently published embedding method exploiting side information at the encoder, is suitable for that framework. We justify its use assessing its security level with respect to the Cachin's criterion. We derive a public-key stego-system following the ideas of R. Anderson and P. Petitcolas. This technique is eventually applied to PCM audio contents. Experimental performances are detailed in terms of bit-rate and Kullback-Leibler distance.

  9. Key energy technologies for Europe

    Energy Technology Data Exchange (ETDEWEB)

    Holst Joergensen, Birte

    2005-09-01

    The report is part of the work undertaken by the High-Level Expert Group to prepare a report on emerging science and technology trends and the implications for EU and Member State research policies. The outline of the report is: 1) In the introductory section, energy technologies are defined and for analytical reasons further narrowed down; 2) The description of the socio-economic challenges facing Europe in the energy field is based on the analysis made by the International Energy Agency going back to 1970 and with forecasts to 2030. Both the world situation and the European situation are described. This section also contains an overview of the main EU policy responses to energy. Both EU energy R and D as well as Member State energy R and D resources are described in view of international efforts; 3) The description of the science and technology base is made for selected energy technologies, including energy efficiency, biomass, hydrogen, and fuel cells, photovoltaics, clean fossil fuel technologies and CO{sub 2} capture and storage, nuclear fission and fusion. When possible, a SWOT is made for each technology and finally summarised; 4) The forward look highlights some of the key problems and uncertainties related to the future energy situation. Examples of recent energy foresights are given, including national energy foresights in Sweden and the UK as well as links to a number of regional and national foresights and roadmaps; 5) Appendix 1 contains a short description of key international organisations dealing with energy technologies and energy research. (ln)

  10. Fluorescence-based proxies for lignin in freshwater dissolved organic matter

    Science.gov (United States)

    Hernes, Peter J.; Bergamaschi, Brian A.; Eckard, Robert S.; Spencer, Robert G.M.

    2009-01-01

    Lignin phenols have proven to be powerful biomarkers in environmental studies; however, the complexity of lignin analysis limits the number of samples and thus spatial and temporal resolution in any given study. In contrast, spectrophotometric characterization of dissolved organic matter (DOM) is rapid, noninvasive, relatively inexpensive, requires small sample volumes, and can even be measured in situ to capture fine-scale temporal and spatial detail of DOM cycling. Here we present a series of cross-validated Partial Least Squares models that use fluorescence properties of DOM to explain up to 91% of lignin compositional and concentration variability in samples collected seasonally over 2 years in the Sacramento River/San Joaquin River Delta in California, United States. These models were subsequently used to predict lignin composition and concentration from fluorescence measurements collected during a diurnal study in the San Joaquin River. While modeled lignin composition remained largely unchanged over the diurnal cycle, changes in modeled lignin concentrations were much greater than expected and indicate that the sensitivity of fluorescence-based proxies for lignin may prove invaluable as a tool for selecting the most informative samples for detailed lignin characterization. With adequate calibration, similar models could be used to significantly expand our ability to study sources and processing of DOM in complex surface water systems.

  11. Silicon isotopes in allophane as a proxy for mineral formation in volcanic soils

    Energy Technology Data Exchange (ETDEWEB)

    Opfergelt, S., E-mail: sophie.opfergelt@uclouvain.be [Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN (United Kingdom)] [Earth and Life Institute, Universite catholique de Louvain, Croix du Sud 2/10, 1348 Louvain-la-Neuve (Belgium); Georg, R.B. [Trent University, Worsfold Water Quality Centre, 1600 West Bank Dr., Peterborough, Ontario (Canada); Burton, K.W. [Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN (United Kingdom); Guicharnaud, R. [Agricultural University of Iceland, Keldnaholt 112, Reykjavik (Iceland); Siebert, C. [Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN (United Kingdom); Gislason, S.R. [Institute of Earth Sciences, University of Iceland, Sturlugata 7, 101 Reykjavik (Iceland); Halliday, A.N. [Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN (United Kingdom)

    2011-06-15

    Highlights: > The fate of dissolved Si in volcanic soils strongly depends on Al availability. > Lighter {delta}{sup 30}Si ratios in allophane relative to the basalt reflect weathering processes. > Heavier {delta}{sup 30}Si ratios in allophane indicate Si precipitation as Al is humus-complexed. > Allophane {delta}{sup 30}Si ratios could be useful in paleo-environmental reconstruction. - Abstract: Weathering of basaltic ash in volcanic areas produces andosols, rich in allophane and ferrihydrite. Since the rate of mineral formation is very useful in climate and geochemical modelling, this study investigates Si isotope compositions of allophane as a proxy for mineral formation. Allophane formed in contrasting conditions in five Icelandic soil profiles displays silicon isotope signatures lighter than the basalt in less weathered soils (-0.64 {+-} 0.15 per mille), and heavier in more weathered organic-rich soils (+0.23 {+-} 0.10 per mille). The fate of the dissolved Si in those volcanic soils strongly depends on Al availability. In organic-rich soils, most of Al is humus-complexed, and the results support that Si precipitates as opaline silica by super-saturation, leaving an isotopically heavier dissolved Si pool to form allophane with uncomplexed Al. This study highlights that Si isotopes can be useful to record successive soil processes involved in mineral formation, which is potentially useful in environmental paleo-reconstruction.

  12. Comparison of new geochemical proxies in a stalagmite from sub tropical Mexico

    Science.gov (United States)

    Ernesto, H.; Bernal, J.; Lounejeva, E.; McCulloch, M.; Morales, P.; Cienfuegos, E.

    2007-05-01

    The mexican subtropics represent an interesting area to understand past climate change and variability since it is located within the current northern limit of the Inter Tropical Convergence Zone(ITCZ). Consequently, the area is very sensitive to changes in the average position of the ITCZ. We have collected a 33cm stalagmite from Cuetzalan, Pue. Mex (20°00'N, 97°32'W), that grew between 24.08 to 22.35 ky B.P. The stalagmite was analyzed for Sr/Ca, Ba/Ca, Mg/Ca, U/Ca molar ratios, δ13C, δ18O, [234U/238U], and other trace elements, and represents the first stalagmite record from tropical Mexico. Significant variations in the [234U/238U] in the stalagmite, suggest changes in the local weathering rates that are not reflected in other geochemical proxies. However, comparison of the E/Ca and δ18O with records from Hulu (China) and Botuvera (Brazil) caves suggest that the climate in the area was in line with the global climate system.

  13. SO2 as a possible proxy for volcanic ash in aviation hazard avoidance

    Science.gov (United States)

    Sears, T. M.; Thomas, G. E.; Carboni, E.; Smith, A. J. A.; Grainger, R. G.

    2013-06-01

    Airborne volcanic ash poses a significant danger to aircraft, but is difficult to quantify accurately using satellite data, while sulphur dioxide is much easier to detect accurately, but is much less of a direct hazard to aviation. This paper investigates the reliability of using SO2 as a proxy for the location of volcanic ash, using an SO2 retrieval from the Infrared Atmospheric Sounding Interferometer (IASI) and ash detections from IASI and the Advanced Along Track Scanning Radiometer (AATSR). Using a numerical "missed ash fraction" applied to the eruptions of Eyjafjallajökull in 2010 and Puyehue-Cordón Caulle in 2011 reveals that the SO2 flag typically misses ˜30% of the detectable ash. Furthermore, the missed ash fraction is found to be highly variable, both between the two eruptions and over the course of each eruption, with values of over 80% found on some days. The detection threshold of the AATSR ash flag is also investigated using radiative transfer calculations, allowing the threshold of the IASI flag to be inferred, and these are related to the ash contamination levels.

  14. CAN ACCOUNTING INFORMATION ACT AS A PROXY FOR EX ANTE UNCERTAINTY IN INITIAL PUBLIC OFFERINGS?

    Directory of Open Access Journals (Sweden)

    Tatang Ary Gumanti

    2003-06-01

    Full Text Available This paper reviews and summarizes previous works and the rationale for the proposition that accounting information is in fact value relevant in the determination of an initial public offering IPO.Theoretical and empirical evidence has indicated that certain accounting measures can he used as proxies for total firm risk, that is, they could determine the riskiness of a corporation. The literature also advocates that accounting information is relevant in determining the value and thus the riskiness of a corporation through the use of accounting analysis. Since most of the information available in the prospectus is accounting information, it is arguable that this information represents a potential source for assessing the issuing firm. Some scholars have also advocated the possibility of using accounting information in assessing the value of firm making an IPO. Numerous papers have provided analytical and empirical evidence of the association between accounting numbers and the value of IPOs. The conclusion generally comes to show that information in the prospectus is value relevant concerning the IPO. The paper shows that it is indeed an arguable to use accounting information in the valuation of an IPO. Accordingly, it is an empirical issue whether accounting information has the property in explaining the ex-ante uncertainty of an IPO.

  15. Modelling an alkenone-like proxy record in the NW African upwelling

    Directory of Open Access Journals (Sweden)

    X. Giraud

    2006-01-01

    Full Text Available A regional biogeochemical model is applied to the NW African coastal upwelling between 19° N and 27° N to investigate how a water temperature proxy, alkenones, are produced at the sea surface and recorded in the slope sediments. The biogeochemical model has two phytoplankton groups: an alkenone producer group, considered to be coccolithophores, and a group comprising other phytoplankton. The Regional Ocean Modelling System (ROMS is used to simulate the ocean circulation and takes advantage of the Adaptive Grid Refinement in Fortran (AGRIF package to set up an embedded griding system. In the simulations the alkenone temperature records in the sediments are between 1.1 and 2.3°C colder than the annual mean SSTs. Despite the seasonality of the coccolithophore production, this temperature difference is not mainly due to a seasonal bias, nor to the lateral advection of phytoplankton and phytodetritus seaward from the cold near-shore waters, but to the production depth of the coccolithophores. If coretop alkenone temperatures are effectively recording the annual mean SSTs, the amount of alkenone produced must vary among the coccolithophores in the water column and depend on physiological factors (e.g. growth rate, nutrient stress.

  16. Ultraviolet absorbance as a proxy for total dissolved mercury in streams.

    Science.gov (United States)

    Dittman, Jason A; Shanley, James B; Driscoll, Charles T; Aiken, George R; Chalmers, Ann T; Towse, Janet E

    2009-06-01

    Stream water samples were collected over a range of hydrologic and seasonal conditions at three forested watersheds in the northeastern USA. Samples were analyzed for dissolved total mercury (THg(d)), DOC concentration and DOC composition, and UV(254) absorbance across the three sites over different seasons and flow conditions. Pooling data from all sites, we found a strong positive correlation of THg(d) to DOC (r(2)=0.87), but progressively stronger correlations of THg(d) with the hydrophobic acid fraction (HPOA) of DOC (r(2)=0.91) and with UV(254) absorbance (r(2)=0.92). The strength of the UV(254) absorbance-THg(d) relationship suggests that optical properties associated with dissolved organic matter may be excellent proxies for THg(d) concentration in these streams. Ease of sample collection and analysis, the potential application of in-situ optical sensors, and the possibility for intensive monitoring over the hydrograph make this an effective, inexpensive approach to estimate THg(d) flux in drainage waters.

  17. Are Sea Surface Temperature satellite measurements reliable proxies of lagoon temperature in the South Pacific?

    Science.gov (United States)

    Van Wynsberge, Simon; Menkes, Christophe; Le Gendre, Romain; Passfield, Teuru; Andréfouët, Serge

    2017-12-01

    In remote coral reef environments, lagoon and reef in situ measurements of temperature are scarce. Sea Surface Temperature (SST) measured by satellite has been frequently used as a proxy of the lagoon temperature experienced by coral reef organisms (TL) especially during coral bleaching events. However, the link between SST and TL is poorly characterized. First, we compared the correlation between various SST series and TL from 2012 to 2016 in three atolls and one island in the Central South Pacific Ocean. Simple linear correlation between SST and TL ranged between 0.44 and 0.97 depending on lagoons, localities of sensors, and type of SST data. High-resolution-satellite-measurements of SST inside the lagoons did not outperform oceanic SST series, suggesting that SST products are not adapted for small lagoons. Second, we modelled the difference between oceanic SST and TL as a function of the drivers of lagoon water renewal and mixing, namely waves, tide, wind, and season. The multivariate models reduced significantly the bias between oceanic SST and TL. In atoll lagoons, and probably in other hydrodynamically semi-open systems, a correction taking into account these factors is necessary when SST are used to characterize organisms' thermal stress thresholds.

  18. Multi-periodic climate dynamics: spectral analysis of long-term instrumental and proxy temperature records

    Science.gov (United States)

    Lüdecke, H.-J.; Hempelmann, A.; Weiss, C. O.

    2013-02-01

    The longest six instrumental temperature records of monthly means reach back maximally to 1757 AD and were recorded in Europe. All six show a V-shape, with temperature drop in the 19th and rise in the 20th century. Proxy temperature time series of Antarctic ice cores show this same characteristic shape, indicating this pattern as a global phenomenon. We used the mean of the six instrumental records for analysis by discrete Fourier transform (DFT), wavelets, and the detrended fluctuation analysis (DFA). For comparison, a stalagmite record was also analyzed by DFT. The harmonic decomposition of the abovementioned mean shows only six significant frequencies above periods over 30 yr. The Pearson correlation between the mean, smoothed by a 15-yr running average (boxcar) and the reconstruction using the six significant frequencies, yields r = 0.961. This good agreement has a > 99.9% confidence level confirmed by Monte Carlo simulations. It shows that the climate dynamics is governed at present by periodic oscillations. We find indications that observed periodicities result from intrinsic dynamics.

  19. Multi-periodic climate dynamics: spectral analysis of long-term instrumental and proxy temperature records

    Directory of Open Access Journals (Sweden)

    H.-J. Lüdecke

    2013-02-01

    Full Text Available The longest six instrumental temperature records of monthly means reach back maximally to 1757 AD and were recorded in Europe. All six show a V-shape, with temperature drop in the 19th and rise in the 20th century. Proxy temperature time series of Antarctic ice cores show this same characteristic shape, indicating this pattern as a global phenomenon. We used the mean of the six instrumental records for analysis by discrete Fourier transform (DFT, wavelets, and the detrended fluctuation analysis (DFA. For comparison, a stalagmite record was also analyzed by DFT. The harmonic decomposition of the abovementioned mean shows only six significant frequencies above periods over 30 yr. The Pearson correlation between the mean, smoothed by a 15-yr running average (boxcar and the reconstruction using the six significant frequencies, yields r = 0.961. This good agreement has a > 99.9% confidence level confirmed by Monte Carlo simulations. It shows that the climate dynamics is governed at present by periodic oscillations. We find indications that observed periodicities result from intrinsic dynamics.

  20. The “Serpentine Syndrome” (H. Jenny, 1980: A Proxy for Soil Remediation

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    Claudio Bini

    2014-12-01

    Full Text Available Serpentine soils have relatively high concentrations of PTEs (Co, Cr, Cu, Fe, Ni but generally low amounts of major nutrients. They often bear a distinctive vegetation, and a frequently-used approach to understanding serpentine ecology and related environmental hazard has been the chemical analysis of soils and plants. In this paper we report past and current studies on serpentine soils and serpentinophytes. The serpentine vegetation differs from the conterminous non-serpentine areas, being often endemic, and showing macroscopic physionomical characters. Similarly, at microscopic level cytomorphological characteristics of the roots and variations in biochemical parameters were recorded in serpentinophytes. Light microscopy observations showed depressed mitotic activity in the meristematic zone, and consequent reduced root growth. The different tolerance mechanisms responsible for plant adaption to high concentrations of PTEs in serpentine soils can be related to the capacity of plants to limit metal uptake and translocation. The majority of serpentinophytes tend to limit metal absorption to roots: the cell wall constitutes a barrier against metal penetration inside plant tissues. Only a few species are able to accumulate metals in their aerial parts, acting a tolerance mechanism to very high metal concentrations. Serpentinophytes, therefore, could represent proxies for plants  used in remediation of metal-contaminated soils and in phytomining as well.