WorldWideScience

Sample records for spontaneous anonymous threshold

  1. Privacy preserving data anonymization of spontaneous ADE reporting system dataset.

    Science.gov (United States)

    Lin, Wen-Yang; Yang, Duen-Chuan; Wang, Jie-Teng

    2016-07-18

    To facilitate long-term safety surveillance of marketing drugs, many spontaneously reporting systems (SRSs) of ADR events have been established world-wide. Since the data collected by SRSs contain sensitive personal health information that should be protected to prevent the identification of individuals, it procures the issue of privacy preserving data publishing (PPDP), that is, how to sanitize (anonymize) raw data before publishing. Although much work has been done on PPDP, very few studies have focused on protecting privacy of SRS data and none of the anonymization methods is favorable for SRS datasets, due to which contain some characteristics such as rare events, multiple individual records, and multi-valued sensitive attributes. We propose a new privacy model called MS(k, θ (*) )-bounding for protecting published spontaneous ADE reporting data from privacy attacks. Our model has the flexibility of varying privacy thresholds, i.e., θ (*) , for different sensitive values and takes the characteristics of SRS data into consideration. We also propose an anonymization algorithm for sanitizing the raw data to meet the requirements specified through the proposed model. Our algorithm adopts a greedy-based clustering strategy to group the records into clusters, conforming to an innovative anonymization metric aiming to minimize the privacy risk as well as maintain the data utility for ADR detection. Empirical study was conducted using FAERS dataset from 2004Q1 to 2011Q4. We compared our model with four prevailing methods, including k-anonymity, (X, Y)-anonymity, Multi-sensitive l-diversity, and (α, k)-anonymity, evaluated via two measures, Danger Ratio (DR) and Information Loss (IL), and considered three different scenarios of threshold setting for θ (*) , including uniform setting, level-wise setting and frequency-based setting. We also conducted experiments to inspect the impact of anonymized data on the strengths of discovered ADR signals. With all three

  2. Thermal nociceptive threshold testing detects altered sensory processing in broiler chickens with spontaneous lameness.

    Directory of Open Access Journals (Sweden)

    Becky Hothersall

    Full Text Available Lameness is common in commercially reared broiler chickens but relationships between lameness and pain (and thus bird welfare have proved complex, partly because lameness is often partially confounded with factors such as bodyweight, sex and pathology. Thermal nociceptive threshold (TNT testing explores the neural processing of noxious stimuli, and so can contribute to our understanding of pain. Using an acute model of experimentally induced articular pain, we recently demonstrated that TNT was reduced in lame broiler chickens, and was subsequently attenuated by administration of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs. This study extended these findings to a large sample of commercial broilers. It examined factors affecting thermal threshold (Part 1 and the effect of an NSAID drug (meloxicam, 5 mg/kg and of an opioid (butorphanol; 4 mg/kg (Part 2. Spontaneously lame and matched non-lame birds (n=167 from commercial farms were exposed to ramped thermal stimulations via a probe attached to the lateral aspect of the tarsometatarsus. Baseline skin temperature and temperature at which a behavioural avoidance response occurred (threshold were recorded. In Part 1 bird characteristics influencing threshold were modelled; In Part 2 the effect of subcutaneous administration of meloxicam or butorphanol was investigated. Unexpectedly, after accounting for other influences, lameness increased threshold significantly (Part 1. In Part 2, meloxicam affected threshold differentially: it increased further in lame birds and decreased in non-lame birds. No effect of butorphanol was detected. Baseline skin temperature was also consistently a significant predictor of threshold. Overall, lameness significantly influenced threshold after other bird characteristics were taken into account. This, and a differential effect of meloxicam on lame birds, suggests that nociceptive processing may be altered in lame birds, though mechanisms for this require further

  3. Sub-threshold spinal cord stimulation facilitates spontaneous motor activity in spinal rats

    Science.gov (United States)

    2013-01-01

    Background Epidural stimulation of the spinal cord can be used to enable stepping on a treadmill (electrical enabling motor control, eEmc) after a complete mid-thoracic spinal cord transection in adult rats. Herein we have studied the effects of eEmc using a sub-threshold intensity of stimulation combined with spontaneous load-bearing proprioception to facilitate hindlimb stepping and standing during daily cage activity in paralyzed rats. Methods We hypothesized that eEmc combined with spontaneous cage activity would greatly increase the frequency and level of activation of the locomotor circuits in paralyzed rats. Spontaneous cage activity was recorded using a specially designed swivel connector to record EMG signals and an IR based camcorder to record video. Results and conclusion The spinal rats initially were very lethargic in their cages showing little movement. Without eEmc, the rats remained rather inactive with the torso rarely being elevated from the cage floor. When the rats used their forelimbs to move, the hindlimbs were extended and dragged behind with little or no flexion. In contrast, with eEmc the rats were highly active and the hindlimbs showed robust alternating flexion and extension resulting in step-like movements during forelimb-facilitated locomotion and often would stand using the sides of the cages as support. The mean and summed integrated EMG levels in both a hindlimb flexor and extensor muscle were higher with than without eEmc. These data suggest that eEmc, in combination with the associated proprioceptive input, can modulate the spinal networks to significantly amplify the amount and robustness of spontaneous motor activity in paralyzed rats. PMID:24156340

  4. Glutamate released spontaneously from astrocytes sets the threshold for synaptic plasticity.

    Science.gov (United States)

    Bonansco, Christian; Couve, Alejandro; Perea, Gertrudis; Ferradas, Carla Á; Roncagliolo, Manuel; Fuenzalida, Marco

    2011-04-01

    Astrocytes exhibit spontaneous calcium oscillations that could induce the release of glutamate as gliotransmitter in rat hippocampal slices. However, it is unknown whether this spontaneous release of astrocytic glutamate may contribute to determining the basal neurotransmitter release probability in central synapses. Using whole-cell recordings and Ca(2+) imaging, we investigated the effects of the spontaneous astrocytic activity on neurotransmission and synaptic plasticity at CA3-CA1 hippocampal synapses. We show here that the metabolic gliotoxin fluorocitrate (FC) reduces the amplitude of evoked excitatory postsynaptic currents and increases the paired-pulse facilitation, mainly due to the reduction of the neurotransmitter release probability and the synaptic potency. FC also decreased intracellular Ca(2+) signalling and Ca(2+) -dependent glutamate release from astrocytes. The addition of glutamine rescued the effects of FC over the synaptic potency; however, the probability of neurotransmitter release remained diminished. The blockage of group I metabotropic glutamate receptors mimicked the effects of FC on the frequency of miniature synaptic responses. In the presence of FC, the Ca(2+) chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N ',N '-tetra-acetate or group I metabotropic glutamate receptor antagonists, the excitatory postsynaptic current potentiation induced by the spike-timing-dependent plasticity protocol was blocked, and it was rescued by delivering a stronger spike-timing-dependent plasticity protocol. Taken together, these results suggest that spontaneous glutamate release from astrocytes contributes to setting the basal probability of neurotransmitter release via metabotropic glutamate receptor activation, which could be operating as a gain control mechanism that regulates the threshold of long-term potentiation. Therefore, endogenous astrocyte activity provides a novel non-neuronal mechanism that could be critical for transferring information in

  5. Solid state solvation effect and reduced amplified spontaneous emission threshold value of glass forming DCM derivative in PMMA films

    Energy Technology Data Exchange (ETDEWEB)

    Vembris, Aivars, E-mail: aivars.vembris@cfi.lu.lv [Institute of Solid State Physics, University of Latvia, 8 Kengaraga Street, Riga LV 1063 (Latvia); Zarins, Elmars; Kokars, Valdis [Institute of Applied Chemistry, Riga Technical University, 14/24 Azenes Street, Riga LV 1048 (Latvia)

    2015-02-15

    Molecule crystallization is one of the limitations for obtaining high-gain organic laser systems. One of the examples is well known red laser dye 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM). The lowest threshold value of amplified spontaneous emission was achieved by doping 2 wt% of DCM molecule in tris-(8-hydroxy quinoline) aluminum (Alq{sub 3}) matrix. Further increase of the DCM dye concentration makes the system less efficient as its threshold value increases. It is due to large intermolecular interaction, which induces photoluminescence quenching. Compounds with reduced intermolecular interaction could be prospective in organic laser systems due to higher possible doping. In this work photoluminescence and amplified spontaneous emission properties of modified DCM molecule in poly(methyl methacrylate) (PMMA) matrix were investigated. Bulky trityloxyethyl groups were attached to the donor part of DCM. These groups increase intermolecular distance wherewith reduce photoluminescence quenching. More than one order of magnitude lower excitation threshold energy of the amplified spontaneous emission was achieved in doped polymer films with investigated compound in comparison to doped polymer with DCM. It means that the investigated compound is more perspective as a laser material compared to the previously studied. In addition, amplified spontaneous emission maximum could be tuned within 15 nm by changing concentration from 0.1 wt% to 10 wt% DWK-1 in PMMA matrix due to solid state solvation effect. - Highlights: • Bulky groups attached to DCM dye reduce photoluminescence quenching. • Amplified spontaneous emission is in red spectral region. • Amplified spontaneous emission spectra were tuned by 15 nm. • Amplified spontaneous emission threshold value was reduced by one order of magnitude.

  6. Controlling Crystallization of All-Inorganic Perovskite Films for Ultralow-Threshold Amplification Spontaneous Emission.

    Science.gov (United States)

    Yong, Zi-Jun; Zhou, Yang; Ma, Ju-Ping; Chen, Ya-Meng; Yang, Jun-Yi; Song, Ying-Lin; Wang, Jing; Sun, Hong-Tao

    2017-09-27

    All-inorganic lead halide perovskites have gained considerable interest owing to their potential applications in an array of high-performance optoelectronic devices. However, producing highly luminescent, nearly pinhole-free, all-inorganic perovskite films through a simple solution process remains challenging. Here, we provide a detailed investigation of the crystallization control of inorganic perovskite films fabricated by a one-step spin-coating process. Our results reveal that the coating temperature in the fabrication process is of paramount importance in influencing perovskite crystallization and that lowering the coating temperature and fine stoichiometry modification of the precursors favor the suppression of trap states in CsPbBr 3 perovskite films. A broad range of experimental characterizations help us identify that nonsynergistic assembly of solutes, resulting from poor diffusion capability of inorganic salts, is the dominant cause for the inhomogeneous element distribution, low luminescence yield, and poor surface coverage of the resulting films. Importantly, we find that polyethylene glycol can also be used for tailoring the crystallization process, which enables the attainment of high-quality CsPbBr 3 films with a maximum luminescence yield of ∼30%. Finally, we demonstrate that amplification spontaneous emission with an ultralow threshold can be readily accomplished by using the developed film as an emissive component. Our findings provide deep insights into the crystallization control of CsPbBr 3 perovskite films and establish a systematic route to high-quality all-inorganic perovskite films, paving the way for widespread optoelectronic applications.

  7. Against anonymity.

    Science.gov (United States)

    Baker, Robert

    2014-05-01

    In 'New Threats to Academic Freedom' Francesca Minerva argues that anonymity for the authors of controversial articles is a prerequisite for academic freedom in the Internet age. This argument draws its intellectual and emotional power from the author's account of the reaction to the on-line publication of ' After-birth abortion: why should the baby live?'--an article that provoked cascades of hostile postings and e-mails. Reflecting on these events, Minerva proposes that publishers should offer the authors of controversial articles the option of publishing their articles anonymously. This response reviews the history of anonymous publication and concludes that its reintroduction in the Internet era would recreate problems similar to those that led print journals to abandon the practice: corruption of scholarly discourse by invective and hate speech, masked conflicts of interest, and a diminution of editorial accountability. It also contends that Minerva misreads the intent of the hostile e-mails provoked by 'After-birth abortion,' and that ethicists who publish controversial articles should take responsibility by dialoguing with their critics--even those whose critiques are emotionally charged and hostile. © 2014 John Wiley & Sons Ltd.

  8. Enhancement of spontaneous emission rate and reduction in amplified spontaneous emission threshold in electrodeposited three-dimensional ZnO photonic crystal

    Science.gov (United States)

    Zhong, Yongchun; Yue, Zhounan; Wong, George K. L.; Xi, Yan Yan; Hsu, Yuk Fan; Djurišić, Aleksandra B.; Dong, Jian-Wen; Chen, Wen-Jie; Wong, Kam Sing

    2010-11-01

    ZnO photonic crystal (PC) with face-center-cube type structure is fabricated by electrodeposition using holographic lithographically made organic (SU-8) template. Photonic band gap effect (reflection peak and transmission dip in infrared spectral region) is clearly seen. Observation of strong enhancement and blueshift of the emission peak (from 383.8 to 378.8 nm), shortening of the exciton photoluminescence lifetime (from 88 to 34 ps), and reduction in amplified spontaneous emission threshold of ZnO PC compared to that of the reference nonstructured electrodeposited ZnO showed clear evidence of PC structure affecting the ZnO exciton emission.

  9. Very long spatial and temporal spontaneous coherence of 2D polariton condensates across the parametric threshold

    DEFF Research Database (Denmark)

    Spano, R.; Cuadra, J.; Lingg, C.

    2011-01-01

    , and a relative large beam area (∅~50 μm) to obtain a true 2D condensate. Its coherence properties are measured with a Michelson interferometer. A finite correlation length is measured at an energy δE=-0.19 meV from the parametric threshold, as shown in Fig. 1(A). Once the threshold is reached, by changing...

  10. Anonymity in voting revisited

    NARCIS (Netherlands)

    Jonker, Hugo; Pieters, Wolter; Chaum, David; Jakobsson, Markus; Rivest, Ronald L.; Ryan, Peter Y.A.; Benaloh, Josh; Kutylowski, Miroslaw; Adida, Ben

    According to international law, anonymity of the voter is a fundamental precondition for democratic elections. In electronic voting, several aspects of voter anonymity have been identified. In this paper, we re-examine anonymity with respect to voting, and generalise existing notions of anonymity in

  11. Continuous-wave infrared optical gain and amplified spontaneous emission at ultralow threshold by colloidal HgTe quantum dots.

    Science.gov (United States)

    Geiregat, Pieter; Houtepen, Arjan J; Sagar, Laxmi Kishore; Infante, Ivan; Zapata, Felipe; Grigel, Valeriia; Allan, Guy; Delerue, Christophe; Van Thourhout, Dries; Hens, Zeger

    2018-01-01

    Colloidal quantum dots (QDs) raise more and more interest as solution-processable and tunable optical gain materials. However, especially for infrared active QDs, optical gain remains inefficient. Since stimulated emission involves multifold degenerate band-edge states, population inversion can be attained only at high pump power and must compete with efficient multi-exciton recombination. Here, we show that mercury telluride (HgTe) QDs exhibit size-tunable stimulated emission throughout the near-infrared telecom window at thresholds unmatched by any QD studied before. We attribute this unique behaviour to surface-localized states in the bandgap that turn HgTe QDs into 4-level systems. The resulting long-lived population inversion induces amplified spontaneous emission under continuous-wave optical pumping at power levels compatible with solar irradiation and direct current electrical pumping. These results introduce an alternative approach for low-threshold QD-based gain media based on intentional trap states that paves the way for solution-processed infrared QD lasers and amplifiers.

  12. Continuous-wave infrared optical gain and amplified spontaneous emission at ultralow threshold by colloidal HgTe quantum dots

    Science.gov (United States)

    Geiregat, Pieter; Houtepen, Arjan J.; Sagar, Laxmi Kishore; Infante, Ivan; Zapata, Felipe; Grigel, Valeriia; Allan, Guy; Delerue, Christophe; van Thourhout, Dries; Hens, Zeger

    2018-01-01

    Colloidal quantum dots (QDs) raise more and more interest as solution-processable and tunable optical gain materials. However, especially for infrared active QDs, optical gain remains inefficient. Since stimulated emission involves multifold degenerate band-edge states, population inversion can be attained only at high pump power and must compete with efficient multi-exciton recombination. Here, we show that mercury telluride (HgTe) QDs exhibit size-tunable stimulated emission throughout the near-infrared telecom window at thresholds unmatched by any QD studied before. We attribute this unique behaviour to surface-localized states in the bandgap that turn HgTe QDs into 4-level systems. The resulting long-lived population inversion induces amplified spontaneous emission under continuous-wave optical pumping at power levels compatible with solar irradiation and direct current electrical pumping. These results introduce an alternative approach for low-threshold QD-based gain media based on intentional trap states that paves the way for solution-processed infrared QD lasers and amplifiers.

  13. Data anonymization patent landscape

    OpenAIRE

    Mirjana Pejić Bach; Jasmina Pivar; Ksenija Dumičić

    2017-01-01

    The omnipresent, unstoppable increase in digital data has led to a greater understanding of the importance of data privacy. Different approaches are used to implement data privacy. The goal of this paper is to develop a data anonymization patent landscape, by determining the following: (i) the trend in data anonymization patenting, (ii) the type of technical content protected in data anonymization, (iii) the organizations and countries most active in patenting data anonymization know-how; and...

  14. Anonymous steps: gender and Gamblers Anonymous

    OpenAIRE

    Rogers, Jim

    2015-01-01

    The biggest source of help for problem gamblers remains gamblers anonymous (GA) in terms of accessibility and availability. GA has traditionally been very much a male preserve. This paper reports on a literature review of Gamblers Anonymous together with data from observations of a contemporary open GA meeting over a one year period. Whilst some studies from North America suggest a changing culture and gender balance within GA programmes observations from the North of England, supported b...

  15. Quantum anonymous voting with anonymity check

    International Nuclear Information System (INIS)

    Horoshko, Dmitri; Kilin, Sergei

    2011-01-01

    We propose a new protocol for quantum anonymous voting having serious advantages over the existing protocols: it protects both the voters from a curious tallyman and all the participants from a dishonest voter in unconditional way. The central idea of the protocol is that the ballots are given back to the voters after the voting process, which gives a possibility for two voters to check the anonymity of the vote counting process by preparing a special entangled state of two ballots. Any attempt of cheating from the side of the tallyman results in destroying the entanglement, which can be detected by the voters.

  16. Data anonymization patent landscape

    Directory of Open Access Journals (Sweden)

    Mirjana Pejić Bach

    2017-01-01

    Full Text Available The omnipresent, unstoppable increase in digital data has led to a greater understanding of the importance of data privacy. Different approaches are used to implement data privacy. The goal of this paper is to develop a data anonymization patent landscape, by determining the following: (i the trend in data anonymization patenting, (ii the type of technical content protected in data anonymization, (iii the organizations and countries most active in patenting data anonymization know-how; and (iv the topics emerging most often in patent titles. Patents from the PatSeer database relating to data anonymization from 2001 to 2015 were analyzed. We used the longitudinal approach in combination with text mining techniques to develop a data anonymization patent landscape. The results indicated the following. The number of single patent families is growing with a high increase after 2010, thus indicating a positive trend in the area of patenting data anonymization solutions. The majority of patenting activities relate to the G Physics section. Organizations from the USA and Japan assigned the majority of patents related to data anonymization. The results of text mining indicate that the most often used word in titles of data anonymization patents are “anonym*, “method”, “data” and “system”. Several additional words that indicated the most frequent topics related to data anonymization were: “equipment”, “software”, “protection”, “identification”, or “encryption”, and specific topics such as “community”, “medical”, or “service”.

  17. Anonymous women? Gamblers Anonymous and gender

    OpenAIRE

    Rogers, Jim

    2016-01-01

    One of the rapidly changing elements in gambling environments is the increasing participation of women in many forms of gambling, and the growing proportions of problem gamblers who are female. It is known that women who develop gambling problems differ from men in a range of ways:for example they are more likely to have co-morbidities such as anxiety and depression, and to gamble as an 'escape' from such co-occuring problems. Gamblers Anonymous (GA) has a number of meetings across New Zeala...

  18. Anonymous Connections and Onion Routing

    National Research Council Canada - National Science Library

    Syverson, Paul F; Goldschlag, David M; Reed, Michael G

    1997-01-01

    .... Unmodified Internet applications can use these anonymous connections by means of proxies. The proxies may also make communication anonymous by removing identifying information from the data stream...

  19. Anonymization of Court Orders

    DEFF Research Database (Denmark)

    Povlsen, Claus; Jongejan, Bart; Hansen, Dorte Haltrup

    We describe an anonymization tool that was commissioned by and specified together with Schultz, a publishing company specialized in Danish law related publications. Unavailability of training data and the need to guarantee compliance with pre-existing anonymization guidelines forced us to implement...... a tool using manually crafted rules. We used Bracmat, a programming language that is specialized in transforming tree data structures, to meet the requirement to pass the XML structure of the input document unscathed through the whole workflow. The tool attains a reassuringly good recall, makes almost...

  20. Use of an Impedance Threshold Device in Spontaneously Breathing Patients with Hypotension Secondary to Trauma: An Observational Cohort Feasibility Study

    Science.gov (United States)

    2014-09-09

    hypotension due to multiple causes ; the patients of primary interest experienced a traumatic injury. Upon determination of hypotension (systolic blood...to vasovagal syncope , dehydration, and renal dialysis; (3) provide a treatment of right- sided heart failure after myocardial infarction; and (4...Research, the ITD has been used for treat- ment of hypotension due to multiple causes in spontaneously breathing patients.6,9 The US Army is specifically

  1. Anonymous Authentication for Smartcards

    Directory of Open Access Journals (Sweden)

    J. Hajny

    2010-06-01

    Full Text Available The paper presents an innovative solution in the field of RFID (Radio-Frequency IDentification smartcard authentication. Currently the smartcards are used for many purposes - e.g. employee identification, library cards, student cards or even identity credentials. Personal identity is revealed to untrustworthy entities every time we use these cards. Such information could later be used without our knowledge and for harmful reasons like shopping pattern scanning or even movement tracking. We present a communication scheme for keeping one’s identity private in this paper. Although our system provides anonymity, it does not allow users to abuse this feature. The system is based on strong cryptographic primitives that provide features never available before. Besides theoretical design of the anonymous authentication scheme and its analysis we also provide implementation results.

  2. Deniable Anonymous Group Authentication

    Science.gov (United States)

    2014-02-13

    providers, such as Facebook or Twitter, and the use of public-key encryption and linkable ring signatures. Linkable ring signatures [44,45] allow a...2007. [36] R. Henry and I. Goldberg. Batch proofs of partial knowledge. University of Waterloo, Technical report CACR, 2012 . [37] R. Henry and I...CT-RSA, 2006. [41] M. Layouni and H. Vangheluwe. Anonymous k-show credentials. In ’07 EuroPKI, 2007. [42] B. Lee, C. Boyd, E. Dawson, K. Kim, J. Yang

  3. Low threshold Amplified Spontaneous Emission properties in deep blue of poly[(9,9-dioctylfluorene-2,7-dyil)-alt-p-phenylene] thin films

    Science.gov (United States)

    Lattante, Sandro; De Giorgi, Maria Luisa; Pasini, Mariacecilia; Anni, Marco

    2017-10-01

    Amongst the different optoelectronic applications of conjugated polymers, the development of new active materials for optically pumped organic lasers is still an open question particularly in the blue-near UV spectral range. We investigate the emission properties of poly[(9,9-dioctylfluorene-2,7-dyil)- alt-p-phenylene] (PFP) neat films under nanosecond pump. We demonstrate that thanks to the introduction of a phenylene moiety between two fluorene units it is possible to obtain Amplified Spontaneous Emission (ASE) with a lower threshold and a blue shifted wavelength with respect to poly(9,9-dioctylfluorene) (PFO). We demonstrate efficient ASE with a minimum threshold as low as 23 μJcm-2 and a minimum ASE wavelength of 436 nm. A maximum net optical gain of about 26 cm-1 is measured at an excitation density of 0.23 mJcm-2. These results make the PFP a good active material for optically pumped deep blue organic lasers.

  4. Low threshold amplified spontaneous emission from tin oxide quantum dots: a instantiation of dipole transition silence semiconductors.

    Science.gov (United States)

    Pan, Shu Sheng; Yu, Siu Fung; Zhang, Wen Fei; Zhu, Hai; Lu, Wei; Jin, Li Min

    2013-12-07

    Direct bandgap semiconductors, such as In2O3, Cu2O, and SnO2, have enormous applications in photochemistry, photovoltaics, and optoelectronics. Due to the same parity of conduction and valence bands, the dipole transition is silent in these direct bandgap semiconductors. The low band-to-band transition efficiency prevents them from high intensity light emission or absorption. Here, we report the fabrication of SnO2 quantum dots (QDs) with sizes less than the exciton Bohr radius by a facile "top-down" strategy based on laser fragmentation of SnO in water. The SnO2 QDs shows exciton emission at ∼300 nm with a high quantum yield of ~17%. Amplified spontaneous exciton emission is also achieved from a thin layer of SnO2 QDs dispersed in PEG400 on a quartz substrate. Therefore, we have shown that SnO2 QDs can be a potential luminescent material suitable for the realization of ultraviolet B lasing devices.

  5. Spontaneous Subarachnoid Hemorrhage: A Systematic Review and Meta-analysis Describing the Diagnostic Accuracy of History, Physical Examination, Imaging, and Lumbar Puncture With an Exploration of Test Thresholds.

    Science.gov (United States)

    Carpenter, Christopher R; Hussain, Adnan M; Ward, Michael J; Zipfel, Gregory J; Fowler, Susan; Pines, Jesse M; Sivilotti, Marco L A

    2016-09-01

    Spontaneous subarachnoid hemorrhage (SAH) is a rare, but serious etiology of headache. The diagnosis of SAH is especially challenging in alert, neurologically intact patients, as missed or delayed diagnosis can be catastrophic. The objective was to perform a diagnostic accuracy systematic review and meta-analysis of history, physical examination, cerebrospinal fluid (CSF) tests, computed tomography (CT), and clinical decision rules for spontaneous SAH. A secondary objective was to delineate probability of disease thresholds for imaging and lumbar puncture (LP). PubMed, Embase, Scopus, and research meeting abstracts were searched up to June 2015 for studies of emergency department patients with acute headache clinically concerning for spontaneous SAH. QUADAS-2 was used to assess study quality and, when appropriate, meta-analysis was conducted using random effects models. Outcomes were sensitivity, specificity, and positive (LR+) and negative (LR-) likelihood ratios. To identify test and treatment thresholds, we employed the Pauker-Kassirer method with Bernstein test indication curves using the summary estimates of diagnostic accuracy. A total of 5,022 publications were identified, of which 122 underwent full-text review; 22 studies were included (average SAH prevalence = 7.5%). Diagnostic studies differed in assessment of history and physical examination findings, CT technology, analytical techniques used to identify xanthochromia, and criterion standards for SAH. Study quality by QUADAS-2 was variable; however, most had a relatively low risk of biases. A history of neck pain (LR+ = 4.1; 95% confidence interval [CI] = 2.2 to 7.6) and neck stiffness on physical examination (LR+ = 6.6; 95% CI = 4.0 to 11.0) were the individual findings most strongly associated with SAH. Combinations of findings may rule out SAH, yet promising clinical decision rules await external validation. Noncontrast cranial CT within 6 hours of headache onset accurately ruled in (LR+ = 230; 95

  6. How to Bootstrap Anonymous Communication

    DEFF Research Database (Denmark)

    Jakobsen, Sune K.; Orlandi, Claudio

    2015-01-01

    formal study in this direction. To solve this problem, we introduce the concept of anonymous steganography: think of a leaker Lea who wants to leak a large document to Joe the journalist. Using anonymous steganography Lea can embed this document in innocent looking communication on some popular website...... (such as cat videos on YouTube or funny memes on 9GAG). Then Lea provides Joe with a short key k which, when applied to the entire website, recovers the document while hiding the identity of Lea among the large number of users of the website. Our contributions include: { Introducing and formally dening...... anonymous steganography, { A construction showing that anonymous steganography is possible (which uses recent results in circuits obfuscation), { A lower bound on the number of bits which are needed to bootstrap anonymous communication....

  7. How to Bootstrap Anonymous Communication

    DEFF Research Database (Denmark)

    Jakobsen, Sune K.; Orlandi, Claudio

    2015-01-01

    formal study in this direction. To solve this problem, we introduce the concept of anonymous steganography: think of a leaker Lea who wants to leak a large document to Joe the journalist. Using anonymous steganography Lea can embed this document in innocent looking communication on some popular website...... (such as cat videos on YouTube or funny memes on 9GAG). Then Lea provides Joe with a short key $k$ which, when applied to the entire website, recovers the document while hiding the identity of Lea among the large number of users of the website. Our contributions include: - Introducing and formally...... defining anonymous steganography, - A construction showing that anonymous steganography is possible (which uses recent results in circuits obfuscation), - A lower bound on the number of bits which are needed to bootstrap anonymous communication....

  8. Concept analysis: lack of anonymity.

    Science.gov (United States)

    Swan, Marilyn A; Hobbs, Barbara B

    2017-05-01

    To re-examine and expand understanding of the concept 'lack of anonymity' as a component of rural nursing theory. Early healthcare literature reports lack of anonymity as part of social and working environments, particularly rural nursing. Rural nursing theory included the first published concept analysis on lack of anonymity but lacked empirical referents. Workforce, societal and rural healthcare changes support an updated analysis. To further understand lack of anonymity, its present day use and applicability to diverse environments, research from multiple disciplines was reviewed. Concept analysis. A literature search using eight terms in eleven databases was conducted of literature published between 2008-2013. Walker and Avant's concept analysis methodology guided the analysis. The previous concept analysis is supported in part by current literature. The defining attributes, 'identifiable', 'establishing boundaries for public and private self and interconnectedness' in a community were updated. Updated antecedents include: (i) environmental context; (ii) opportunities to become visible; (iii) developing relationships and (iv) unconscious or limited awareness of public or personal privacy. Consequences are: (i) familiarity; (ii) visibility; (iii) awareness of privacy and (iv) manage or balance of lack of anonymity. Cases were constructed and empirical referents identified. The concept of lack of anonymity was updated; portions of the original definition remain unchanged. Empirical referents reveal the defining attributes in daily life and may guide future research on the effect of lack of anonymity on nursing practice. This analysis advances the conceptual understanding of rural nursing theory. © 2016 John Wiley & Sons Ltd.

  9. On Backward-Style Anonymity Verification

    Science.gov (United States)

    Kawabe, Yoshinobu; Mano, Ken; Sakurada, Hideki; Tsukada, Yasuyuki

    Many Internet services and protocols should guarantee anonymity; for example, an electronic voting system should guarantee to prevent the disclosure of who voted for which candidate. To prove trace anonymity, which is an extension of the formulation of anonymity by Schneider and Sidiropoulos, this paper presents an inductive method based on backward anonymous simulations. We show that the existence of an image-finite backward anonymous simulation implies trace anonymity. We also demonstrate the anonymity verification of an e-voting protocol (the FOO protocol) with our backward anonymous simulation technique. When proving the trace anonymity, this paper employs a computer-assisted verification tool based on a theorem prover.

  10. Anonymous Transactions in Computer Networks

    Science.gov (United States)

    Dolev, Shlomi; Kopeetsky, Marina

    We present schemes for providing anonymous transactions while privacy and anonymity are preserved, providing user anonymous authentication in distributed networks such as the Internet. We first present a practical scheme for anonymous transactions while the transaction resolution is assisted by a Trusted Authority. This practical scheme is extended to a theoretical scheme where a Trusted Authority is not involved in the transaction resolution. Given an authority that generates for each player hard to produce evidence EVID (e. g., problem instance with or without a solution) to each player, the identity of a user U is defined by the ability to prove possession of said evidence. We use Zero-Knowledge proof techniques to repeatedly identify U by providing a proof that U has evidence EVID, without revealing EVID, therefore avoiding identity theft.

  11. Does anonymity increase the reporting of mental health symptoms?

    Science.gov (United States)

    Fear, Nicola T; Seddon, Rachel; Jones, Norman; Greenberg, Neil; Wessely, Simon

    2012-09-17

    There is no doubt that the perceived stigma of having a mental disorder acts as a barrier to help seeking. It is possible that personnel may be reluctant to admit to symptoms suggestive of poor mental health when such data can be linked to them, even if their personal details are only used to help them access further care. This may be particularly relevant because individuals who have a mental health problem are more likely to experience barriers to care and hold stigmatizing beliefs. If that is the case, then mental health screening programmers may not be effective in detecting those most in need of care. We aimed to compare mental health symptom reporting when using an anonymous versus identifiable questionnaire among UK military personnel on deployment in Iraq. Survey among UK military personnel using two questionnaires, one was anonymous (n = 315) and one collected contact details (i.e. identifiable, n = 296). Distribution was by alternate allocation. Data were collected in Iraq during January-February 2009. No significant difference in the reporting of symptoms of common mental disorders was found (18.1% of identifiable vs. 22.9% of anonymous participants). UK military personnel were more likely to report sub-threshold and probable PTSD when completing questionnaires anonymously (sub-threshold PTSD: 2.4% of identifiable vs. 5.8% of anonymous participants; probable PTSD: 1.7% of identifiable vs. 4.8% of anonymous participants). Of the 11 barriers to care and perceived social stigma statements considered, those completing the anonymous questionnaire compared to those completing the identifiable questionnaire were more likely to endorse three statements: "leaders discourage the use of mental health services" (9.3% vs. 4.6%), "it would be too embarrassing" (41.6% vs. 32.5%) and "I would be seen as weak" (46.6% vs. 34.2%). We found a significant effect on the reporting of sub-threshold and probable PTSD and certain stigmatizing beliefs (but not common mental

  12. Does anonymity increase the reporting of mental health symptoms?

    Directory of Open Access Journals (Sweden)

    Fear Nicola T

    2012-09-01

    Full Text Available Abstract Background There is no doubt that the perceived stigma of having a mental disorder acts as a barrier to help seeking. It is possible that personnel may be reluctant to admit to symptoms suggestive of poor mental health when such data can be linked to them, even if their personal details are only used to help them access further care. This may be particularly relevant because individuals who have a mental health problem are more likely to experience barriers to care and hold stigmatizing beliefs. If that is the case, then mental health screening programmers may not be effective in detecting those most in need of care. We aimed to compare mental health symptom reporting when using an anonymous versus identifiable questionnaire among UK military personnel on deployment in Iraq. Methods Survey among UK military personnel using two questionnaires, one was anonymous (n = 315 and one collected contact details (i.e. identifiable, n = 296. Distribution was by alternate allocation. Data were collected in Iraq during January-February 2009. Results No significant difference in the reporting of symptoms of common mental disorders was found (18.1% of identifiable vs. 22.9% of anonymous participants. UK military personnel were more likely to report sub-threshold and probable PTSD when completing questionnaires anonymously (sub-threshold PTSD: 2.4% of identifiable vs. 5.8% of anonymous participants; probable PTSD: 1.7% of identifiable vs. 4.8% of anonymous participants. Of the 11 barriers to care and perceived social stigma statements considered, those completing the anonymous questionnaire compared to those completing the identifiable questionnaire were more likely to endorse three statements: “leaders discourage the use of mental health services” (9.3% vs. 4.6%, “it would be too embarrassing” (41.6% vs. 32.5% and “I would be seen as weak” (46.6% vs. 34.2%. Conclusions We found a significant effect on the reporting of sub-threshold

  13. Data Retention and Anonymity Services

    Science.gov (United States)

    Berthold, Stefan; Böhme, Rainer; Köpsell, Stefan

    The recently introduced legislation on data retention to aid prosecuting cyber-related crime in Europe also affects the achievable security of systems for anonymous communication on the Internet. We argue that data retention requires a review of existing security evaluations against a new class of realistic adversary models. In particular, we present theoretical results and first empirical evidence for intersection attacks by law enforcement authorities. The reference architecture for our study is the anonymity service AN.ON, from which we also collect empirical data. Our adversary model reflects an interpretation of the current implementation of the EC Directive on Data Retention in Germany.

  14. k-Times Anonymous Authentication

    Science.gov (United States)

    Teranishi, Isamu; Furukawa, Jun; Sako, Kazue

    We propose an authentication scheme in which users can be authenticated anonymously so long as times that they are authenticated is within an allowable number. The proposed scheme has two features: 1) no one, not even an authority, can identify users who have been authenticated within the allowable number, 2) anyone can trace, without help from the authority, dishonest users who have been authenticated beyond the allowable number by using the records of these authentications. Our scheme can be applied to e-voting, e-cash, electronic coupons, and trial browsing of content. In these applications, our scheme, unlike the previous one, conceals users' participation from protocols and guarantees that they will remain anonymous to everyone.

  15. Pattern-Guided k-Anonymity

    OpenAIRE

    Rolf Niedermeier; André Nichterlein; Robert Bredereck

    2013-01-01

    We suggest a user-oriented approach to combinatorial data anonymization. A data matrix is called k-anonymous if every row appears at least k times—the goal of the NP-hard k-ANONYMITY problem then is to make a given matrix k-anonymous by suppressing (blanking out) as few entries as possible. Building on previous work and coping with corresponding deficiencies, we describe an enhanced k-anonymization problem called PATTERN-GUIDED k-ANONYMITY, where the users specify in which combinations suppre...

  16. Anonymous Web Browsing and Hosting

    OpenAIRE

    MANOJ KUMAR; ANUJ RANI

    2013-01-01

    In today’s high tech environment every organization, individual computer users use internet for accessing web data. To maintain high confidentiality and security of the data secure web solutions are required. In this paper we described dedicated anonymous web browsing solutions which makes our browsing faster and secure. Web application which play important role for transferring our secret information including like email need more and more security concerns. This paper also describes that ho...

  17. Revocable Anonymous Access to the Internet?

    Science.gov (United States)

    Claessens, Joris; Diaz, Claudia; Goemans, Caroline; Preneel, Bart; Vandewalle, Joos; Dumortier, Jos

    2003-01-01

    Users of telecommunications networks are concerned about privacy, and desire anonymous access, while some organizations are concerned about how this anonymous access might be abused. Proposes a solution for revocable anonymous access to the Internet. Presents some legal background and motivation for such a solution. Indicates some difficulties and…

  18. Anonymous Boh avatud kunsti maastikul / Raivo Kelomees

    Index Scriptorium Estoniae

    Kelomees, Raivo, 1960-

    2010-01-01

    Anonymous Bohi näitus Tartu Kunstimajas, avatud 30. juulini 2010. Anonymous Boh on koos Non Grataga läbi viinud performance´id Euroopas, Ameerikas ja Aasias. Anonymous Bohi vastused oma näituse ja loominguga seotud küsimustele

  19. An Anonymous Credit Card System

    Science.gov (United States)

    Androulaki, Elli; Bellovin, Steven

    Credit cards have many important benefits; however, these same benefits often carry with them many privacy concerns. In particular, the need for users to be able to monitor their own transactions, as well as bank’s need to justify its payment requests from cardholders, entitle the latter to maintain a detailed log of all transactions its credit card customers were involved in. A bank can thus build a profile of each cardholder even without the latter’s consent. In this paper, we present a practical and accountable anonymous credit system based on ecash, with a privacy preserving mechanism for error correction and expense-reporting.

  20. Protecting privacy using k-anonymity.

    Science.gov (United States)

    El Emam, Khaled; Dankar, Fida Kamal

    2008-01-01

    There is increasing pressure to share health information and even make it publicly available. However, such disclosures of personal health information raise serious privacy concerns. To alleviate such concerns, it is possible to anonymize the data before disclosure. One popular anonymization approach is k-anonymity. There have been no evaluations of the actual re-identification probability of k-anonymized data sets. Through a simulation, we evaluated the re-identification risk of k-anonymization and three different improvements on three large data sets. Re-identification probability is measured under two different re-identification scenarios. Information loss is measured by the commonly used discernability metric. For one of the re-identification scenarios, k-Anonymity consistently over-anonymizes data sets, with this over-anonymization being most pronounced with small sampling fractions. Over-anonymization results in excessive distortions to the data (i.e., high information loss), making the data less useful for subsequent analysis. We found that a hypothesis testing approach provided the best control over re-identification risk and reduces the extent of information loss compared to baseline k-anonymity. Guidelines are provided on when to use the hypothesis testing approach instead of baseline k-anonymity.

  1. Comparing Random-based and k-Anonymity-Based Algorithms for Graph Anonymization

    OpenAIRE

    Casas Roma, Jordi; Torra, Vicenç; Herrera Joancomartí, Jordi

    2012-01-01

    Recently, several anonymization algorithms have appeared for privacy preservation on graphs. Some of them are based on random- ization techniques and on k-anonymity concepts. We can use both of them to obtain an anonymized graph with a given k-anonymity value. In this paper we compare algorithms based on both techniques in order to obtain an anonymized graph with a desired k-anonymity value. We want to analyze the complexity of these methods to generate anonymized graphs and the quality...

  2. Pattern-Guided k-Anonymity

    Directory of Open Access Journals (Sweden)

    Rolf Niedermeier

    2013-10-01

    Full Text Available We suggest a user-oriented approach to combinatorial data anonymization. A data matrix is called k-anonymous if every row appears at least k times—the goal of the NP-hard k-ANONYMITY problem then is to make a given matrix k-anonymous by suppressing (blanking out as few entries as possible. Building on previous work and coping with corresponding deficiencies, we describe an enhanced k-anonymization problem called PATTERN-GUIDED k-ANONYMITY, where the users specify in which combinations suppressions may occur. In this way, the user of the anonymized data can express the differing importance of various data features. We show that PATTERN-GUIDED k-ANONYMITY is NP-hard. We complement this by a fixed-parameter tractability result based on a “data-driven parameterization” and, based on this, develop an exact integer linear program (ILP-based solution method, as well as a simple, but very effective, greedy heuristic. Experiments on several real-world datasets show that our heuristic easily matches up to the established “Mondrian” algorithm for k-ANONYMITY in terms of the quality of the anonymization and outperforms it in terms of running time.

  3. Automatic Control of Configuration of Web Anonymization

    OpenAIRE

    Tomas Sochor

    2013-01-01

    Anonymization of the Internet traffic usually hides details about the request originator from the target server. Such a disguise might be required in some situations, especially in the case of web browsing. Although the web traffic anonymization is not a part of the http specification, it could be achieved using a certain extra tool. Significant deceleration of anonymized traffic compared to normal traffic is inevitable but it can be controlled in some cases as this article suggests. The resu...

  4. Practical anonymity hiding in plain sight online

    CERN Document Server

    Loshin, Peter

    2013-01-01

    For those with legitimate reason to use the Internet anonymously--diplomats, military and other government agencies, journalists, political activists, IT professionals, law enforcement personnel, political refugees and others--anonymous networking provides an invaluable tool, and many good reasons that anonymity can serve a very important purpose. Anonymous use of the Internet is made difficult by the many websites that know everything about us, by the cookies and ad networks, IP-logging ISPs, even nosy officials may get involved. It is no longer possible to turn off browser cookies to be l

  5. Is it OK to be an Anonymous?

    NARCIS (Netherlands)

    Serracino Inglott, P.

    2013-01-01

    Do the deviant acts carried out by the collective known as Anonymous qualify as vigilante activity, and if so, can they be justified? Addressing this question helps expose the difficulties of morally evaluating technologically enabled deviance. Anonymous is a complex, fluid actor but not as

  6. Atheists, agnostics and Alcoholics Anonymous.

    Science.gov (United States)

    Tonigan, J Scott; Miller, W R; Schermer, Carol

    2002-09-01

    In spite of the strong emphasis in AA on spiritual beliefs and practices, findings are mixed about the importance of such beliefs in predicting AA affiliation. This study of the Project MATCH outpatient (N = 952) and aftercare (N = 774) samples tested three hypotheses about the role of client God belief and subsequent AA attendance and benefit, taking into account that some individuals may, in fact, deny the existence of a God. Longitudinal analyses were conducted (N = 1,526) investigating client God beliefs, AA attendance, patterns of AA attendance and alcohol use. Assessments were conducted at intake and in 3-month intervals using the Form 90, Religious Behaviors and Background, and the Alcoholics Anonymous Inventory. 12-Step treatment was significantly more likely to promote pre-post shifts in client God beliefs, and atheist and agnostic clients attended AA significantly less often throughout follow-up relative to clients self-labeled as spiritual and religious. AA attendance, however, was significantly associated with increased abstinence and reductions in drinking intensity regardless of God belief. Finally, no differences in percent days abstinence and drinking intensity were found between atheist and agnostic versus spiritual and religious clients, but clients unsure about their God belief reported significantly higher drinking frequency relative to the other groups. God belief appears to be relatively unimportant in deriving AA-related benefit, but atheist and agnostic clients are less likely to initiate and sustain AA attendance relative to spiritual and religious clients. This apparent reticence to affiliate with AA ought to be clinically recognized when encouraging AA participation.

  7. The selective adaptation of the alcoholics anonymous program by Gamblers Anonymous.

    Science.gov (United States)

    Browne, B R

    1991-09-01

    This paper is largely based on a year long observation study of Gamblers Anonymous and Alcoholics Anonymous meetings in northern California. The paper argues, contrary to popular assumption, that Gamblers Anonymous is significantly different from Alcoholics Anonymous. Differences, in members' consciousness for example, are discussed. The paper contends that although there is some12 step consciousness in G.A., the dominant consciousness ispage 17 consciousness. The significant differences are attributed to the selective adaptation of the Alcoholics Anonymous program. Several consequences of these differences, such as the central role of a language of the self in A.A. and not in G.A., are highlighted.

  8. Purpose-restricted Anonymous Mobile Communications Using Anonymous Signatures in Online Credential Systems

    DEFF Research Database (Denmark)

    Fathi, Hanane; Shin, SeongHan; Kobara, Kazukuni

    2010-01-01

    To avoid the risk of long-term storage of secrets on a portable device, an online credential system supports the roaming user in retrieving securely at various locations his private key and other material to generate anonymous signatures. The protocol proposed here allows a roaming mobile user...... to access anonymously services such as whistle blowing and net-counselling. Our approach: (1) allows a mobile user, remembering a short password, to anonymously and securely retrieve the credentials necessary for his anonymous communication without assuming a pre-established anonymous channel...

  9. A flexible approach to distributed data anonymization.

    Science.gov (United States)

    Kohlmayer, Florian; Prasser, Fabian; Eckert, Claudia; Kuhn, Klaus A

    2014-08-01

    Sensitive biomedical data is often collected from distributed sources, involving different information systems and different organizational units. Local autonomy and legal reasons lead to the need of privacy preserving integration concepts. In this article, we focus on anonymization, which plays an important role for the re-use of clinical data and for the sharing of research data. We present a flexible solution for anonymizing distributed data in the semi-honest model. Prior to the anonymization procedure, an encrypted global view of the dataset is constructed by means of a secure multi-party computing (SMC) protocol. This global representation can then be anonymized. Our approach is not limited to specific anonymization algorithms but provides pre- and postprocessing for a broad spectrum of algorithms and many privacy criteria. We present an extensive analytical and experimental evaluation and discuss which types of methods and criteria are supported. Our prototype demonstrates the approach by implementing k-anonymity, ℓ-diversity, t-closeness and δ-presence with a globally optimal de-identification method in horizontally and vertically distributed setups. The experiments show that our method provides highly competitive performance and offers a practical and flexible solution for anonymizing distributed biomedical datasets. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. A Mechanism for Anonymous Credit Card Systems

    Science.gov (United States)

    Tamura, Shinsuke; Yanase, Tatsuro

    This paper proposes a mechanism for anonymous credit card systems, in which each credit card holder can conceal individual transactions from the credit card company, while enabling the credit card company to calculate the total expenditures of transactions of individual card holders during specified periods, and to identify card holders who executed dishonest transactions. Based on three existing mechanisms, i.e. anonymous authentication, blind signature and secure statistical data gathering, together with implicit transaction links proposed here, the proposed mechanism enables development of anonymous credit card systems without assuming any absolutely trustworthy entity like tamper resistant devices or organizations faithful both to the credit card company and card holders.

  11. Stationary Anonymous Sequential Games with Undiscounted Rewards.

    Science.gov (United States)

    Więcek, Piotr; Altman, Eitan

    Stationary anonymous sequential games with undiscounted rewards are a special class of games that combine features from both population games (infinitely many players) with stochastic games. We extend the theory for these games to the cases of total expected reward as well as to the expected average reward. We show that in the anonymous sequential game equilibria correspond to the limits of those of related finite population games as the number of players grows to infinity. We provide examples to illustrate our results.

  12. Anon-Pass: Practical Anonymous Subscriptions

    Science.gov (United States)

    Lee, Michael Z.; Dunn, Alan M.; Katz, Jonathan; Waters, Brent; Witchel, Emmett

    2014-01-01

    We present the design, security proof, and implementation of an anonymous subscription service. Users register for the service by providing some form of identity, which might or might not be linked to a real-world identity such as a credit card, a web login, or a public key. A user logs on to the system by presenting a credential derived from information received at registration. Each credential allows only a single login in any authentication window, or epoch. Logins are anonymous in the sense that the service cannot distinguish which user is logging in any better than random guessing. This implies unlinkability of a user across different logins. We find that a central tension in an anonymous subscription service is the service provider’s desire for a long epoch (to reduce server-side computation) versus users’ desire for a short epoch (so they can repeatedly “re-anonymize” their sessions). We balance this tension by having short epochs, but adding an efficient operation for clients who do not need unlinkability to cheaply re-authenticate themselves for the next time period. We measure performance of a research prototype of our protocol that allows an independent service to offer anonymous access to existing services. We implement a music service, an Android-based subway-pass application, and a web proxy, and show that adding anonymity adds minimal client latency and only requires 33 KB of server memory per active user. PMID:24504081

  13. Performance evaluation of various K- anonymity techniques

    Science.gov (United States)

    Maheshwarkar, Nidhi; Pathak, Kshitij; Chourey, Vivekanand

    2011-12-01

    Today's advanced scenario where each information is available in one click, data security is the main aspect. Individual information which sometimes needs to be hiding is easily available using some tricks. Medical information, income details are needed to be kept away from adversaries and so, are stored in private tables. Some publicly released information contains zip code, sex, birth date. When this released information is linked with the private table, adversary can detect the whole confidential information of individuals or respondents, i.e. name, medical status. So to protect respondents identity, a new concept k-anonymity is used which means each released record has at least (k-1) other records in the release whose values are distinct over those fields that appear in the external data. K-anonymity can be achieved easily in case of single sensitive attributes i.e. name, salary, medical status, but it is quiet difficult when multiple sensitive attributes are present. Generalization and Suppression are used to achieve k-anonymity. This paper provides a formal introduction of k-anonymity and some techniques used with it l-diversity, t-closeness. This paper covers k-anonymity model and the comparative study of these concepts along with a new proposed concept for multiple sensitive attributes.

  14. Is it OK to be an Anonymous?

    Directory of Open Access Journals (Sweden)

    Philip Serracino-Inglott

    2013-12-01

    Full Text Available Do the deviant acts carried out by the collective known as Anonymous qualify as vigilante activity, and if so, can they be justified? Addressing this question helps expose the difficulties of morally evaluating technologically enabled deviance. Anonymous is a complex, fluid actor but not as mysterious as popularly portrayed. Under a definition of vigilantism that includes reprobative punishment rather than violence as a key element, Anonymous are vigilantes. Many of its Ops can be justified in view of the mismatch between formal norm enforcement practice and Internet natives’ experience of it. Anons are more like eco-warriors than terrorists. While their actions are contentious, their force is framed in a vision of common good that is not unreasonable. Engaging with online deviants is shown to be a productive way of identifying the weaknesses in concepts underpinning moral evaluation of Internet-enabled phenomena.

  15. Scalable and Anonymous Group Communication with MTor

    Directory of Open Access Journals (Sweden)

    Lin Dong

    2016-04-01

    Full Text Available This paper presents MTor, a low-latency anonymous group communication system. We construct MTor as an extension to Tor, allowing the construction of multi-source multicast trees on top of the existing Tor infrastructure. MTor does not depend on an external service to broker the group communication, and avoids central points of failure and trust. MTor’s substantial bandwidth savings and graceful scalability enable new classes of anonymous applications that are currently too bandwidth-intensive to be viable through traditional unicast Tor communication-e.g., group file transfer, collaborative editing, streaming video, and real-time audio conferencing.

  16. Anonymous communication networks protecting privacy on the web

    CERN Document Server

    Peng, Kun

    2014-01-01

    In today's interactive network environment, where various types of organizations are eager to monitor and track Internet use, anonymity is one of the most powerful resources available to counterbalance the threat of unknown spectators and to ensure Internet privacy.Addressing the demand for authoritative information on anonymous Internet usage, Anonymous Communication Networks: Protecting Privacy on the Web examines anonymous communication networks as a solution to Internet privacy concerns. It explains how anonymous communication networks make it possible for participants to communicate with

  17. An outcome study of Gamblers Anonymous.

    Science.gov (United States)

    Stewart, R M; Brown, R I

    1988-02-01

    Retrospective and prospective studies of a total sample of 232 attenders at groups of Gamblers Anonymous suggest that total abstinence from gambling was maintained by 8% of all comers at one year from first attendance and by 7% at two years.

  18. Anticipating anonymity in screening program databases.

    Science.gov (United States)

    Caballero, Rafael; Sen, Sagar; Nygård, Jan F

    2017-07-01

    In this paper, we propose a technique for improving anonymity in screening program databases to increase the privacy for the participants in these programs. The data generated by the invitation process (screening centre, appointment date) is often made available to researchers for medical research and for evaluation and improvement of the screening program. This information, combined with other personal quasi-identifiers such as the ZIP code, gender or age, can pose a risk of disclosing the identity of the individuals participating in the program, and eventually their test results. We present two algorithms that produce a set of screening appointments that aim to increase anonymity of the resulting dataset. The first one, based on the constraint programming paradigm, defines the optimal appointments, while the second one is a suboptimal heuristic algorithm that can be used with real size datasets. The level of anonymity is measured using the new concept of generalized k-anonymity, which allows us to show the utility of the proposal by means of experiments, both using random data and data based on screening invitations from the Norwegian Cancer Registry. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Anonymous publication of sensitive transactional data

    KAUST Repository

    Ghinita, Gabriel

    2011-02-01

    Existing research on privacy-preserving data publishing focuses on relational data: in this context, the objective is to enforce privacy-preserving paradigms, such as k-anonymity and ℓ-diversity, while minimizing the information loss incurred in the anonymizing process (i.e., maximize data utility). Existing techniques work well for fixed-schema data, with low dimensionality. Nevertheless, certain applications require privacy-preserving publishing of transactional data (or basket data), which involve hundreds or even thousands of dimensions, rendering existing methods unusable. We propose two categories of novel anonymization methods for sparse high-dimensional data. The first category is based on approximate nearest-neighbor (NN) search in high-dimensional spaces, which is efficiently performed through locality-sensitive hashing (LSH). In the second category, we propose two data transformations that capture the correlation in the underlying data: 1) reduction to a band matrix and 2) Gray encoding-based sorting. These representations facilitate the formation of anonymized groups with low information loss, through an efficient linear-time heuristic. We show experimentally, using real-life data sets, that all our methods clearly outperform existing state of the art. Among the proposed techniques, NN-search yields superior data utility compared to the band matrix transformation, but incurs higher computational overhead. The data transformation based on Gray code sorting performs best in terms of both data utility and execution time. © 2006 IEEE.

  20. Stroke rehabilitation reaches a threshold.

    Directory of Open Access Journals (Sweden)

    Cheol E Han

    2008-08-01

    Full Text Available Motor training with the upper limb affected by stroke partially reverses the loss of cortical representation after lesion and has been proposed to increase spontaneous arm use. Moreover, repeated attempts to use the affected hand in daily activities create a form of practice that can potentially lead to further improvement in motor performance. We thus hypothesized that if motor retraining after stroke increases spontaneous arm use sufficiently, then the patient will enter a virtuous circle in which spontaneous arm use and motor performance reinforce each other. In contrast, if the dose of therapy is not sufficient to bring spontaneous use above threshold, then performance will not increase and the patient will further develop compensatory strategies with the less affected hand. To refine this hypothesis, we developed a computational model of bilateral hand use in arm reaching to study the interactions between adaptive decision making and motor relearning after motor cortex lesion. The model contains a left and a right motor cortex, each controlling the opposite arm, and a single action choice module. The action choice module learns, via reinforcement learning, the value of using each arm for reaching in specific directions. Each motor cortex uses a neural population code to specify the initial direction along which the contralateral hand moves towards a target. The motor cortex learns to minimize directional errors and to maximize neuronal activity for each movement. The derived learning rule accounts for the reversal of the loss of cortical representation after rehabilitation and the increase of this loss after stroke with insufficient rehabilitation. Further, our model exhibits nonlinear and bistable behavior: if natural recovery, motor training, or both, brings performance above a certain threshold, then training can be stopped, as the repeated spontaneous arm use provides a form of motor learning that further bootstraps performance and

  1. Anonymity-Preserving Public-Key Encryption

    DEFF Research Database (Denmark)

    Kohlweiss, Markulf; Maurer, Ueli; Onete, Cristina

    2013-01-01

    A receiver-anonymous channel allows a sender to send a message to a receiver without an adversary learning for whom the message is intended. Wireless broadcast channels naturally provide receiver anonymity, as does multi-casting one message to a receiver population containing the intended receiver...... by applying a cryptographic scheme explicit in the constructed (ideal) resource; this specifies the exact requirements for the applicability of a cryptographic scheme in a given context. It also allows to decide which of the existing security properties of such a cryptographic scheme are adequate...... for the considered scenario, and which are too weak or too strong. Here, we show that weak robustness is necessary but that so-called strong robustness is unnecessarily strong in that it does not construct a (natural) stronger resource....

  2. Academic freedom, public reactions, and anonymity.

    Science.gov (United States)

    Häyry, Matti

    2014-05-01

    Academic freedom can be defined as immunity against adverse reactions from the general public, designed to keep scholars unintimidated and productive even after they have published controversial ideas. Francesca Minerva claims that this notion of strict instrumental academic freedom is supported by Ronald Dworkin, and that anonymity would effectively defend the sphere of immunity implied by it. Against this, I argue that the idea defended by Minerva finds no support in the work by Dworkin referred to; that anonymity would not in most cases effectively protect the kind of immunity sought after; and that in some cases it would not even be desirable to protect scholars from public reactions to their controversial claims. © 2014 John Wiley & Sons Ltd.

  3. Anonymous electronic trading versus floor trading

    OpenAIRE

    Franke, Günter; Hess, Dieter

    1995-01-01

    This paper compares the attractiveness of floor trading and anonymous electronic trading systems. It is argued that in times of low information intensity the insight into the order book of the electronic trading system provides more valuable information than floor trading, but in times of high information intensity the reverse is true. Thus, the electronic system's market share in trading activity should decline in times of high information intensity. This hypothesis is tested by data on BUND...

  4. Spontaneous pneumothorax

    Directory of Open Access Journals (Sweden)

    Davari R

    1996-07-01

    Full Text Available A case with bilateral spontaneous pneumothorax was presented. Etiology, mechanism, and treatment were discussed on the review of literature. Spontaneous Pneumothorax is a clinical entity resulting from a sudden non traumatic rupture of the lung. Biach reported in 1880 that 78% of 916 patients with spontaneous pneumothorax had tuberculosis. Kjergaard emphasized 1932 the primary importance of subpleural bleb disease. Currently the clinical spectrum of spontaneous pneumothorax seems to have entered a third era with the recognition of the interstitial lung disease and AIDS as a significant etiology. Standard treatment is including: observation, thoracocentesis, tube thoracostomy. Chemical pleurodesis, bullectomy or wedge resection of lung with pleural abrasion and occasionally pleurectomy. Little information has been reported regarding the efficacy of such treatment in spontaneous pneumothorax secondary to non bleb disease

  5. Anonymous quantum communications using the quantum one-time pad

    International Nuclear Information System (INIS)

    Wang, Qing-Le; Gao, Fei-; Liu, Bin; Song, Ting-Ting; Wen, Qiao-Yan

    2015-01-01

    We present the first quantum secure communication protocol for an anonymous receiver without the assistance of anonymous entanglement. In previous works, if a public sender wants to send quantum messages to a chosen receiver while protecting the identity of the receiver from others, all participants should cooperate first to construct the entanglement between the sender and the anonymous receiver. This is the most important process in anonymous quantum communications. With anonymous entanglement, the sender can communicate quantum messages to the anonymous receiver by applying teleportation protocols. In contrast, our protocol is novel and achieves communication of quantum messages directly from the public sender to the anonymous receiver based on the quantum one-time pad and current achievements. Notably, the anonymity of the receiver, as well as the privacy of the quantum messages, is perfectly protected with the exception of an exponentially small probability in our protocol. (paper)

  6. Study on Privacy Protection Algorithm Based on K-Anonymity

    Science.gov (United States)

    FeiFei, Zhao; LiFeng, Dong; Kun, Wang; Yang, Li

    Basing on the study of K-Anonymity algorithm in privacy protection issue, this paper proposed a "Degree Priority" method of visiting Lattice nodes on the generalization tree to improve the performance of K-Anonymity algorithm. This paper also proposed a "Two Times K-anonymity" methods to reduce the information loss in the process of K-Anonymity. Finally, we used experimental results to demonstrate the effectiveness of these methods.

  7. Assessing Anonymous Communication on the Internet: Policy Deliberations.

    Science.gov (United States)

    Kling, Rob; Lee, Yaching; Frankel, Mark S.; Teich, Al

    1999-01-01

    Examines the social character of anonymous online communication and the ways that anonymous communication has played important roles for professionals such as journalists and the police. Explains some of the new technological supports for anonymous communication on the Internet. Discusses some of the nuances behind the controversies and policy…

  8. Anonymity: An Impediment to Performance in Healthcare

    Directory of Open Access Journals (Sweden)

    Daniel W. Karlsberg

    2014-01-01

    Full Text Available Many teaching hospitals employ a care team structure composed of a broad range of healthcare providers with different skill sets. Each member of this team has a distinct role and a different level of training ranging from attending physician to resident, intern, and medical student. Often times, these different roles lead to greater complexity and confusion for both patients and nursing staff. It has been demonstrated that patients have a great degree of difficulty in identifying members of their care team. This anonymity also exists between nursing staff and other care providers. In order to better understand the magnitude of anonymity within the teaching hospital, a ten-question survey was sent to nurses across three different departments. Results from this survey demonstrated that 71% of nurses are “Always” or “Often” able to identify which care team is responsible for their patients, while 79% of nurses reported that they either “Often” or “Sometimes” page a provider who is not currently caring for a given patient. Furthermore, 33% of nurses felt that they were either “Rarely” or “Never” able to recognize, by face and name, attending level providers. Residents were “Rarely” or “Never” recognized by face and name 37% of the time, and interns 42% of the time. Contacting the wrong provider repeatedly leads to de facto delays in medication, therapy, and diagnosis. Additionally, these unnecessary interruptions slow workflow for both nurses and members of the care team, making hospital care less efficient and safe overall. Technological systems should focus on reducing anonymity within the hospital in order to enhance healthcare delivery.

  9. An Extensive Study on Data Anonymization Algorithms Based on K-Anonymity

    Science.gov (United States)

    Simi, Ms. M. S.; Sankara Nayaki, Mrs. K.; Sudheep Elayidom, M., Dr.

    2017-08-01

    For business and research oriented works engaging Data Analysis and Cloud services needing qualitative data, many organizations release huge microdata. It excludes an individual’s explicit identity marks like name, address and comprises of specific information like DOB, Pin-code, sex, marital status, which can be combined with other public data to recognize a person. This implication attack can be manipulated to acquire any sensitive information from social network platform, thereby putting the privacy of a person in grave danger. To prevent such attacks by modifying microdata, K-anonymization is used. With potentially increasing data, the effective method to anonymize it stands challenging. After series of trails and systematic comparison, in this paper, we propose three best algorithms along with its efficiency and effectiveness. Studies help researchers to identify the relationship between the values of k, degree of anonymization, choosing a quasi-identifier and focus on execution time.

  10. Suicidal behavior among members of Gamblers Anonymous.

    Science.gov (United States)

    Frank, M L; Lester, D; Wexler, A

    1991-09-01

    A national sample of 500 members of Gamblers Anonymous was surveyed by mail in order to gather information on suicidal history. One hundred sixty two usable surveys were returned representing 32.4% of the original sample. Compulsive gamblers who had a history of suicidal preoccupation began gambling at an earlier age than nonsuicidal gamblers and were more likely to have stolen to support their gambling. They also tended to have addicted relatives and children more than nonsuicidal gamblers did. The data suggest that those gamblers who had been suicidal tend to be more serious gamblers than nonsuicidal respondents.

  11. 'Gift without a price tag': altruism in anonymous semen donation.

    Science.gov (United States)

    Yee, Samantha

    2009-01-01

    Commercialization of human gametes is now legally prohibited in Canada under the Assisted Human Reproduction Act 2004, making semen donation in Canada altruistic and anonymous by law. Donors must be altruistically motivated to donate gametes without receiving monetary rewards. Globally speaking, Canada is neither the first nor the only country in the world that has legislation to support altruistic gamete donation. Other countries have advocated similar systems either through legislative changes or implementation of best practice models. This paper is a review of literature assessing the differences in donation behaviours under paid and altruistic donation models. It provides contextual information of the current semen donation situation in Canada, while drawing upon relevant literature and research data from other countries as references. The author also attempts to re-conceptualize the meanings of altruism through exploring the complex interplay between psycho-social and institutional factors in influencing donors' behaviours. Although there is a substantial amount of research studying the impacts on donor recruitment when payment is withdrawn, very few research studies are found that focus on exploring altruistic donor recruitment strategies. It is unrealistic to expect the altruistic donation culture to emerge spontaneously in Canada without any multi-level efforts to coordinate the recruitment strategies. Research programmes are greatly needed to generate empirical knowledge that can guide the development of altruistic donor recruitment models geared to the current socio-cultural environment and legislative framework in Canada. The findings will be invaluable when the legislation comes up for parliamentary review in the near future.

  12. Browsing the Internet: good-bye anonymity!

    CERN Multimedia

    Computer Security Team

    2012-01-01

    Do you consider browsing the Internet to be your private business? When visiting random web-sites, how far do you assume you are anonymous? Would it matter to you that Google or Facebook can profile your browsing behaviour in order to better target you with advertisements? Did you notice that you already get targeted ads when you are logged on to Google or Facebook even if you are visiting completely different websites? If matters to you, note that browsing anonymously on the Internet is far from easy.   When you are connected to the Internet, you give away a variety of information: your PC’s IP address, some browser settings like language or screen size, and, probably, your login information. So how private is private? You might argue that your current IP address has been picked from a pool of addresses and therefore regularly changes, so it does not necessarily always pinpoint you. On the other hand, with the dawn of IPv6 there is no need any more for shared IP addresses as the...

  13. Our Anonymous Online Research Participants Are Not Always Anonymous: Is This a Problem?

    Science.gov (United States)

    Dawson, Phillip

    2014-01-01

    When educational research is conducted online, we sometimes promise our participants that they will be anonymous--but do we deliver on this promise? We have been warned since 1996 to be careful when using direct quotes in Internet research, as full-text web search engines make it easy to find chunks of text online. This paper details an empirical…

  14. Anonymous HIV surveillance in Saughton Prison, Edinburgh.

    Science.gov (United States)

    Bird, A G; Gore, S M; Jolliffe, D W; Burns, S M

    1992-07-01

    To estimate the prevalence of HIV by anonymous saliva testing in Her Majesty's Prison, Saughton (Saughton Prison), Edinburgh, UK. To elicit linked anonymous risk factor information from which to estimate risk scores for those who had taken an HIV blood test and, among drug injectors, for those who were HIV-1-antibody-positive on saliva testing. Saughton Prison on 15 and 16 August 1991; HIV Immunology and Regional Virus Laboratories, Edinburgh, and the Medical Research Council Biostatistics Unit, Cambridge, UK. Male inmates (378 out of a total of 499) of Saughton Prison. Answers to a brief questionnaire about age, usual residence, present and past custodial sentences, drug injecting and sexual behaviour prior to and in prison, HIV testing and history of acute hepatitis. HIV-1-antibody status was established by saliva testing. Eighteen per cent of participants were injecting drug users (IDU), of whom approximately one-half (47%) had injected while inside prison. Ninety men (26%), including 40 (14%) of 278 participants who had never injected drugs and 77% of IDU participants, had taken an HIV blood test. Nine per cent of all participants and 35% of IDU participants had had an acute attack of hepatitis. Forty-one (62%) of 66 IDU had been imprisoned five or more times before their current prison sentence. After taking account of region of residence, injecting drug history and acute hepatitis, aspects of sentencing and sexual behaviour were not determinants of those who had been tested for HIV. On the study days, 18 out of 499 (3.6%) participants were known to prison medical officers to be HIV-infected. Following saliva testing, HIV prevalence was 17 out of 375 (4.5%) inmates tested. All 17 had at some time 'taken the blood test for HIV' and all had injected non-medically prescribed drugs. Edinburgh residence, age 26-30 years, have injected in prison and having first injected before 1983 all contributed to the risk score for whether an IDU was HIV-1-antibody-positive on

  15. Digital anonymity on the internet : new rules for anonymous electronic transactions? an exploration of the private law implications of digital anonymity

    NARCIS (Netherlands)

    Grijpink, J.H.A.M.; Prins, C.

    2001-01-01

    This article sets out the most important conclusions of the first stage of a study into the dimensions of digital anonymity. It is intended to set out the problem, make people aware of the intricacies of the problem and thus stimulate the debate on useful legal structures for anonymity. The

  16. The k-Anonymity Problem Is Hard

    Science.gov (United States)

    Bonizzoni, Paola; Della Vedova, Gianluca; Dondi, Riccardo

    The problem of publishing personal data without giving up privacy is becoming increasingly important. An interesting formalization recently proposed is the k-anonymity. This approach requires that the rows in a table are clustered in sets of size at least k and that all the rows in a cluster are related to the same tuple, after the suppression of some records. The problem has been shown to be NP-hard when the values are over a ternary alphabet, k = 3 and the rows length is unbounded. In this paper we give a lower bound on the approximation of two restrictions of the problem, when the records values are over a binary alphabet and k = 3, and when the records have length at most 8 and k = 4, showing that these restrictions of the problem are APX-hard.

  17. Spontaneous deregulation

    NARCIS (Netherlands)

    Edelman, Benjamin; Geradin, Damien

    Platform businesses such as Airbnb and Uber have risen to success partly by sidestepping laws and regulations that encumber their traditional competitors. Such rule flouting is what the authors call “spontaneous private deregulation,” and it’s happening in a growing number of industries. The authors

  18. Really not god: Secularization and pragmatism in Gamblers Anonymous.

    Science.gov (United States)

    Browne, B R

    1994-09-01

    The paper argues that despite maintaining the image of a twelve-step organization, the central theme of the history of Gamblers Anonymous (GA) in the United States is the increasing secularization of the program of the recovery. The paper documents the increasing secularization and pragmatism of Gamblers Anonymous, as reflected in key documents, despite the spiritual vision of its founding member. The author speculates on why Gamblers Anonymous took a secularized development path. Further research is called for.

  19. Utility-preserving anonymization for health data publishing.

    Science.gov (United States)

    Lee, Hyukki; Kim, Soohyung; Kim, Jong Wook; Chung, Yon Dohn

    2017-07-11

    Publishing raw electronic health records (EHRs) may be considered as a breach of the privacy of individuals because they usually contain sensitive information. A common practice for the privacy-preserving data publishing is to anonymize the data before publishing, and thus satisfy privacy models such as k-anonymity. Among various anonymization techniques, generalization is the most commonly used in medical/health data processing. Generalization inevitably causes information loss, and thus, various methods have been proposed to reduce information loss. However, existing generalization-based data anonymization methods cannot avoid excessive information loss and preserve data utility. We propose a utility-preserving anonymization for privacy preserving data publishing (PPDP). To preserve data utility, the proposed method comprises three parts: (1) utility-preserving model, (2) counterfeit record insertion, (3) catalog of the counterfeit records. We also propose an anonymization algorithm using the proposed method. Our anonymization algorithm applies full-domain generalization algorithm. We evaluate our method in comparison with existence method on two aspects, information loss measured through various quality metrics and error rate of analysis result. With all different types of quality metrics, our proposed method show the lower information loss than the existing method. In the real-world EHRs analysis, analysis results show small portion of error between the anonymized data through the proposed method and original data. We propose a new utility-preserving anonymization method and an anonymization algorithm using the proposed method. Through experiments on various datasets, we show that the utility of EHRs anonymized by the proposed method is significantly better than those anonymized by previous approaches.

  20. P-Sensitive K-Anonymity with Generalization Constraints

    OpenAIRE

    Alina Campan; Traian Marius Truta; Nicholas Cooper

    2010-01-01

    Numerous privacy models based on the k-anonymity property and extending the k-anonymity model have been introduced in the last few years in data privacy research: l-diversity, p-sensitive k-anonymity, (a, k) anonymity, t-closeness, etc. While differing in their methods and quality of their results, they all focus first on masking the data, and then protecting the quality of the data as a whole. We consider a new approach, where requirements on the amount of distortion allowed on the initial d...

  1. An Applet-based Anonymous Distributed Computing System.

    Science.gov (United States)

    Finkel, David; Wills, Craig E.; Ciaraldi, Michael J.; Amorin, Kevin; Covati, Adam; Lee, Michael

    2001-01-01

    Defines anonymous distributed computing systems and focuses on the specifics of a Java, applet-based approach for large-scale, anonymous, distributed computing on the Internet. Explains the possibility of a large number of computers participating in a single computation and describes a test of the functionality of the system. (Author/LRW)

  2. Anonymity and Openness in Donor Conception: the New Danish Model

    DEFF Research Database (Denmark)

    Herrmann, Janne Rothmar

    2013-01-01

    bank is based in Denmark and consequently anonymous sperm is also exported abroad, even into jurisdictions where anonymity is banned illegal. This commentary traces the raison d’être of anonymity in Danish law, accounts for the legal framework for the internet sale of sperm and examines the new Danish......Whereas the regulatory trend in many European countries has been a move towards openness in donation, Denmark has maintained the possibility of donating and receiving donated sperm completely anonymously. For that reason the supply of donated sperm remains so high that the world’s largest sperm...... model in donor conception which offers women/couples a choice of anonymity or openness in donation.This paper is based on my talk on June 20, 2013 at London School of Economics at the conference “New Families and Genetic Identities: Developments in law, policy and research” organised by the Morgan...

  3. A Differentiated Anonymity Algorithm for Social Network Privacy Preservation

    Directory of Open Access Journals (Sweden)

    Yuqin Xie

    2016-12-01

    Full Text Available Devising methods to publish social network data in a form that affords utility without compromising privacy remains a longstanding challenge, while many existing methods based on k-anonymity algorithms on social networks may result in nontrivial utility loss without analyzing the social network topological structure and without considering the attributes of sparse distribution. Toward this objective, we explore the impact of the attributes of sparse distribution on data utility. Firstly, we propose a new utility metric that emphasizes network structure distortion and attribute value loss. Furthermore, we design and implement a differentiated k-anonymity l-diversity social network anonymity algorithm, which seeks to protect users’ privacy in social networks and increase the usability of the published anonymized data. Its key idea is that it divides a node into two child nodes and only anonymizes sensitive values to satisfy anonymity requirements. The evaluation results show that our method can effectively improve the data utility as compared to generalized anonymizing algorithms.

  4. Alcoholics Anonymous and nursing. Lessons in holism and spiritual care.

    Science.gov (United States)

    McGee, E M

    2000-03-01

    Alcoholic Anonymous (AA) is a worldwide, million-member organization that has assisted countless alcoholics to achieve sobriety through a spiritual program of recovery from alcoholism. Based on spiritual principles known as the "Twelve Steps" and "Twelve Traditions," AA has provided a model for other recovery programs such as Narcotics Anonymous (NA), Gamblers Anonymous (GA), and Sex and Love Addicts Anonymous (SLAA). Recovery in AA appears to involve a process of self-transcendence. In recent years, nursing scholars have increasingly explored the concepts of self-transcendence and spirituality as they apply to nursing theory and practice. This article explores the roots and spiritual dimensions of 12-step recovery programs. It further explores the ways in which theoretical and clinical knowledge about the delivery of spiritual care interventions may be gained from an understanding of AA's spiritual approach to recovery.

  5. Unraveling an Old Cloak: k-anonymity for Location Privacy

    OpenAIRE

    Shokri, Reza; Troncoso, Carmela; Diaz, Claudia; Freudiger, Julien; Hubaux, Jean-Pierre

    2010-01-01

    There is a rich collection of literature that aims at protecting the privacy of users querying location-based services. One of the most popular location privacy techniques consists in cloaking users' locations such that k users appear as potential senders of a query, thus achieving k-anonymity. This paper analyzes the effectiveness of k-anonymity approaches for protecting location privacy in the presence of various types of adversaries. The unraveling of the scheme unfolds the inconsistency b...

  6. System for Anonymous Data Collection Based on Group Signature Scheme

    Directory of Open Access Journals (Sweden)

    David Troják

    2016-01-01

    Full Text Available This paper deals with an anonymous data collection in the Internet of Things (IoT. the privacy and anonymity of the data source is important for many IoT applications, such as in agriculture, health, and automotive. the proposed data‑collection system provides anonymity for the data sources by applying a cooperation group scheme. the group scheme also provides a low power consumption. the system is built upon the Tor (The Onion Router anonymous network, which is a part of the Internet darknet. the proposed system was designed for the Android devices on the client side and for Java environment on the server side. We evaluated the anonymous data collection in a real‑use scenario that covers selected data acquisition (e.g. signal strength from smartphones triggered by their geographical location change. the results show that the proposed system provides the sufficient data source anonymity, an effective revocation, a low computational cost and a low overhead.

  7. Detection thresholds of macaque otolith afferents.

    Science.gov (United States)

    Yu, Xiong-Jie; Dickman, J David; Angelaki, Dora E

    2012-06-13

    The vestibular system is our sixth sense and is important for spatial perception functions, yet the sensory detection and discrimination properties of vestibular neurons remain relatively unexplored. Here we have used signal detection theory to measure detection thresholds of otolith afferents using 1 Hz linear accelerations delivered along three cardinal axes. Direction detection thresholds were measured by comparing mean firing rates centered on response peak and trough (full-cycle thresholds) or by comparing peak/trough firing rates with spontaneous activity (half-cycle thresholds). Thresholds were similar for utricular and saccular afferents, as well as for lateral, fore/aft, and vertical motion directions. When computed along the preferred direction, full-cycle direction detection thresholds were 7.54 and 3.01 cm/s(2) for regular and irregular firing otolith afferents, respectively. Half-cycle thresholds were approximately double, with excitatory thresholds being half as large as inhibitory thresholds. The variability in threshold among afferents was directly related to neuronal gain and did not depend on spike count variance. The exact threshold values depended on both the time window used for spike count analysis and the filtering method used to calculate mean firing rate, although differences between regular and irregular afferent thresholds were independent of analysis parameters. The fact that minimum thresholds measured in macaque otolith afferents are of the same order of magnitude as human behavioral thresholds suggests that the vestibular periphery might determine the limit on our ability to detect or discriminate small differences in head movement, with little noise added during downstream processing.

  8. Efficient and anonymous two-factor user authentication in wireless sensor networks: achieving user anonymity with lightweight sensor computation.

    Science.gov (United States)

    Nam, Junghyun; Choo, Kim-Kwang Raymond; Han, Sangchul; Kim, Moonseong; Paik, Juryon; Won, Dongho

    2015-01-01

    A smart-card-based user authentication scheme for wireless sensor networks (hereafter referred to as a SCA-WSN scheme) is designed to ensure that only users who possess both a smart card and the corresponding password are allowed to gain access to sensor data and their transmissions. Despite many research efforts in recent years, it remains a challenging task to design an efficient SCA-WSN scheme that achieves user anonymity. The majority of published SCA-WSN schemes use only lightweight cryptographic techniques (rather than public-key cryptographic techniques) for the sake of efficiency, and have been demonstrated to suffer from the inability to provide user anonymity. Some schemes employ elliptic curve cryptography for better security but require sensors with strict resource constraints to perform computationally expensive scalar-point multiplications; despite the increased computational requirements, these schemes do not provide user anonymity. In this paper, we present a new SCA-WSN scheme that not only achieves user anonymity but also is efficient in terms of the computation loads for sensors. Our scheme employs elliptic curve cryptography but restricts its use only to anonymous user-to-gateway authentication, thereby allowing sensors to perform only lightweight cryptographic operations. Our scheme also enjoys provable security in a formal model extended from the widely accepted Bellare-Pointcheval-Rogaway (2000) model to capture the user anonymity property and various SCA-WSN specific attacks (e.g., stolen smart card attacks, node capture attacks, privileged insider attacks, and stolen verifier attacks).

  9. Interim policy on establishment and operation of internet open, anonymous information servers and services

    OpenAIRE

    Acting Dean of Computer and Information Services

    1995-01-01

    Purpose. To establish interim NPS general policy regarding establishment and operation of Open, Anonymous Information Servers and Services, such as World Wide Web (http), Gopher, Anonymous FTP, etc...

  10. Anonymity in Peer-assisted CDNs: Inference Attacks and Mitigation

    Directory of Open Access Journals (Sweden)

    Jia Yaoqi

    2016-10-01

    Full Text Available The peer-assisted CDN is a new content distribution paradigm supported by CDNs (e.g., Akamai, which enables clients to cache and distribute web content on behalf of a website. Peer-assisted CDNs bring significant bandwidth savings to website operators and reduce network latency for users. In this work, we show that the current designs of peer-assisted CDNs expose clients to privacy-invasive attacks, enabling one client to infer the set of browsed resources of another client. To alleviate this, we propose an anonymous peer-assisted CDN (APAC, which employs content delivery while providing initiator anonymity (i.e., hiding who sends the resource request and responder anonymity (i.e., hiding who responds to the request for peers. APAC can be a web service, compatible with current browsers and requiring no client-side changes. Our anonymity analysis shows that our APAC design can preserve a higher level of anonymity than state-of-the-art peer-assisted CDNs. In addition, our evaluation demonstrates that APAC can achieve desired performance gains.

  11. Criminal offenses in gamblers anonymous and hospital treated pathological gamblers.

    Science.gov (United States)

    Blaszczynski, A P; McConaghy, N

    1994-06-01

    The purpose of this study was to compare the nature and prevalence of gambling and non-gambling related offenses in samples of pathological gamblers seeking behavioural treatment from a hospital-based program and those attending Gamblers Anonymous. A semi-structured interview schedule obtaining demographic data and details of the nature, frequency, and consequent legal action of criminal offenses committed was administered to 152 consecutive hospital treated pathological gamblers, and 154 Gamblers Anonymous attendees who volunteered to participate in the study. Of the total sample, 59% admitted a gambling-related offense, and 23% to a conviction. There was no difference in the proportion of hospital treated and Gamblers Anonymous subjects who offended. The most common gambling-related offenses were larceny, embezzlement and misappropriation. Gamblers committed a median of ten offenses over an average ten year period of pathological gambling with a median value of $ A 300(1) per offense. The median value for each non-gambling-related offense was $ A 130. Except for the significantly older mean age of Gamblers Anonymous subjects, hospital treated gamblers did not differ from Gamblers Anonymous attenders on relevant demographic features or parameters of gambling behaviour. Findings were interpreted to suggest a possible causal link between pathological gambling and the commission of non-violent property offenses.

  12. How to kill gamete donation: retrospective legislation and donor anonymity.

    Science.gov (United States)

    Pennings, Guido

    2012-10-01

    Victoria (Australia) is considering retrospective legislation on the abolition of gamete donor anonymity. Retrospective legislation evokes many negative emotions mainly because it is considered unfair. It also makes it impossible for citizens to organize their life with reasonable certainty of the consequences. Introduction of this law for donor anonymity is defended by the right of the child to know its genetic origins. Against this law, people appeal to the right to privacy and confidentiality of the donor. This paper analyses the arguments for and against a retrospective law on donor anonymity by looking at the conditions that should be respected when two principles (the donor's right to privacy and the child's right to genetic information) have to be balanced. It is concluded that the justification for introducing retrospective law is lacking: the conditions are not fulfilled. Moreover, retroactive laws in the context of gamete donation may jeopardize the whole practice by destroying the trust of candidate donors and recipients in the government.

  13. Anonymous pastoral care for problems pertaining to sexuality.

    Science.gov (United States)

    van Drie, A; Ganzevoort, R R; Spiering, M

    2014-12-01

    Anonymous pastoral care is one of the options for help in problems pertaining to sexuality. This paper explores the topics they seek help for, the religious aspects involved, and the relation between the normativity of their church tradition on the one hand and sexual and spiritual health criteria on the other. We analyzed helpseeking questions of two protestant Christian organizations in the Netherlands providing anonymous pastoral care: Refoweb and EO-Nazorg. Sexual themes were addressed in 19 and 2.3 % of the submitted questions, respectively. Of the helpseekers, 56 % is female, 15 % male, and 29 % unknown. Questions and problems for which people seek anonymous pastoral care focus primarily on premarital abstinence, gender roles, contraception, sexual orientation and masturbation. The authority of the Bible seems to be important for questioners, especially when dealing with ethical questions. Different relations between the normativity of the church tradition and sexual and spiritual health are discussed.

  14. Verifying Anonymous Credential Systems in Applied Pi Calculus

    Science.gov (United States)

    Li, Xiangxi; Zhang, Yu; Deng, Yuxin

    Anonymous credentials are widely used to certify properties of a credential owner or to support the owner to demand valuable services, while hiding the user's identity at the same time. A credential system (a.k.a. pseudonym system) usually consists of multiple interactive procedures between users and organizations, including generating pseudonyms, issuing credentials and verifying credentials, which are required to meet various security properties. We propose a general symbolic model (based on the applied pi calculus) for anonymous credential systems and give formal definitions of a few important security properties, including pseudonym and credential unforgeability, credential safety, pseudonym untraceability. We specialize the general formalization and apply it to the verification of a concrete anonymous credential system proposed by Camenisch and Lysyanskaya. The analysis is done automatically with the tool ProVerif and several security properties have been verified.

  15. Structure and Anonymity of the Bitcoin Transaction Graph

    Directory of Open Access Journals (Sweden)

    Kay Hamacher

    2013-05-01

    Full Text Available The Bitcoin network of decentralized payment transactions has attracted a lot of attention from both Internet users and researchers in recent years. Bitcoin utilizes a peer-to-peer network to issue anonymous payment transactions between different users. In the currently used Bitcoin clients, the full transaction history is available at each node of the network to prevent double spending without the need for a central authority, forming a valuable source for empirical research on network structure, network dynamics, and the implied anonymity challenges, as well as guidance on the future evolution of complex payment systems. We found dynamical effects of which some increase anonymity while others decrease it. Most importantly, several parameters of the Bitcoin transaction graph seem to have become stationary over the last 12–18 months. We discuss the implications.

  16. Secure and Efficient Anonymous Authentication Scheme in Global Mobility Networks

    Directory of Open Access Journals (Sweden)

    Jun-Sub Kim

    2013-01-01

    Full Text Available In 2012, Mun et al. pointed out that Wu et al.’s scheme failed to achieve user anonymity and perfect forward secrecy and disclosed the passwords of legitimate users. And they proposed a new enhancement for anonymous authentication scheme. However, their proposed scheme has vulnerabilities that are susceptible to replay attack and man-in-the-middle attack. It also incurs a high overhead in the database. In this paper, we examine the vulnerabilities in the existing schemes and the computational overhead incurred in the database. We then propose a secure and efficient anonymous authentication scheme for roaming service in global mobility network. Our proposed scheme is secure against various attacks, provides mutual authentication and session key establishment, and incurs less computational overhead in the database than Mun et al.'s scheme.

  17. Authority and Hierarchy within Anonymous Internet Relay Chat Networks

    Directory of Open Access Journals (Sweden)

    Stewart Kenton Bertram

    2015-09-01

    Full Text Available 'The protest group Anonymous has emerged as one of the most significant social movements of recent years, announcing their arrival as a globally recognized brand with regular disruptive cyber attacks and the leak of large volumes of sensitive data. Despite the obvious significance of Anonymous, to date, little academic research has been focused on what role hierarchy and internal authority play (if any within the group. Bespoke software was used to structure over 5000 examples of IRC log files, so that a base line descriptive statistical picture could be drawn, as well as a more granular enumeration of the privileges associated with individual users.'

  18. Anonymizing patient genomic data for public sharing association studies.

    Science.gov (United States)

    Fernandez-Lozano, Carlos; Lopez-Campos, Guillermo; Seoane, Jose A; Lopez-Alonso, Victoria; Dorado, Julian; Martín-Sanchez, Fernando; Pazos, Alejandro

    2013-01-01

    The development of personalized medicine is tightly linked with the correct exploitation of molecular data, especially those associated with the genome sequence along with these use of genomic data there is an increasing demand to share these data for research purposes. Transition of clinical data to research is based in the anonymization of these data so the patient cannot be identified, the use of genomic data poses a great challenge because its nature of identifying data. In this work we have analyzed current methods for genome anonymization and propose a one way encryption method that may enable the process of genomic data sharing accessing only to certain regions of genomes for research purposes.

  19. Forming Circle Formations of Anonymous Mobile Agents With Order Preservation

    NARCIS (Netherlands)

    Wang, Chen; Xie, Guangming; Cao, Ming

    2013-01-01

    We propose distributed control laws for a group of anonymous mobile agents to form desired circle formations when the agents move in the one-dimensional space of a circle. The agents are modeled by kinematic points. They share the common knowledge of the orientation of the circle, but are oblivious

  20. Leader Election in Anonymous Rings: Franklin Goes Probabilistic

    NARCIS (Netherlands)

    Bakhshi, Rena; Fokkink, Wan; Pang, Jun; van de Pol, Jan Cornelis; Ausiello, G.; Karhumäki, J.; Mauri, G.; Ong, L.

    2008-01-01

    We present a probabilistic leader election algorithm for anonymous, bidirectional, asynchronous rings. It is based on an algorithm from Franklin, augmented with random identity selection, hop counters to detect identity clashes, and round numbers modulo 2. As a result, the algorithm is finite-state,

  1. Leader election in anonymous rings: Franklin goes probabilistic

    NARCIS (Netherlands)

    R. Bakhshi; W.J. Fokkink (Wan); J. Pang; J.C. van de Pol (Jaco); G. Ausiello

    2008-01-01

    htmlabstractWe present a probabilistic leader election algorithm for anonymous, bidirectional, asynchronous rings. It is based on an algorithm from Franklin, augmented with random identity selection, hop counters to detect identity clashes, and round numbers modulo 2. As a result, the algorithm is

  2. Simplifying Itai-Rodeh Leader Election for Anonymous Rings

    NARCIS (Netherlands)

    Fokkink, W.J.; Pang, J.

    2005-01-01

    We present two probabilistic leader election algorithms for anonymous unidirectional rings with FIFO channels, based on an algorithm from Itai and Rodeh [A. Itai and M. Rodeh. Symmetry breaking in distributive networks. In Proc. FOCS'81, pp. 150-158. IEEE Computer Society, 1981]. In contrast to the

  3. Anonymity and Openness in Donor Conception: the New Danish Model

    DEFF Research Database (Denmark)

    Herrmann, Janne Rothmar

    2013-01-01

    model in donor conception which offers women/couples a choice of anonymity or openness in donation.This paper is based on my talk on June 20, 2013 at London School of Economics at the conference “New Families and Genetic Identities: Developments in law, policy and research” organised by the Morgan...

  4. Circle formation for anonymous mobile robots with order preservation

    NARCIS (Netherlands)

    Wang, Chen; Cao, Ming; Xie, Guangming; Wang, Long

    2012-01-01

    This paper proposes a distributed control law for a group of mobile robots to form any given formation on a circle of a prescribed radius. The robots are modeled by point masses with the constraint that all of them can move only on the circle. In particular, robots are oblivious, anonymous, and

  5. Anonymity versus Perceived Patron Identity in Virtual Reference Transcripts

    Science.gov (United States)

    Roper, Kristin Grabarek; Sobel, Karen

    2012-01-01

    Librarians who provide virtual reference services often perceive that their patrons self-identify to some degree, even when transactions are anonymous. They also develop a sense of patrons' greatest research-related needs over time. In this article, two librarians analyze two years' worth of virtual reference transcripts to determine what patrons…

  6. Who Goes There? Staying Anonymous on the Internet

    Science.gov (United States)

    Descy, Don E.

    2009-01-01

    Privacy is a thing of the past. Monitoring is everywhere. If one is looking at this online, the author is sure that lots of information has been stored and linked to anyone about that action. Nevertheless, at least people can try to play with "their" minds and surf the web anonymously. In this article, the author discusses ways to try to hide…

  7. Does spousal participation in Gamblers Anonymous benefit compulsive gamblers?

    Science.gov (United States)

    Johnson, E E; Nora, R M

    1992-12-01

    Extent of gambling-free periods was compared for 90 compulsive gamblers, 44 with spouses who participated in Gamblers Anonymous and 46 with spouses who did not. Although the results were in the direction of a beneficial effect of spousal participation, the relationship was statistically nonsignificant.

  8. Gamblers anonymous and cognitive-behavioral therapies for pathological gamblers.

    Science.gov (United States)

    Petry, Nancy M

    2005-01-01

    Numerous types of treatments for pathological gambling have been described, but two of the most common are Gamblers Anonymous (GA) and cognitive-behavioral therapy. This paper describes some outcome data associated with the two approaches. It also reviews evidence suggesting that a combined intervention may enhance therapy engagement and reduce relapse rates.

  9. Effectiveness of Parents' Anonymous in Reducing Child Abuse.

    Science.gov (United States)

    Post-Kammer, Phyllis

    1988-01-01

    Studied Parents Anonymous (PA), organization created to provide support group services for families and to develop community awareness of child abuse and neglect, in order to describe function of PA to school counselors for their use as referral source and to determine program's impact on parents' self-concept, understanding of children, and…

  10. Anonymous living liver donation: donor profiles and outcomes.

    Science.gov (United States)

    Reichman, T W; Fox, A; Adcock, L; Wright, L; Abbey, S E; Levy, G; Grant, D R

    2010-09-01

    There are no published series of the assessment process, profiles and outcomes of anonymous, directed or nondirected live liver donation. The outcomes of 29 consecutive potential anonymous liver donors at our center were assessed. We used our standard live liver assessment process, augmented with the following additional acceptance criteria: a logical rationale for donation, a history of social altruism, strong social supports and a willingness to maintain confidentiality of patient information. Seventeen potential donors were rejected and 12 donors were ultimately accepted (six male, six female). All donors were strongly motivated by a desire and sense of responsibility to help others. Four donations were directed toward recipients who undertook media appeals. The donor operations included five left lateral segmentectomies and seven right hepatectomies. The overall donor morbidity was 40% with one patient having a transient Clavien level 3 complication (a pneumothorax). All donors are currently well. None expressed regret about their decision to donate, and all volunteered the opinion that donation had improved their lives. The standard live liver donor assessment process plus our additional requirements appears to provide a robust assessment process for the selection of anonymous live liver donors. Acceptance of anonymous donors enlarges the donor liver pool. © 2010 The Authors Journal compilation © 2010 The American Society of Transplantation and the American Society of Transplant Surgeons.

  11. Father-Daughter Incest: Data from an Anonymous Computerized Survey

    Science.gov (United States)

    Stroebel, Sandra S.; O'Keefe, Stephen L.; Beard, Keith W.; Kuo, Shih-Ya; Swindell, Samuel V. S.; Kommor, Martin J.

    2012-01-01

    Retrospective data were entered anonymously by 1,521 adult women using computer-assisted self-interview. Nineteen were classified as victims of father-daughter incest, and 241 were classified as victims of sexual abuse by an adult other than their father before reaching 18 years of age. The remaining 1,261 served as controls. Incest victims were…

  12. A reciprocal framework for spatial K-anonymity

    KAUST Repository

    Ghinita, Gabriel

    2010-05-01

    Spatial K-anonymity (SKA) exploits the concept of K-anonymity in order to protect the identity of users from location-based attacks. The main idea of SKA is to replace the exact location of a user U with an anonymizing spatial region (ASR) that contains at least K-1 other users, so that an attacker can pinpoint U with probability at most 1/K. Simply generating an ASR that includes K users does not guarantee SKA. Previous work defined the reciprocity property as a sufficient condition for SKA. However, the only existing reciprocal method, Hilbert Cloak, relies on a specialized data structure. In contrast, we propose a general framework for implementing reciprocal algorithms using any existing spatial index on the user locations. We discuss ASR construction methods with different tradeoffs on effectiveness (i.e., ASR size) and efficiency (i.e., construction cost). Then, we present case studies of applying our framework on top of two popular spatial indices (namely, R*-trees and Quad-trees). Finally, we consider the case where the attacker knows the query patterns of each user. The experimental results verify that our methods outperform Hilbert Cloak. Moreover, since we employ general-purpose spatial indices, the proposed system is not limited to anonymization, but supports conventional spatial queries as well. © 2009 Elsevier B.V. All rights reserved.

  13. Policy-Aware Sender Anonymity in Location-Based Services

    Science.gov (United States)

    Vyas, Avinash

    2011-01-01

    Sender anonymity in Location-based services (LBS) refers to hiding the identity of a mobile device user who sends requests to the LBS provider for services in her proximity (e.g. "find the nearest gas station etc."). The goal is to keep the requester's interest private even from attackers who (via hacking or subpoenas) gain access to the LBS…

  14. Visibility and anonymity effects on attraction and group cohesiveness

    NARCIS (Netherlands)

    Lea, Martin; Spears, Russell; Watt, Susan E.

    2007-01-01

    This study investigated attraction and group cohesiveness under different visibility and anonymity conditions for social categories that differed in their capacity to be visually cued. Using computer-mediated communication in 36 mixed gender (visually cued category) and nationality (non-visually

  15. Social distance and anonymity modulate fairness consideration: An ERP study

    Science.gov (United States)

    Yu, Rongjun; Hu, Pan; Zhang, Ping

    2015-01-01

    Previous research indicated that fairness consideration can be influenced by social distance. However, it is not clear whether social distance and anonymity have an interactive impact on fairness evaluation during asset distribution and whether these processes can be documented in brain activity. Using a modified ultimatum game combined with measures of event related potential (ERP), we examined how social distance and anonymity modulate brain response to inequality. At the behavior level, we found that acceptance rate and reaction time can be substantially modified by social distance and anonymity. Feedback-related negativity, an ERP component associated with conflict between cognitive and emotion motives, was more negative in response to unfairness than fairness from strangers; however, it showed an opposite trend for unfair offers provided by friends, suggesting that the influence of social distance on fairness perception is relatively fast. The P300 in response to fair offers was more positive when the proposers made offers when uncertain about partner identity than when certain about partner identity. These results suggest that unfairness is evaluated in a fast conflict detection stage and a slower stage that integrates more complex social contextual factors such as anonymity. PMID:26293456

  16. An Analysis of College Students' Anonymous Questions about Human Sexuality.

    Science.gov (United States)

    Valois, Robert F.; Waring, Kathryn A.

    1991-01-01

    Study analyzed the frequency and type of questions about sexuality submitted anonymously by college students in health education courses over five semesters. The most common categories were sexual arousal/response; general anatomy/physiology; contraception; dating/relationships; pregnancy/fertility; and sexually transmitted diseases. The appendix…

  17. "Un-Googling” publications: The ethics and problems of anonymization

    DEFF Research Database (Denmark)

    Shklovski, Irina; Vertesi, Janet

    2013-01-01

    to the ethics of exposure of our research participants. We present one approach to anonymization of research results with search engines in mind, which we call un-Googling, that we have developed to minimize risk to our participants. We discuss the considerations that this approach raises and pose a challenge...

  18. Anonymous pastoral care for problems pertaining to sexuality

    NARCIS (Netherlands)

    van Drie, A.; Ganzevoort, R.R.; Spiering, M.

    2014-01-01

    Anonymous pastoral care is one of the options for help in problems pertaining to sexuality. This paper explores the topics they seek help for, the religious aspects involved, and the relation between the normativity of their church tradition on the one hand and sexual and spiritual health criteria

  19. Threshold quantum cryptography

    International Nuclear Information System (INIS)

    Tokunaga, Yuuki; Okamoto, Tatsuaki; Imoto, Nobuyuki

    2005-01-01

    We present the concept of threshold collaborative unitary transformation or threshold quantum cryptography, which is a kind of quantum version of threshold cryptography. Threshold quantum cryptography states that classical shared secrets are distributed to several parties and a subset of them, whose number is greater than a threshold, collaborates to compute a quantum cryptographic function, while keeping each share secretly inside each party. The shared secrets are reusable if no cheating is detected. As a concrete example of this concept, we show a distributed protocol (with threshold) of conjugate coding

  20. Theory of threshold phenomena

    International Nuclear Information System (INIS)

    Hategan, Cornel

    2002-01-01

    Theory of Threshold Phenomena in Quantum Scattering is developed in terms of Reduced Scattering Matrix. Relationships of different types of threshold anomalies both to nuclear reaction mechanisms and to nuclear reaction models are established. Magnitude of threshold effect is related to spectroscopic factor of zero-energy neutron state. The Theory of Threshold Phenomena, based on Reduced Scattering Matrix, does establish relationships between different types of threshold effects and nuclear reaction mechanisms: the cusp and non-resonant potential scattering, s-wave threshold anomaly and compound nucleus resonant scattering, p-wave anomaly and quasi-resonant scattering. A threshold anomaly related to resonant or quasi resonant scattering is enhanced provided the neutron threshold state has large spectroscopic amplitude. The Theory contains, as limit cases, Cusp Theories and also results of different nuclear reactions models as Charge Exchange, Weak Coupling, Bohr and Hauser-Feshbach models. (author)

  1. Spontaneous pneumothorax in weightlifters.

    Science.gov (United States)

    Marnejon, T; Sarac, S; Cropp, A J

    1995-06-01

    Spontaneous pneumothorax is infrequently caused by strenuous exertion. To our knowledge there has only been one case of spontaneous pneumothorax associated with weightlifting reported in the medical literature. We describe three consecutive cases of spontaneous pneumothorax associated with weightlifting. We postulate that spontaneous pneumothorax in these patients may be secondary to improper breathing techniques. It is important that physicians and weight trainers be aware of the association between weight lifting and spontaneous pneumothorax and assure that proper instruction is given to athletes who work with weights.

  2. Efficient Asymmetric Index Encapsulation Scheme for Anonymous Content Centric Networking

    Directory of Open Access Journals (Sweden)

    Rong Ma

    2017-01-01

    Full Text Available Content Centric Networking (CCN is an effective communication paradigm that well matches the features of wireless environments. To be considered a viable candidate in the emerging wireless networks, despite the clear benefits of location-independent security, CCN must at least have parity with existing solutions for confidential and anonymous communication. This paper designs a new cryptographic scheme, called Asymmetric Index Encapsulation (AIE, that enables the router to test whether an encapsulated header matches the token without learning anything else about both of them. We suggest using the AIE as the core protocol of anonymous Content Centric Networking. A construction of AIE which strikes a balance between efficiency and security is given. The scheme is proved to be secure based on the DBDH assumption in the random oracle with tight reduction, while the encapsulated header and the token in our system consist of only three elements.

  3. Doctor Anonymous: Creating Contexts for Homosexuality as Mental Illness.

    Science.gov (United States)

    Glass, Guy Fredrick

    2018-03-01

    In this essay, the author describes how he faced institutionalized homophobia during his psychiatric training, and how he later wrote a play inspired by the life of a gay psychiatrist. Despite Freud's supportive stance, homosexuality aroused the antipathy of American organized psychiatry and psychoanalysis and came to be listed as an illness in the Diagnostic and Statistical Manual (DSM). Dr. John E. Fryer outed himself as "Dr. H Anonymous" at a 1972 meeting of the American Psychiatric Association, and the next year homosexuality was removed from the DSM. The 2014 play Doctor Anonymous offers a fictionalized account of this watershed moment in the history of the gay rights movement. The author discusses his own psychotherapeutic work with gay male patients, including those who had previously been treated with conversion therapy, and explores how the play mirrors his own life experience and the experience of his patients.

  4. Anonymous voting for multi-dimensional CV quantum system

    International Nuclear Information System (INIS)

    Shi Rong-Hua; Xiao Yi; Shi Jin-Jing; Guo Ying; Lee, Moon-Ho

    2016-01-01

    We investigate the design of anonymous voting protocols, CV-based binary-valued ballot and CV-based multi-valued ballot with continuous variables (CV) in a multi-dimensional quantum cryptosystem to ensure the security of voting procedure and data privacy. The quantum entangled states are employed in the continuous variable quantum system to carry the voting information and assist information transmission, which takes the advantage of the GHZ-like states in terms of improving the utilization of quantum states by decreasing the number of required quantum states. It provides a potential approach to achieve the efficient quantum anonymous voting with high transmission security, especially in large-scale votes. (paper)

  5. A Secure Mobility Network Authentication Scheme Ensuring User Anonymity

    Directory of Open Access Journals (Sweden)

    Ya-Fen Chang

    2017-12-01

    Full Text Available With the rapid growth of network technologies, users are used to accessing various services with their mobile devices. To ensure security and privacy in mobility networks, proper mechanisms to authenticate the mobile user are essential. In this paper, a mobility network authentication scheme based on elliptic curve cryptography is proposed. In the proposed scheme, a mobile user can be authenticated without revealing who he is for user anonymity, and a session key is also negotiated to protect the following communications. The proposed mobility network authentication scheme is analyzed to show that it can ensure security, user anonymity, and convenience. Moreover, Burrows-Abadi-Needham logic (BAN logic is used to deduce the completeness of the proposed authentication scheme.

  6. Anonymity communication VPN and Tor: a comparative study

    Science.gov (United States)

    Ramadhani, E.

    2018-03-01

    VPN and Tor is a technology based on anonymity communication. These two technologies have their advantage and disadvantage. The objective of this paper is to find the difference between VPN and Tor technologies by comparing their security of communication on the public network based on the CIA triad concept. The comparative study in this paper is based on the survey method. At last, the result of this paper is a recommendation on when to use a VPN and Tor to secure communication

  7. Can anonymous posters on medical forums be reidentified?

    Science.gov (United States)

    Bobicev, Victoria; Sokolova, Marina; El Emam, Khaled; Jafer, Yasser; Dewar, Brian; Jonker, Elizabeth; Matwin, Stan

    2013-10-03

    Participants in medical forums often reveal personal health information about themselves in their online postings. To feel comfortable revealing sensitive personal health information, some participants may hide their identity by posting anonymously. They can do this by using fake identities, nicknames, or pseudonyms that cannot readily be traced back to them. However, individual writing styles have unique features and it may be possible to determine the true identity of an anonymous user through author attribution analysis. Although there has been previous work on the authorship attribution problem, there has been a dearth of research on automated authorship attribution on medical forums. The focus of the paper is to demonstrate that character-based author attribution works better than word-based methods in medical forums. The goal was to build a system that accurately attributes authorship of messages posted on medical forums. The Authorship Attributor system uses text analysis techniques to crawl medical forums and automatically correlate messages written by the same authors. Authorship Attributor processes unstructured texts regardless of the document type, context, and content. The messages were labeled by nicknames of the forum participants. We evaluated the system's performance through its accuracy on 6000 messages gathered from 2 medical forums on an in vitro fertilization (IVF) support website. Given 2 lists of candidate authors (30 and 50 candidates, respectively), we obtained an F score accuracy in detecting authors of 75% to 80% on messages containing 100 to 150 words on average, and 97.9% on longer messages containing at least 300 words. Authorship can be successfully detected in short free-form messages posted on medical forums. This raises a concern about the meaningfulness of anonymous posting on such medical forums. Authorship attribution tools can be used to warn consumers wishing to post anonymously about the likelihood of their identity being

  8. Gamblers Anonymous as a Recovery Pathway: A Scoping Review

    OpenAIRE

    Schuler, Andr?e; Ferentzy, Peter; Turner, Nigel E.; Skinner, Wayne; McIsaac, Kathryn E.; Ziegler, Carolyn P.; Matheson, Flora I.

    2016-01-01

    Given the preponderance of Gamblers Anonymous (GA), there has been relatively little effort to explore the existing evidence base on its effectiveness as a recovery approach for problem gambling. To remedy this gap in the literature we conducted a scoping review of the literature on mutual aid for individuals experiencing problem gambling published between 2002 and 2015. We searched 13 databases and reviewed reference lists and websites of relevant organizations. We reviewed records for eligi...

  9. Forensic linguistics: Applications of forensic linguistics methods to anonymous letters

    OpenAIRE

    NOVÁKOVÁ, Veronika

    2011-01-01

    The title of my bachelor work is ?Forensic linguistics: Applications of forensic linguistics methods to anonymous letters?. Forensic linguistics is young and not very known branch of applied linguistics. This bachelor work wants to introduce forensic linguistics and its method. The bachelor work has two parts ? theory and practice. The theoretical part informs about forensic linguistics in general. Its two basic aspects utilized in forensic science and respective methods. The practical part t...

  10. Enhancing physicians' use of Alcoholics Anonymous: Internet-based training.

    Science.gov (United States)

    Sellers, Brealyn; Galanter, Marc; Dermatis, Helen; Nachbar, Martin

    2005-01-01

    Alcoholics Anonymous is not yet fully employed by the medical community as a means to enhance patient outcome. The purpose of this study was to evaluate visitors' use of an Internet course on Alcoholics Anonymous, and to compare how various disciplines learned about, gained access to and participated in the course. Demographic information was collected from 414 visitors to the course. 64% of the 414 respondents received their last educational degree within the last 10 years, and had an interest in the topic of addiction prior to their accessing the site. 294 (71%) of those who accessed the course completed it, and those who accessed it learned about it from various sources other than print advertisement in professional journals. Within the 230 physician respondents, 143 (62%) were psychiatrists, 82 (78%) of whom learned about the Internet course via professional journal. Given the need for further training among physicians in the use of Alcoholics Anonymous, the Internet can be utilized to make information available to a large number of people. Because it allows the user to access information outside the traditional means, the barriers to its use are minimal, and it has the potential to effectively convey useful clinical information.

  11. k-Degree Anonymity Model for Social Network Data Publishing

    Directory of Open Access Journals (Sweden)

    MACWAN, K. R.

    2017-11-01

    Full Text Available Publicly accessible platform for social networking has gained special attraction because of its easy data sharing. Data generated on such social network is analyzed for various activities like marketing, social psychology, etc. This requires preservation of sensitive attributes before it becomes easily accessible. Simply removing the personal identities of the users before publishing data is not enough to maintain the privacy of the individuals. The structure of the social network data itself reveals much information regarding its users and their connections. To resolve this problem, k-degree anonymous method is adopted. It emphasizes on the modification of the graph to provide at least k number of nodes that contain the same degree. However, this approach is not efficient on a huge amount of social data and the modification of the original data fails to maintain data usefulness. In addition to this, the current anonymization approaches focus on a degree sequence-based graph model which leads to major modification of the graph topological properties. In this paper, we have proposed an improved k-degree anonymity model that retain the social network structural properties and also to provide privacy to the individuals. Utility measurement approach for community based graph model is used to verify the performance of the proposed technique.

  12. All or Nothing: The False Promise of Anonymity

    Directory of Open Access Journals (Sweden)

    Neil Walker

    2017-05-01

    Full Text Available In early 2016, the International Committee of Medical Journal Editors (ICMJE proposed that responsible sharing of de-identified individual-level data be required for clinical trials published in their affiliated journals. There would be a delay in implementing this policy to allow for the necessary informed consents to work their way through ethical review. Meanwhile, some researchers and policy makers have conflated the notions of de-identification and anonymity. The former is a process that seeks to mitigate disclosure risk though careful application of rules and statistical analysis, while the latter is an absolute state. The consequence of confusing the process and the state is profound. Extensions to the ICMJE proposal based on the presumed anonymity of data include: sharing unconsented data; sharing data without managing access, as Open Data; and proposals to sell data. This essay aims to show that anonymity (the state cannot be guaranteed by de-identification (the process, and so these extensions to the ICMJE proposal should be rejected on governance grounds, if no other. This is not as negative a position as it might seem, as other disciplines have been aware of these limitations and concomitant responsibilities for many years. The essay concludes with an example from social science of managed access strategies that could be adopted by the medical field.

  13. Traveling the Silk Road: A Measurement of a Large Anonymous Online Marketplace

    Science.gov (United States)

    2012-11-28

    Silk Road, an anonymous, international online marketplace that operates as a Tor hidden service and uses Bitcoin as its exchange currency. We gather...analysis of Silk Road, an anonymous, international on- line marketplace that operates as a Tor hidden service and uses Bitcoin as its exchange currency. We...anonymity, Silk Road needs to also preserve payment anonymity. To that effect, Silk Road only supports Bitcoin (BTC, [30]) as a trading currency

  14. Quantum election scheme based on anonymous quantum key distribution

    International Nuclear Information System (INIS)

    Zhou Rui-Rui; Yang Li

    2012-01-01

    An unconditionally secure authority-certified anonymous quantum key distribution scheme using conjugate coding is presented, based on which we construct a quantum election scheme without the help of an entanglement state. We show that this election scheme ensures the completeness, soundness, privacy, eligibility, unreusability, fairness, and verifiability of a large-scale election in which the administrator and counter are semi-honest. This election scheme can work even if there exist loss and errors in quantum channels. In addition, any irregularity in this scheme is sensible. (general)

  15. Resisting stigma, embracing solidarity: An ethnographic study of shopaholics anonymous

    Directory of Open Access Journals (Sweden)

    Rachel Demerling

    2011-03-01

    Full Text Available In recent years, an increased interest in the phenomenon of compulsive buying, which is better known as “shopaholism”, has occurred. This behaviour has been conceptualized as being an uncontrollable urge to purchase things which is pleasurable for an individual or relieves their distress and which results in negative consequences for that individual. This article examines the experiences of individuals within a Shopaholics Anonymous group to understand why individuals decide to join a support group and explore the dynamics of interaction among participants and how that shapes the outcome of their addiction.

  16. Business Information Exchange System with Security, Privacy, and Anonymity

    Directory of Open Access Journals (Sweden)

    Sead Muftic

    2016-01-01

    Full Text Available Business Information Exchange is an Internet Secure Portal for secure management, distribution, sharing, and use of business e-mails, documents, and messages. It has three applications supporting three major types of information exchange systems: secure e-mail, secure instant messaging, and secure sharing of business documents. In addition to standard security services for e-mail letters, which are also applied to instant messages and documents, the system provides innovative features of privacy and full anonymity of users and their locations, actions, transactions, and exchanged resources. In this paper we describe design, implementation, and use of the system.

  17. Resistive Threshold Logic

    OpenAIRE

    James, A. P.; Francis, L. R. V. J.; Kumar, D.

    2013-01-01

    We report a resistance based threshold logic family useful for mimicking brain like large variable logic functions in VLSI. A universal Boolean logic cell based on an analog resistive divider and threshold logic circuit is presented. The resistive divider is implemented using memristors and provides output voltage as a summation of weighted product of input voltages. The output of resistive divider is converted into a binary value by a threshold operation implemented by CMOS inverter and/or O...

  18. Threshold Signature Schemes Application

    Directory of Open Access Journals (Sweden)

    Anastasiya Victorovna Beresneva

    2015-10-01

    Full Text Available This work is devoted to an investigation of threshold signature schemes. The systematization of the threshold signature schemes was done, cryptographic constructions based on interpolation Lagrange polynomial, elliptic curves and bilinear pairings were examined. Different methods of generation and verification of threshold signatures were explored, the availability of practical usage of threshold schemes in mobile agents, Internet banking and e-currency was shown. The topics of further investigation were given and it could reduce a level of counterfeit electronic documents signed by a group of users.

  19. Nonexposure Accurate Location K-Anonymity Algorithm in LBS

    Directory of Open Access Journals (Sweden)

    Jinying Jia

    2014-01-01

    Full Text Available This paper tackles location privacy protection in current location-based services (LBS where mobile users have to report their exact location information to an LBS provider in order to obtain their desired services. Location cloaking has been proposed and well studied to protect user privacy. It blurs the user’s accurate coordinate and replaces it with a well-shaped cloaked region. However, to obtain such an anonymous spatial region (ASR, nearly all existent cloaking algorithms require knowing the accurate locations of all users. Therefore, location cloaking without exposing the user’s accurate location to any party is urgently needed. In this paper, we present such two nonexposure accurate location cloaking algorithms. They are designed for K-anonymity, and cloaking is performed based on the identifications (IDs of the grid areas which were reported by all the users, instead of directly on their accurate coordinates. Experimental results show that our algorithms are more secure than the existent cloaking algorithms, need not have all the users reporting their locations all the time, and can generate smaller ASR.

  20. Nonexposure accurate location K-anonymity algorithm in LBS.

    Science.gov (United States)

    Jia, Jinying; Zhang, Fengli

    2014-01-01

    This paper tackles location privacy protection in current location-based services (LBS) where mobile users have to report their exact location information to an LBS provider in order to obtain their desired services. Location cloaking has been proposed and well studied to protect user privacy. It blurs the user's accurate coordinate and replaces it with a well-shaped cloaked region. However, to obtain such an anonymous spatial region (ASR), nearly all existent cloaking algorithms require knowing the accurate locations of all users. Therefore, location cloaking without exposing the user's accurate location to any party is urgently needed. In this paper, we present such two nonexposure accurate location cloaking algorithms. They are designed for K-anonymity, and cloaking is performed based on the identifications (IDs) of the grid areas which were reported by all the users, instead of directly on their accurate coordinates. Experimental results show that our algorithms are more secure than the existent cloaking algorithms, need not have all the users reporting their locations all the time, and can generate smaller ASR.

  1. A Remote User Authentication Scheme with Anonymity for Mobile Devices

    Directory of Open Access Journals (Sweden)

    Soobok Shin

    2012-04-01

    Full Text Available With the rapid growth of information technologies, mobile devices have been utilized in a variety of services such as e-commerce. When a remote server provides such e-commerce services to a user, it must verify the legitimacy of the user over an insecure communication channel. Therefore, remote user authentication has been widely deployed to verify the legitimacy of remote user login requests using mobile devices like smart cards. In this paper we propose a smart card-based authentication scheme that provides both user anonymity and mutual authentication between a remote server and a user. The proposed authentication scheme is a simple and efficient system applicable to the limited resource and low computing performance of the smart card. The proposed scheme provides not only resilience to potential attacks in the smart card-based authentication scheme, but also secure authentication functions. A smart card performs a simple one-way hash function, the operations of exclusive-or and concatenation in the authentication phase of the proposed scheme. The proposed scheme also provides user anonymity using a dynamic identity and key agreement, and secure password change.

  2. Keeping mum about dad: "contracts" to protect gamete donor anonymity.

    Science.gov (United States)

    Rees, Anne

    2012-06-01

    This article considers the legal status of so-called contracts for anonymity between fertility clinics and donors of gametes that were made in the period before legislation authorising disclosure. It notes that while clinics frequently cite the existence of these "contracts" to argue against retrospective legislation authorising disclosure of the donor's identity, they may be nothing more than one-sided statements of informed consent. However, the article notes that even if an agreement between a donor and a clinic is not contractual, it does not follow that a person conceived through assisted reproductive technology has any right of access to the identity of the donor. The writer has not been able to locate examples of written promises by the clinics promising anonymity. There are written promises by the donors not to seek the identity of the recipients. These promises do not bind the resulting offspring nor do they appear to be supported by consideration. The article suggests that the basis for any individual donor to restrain a clinic from revealing their identity may be found in promissory estoppel. Nevertheless, there is no real issue in Australia concerning clinics revealing these details absent legislative authority. The issue is whether parliaments will legislate to authorise the disclosure. The article notes that it would be rare for parliaments to legislate to overturn existing legal contracts but suggests that the contract argument may not be as strong as has been thought.

  3. Spontaneous uterine rupture

    African Journals Online (AJOL)

    ABSTRACT. Rupture of a gravid uterus is a surgical emergency. Predisposing factors include a scarred uterus. Spontaneous rupture of an unscarred uterus during pregnancy is a rare occurrence. We hereby present the case of a spontaneous complete uterine rupture at a gestational age of 34 weeks in a 35 year old patient ...

  4. Spontaneous intracranial hypotension.

    LENUS (Irish Health Repository)

    Fullam, L

    2012-01-31

    INTRODUCTION: Spontaneous\\/primary intracranial hypotension is characterised by orthostatic headache and is associated with characteristic magnetic resonance imaging findings. CASE REPORT: We present a case report of a patient with typical symptoms and classical radiological images. DISCUSSION: Spontaneous intracranial hypotension is an under-recognised cause of headache and can be diagnosed by history of typical orthostatic headache and findings on MRI brain.

  5. Threshold concepts in prosthetics.

    Science.gov (United States)

    Hill, Sophie

    2017-12-01

    Curriculum documents identify key concepts within learning prosthetics. Threshold concepts provide an alternative way of viewing the curriculum, focussing on the ways of thinking and practicing within prosthetics. Threshold concepts can be described as an opening to a different way of viewing a concept. This article forms part of a larger study exploring what students and staff experience as difficult in learning about prosthetics. To explore possible threshold concepts within prosthetics. Qualitative, interpretative phenomenological analysis. Data from 18 students and 8 staff at two universities with undergraduate prosthetics and orthotics programmes were generated through interviews and questionnaires. The data were analysed using an interpretative phenomenological analysis approach. Three possible threshold concepts arose from the data: 'how we walk', 'learning to talk' and 'considering the person'. Three potential threshold concepts in prosthetics are suggested with possible implications for prosthetics education. These possible threshold concepts involve changes in both conceptual and ontological knowledge, integrating into the persona of the individual. This integration occurs through the development of memories associated with procedural concepts that combine with disciplinary concepts. Considering the prosthetics curriculum through the lens of threshold concepts enables a focus on how students learn to become prosthetists. Clinical relevance This study provides new insights into how prosthetists learn. This has implications for curriculum design in prosthetics education.

  6. Parameterized Complexity of k-Anonymity: Hardness and Tractability

    Science.gov (United States)

    Bonizzoni, Paola; Della Vedova, Gianluca; Dondi, Riccardo; Pirola, Yuri

    The problem of publishing personal data without giving up privacy is becoming increasingly important. A precise formalization that has been recently proposed is the k-anonymity, where the rows of a table are partitioned in clusters of size at least k and all rows in a cluster become the same tuple after the suppression of some entries. The natural optimization problem, where the goal is to minimize the number of suppressed entries, is hard even when the stored values are over a binary alphabet or the table consists of a bounded number of columns. In this paper we study how the complexity of the problem is influenced by different parameters. First we show that the problem is W[1]-hard when parameterized by the value of the solution (and k). Then we exhibit a fixed-parameter algorithm when the problem is parameterized by the number of columns and the number of different values in any column.

  7. Cloud Based Data Protection in Anonymously Controlled SDN

    Directory of Open Access Journals (Sweden)

    Jian Shen

    2018-01-01

    Full Text Available Nowadays, Software Defined Network (SDN develops rapidly for its novel structure which separates the control plane and the data plane of network devices. Many researchers devoted themselves to the study of such a special network. However, some limitations restrict the development of SDN. On the one hand, the single controller in the conventional model bears all threats, and the corruption of it will result in network paralysis. On the other hand, the data will be increasing more in SDN switches in the data plane, while the storage space of these switches is limited. In order to solve the mentioned issues, we propose two corresponding protocols in this paper. Specifically, one is an anonymous protocol in the control plane, and the other is a verifiable outsourcing protocol in the data plane. The evaluation indicates that our protocol is correct, secure, and efficient.

  8. A machine learning methodology for medical imaging anonymization.

    Science.gov (United States)

    Monteiro, Eriksson; Costa, Carlos; Oliveira, Jose Luis

    2015-08-01

    Privacy protection is a major requirement for the complete success of EHR systems, becoming even more critical in collaborative scenarios, where data is shared among institutions and practitioners. While textual data can be easily de-identified, patient data in medical images implies a more elaborate approach. In this work we present a solution for sensitive word identification in medical images based on a combination of two machine-learning models, achieving a F1-score of 0.94. Three experts evaluated the system performance. They analyzed the output of the present methodology and categorized the studies in three groups: studies that had their sensitive words removed (true positive), studies with complete patient identity (false negative) and studies with mistakenly removed data (false positive). The experts were unanimous regarding the relevance of the present tool in collaborative medical environments, as it may improve the exchange of anonymized patient data between institutions.

  9. Protecting whistle-blowers: Anonymity on the internet

    International Nuclear Information System (INIS)

    Guinnessy, P.

    1997-01-01

    Even though strict legislation exists in many countries, it appears that the next few years should be a golden opportunity for groups to successfully monitor and publish the activity of the nuclear states, and human right violations through use of the Internet. The reasons for this are: 1. The Internet is becoming widespread even in repressive regimes; 2. Software is available to either hide messages from others or hide the mailers account; 3. Information from sites in other countries can be easily obtained to be read inside repressive regimes from the Internet. In this regard It is suggested the Pugwash or a similar organization should set up either an anonymous account to receive information or maybe use a more heavily protected cyperpunk remailer. Such an ability would hopefully prompt more people to notify treaty violations

  10. Father-daughter incest: data from an anonymous computerized survey.

    Science.gov (United States)

    Stroebel, Sandra S; O'Keefe, Stephen L; Beard, Keith W; Kuo, Shih-Ya; Swindell, Samuel V S; Kommor, Martin J

    2012-01-01

    Retrospective data were entered anonymously by 1,521 adult women using computer-assisted self-interview. Nineteen were classified as victims of father-daughter incest, and 241 were classified as victims of sexual abuse by an adult other than their father before reaching 18 years of age. The remaining 1,261 served as controls. Incest victims were more likely than controls to endorse feeling damaged, psychologically injured, estranged from one or both parents, and shamed by others when they tried to open up about their experience. They had been eroticized early on by the incest experience, and it interfered with their adult sexuality. Incest victims experienced coitus earlier than controls and after reaching age 18 had more sex partners and were more likely to have casual sex outside their primary relationship and engage in sex for money than controls. They also had worse scores on scales measuring depression, sexual satisfaction, and communication about sex than controls.

  11. Anonymization of Electronic Medical Records to Support Clinical Analysis

    CERN Document Server

    Gkoulalas-Divanis, Aris

    2013-01-01

    Anonymization of Electronic Medical Records to Support Clinical Analysis closely examines the privacy threats that may arise from medical data sharing, and surveys the state-of-the-art methods developed to safeguard data against these threats. To motivate the need for computational methods, the book first explores the main challenges facing the privacy-protection of medical data using the existing policies, practices and regulations. Then, it takes an in-depth look at the popular computational privacy-preserving methods that have been developed for demographic, clinical and genomic data sharing, and closely analyzes the privacy principles behind these methods, as well as the optimization and algorithmic strategies that they employ. Finally, through a series of in-depth case studies that highlight data from the US Census as well as the Vanderbilt University Medical Center, the book outlines a new, innovative class of privacy-preserving methods designed to ensure the integrity of transferred medical data for su...

  12. Distributed Performance Measurement and Usability Assessment of the Tor Anonymization Network

    Directory of Open Access Journals (Sweden)

    Steffen Kunz

    2012-05-01

    Full Text Available While the Internet increasingly permeates everyday life of individuals around the world, it becomes crucial to prevent unauthorized collection and abuse of personalized information. Internet anonymization software such as Tor is an important instrument to protect online privacy. However, due to the performance overhead caused by Tor, many Internet users refrain from using it. This causes a negative impact on the overall privacy provided by Tor, since it depends on the size of the user community and availability of shared resources. Detailed measurements about the performance of Tor are crucial for solving this issue. This paper presents comparative experiments on Tor latency and throughput for surfing to 500 popular websites from several locations around the world during the period of 28 days. Furthermore, we compare these measurements to critical latency thresholds gathered from web usability research, including our own user studies. Our results indicate that without massive future optimizations of Tor performance, it is unlikely that a larger part of Internet users would adopt it for everyday usage. This leads to fewer resources available to the Tor community than theoretically possible, and increases the exposure of privacy-concerned individuals. Furthermore, this could lead to an adoption barrier of similar privacy-enhancing technologies for a Future Internet.

  13. Anonymity versus privacy: selective information sharing in online cancer communities.

    Science.gov (United States)

    Frost, Jeana; Vermeulen, Ivar E; Beekers, Nienke

    2014-05-14

    Active sharing in online cancer communities benefits patients. However, many patients refrain from sharing health information online due to privacy concerns. Existing research on privacy emphasizes data security and confidentiality, largely focusing on electronic medical records. Patient preferences around information sharing in online communities remain poorly understood. Consistent with the privacy calculus perspective adopted from e-commerce research, we suggest that patients approach online information sharing instrumentally, weighing privacy costs against participation benefits when deciding whether to share certain information. Consequently, we argue that patients prefer sharing clinical information over daily life and identity information that potentially compromises anonymity. Furthermore, we explore whether patients' prior experiences, age, health, and gender affect perceived privacy costs and thus willingness to share information. The goal of the present study is to document patient preferences for sharing information within online health platforms. A total of 115 cancer patients reported sharing intentions for 15 different types of information, demographics, health status, prior privacy experiences, expected community utility, and privacy concerns. Factor analysis on the 15 information types revealed 3 factors coinciding with 3 proposed information categories: clinical, daily life, and identity information. A within-subject ANOVA showed a strong preference for sharing clinical information compared to daily life and identity information (F1,114=135.59, P=.001, η(2)=.93). Also, adverse online privacy experiences, age, and health status negatively affected information-sharing intentions. Female patients shared information less willingly. Respondents' information-sharing intentions depend on dispositional and situational factors. Patients share medical details more willingly than daily life or identity information. The results suggest the need to focus on

  14. Anonymity Versus Privacy: Selective Information Sharing in Online Cancer Communities

    Science.gov (United States)

    Vermeulen, Ivar E; Beekers, Nienke

    2014-01-01

    Background Active sharing in online cancer communities benefits patients. However, many patients refrain from sharing health information online due to privacy concerns. Existing research on privacy emphasizes data security and confidentiality, largely focusing on electronic medical records. Patient preferences around information sharing in online communities remain poorly understood. Consistent with the privacy calculus perspective adopted from e-commerce research, we suggest that patients approach online information sharing instrumentally, weighing privacy costs against participation benefits when deciding whether to share certain information. Consequently, we argue that patients prefer sharing clinical information over daily life and identity information that potentially compromises anonymity. Furthermore, we explore whether patients’ prior experiences, age, health, and gender affect perceived privacy costs and thus willingness to share information. Objective The goal of the present study is to document patient preferences for sharing information within online health platforms. Methods A total of 115 cancer patients reported sharing intentions for 15 different types of information, demographics, health status, prior privacy experiences, expected community utility, and privacy concerns. Results Factor analysis on the 15 information types revealed 3 factors coinciding with 3 proposed information categories: clinical, daily life, and identity information. A within-subject ANOVA showed a strong preference for sharing clinical information compared to daily life and identity information (F 1,114=135.59, P=.001, η2=.93). Also, adverse online privacy experiences, age, and health status negatively affected information-sharing intentions. Female patients shared information less willingly. Conclusions Respondents’ information-sharing intentions depend on dispositional and situational factors. Patients share medical details more willingly than daily life or identity

  15. The Pattern of Drug Abuse in Anonymous Adidcts

    Directory of Open Access Journals (Sweden)

    Seyede Maryam Vahdat-Shariat-Panahi

    2010-04-01

    Full Text Available Objective: Having the information about pattern of substance abuse in the community and its epidemiological features is one of the most important protocols for evaluation, follow–up and control of the use of these substances. The aim of this study was to evaluate the patterns of substances abuse among narcotic anonymous (N. A. addicted patients. Materials & Methods: In this descriptive and analytical study, three hundred patients from narcotic abusers anonymous (N. A. association who were referred to a treatment center in Tehran were participated consecutively. The information about demographic characteristics, socioeconomic status, type of drug and the patterns of substance abuse of all cases were collected by researcher made questionnaire. Data were analyzed by Chi–Square test. Results: 80% of the patients were male. Almost 65. 2% of cases aged less than 40 years. More than two–third of cases had free jobs and 21. 2% of them were unemployed. Also, 32% of patients had college degrees. The most common types of abused substance were opium (88%, cigarette (76.7%, and alcohol (63% and 34% of them used substances intravenously. The use of alcohol (P=0.033, cannabis (P<0.001, cocaine (P=0.009 and ecstasy (P<0.001 was more prevalent significantly in the cases less than 40 years old than the elderly. Conclusion: It seems that the trend of substance abuse has been changed to younger population. The pattern of drug abuse in young adults is more toward psychosis drugs such as cocaine and ecstasy.

  16. Auditory brainstem response latency in forward masking, a marker of sensory deficits in listeners with normal hearing thresholds

    DEFF Research Database (Denmark)

    Mehraei, Golbarg; Paredes Gallardo, Andreu; Shinn-Cunningham, Barbara G.

    2017-01-01

    In rodent models, acoustic exposure too modest to elevate hearing thresholds can nonetheless cause auditory nerve fiber deafferentation, interfering with the coding of supra-threshold sound. Low-spontaneous rate nerve fibers, important for encoding acoustic information at supra-threshold levels...

  17. Regional Seismic Threshold Monitoring

    National Research Council Canada - National Science Library

    Kvaerna, Tormod

    2006-01-01

    ... model to be used for predicting the travel times of regional phases. We have applied these attenuation relations to develop and assess a regional threshold monitoring scheme for selected subregions of the European Arctic...

  18. Unison as a Self-Stabilizing Wave Stream Algorithm in Asynchronous Anonymous Networks

    OpenAIRE

    Boulinier, Christian

    2007-01-01

    Rapport de recherche.; How to pass from local to global scales in anonymous networks? How to organize a selfstabilizing propagation of information with feedback. From the Angluin impossibility results, we cannot elect a leader in a general anonymous network. Thus, it is impossible to build a rooted spanning tree. Many problems can only be solved by probabilistic methods. In this paper we show how to use Unison to design a self-stabilizing barrier synchronization in an anonymous network. We sh...

  19. Enhanced P-Sensitive K-Anonymity Models for Privacy Preserving Data Publishing

    OpenAIRE

    Xiaoxun Sun; Hua Wang; Jiuyong Li; Traian Marius Truta

    2008-01-01

    Publishing data for analysis from a micro data table containing sensitive attributes, while maintaining individual privacy, is a problem of increasing significance today. The k-anonymity model was proposed for privacy preserving data publication. While focusing on identity disclosure, k-anonymity model fails to protect attribute disclosure to some extent. Many efforts are made to enhance the k-anonymity model recently. In this paper, we propose two new privacy protection models called (p, a)-...

  20. Attribute Utility Motivated k-anonymization of Datasets to Support the Heterogeneous Needs of Biomedical Researchers

    OpenAIRE

    Ye, Huimin; Chen, Elizabeth S.

    2011-01-01

    In order to support the increasing need to share electronic health data for research purposes, various methods have been proposed for privacy preservation including k-anonymity. Many k-anonymity models provide the same level of anoymization regardless of practical need, which may decrease the utility of the dataset for a particular research study. In this study, we explore extensions to the k-anonymity algorithm that aim to satisfy the heterogeneous needs of different researchers while preser...

  1. Hydrodynamics of sediment threshold

    Science.gov (United States)

    Ali, Sk Zeeshan; Dey, Subhasish

    2016-07-01

    A novel hydrodynamic model for the threshold of cohesionless sediment particle motion under a steady unidirectional streamflow is presented. The hydrodynamic forces (drag and lift) acting on a solitary sediment particle resting over a closely packed bed formed by the identical sediment particles are the primary motivating forces. The drag force comprises of the form drag and form induced drag. The lift force includes the Saffman lift, Magnus lift, centrifugal lift, and turbulent lift. The points of action of the force system are appropriately obtained, for the first time, from the basics of micro-mechanics. The sediment threshold is envisioned as the rolling mode, which is the plausible mode to initiate a particle motion on the bed. The moment balance of the force system on the solitary particle about the pivoting point of rolling yields the governing equation. The conditions of sediment threshold under the hydraulically smooth, transitional, and rough flow regimes are examined. The effects of velocity fluctuations are addressed by applying the statistical theory of turbulence. This study shows that for a hindrance coefficient of 0.3, the threshold curve (threshold Shields parameter versus shear Reynolds number) has an excellent agreement with the experimental data of uniform sediments. However, most of the experimental data are bounded by the upper and lower limiting threshold curves, corresponding to the hindrance coefficients of 0.2 and 0.4, respectively. The threshold curve of this study is compared with those of previous researchers. The present model also agrees satisfactorily with the experimental data of nonuniform sediments.

  2. Shoplifting and eating disorders: an anonymous self-administered survey.

    Science.gov (United States)

    Yanase, Maya; Sugihara, Genichi; Murai, Toshiya; Noma, Shun'ichi

    2017-04-28

    To explore the characteristics of eating disorders related to shoplifting behavior and identify the risk and protective factors related to shoplifting among patients with eating disorders. Eighty females with eating disorders were recruited from an eating disorders clinic. They were asked to complete anonymous self-report questionnaires on demographic characteristics, shoplifting behavior, psychological characteristics and eating disorder symptomology. We investigated differences in clinical characteristics between those with and without shoplifting history or a current drive to shoplift. The response rate was 92.5%. Of the respondents, 37.8% reported a history of shoplifting and 16.2% a current drive for shoplifting. The patients with shoplifting history had lower socioeconomic status (SES), higher impulsivity and higher symptom severity of eating disorders compared with those without this history. The patients with a current drive for shoplifting had more depressive symptoms, more severe anxiety, more obsessional traits, and higher symptom severity of eating disorders. Severity of illness and SES seem to have a serious impact on shoplifting behavior among eating disordered patients. These findings may suggest risk and protective factors related to shoplifting among eating disordered patients.

  3. iDASH: integrating data for analysis, anonymization, and sharing

    Science.gov (United States)

    Bafna, Vineet; Boxwala, Aziz A; Chapman, Brian E; Chapman, Wendy W; Chaudhuri, Kamalika; Day, Michele E; Farcas, Claudiu; Heintzman, Nathaniel D; Jiang, Xiaoqian; Kim, Hyeoneui; Kim, Jihoon; Matheny, Michael E; Resnic, Frederic S; Vinterbo, Staal A

    2011-01-01

    iDASH (integrating data for analysis, anonymization, and sharing) is the newest National Center for Biomedical Computing funded by the NIH. It focuses on algorithms and tools for sharing data in a privacy-preserving manner. Foundational privacy technology research performed within iDASH is coupled with innovative engineering for collaborative tool development and data-sharing capabilities in a private Health Insurance Portability and Accountability Act (HIPAA)-certified cloud. Driving Biological Projects, which span different biological levels (from molecules to individuals to populations) and focus on various health conditions, help guide research and development within this Center. Furthermore, training and dissemination efforts connect the Center with its stakeholders and educate data owners and data consumers on how to share and use clinical and biological data. Through these various mechanisms, iDASH implements its goal of providing biomedical and behavioral researchers with access to data, software, and a high-performance computing environment, thus enabling them to generate and test new hypotheses. PMID:22081224

  4. Gamblers Anonymous as a Recovery Pathway: A Scoping Review.

    Science.gov (United States)

    Schuler, Andrée; Ferentzy, Peter; Turner, Nigel E; Skinner, Wayne; McIsaac, Kathryn E; Ziegler, Carolyn P; Matheson, Flora I

    2016-12-01

    Given the preponderance of Gamblers Anonymous (GA), there has been relatively little effort to explore the existing evidence base on its effectiveness as a recovery approach for problem gambling. To remedy this gap in the literature we conducted a scoping review of the literature on mutual aid for individuals experiencing problem gambling published between 2002 and 2015. We searched 13 databases and reviewed reference lists and websites of relevant organizations. We reviewed records for eligibility and extracted relevant data from eligible articles. Three reviewers independently assessed the methodological quality of the included studies using the Mixed Methods Appraisal Tool. We identified 17 studies in 25 publications that were eligible for inclusion. Most studies were conducted in the United States, were cross-sectional in design, and involved both male and female adult participants. Results indicate that the evidence for the effectiveness of GA either as a control condition or in conjunction with formal treatment or medication is inconsistent. An emphasis on patience, using the Serenity Prayer as a way to gain acceptance of financial matters and reality, and absolute assertion of identity as a "compulsive gambler" were identified as important aspects of GA's recovery culture. There is a need for large-scale randomized controlled trials to determine GA's effectiveness, as well as research exploring the mechanisms through which GA works, barriers to GA as a recovery approach, and the status of women in the fellowship.

  5. On the Anonymity Risk of Time-Varying User Profiles

    Directory of Open Access Journals (Sweden)

    Silvia Puglisi

    2017-04-01

    Full Text Available Websites and applications use personalisation services to profile their users, collect their patterns and activities and eventually use this data to provide tailored suggestions. User preferences and social interactions are therefore aggregated and analysed. Every time a user publishes a new post or creates a link with another entity, either another user, or some online resource, new information is added to the user profile. Exposing private data does not only reveal information about single users’ preferences, increasing their privacy risk, but can expose more about their network that single actors intended. This mechanism is self-evident in social networks where users receive suggestions based on their friends’ activities. We propose an information-theoretic approach to measure the differential update of the anonymity risk of time-varying user profiles. This expresses how privacy is affected when new content is posted and how much third-party services get to know about the users when a new activity is shared. We use actual Facebook data to show how our model can be applied to a real-world scenario.

  6. Sister-sister incest: data from an anonymous computerized survey.

    Science.gov (United States)

    Stroebel, Sandra S; O'Keefe, Stephen L; Griffee, Karen; Kuo, Shih-Ya; Beard, Keith W; Kommor, Martin J

    2013-01-01

    Retrospective data were entered anonymously by 1,521 adult women using a computer-assisted self-interview. Thirty-one participants were victims of sister-sister incest, 40 were victims of brother-sister incest, 19 were victims of father-daughter incest, 8 were victims of sexual abuse by an adult female (including one mother), and 232 were victims of sexual abuse by an adult male other than their father before reaching 18 years of age. The rest (1,203) served as controls. The victims of sister-sister incest had significantly more problematic outcomes than controls on many measures as adults. Victims of sister-sister incest were more depressed and more likely than controls to be distant from the perpetrator-sister and to have traded sex for money, experienced an unplanned pregnancy, engaged in four different types of masturbation, and engaged in 13 different same-sex behaviors. Our findings were consistent with other reports of early eroticization and persistent hypereroticization of incest victims.

  7. Delineating social network data anonymization via random edge perturbation

    KAUST Repository

    Xue, Mingqiang

    2012-01-01

    Social network data analysis raises concerns about the privacy of related entities or individuals. To address this issue, organizations can publish data after simply replacing the identities of individuals with pseudonyms, leaving the overall structure of the social network unchanged. However, it has been shown that attacks based on structural identification (e.g., a walk-based attack) enable an adversary to re-identify selected individuals in an anonymized network. In this paper we explore the capacity of techniques based on random edge perturbation to thwart such attacks. We theoretically establish that any kind of structural identification attack can effectively be prevented using random edge perturbation and show that, surprisingly, important properties of the whole network, as well as of subgraphs thereof, can be accurately calculated and hence data analysis tasks performed on the perturbed data, given that the legitimate data recipient knows the perturbation probability as well. Yet we also examine ways to enhance the walk-based attack, proposing a variant we call probabilistic attack. Nevertheless, we demonstrate that such probabilistic attacks can also be prevented under sufficient perturbation. Eventually, we conduct a thorough theoretical study of the probability of success of any}structural attack as a function of the perturbation probability. Our analysis provides a powerful tool for delineating the identification risk of perturbed social network data; our extensive experiments with synthetic and real datasets confirm our expectations. © 2012 ACM.

  8. Analytic neutrality, anonymity, abstinence, and elective self-disclosure.

    Science.gov (United States)

    Shill, Merton A

    2004-01-01

    Recent contributions to the psychoanalytic literature propose new ways of understanding analytic neutrality, anonymity, abstinence, and self-disclosure. They advocate elective self-disclosure by the analyst as an antidote to the allegedly game-playing quality of transference and resistance analysis. The analytic relationship, they assert, becomes unreal when attempts are made to observe the principles of neutrality and abstinence. Both are seen as ill-conceived because of the irreducible subjectivity and unwarranted authority of the analyst. These relational and interactional views are criticized because (1) they ignore the fact that transference and resistance analysis have from Freud onward been accepted as minimal criteria qualifying a clinical process as psychoanalytic; (2) elective self-disclosure carries metapsychological implications dismissing not only Freud's theory of motivation but motivation as a basic feature of human personality; (3) they do not recognize interpersonal relations as mental events and so do not consider the ego's ability to create intrapsychic representations of object relations; (4) elective self-disclosures within the empathic parameters of the analytic situation are themselves unreal compared to the reality of the patient's experience with other objects. Abstinence and neutrality as ideals facilitate maintenance of an internal holding environment or container for the analyst's countertransference.

  9. Spontaneous Atraumatic Mediastinal Hemorrhage

    Directory of Open Access Journals (Sweden)

    Morkos Iskander BSc, BMBS, MRCS, PGCertMedEd

    2013-04-01

    Full Text Available Spontaneous atraumatic mediastinal hematomas are rare. We present a case of a previously fit and well middle-aged lady who presented with acute breathlessness and an increasing neck swelling and spontaneous neck bruising. On plain chest radiograph, widening of the mediastinum was noted. The bruising was later confirmed to be secondary to mediastinal hematoma. This life-threatening diagnostic conundrum was managed conservatively with a multidisciplinary team approach involving upper gastrointestinal and thoracic surgeons, gastroenterologists, radiologists, intensivists, and hematologists along with a variety of diagnostic modalities. A review of literature is also presented to help surgeons manage such challenging and complicated cases.

  10. Use of WhatsApp in Higher Education: What's Up with Assessing Peers Anonymously?

    Science.gov (United States)

    Güler, Çetin

    2017-01-01

    The aim of this study is to investigate the use of WhatsApp application in anonymous peer assessment in higher education. The mobile phone application WhatsApp was used as both an anonymous and nonanonymous peer assessment tool in a classroom environment. The participants of the study were the students of two classes (sophomores and juniors), half…

  11. Anonymous Communication Policies for the Internet: Results and Recommendations of the AAAS Conference.

    Science.gov (United States)

    Teich, Al; Frankel, Mark S.; Kling, Rob; Lee, Yaching

    1999-01-01

    Reports the results of a conference on the Internet and anonymous communication organized by the American Association for the Advancement of Science (AAAS). Discusses how anonymous communications can be shaped by the law, education, and public awareness, and highlights the importance of involving all affected interests in policy development.…

  12. Toward Analysis of the Relations Among the Youth Counterculture, Telephone Hotlines, and Anonymity

    Science.gov (United States)

    Baizerman, Michael

    1974-01-01

    During the 1960's, there emerged innovative human service programs for youth. Among the actual differences in these programs compared to their older, established human service agencies was (is) the prominent position of the social value of client anonymity. This anonymity is examined in an attempt to understand its role. (RC)

  13. "People Are Either Too Fake or Too Real": Opportunities and Challenges in Tie-Based Anonymity

    DEFF Research Database (Denmark)

    Ma, Xiao; Andabili, Nazanin; Barkhuus, Louise

    2017-01-01

    In recent years, several mobile applications allowed individuals to anonymously share information with friends and contacts, without any persistent identity marker. The functions of these “tie-based” anonymity services may be notably different than other social media services. We use semi-structu...

  14. The Risk of a Halo Bias as a Reason to Keep Students Anonymous during Grading

    Science.gov (United States)

    Malouff, John M.; Emmerton, Ashley J.; Schutte, Nicola S.

    2013-01-01

    Experts have advocated anonymous grading as a means of eliminating actual or perceived evaluator bias in subjective student assessment. The utility of anonymity in assessment rests on whether information derived from student identity can unduly influence evaluation. The halo effect provides a conceptual background for why a bias might occur. In…

  15. Encouraging College Student Active Engagement in Learning: Student Response Methods and Anonymity

    Science.gov (United States)

    Barr, M. L.

    2017-01-01

    The purpose of this study was to examine the role of anonymity in encouraging college students to be more cognitively engaged in lectures. Kinesiology majors from three universities were asked to respond to questions during two consecutive lectures using response methods of opposing degrees of anonymity, one using "clickers" and the…

  16. Hadron production near threshold

    Indian Academy of Sciences (India)

    Final state interaction effects in → + and → 3He reactions are explored near threshold to study the sensitivity of the cross-sections to the potential and the scattering matrix. The final state scattering wave functions between and and and 3He are described rigorously. The production is ...

  17. Elaborating on Threshold Concepts

    Science.gov (United States)

    Rountree, Janet; Robins, Anthony; Rountree, Nathan

    2013-01-01

    We propose an expanded definition of Threshold Concepts (TCs) that requires the successful acquisition and internalisation not only of knowledge, but also its practical elaboration in the domains of applied strategies and mental models. This richer definition allows us to clarify the relationship between TCs and Fundamental Ideas, and to account…

  18. Boundaries, Thresholds, and Consequences.

    Science.gov (United States)

    Smith, Carl R.

    1997-01-01

    Highlights issues in the debate concerning Individuals with Disabilities Education Act (IDEA) special education legislation as it relates to student discipline and incarcerated juveniles. Focuses on assessment issues and thresholds for diagnosable conditions. Looks at debates surrounding IDEA and some of the consequences of new legislation. (RJM)

  19. Hacktivism 1-2-3: how privacy enhancing technologies change the face of anonymous hacktivism

    Directory of Open Access Journals (Sweden)

    Balázs Bodó

    2014-11-01

    Full Text Available This short essay explores how the notion of hacktivism changes due to easily accessible, military grade Privacy Enhancing Technologies (PETs. Privacy Enhancing Technologies, technological tools which provide anonymous communications and protect users from online surveillance enable new forms of online political activism. Through the short summary of the ad-hoc vigilante group Anonymous, this article describes hacktivism 1.0 as electronic civil disobedience conducted by outsiders. Through the analysis of Wikileaks, the anonymous whistleblowing website, it describes how strong PETs enable the development of hacktivism 2.0, where the source of threat is shifted from outsiders to insiders. Insiders have access to documents with which power can be exposed, and who, by using PETs, can anonymously engage in political action. We also describe the emergence of a third generation of hacktivists who use PETs to disengage and create their own autonomous spaces rather than to engage with power through anonymous whistleblowing.

  20. Attribute Utility Motivated k-anonymization of datasets to support the heterogeneous needs of biomedical researchers.

    Science.gov (United States)

    Ye, Huimin; Chen, Elizabeth S

    2011-01-01

    In order to support the increasing need to share electronic health data for research purposes, various methods have been proposed for privacy preservation including k-anonymity. Many k-anonymity models provide the same level of anoymization regardless of practical need, which may decrease the utility of the dataset for a particular research study. In this study, we explore extensions to the k-anonymity algorithm that aim to satisfy the heterogeneous needs of different researchers while preserving privacy as well as utility of the dataset. The proposed algorithm, Attribute Utility Motivated k-anonymization (AUM), involves analyzing the characteristics of attributes and utilizing them to minimize information loss during the anonymization process. Through comparison with two existing algorithms, Mondrian and Incognito, preliminary results indicate that AUM may preserve more information from original datasets thus providing higher quality results with lower distortion.

  1. Statistical disclosure limitation of health data based on Pk-anonymity.

    Science.gov (United States)

    Kimura, Eizen; Chida, Koji; Ikarashi, Dai; Hamada, Koki; Ishihara, Ken

    2012-01-01

    The Act for the Protection of Personal Information in Japan considers as personal information any quasi-identifier that may be used to obtain information that identifies individuals through comparisons with datasets. Studies using health records are not widely conducted because of the concern regarding the safety of anonymized health records. To increase the safety of such records, we used the Pk-anonymity method. In this method, attributes are probabilistically randomized and then reconstructions are performed on the basis of statistical information from perturbed data. Hence, it is expected to provide more precise statistics and more reliably preserve privacy than the traditional "k-anonymity" method. We anonymized health records, performed cross tabulation, and assessed the error rate using original data. This study shows that the Pk-anonymity method can be used to perform safety statistical disclosures with low error rates, even in small cases.

  2. A hidden service model based on HS-HS anonymous network

    Science.gov (United States)

    Meng, Yitong; Zhao, Xing; Fei, Jinlong; Zhu, Yuefei

    2017-10-01

    The Hidden Service provided by Tor anonymous network can effectively protect the anonymity and security of the Hidden server, this article through the analysis of the data packet structure of Tor, three jump transmission mechanism and link establishment protocol and Hidden Service communication process, in view of the Hidden node number too much, link building Service for too long and too redundant link problem. An improved hidden service model HS-HS is proposed that incorporating multiple transmission link and reuse, and at the same time will be important transit point for reuse protection link anonymity, through the ExperimenTor simulation environment test, verify the improved model of HS-HS can be more effective in guarantee anonymity and security, improve the overall efficiency of data transmission, to meet the needs of today's anonymous service.

  3. Social networks as mediators of the effect of Alcoholics Anonymous.

    Science.gov (United States)

    Kaskutas, Lee Ann; Bond, Jason; Humphreys, Keith

    2002-07-01

    This study tested the hypothesis that the relationship between Alcoholics Anonymous (AA) involvement and reduced substance use is partially explained (or 'mediated') by changes in social networks. This is a naturalistic longitudinal study of the course of alcohol problems. Study sites were the 10 largest public and private alcohol treatment programs in a northern California county. Three hundred and seventy-seven men and 277 women were recruited upon seeking treatment at study sites. At baseline and 1-year follow-up, we assessed alcohol consequences and dependence symptoms, consumption, social support for abstinence, pro-drinking social influences and AA involvement. In the structural equation model, AA involvement was a significant predictor of lower alcohol consumption and fewer related problems. The size of this effect decreased by 36% when network size and support for drinking were included as mediators. In logistic regression models predicting abstinence at follow-up, AA remained highly significant after including social network variables but was again reduced in magnitude. Thirty-day abstinence was predicted by AA involvement (OR=2.9), not having pro-drinking influences in one's network (OR=0.7) and having support for reducing consumption from people met in AA (versus no support; OR=3.4). In contrast, having support from non-AA members was not a significant predictor of abstinence. For alcohol-related outcomes other than abstinence, significant relationships were found for both AA-based and non-AA-based support. The type of social support specifically given by AA members, such as 24-hour availability, role modeling and experientially based advice for staying sober, may help to explain AA's mechanism of action. Results highlight the value of focusing on outcomes reflective of AA's goals (such as abstinence) when studying how AA works.

  4. Anonymity In Survey Courses as Tool for More Diverse Engagement

    Science.gov (United States)

    Samson, P. J.

    2017-12-01

    It is not uncommon that students in introductory survey courses are reluctant to participate in verbal inquiry. In a survey submitted to students of CLIMATE 102, Extreme Weather, over the past four semesters about 45% of male students professed comfort in asking verbal questions in a large lecture hall but less than 25% of females and only 15% of students for whom English is not their first language. Hence, large lecture hall courses may be inadvertently dissuading the inclusion of many of the students we wish to encourage to participate in our discipline. To combat this a system was used in CLIMATE 102 wherein students could pose questions digitally and anonymously. These questions could be seen by all and answered by all. The instructor and/or teaching assistant can also participate and answer or offer corrections to others' answers. The use of this system had three important outcomes: The number of questions posed during class time rose dramatically from previous semesters when only verbal questions were entertained. The number of questions in CLIMATE 102 with this system generally exceeded 500 per semester where the number of students 200. The number of per-capita questions from female students exceeded the male students, thus differences in gender inquiry was eliminated. The number of per-capita questions from students whose first language was not English equaled the native English-speaking students. While it is the goal of higher education to encourage students to participate verbally in class discussions it is important to provide a "safe" environment in the first year(s) as many students are initially uncomfortable participating verbally in class. We hypothesize, but have not researched, that through this process students have the opportunity to see that their questions are as valid as others' in the class and will subsequently gain the confidence to participate verbally.

  5. Spontaneous Appendicocutaneous Fistula I

    African Journals Online (AJOL)

    M T0k0de* MB, BS and. Dr 0. A. AWOj0bi+ FMCS (Nig). ABSTRACT. Ruptured appendicitis is not a common cause of spontaneous enterocutaneous fistula. A case of ruptured retrocaecal appendicitis presenting as an enterocutaneous fistula in a Nigerian woman is presented. The literature on this disorder is also reviewed.

  6. [Spontaneous bacterial peritonitis].

    Science.gov (United States)

    Strauss, Edna; Caly, Wanda Regina

    2003-01-01

    Spontaneous bacterial peritonitis occurs in 30% of patients with ascites due to cirrhosis leading to high morbidity and mortality rates. The pathogenesis of spontaneous bacterial peritonitis is related to altered host defenses observed in end-stage liver disease, overgrowth of microorganisms, and bacterial translocation from the intestinal lumen to mesenteric lymph nodes. Clinical manifestations vary from severe to slight or absent, demanding analysis of the ascitic fluid. The diagnosis is confirmed by a number of neutrophils over 250/mm3 associated or not to bacterial growth in culture of an ascites sample. Enterobacteriae prevail and Escherichia coli has been the most frequent bacterium reported. Mortality rates decreased markedly in the last two decades due to early diagnosis and prompt antibiotic treatment. Third generation intravenous cephalosporins are effective in 70% to 95% of the cases. Recurrence of spontaneous bacterial peritonitis is common and can be prevented by the continuous use of oral norfloxacin. The development of bacterial resistance demands the search for new options in the prophylaxis of spontaneous bacterial peritonitis; probiotics are a promising new approach, but deserve further evaluation. Short-term antibiotic prophylaxis is recommended for patients with cirrhosis and ascites shortly after an acute episode of gastrointestinal bleeding.

  7. Spontaneous Grammar Explanations.

    Science.gov (United States)

    Tjoo, Hong Sing; Lewis, Marilyn

    1998-01-01

    Describes one New Zealand university language teacher's reflection on her own grammar explanations to university-level students of Bahasa Indonesian. Examines form-focused instruction through the teacher's spontaneous answers to students' questions about the form of the language they are studying. The teacher's experiences show that it takes time…

  8. EDITORIAL SPONTANEOUS BACTERIAL PERITONITIS ...

    African Journals Online (AJOL)

    hi-tech

    Spontaneous bacterial peritonitis (SBP) frequent]y occurs in patients with liver cirrhosis and ascites. It is defined as an infection of previously sterile ascitic fluid without any demonstrable intrabdominal source of infection. It is now internationally agreed that a polymorphonuclear (PMN) cell count in the ascitic fluid of over 250 ...

  9. Spontaneous dimensional reduction?

    Science.gov (United States)

    Carlip, Steven

    2012-10-01

    Over the past few years, evidence has begun to accumulate suggesting that spacetime may undergo a "spontaneous dimensional reduction" to two dimensions near the Planck scale. I review some of this evidence, and discuss the (still very speculative) proposal that the underlying mechanism may be related to short-distance focusing of light rays by quantum fluctuations.

  10. Universality of gauge thresholds in non-supersymmetric heterotic vacua

    Directory of Open Access Journals (Sweden)

    Carlo Angelantonj

    2014-09-01

    Full Text Available We compute one-loop threshold corrections to non-abelian gauge couplings in four-dimensional heterotic vacua with spontaneously broken N=2→N=0 supersymmetry, obtained as Scherk–Schwarz reductions of six-dimensional K3 compactifications. As expected, the gauge thresholds are no-longer BPS protected, and receive contributions also from the excitations of the RNS sector. Remarkably, the difference of thresholds for non-abelian gauge couplings is BPS saturated and exhibits a universal behaviour independently of the orbifold realisation of K3. Moreover, the thresholds and their difference develop infra-red logarithmic singularities whenever charged BPS-like states, originating from the twisted RNS sector, become massless at special loci in the classical moduli space.

  11. Hadron production near threshold

    Indian Academy of Sciences (India)

    Abstract. Final state interaction effects in pp → pΛK+ and pd → 3He η reactions are explored near threshold to study the sensitivity of the cross-sections to the pΛ potential and the ηN scattering matrix. The final state scattering wave functions between Λ and p and η and 3He are described rigorously. The Λ production is ...

  12. AIB-OR: improving onion routing circuit construction using anonymous identity-based cryptosystems.

    Science.gov (United States)

    Wang, Changji; Shi, Dongyuan; Xu, Xilei

    2015-01-01

    The rapid growth of Internet applications has made communication anonymity an increasingly important or even indispensable security requirement. Onion routing has been employed as an infrastructure for anonymous communication over a public network, which provides anonymous connections that are strongly resistant to both eavesdropping and traffic analysis. However, existing onion routing protocols usually exhibit poor performance due to repeated encryption operations. In this paper, we first present an improved anonymous multi-receiver identity-based encryption (AMRIBE) scheme, and an improved identity-based one-way anonymous key agreement (IBOWAKE) protocol. We then propose an efficient onion routing protocol named AIB-OR that provides provable security and strong anonymity. Our main approach is to use our improved AMRIBE scheme and improved IBOWAKE protocol in onion routing circuit construction. Compared with other onion routing protocols, AIB-OR provides high efficiency, scalability, strong anonymity and fault tolerance. Performance measurements from a prototype implementation show that our proposed AIB-OR can achieve high bandwidths and low latencies when deployed over the Internet.

  13. Anonymous birth law saves babies--optimization, sustainability and public awareness.

    Science.gov (United States)

    Grylli, Chryssa; Brockington, Ian; Fiala, Christian; Huscsava, Mercedes; Waldhoer, Thomas; Klier, Claudia M

    2016-04-01

    The aims of this study are to assess the impact of Austria's anonymous birth law from the time relevant statistical records are available and to evaluate the use of hatches versus anonymous hospital delivery. This study is a complete census of police-reported neonaticides (1975-2012) as well as anonymous births including baby hatches in Austria during 2002-2012. The time trends of neonaticide rates, anonymous births and baby hatches were analysed by means of Poisson and logistic regression model. Predicted and observed rates were derived and compared using a Bayesian Poisson regression model. Predicted numbers of neonaticides for the period of the active awareness campaign, 2002-2004, were more than three times larger than the observed number (p = 0.0067). Of the 365 women who benefitted from this legislation, only 11.5% chose to put their babies in a baby hatch. Since the law was introduced, a significant decreasing tendency of numbers of anonymous births (p = 047) was observed, while there was significant increase of neonaticide rates (p = 0.0001). The implementation of the anonymous delivery law is associated with a decrease in the number of police-reported neonaticides. The subsequent significantly decreasing numbers of anonymous births with an accompanying increase of neonaticides represents additional evidence for the effectiveness of the measure.

  14. Spontaneous healing of spontaneous coronary artery dissection.

    Science.gov (United States)

    Almafragi, Amar; Convens, Carl; Heuvel, Paul Van Den

    2010-01-01

    Spontaneous coronary artery dissection (SCAD) is a rare cause of acute coronary syndrome and sudden cardiac death. It should be suspected in every healthy young woman without cardiac risk factors, especially during the peripartum or postpartum periods. It is important to check for a history of drug abuse, collagen vascular disease or blunt trauma of the chest. Coronary angiography is essential for diagnosis and early management. We wonder whether thrombolysis might aggravate coronary dissection. All types of treatment (medical therapy, percutaneous intervention or surgery) improve the prognosis without affecting survival times if used appropriately according to the clinical stability and the angiographic features of the involved coronary arteries. Prompt recognition and targeted treatment improve outcomes. We report a case of SCAD in a young female free of traditional cardiovascular risk factors, who presented six hours after thrombolysis for ST elevation myocardial infarction. Coronary angiography showed a dissection of the left anterior descending and immediate branch. She had successful coronary artery bypass grafting, with complete healing of left anterior descending dissection.

  15. Serbs in the poetry of Theodore Prodromos and anonymous Manganeios

    Directory of Open Access Journals (Sweden)

    Stanković Vlada

    2006-01-01

    Full Text Available Numerous rhetorical writings of the Comnenian period constitute a fruitful field of research, both with respect to historical data, i.e. hard historical facts hidden, though still recognizable, behind the peculiar and somewhat abstract mode of expression of the authors of the twelfth century, and with regard to the poetics of the literary works themselves, i.e. the internal elements characteristic not only for the genre chosen, but also for each particular author. A comparative, historical and literary approach to these works renders their sense clearer and their complex allusions more readily understood. This is a matter of some importance, since allusions constitute one of the basic elements of historical rhetoric, which reached its peak at the time of Emperor Manuel Komnenos (1143-1180, especially during the first half of his reign, i.e. till the end of the fifties of the twelfth century. The poetry of Theodore Prodromes and of the somewhat younger Anonymous ('Prodromos' Manganeios is an excellent example of this intertwining of historical and literary elements, i.e. of the presentation of historical data through rhetorical patterns. One has to concentrate on individual works attempting to determine, as far as possible, the date of composition, the circumstances of writing and the purpose of a particular poem, the occasion for which it was written and the character of the expected audience, in order to better understand both the poetry written by these two rhetoricians and the individual features of the authors, as well as their respective positions in the circle around Emperor Manuel Komnenos. The poems dealt with in the present paper stand out for calling the Serbs by their real name. This naming practice was invariably employed by both rhetoricians in cases when new achievements of the basileus were to be announced and proclaimed immediately after the event, on the occasions of first reports, first celebrations of the new victories and

  16. Anonymity and pseudonymity in whistleblowing to the U.S. Office of Research Integrity.

    Science.gov (United States)

    Price, A R

    1998-05-01

    Given the concerns expressed by members of the academic and legal community about whether (and how) to handle anonymous and pseudonymous allegations of scientific misconduct, this paper summaries the experiences of the Office of Research Integrity and its predecessor from 1989 through 1997. Although the record shows that research institutions and the ORI have treated such allegations seriously, the fraction of complainants to the ORI who remain anonymous is small (8% of 986 allegations); few anonymous complaints are sufficiently substantive to be pursued (4% of the 357 formal cases opened in the ORI); and only 1 of these 13 cases resulted in an ORI finding of scientific misconduct.

  17. Spontaneous spinal epidural abscess.

    LENUS (Irish Health Repository)

    Ellanti, P

    2011-10-01

    Spinal epidural abscess is an uncommon entity, the frequency of which is increasing. They occur spontaneously or as a complication of intervention. The classical triad of fever, back pain and neurological symptoms are not always present. High index of suspicion is key to diagnosis. Any delay in diagnosis and treatment can have significant neurological consequences. We present the case of a previously well man with a one month history of back pain resulting from an epidural abscess.

  18. Efficient Threshold Zero-Knowledge with Applications to User-Centric Protocols

    DEFF Research Database (Denmark)

    Mikkelsen, Gert Læssøe; Keller, Marcel; Rupp, Andy

    2012-01-01

    -cash system and the bilinear anonymous credential scheme by Camenisch and Lysyanskaya. Distributing the user party in such protocols has several practical advantages: First, the security of a user can be increased by sharing secrets and computations over multiple devices owned by the user. In this way, losing...... control of a single device does not result in a security breach. Second, this approach also allows groups of users to jointly control an application (e.g., a joint e-cash account), not giving a single user full control. The distributed versions of the protocols we propose in this paper are relatively......, such as identification schemes, electronic cash (e-cash), and anonymous credentials. We present a security model for threshold proofs of knowledge and develop threshold versions of well-known primitives such as range proofs, zero-knowledge proofs for preimages of homomorphisms (which generalizes PoKs of discrete...

  19. Hacktivism 1-2-3: how privacy enhancing technologies change the face of anonymous hacktivism

    NARCIS (Netherlands)

    Bodó, B.

    2014-01-01

    This short essay explores how the notion of hacktivism changes due to easily accessible, military grade Privacy Enhancing Technologies (PETs). Privacy Enhancing Technologies, technological tools which provide anonymous communications and protect users from online surveillance enable new forms of

  20. The Role of the Anonymous Voice in Post-Publication Peer Review Versus Traditional Peer Review

    Directory of Open Access Journals (Sweden)

    Jaime A. Teixeira da Silva

    2015-12-01

    Full Text Available Traditional peer review (TPR has several limitations and weaknesses. Post-publication peer review is one practical way to repair the ills of TPR and reinforce it. A literature that is marked by errors is unhealthy and should, if given the opportunity, be corrected or further improved. The anonymous voice is one source of critique and differs from the blind peer review in TPR in which the reviewer remains anonymous to the authors and/or vice versa, but the identity is known to the editor. If unregulated, the anonymous voice can pose a threat to established editorial norms in TPR, to one of the most important criteria of science publishing, i.e., transparency, and to worthwhile discussion. Yet, if the anonymous voice is not heard, then a vast and potentially valuable pool of untapped opinions may be lost, opinions that may provide valuable solutions to improving TPR.

  1. Anonymous letters? DNA and fingerprints technologies combined to solve a case.

    Science.gov (United States)

    Barbaro, A; Cormaci, P; Teatino, A; La Marca, A; Barbaro, A

    2004-12-02

    Two brothers, living in two different cities, received two different anonymous letters. We performed latent prints development and DNA research on the letters and also on a glass used by a cousin suspected to be the letters' sender.

  2. Security Analysis and Improvement of an Anonymous Authentication Scheme for Roaming Services

    Directory of Open Access Journals (Sweden)

    Youngsook Lee

    2014-01-01

    Full Text Available An anonymous authentication scheme for roaming services in global mobility networks allows a mobile user visiting a foreign network to achieve mutual authentication and session key establishment with the foreign-network operator in an anonymous manner. In this work, we revisit He et al.’s anonymous authentication scheme for roaming services and present previously unpublished security weaknesses in the scheme: (1 it fails to provide user anonymity against any third party as well as the foreign agent, (2 it cannot protect the passwords of mobile users due to its vulnerability to an offline dictionary attack, and (3 it does not achieve session-key security against a man-in-the-middle attack. We also show how the security weaknesses of He et al.’s scheme can be addressed without degrading the efficiency of the scheme.

  3. To Speak or Not to Speak: Developing Legal Standards for Anonymous Speech on the Internet

    Directory of Open Access Journals (Sweden)

    Tomas A. Lipinski

    2002-01-01

    Full Text Available This paper explores recent developments in the regulation of Internet speech, in specific, injurious or defamatory speech and the impact such speech has on the rights of anonymous speakers to remain anonymous as opposed to having their identity revealed to plaintiffs or other third parties. The paper proceeds in four sections.  First, a brief history of the legal attempts to regulate defamatory Internet speech in the United States is presented. As discussed below this regulation has altered the traditional legal paradigm of responsibility and as a result creates potential problems for the future of anonymous speech on the Internet.  As a result plaintiffs are no longer pursuing litigation against service providers but taking their dispute directly to the anonymous speaker. Second, several cases have arisen in the United States where plaintiffs have requested that the identity of an anonymous Internet speaker be revealed.  These cases are surveyed.  Third, the cases are analyzed in order to determine the factors that courts require to be present before the identity of an anonymous speaker will be revealed.  The release is typically accomplished by the enforcement of a discovery subpoena instigated by the party seeking the identity of the anonymous speaker. The factors courts have used are as follows: jurisdiction, good faith (both internal and external, necessity (basic and sometimes absolute, and at times proprietary interest. Finally, these factors are applied in three scenarios--e-commerce, education, and employment--to guide institutions when adopting policies that regulate when the identity of an anonymous speaker--a customer, a student or an employee--would be released as part of an internal initiative, but would nonetheless be consistent with developing legal standards.

  4. An Enhancing Security Research of Tor Anonymous Communication to Against DDos Attacks

    OpenAIRE

    Feng Tao; Zhao Ming-Tao

    2017-01-01

    Tor (The Second Onion Router) is modified by the first generation onion router and known as the most prevalent anonymous communication system. According to the advantage of low latency, high confidentiality of transmission content, high security of communication channels and et al., Tor is widely used in anonymous Web browsing, instant message and so on. However, the vulnerability and blemish of Tor affect system security. An identity and Signcryption-based concurrent signature scheme was use...

  5. Spontaneous Thigh Compartment Syndrome

    Directory of Open Access Journals (Sweden)

    Khan, Sameer K

    2011-02-01

    Full Text Available A young man presented with a painful and swollen thigh, without any history of trauma, illness, coagulopathic medication or recent exertional exercise. Preliminary imaging delineated a haematoma in the anterior thigh, without any fractures or muscle trauma. Emergent fasciotomies were performed. No pathology could be identified intra-operatively, or on follow-up imaging. A review of thigh compartment syndromes described in literature is presented in a table. Emergency physicians and traumatologists should be cognisant of spontaneous atraumatic presentations of thigh compartment syndrome, to ensure prompt referral and definitive management of this limb-threatening condition. [West J Emerg Med. 2011;12(1:134-138].

  6. Oscillatory Threshold Logic

    Science.gov (United States)

    Borresen, Jon; Lynch, Stephen

    2012-01-01

    In the 1940s, the first generation of modern computers used vacuum tube oscillators as their principle components, however, with the development of the transistor, such oscillator based computers quickly became obsolete. As the demand for faster and lower power computers continues, transistors are themselves approaching their theoretical limit and emerging technologies must eventually supersede them. With the development of optical oscillators and Josephson junction technology, we are again presented with the possibility of using oscillators as the basic components of computers, and it is possible that the next generation of computers will be composed almost entirely of oscillatory devices. Here, we demonstrate how coupled threshold oscillators may be used to perform binary logic in a manner entirely consistent with modern computer architectures. We describe a variety of computational circuitry and demonstrate working oscillator models of both computation and memory. PMID:23173034

  7. Spontaneous Tumor Lysis Syndrome

    Directory of Open Access Journals (Sweden)

    Alicia C. Weeks MD

    2015-08-01

    Full Text Available Tumor lysis syndrome (TLS is a known complication of malignancy and its treatment. The incidence varies on malignancy type, but is most common with hematologic neoplasms during cytotoxic treatment. Spontaneous TLS is thought to be rare. This case study is of a 62-year-old female admitted with multisystem organ failure, with subsequent diagnosis of aggressive B cell lymphoma. On admission, laboratory abnormalities included renal failure, elevated uric acid (20.7 mg/dL, and 3+ amorphous urates on urinalysis. Oliguric renal failure persisted despite aggressive hydration and diuretic use, requiring initiation of hemodialysis prior to chemotherapy. Antihyperuricemic therapy and hemodialysis were used to resolve hyperuricemia. However, due to multisystem organ dysfunction syndrome with extremely poor prognosis, the patient ultimately expired in the setting of a terminal ventilator wean. Although our patient did not meet current TLS criteria, she required hemodialysis due to uric acid nephropathy, a complication of TLS. This poses the clinical question of whether adequate diagnostic criteria exist for spontaneous TLS and if the lack of currently accepted guidelines has resulted in the underestimation of its incidence. Allopurinol and rasburicase are commonly used for prevention and treatment of TLS. Although both drugs decrease uric acid levels, allopurinol mechanistically prevents formation of the substrate rasburicase acts to solubilize. These drugs were administered together in our patient, although no established guidelines recommend combined use. This raises the clinical question of whether combined therapy is truly beneficial or, conversely, detrimental to patient outcomes.

  8. Verbal Venting in the Social Web: Effects of Anonymity and Group Norms on Aggressive Language Use in Online Comments

    Directory of Open Access Journals (Sweden)

    Leonie Rösner

    2016-08-01

    Full Text Available Scholars often blame the occurrence of aggressive behavior in online discussions on the anonymity of the Internet; however, even on today’s less anonymous platforms, such as social networking sites, users write plenty of aggressive comments, which can elicit a whole wave of negative remarks. Drawing on the social identity and deindividuation effects (SIDE model, this research conducts a laboratory experiment with a 2 (anonymity vs. no anonymity × 2 (aggressive norm vs. non-aggressive norm between-subjects design in order to disentangle the effects of anonymity, social group norms, and their interactions on aggressive language use in online comments. Results reveal that participants used more aggressive expressions in their comments when peer comments on a blog included aggressive wording (i.e., the social group norm was aggressive. Anonymity had no direct effect; however, we found a tendency that users’ conformity to an aggressive social norm of commenting is stronger in an anonymous environment.

  9. Estimates of Non-Heterosexual Prevalence: The Roles of Anonymity and Privacy in Survey Methodology.

    Science.gov (United States)

    Robertson, Ronald E; Tran, Felix W; Lewark, Lauren N; Epstein, Robert

    2017-08-07

    When do people feel comfortable enough to provide honest answers to sensitive questions? Focusing specifically on sexual orientation prevalence-a measure that is sensitive to the pressures of heteronormativity-the present study was conducted to examine the variability in U.S. estimates of non-heterosexual identity prevalence and to determine how comfortable people are with answering questions about their sexual orientation when asked through commonly used survey modes. We found that estimates of non-heterosexual prevalence in the U.S. increased as the privacy and anonymity of the survey increased. Utilizing an online questionnaire, we rank-ordered 16 survey modes by asking people to rate their level of comfort with each mode in the context of being asked questions about their sexual orientation. A demographically diverse sample of 652 individuals in the U.S. rated each mode on a scale from -5 (very uncomfortable) to +5 (very comfortable). Modes included anonymous (name not required) and non-anonymous (name required) versions of questions, as well as self-administered and interviewer-administered versions. Subjects reported significantly higher mean comfort levels with anonymous modes than with non-anonymous modes and significantly higher mean comfort levels with self-administered modes than with interviewer-administered modes. Subjects reported the highest mean comfort level with anonymous online surveys and the lowest with non-anonymous personal interviews that included a video recording. Compared with the estimate produced by an online survey with a nationally representative sample, surveys utilizing more intrusive methodologies may have underestimated non-heterosexual prevalence in the U.S. by between 50 and 414%. Implications for public policy are discussed.

  10. Iris pigmentation and AC thresholds.

    Science.gov (United States)

    Roche, A F; Mukherjee, D; Chumlea, W C; Siervogel, R M

    1983-03-01

    Data from 160 White children were used to analyze possible associations between iris pigmentation and AC pure-tone thresholds. Iris pigmentation was graded from iris color using glass models of eyes, and AC thresholds were obtained under carefully controlled conditions. Analyses of variance using two groupings of iris color grades showed no evidence of an association between iris color grade and AC thresholds. Furthermore, inspection of arrays of the actual glass eye models, in conjunction with the order of mean thresholds at each test frequency, did not indicate the presence of an association between iris color grades and thresholds. It was concluded that while iris pigmentation may be related to some aspects of hearing ability, it does not appear to be related to AC thresholds in children.

  11. Spontaneous Intracranial Hypotension

    International Nuclear Information System (INIS)

    Joash, Dr.

    2015-01-01

    Epidemiology is not only rare but an important cause of new daily persistent headaches among young & middle age individuals. The Etiology & Pathogenesis is generally caused by spinal CSF leak. Precise cause remains largely unknown, underlying structural weakness of spinal meninges is suspected. There are several MR Signs of Intracranial Hypotension that include:- diffuse pachymeningeal (dural) enhancement; bilateral subdural, effusion/hematomas; Downward displacement of brain; enlargement of pituitary gland; Engorgement of dural venous sinuses; prominence of spinal epidural venous plexus and Venous sinus thrombosis & isolated cortical vein thrombosis. The sum of volumes of intracranial blood, CSF & cerebral tissue must remain constant in an intact cranium. Treatment in Many cases can be resolved spontaneously or by use Conservative approach that include bed rest, oral hydration, caffeine intake and use of abdominal binder. Imaging Modalities for Detection of CSF leakage include CT myelography, Radioisotope cisternography, MR myelography, MR imaging and Intrathecal Gd-enhanced MR

  12. Spontaneous wave packet reduction

    International Nuclear Information System (INIS)

    Ghirardi, G.C.

    1994-06-01

    There are taken into account the main conceptual difficulties met by standard quantum mechanics in dealing with physical processes involving macroscopic system. It is stressed how J.A.Wheeler's remarks and lucid analysis have been relevant to pinpoint and to bring to its extreme consequences the puzzling aspects of quantum phenomena. It is shown how the recently proposed models of spontaneous dynamical reduction represent a consistent way to overcome the conceptual difficulties of the standard theory. Obviously, many nontrivial problems remain open, the first and more relevant one being that of generalizing the model theories considered to the relativistic case. This is the challenge of the dynamical reduction program. 43 refs, 2 figs

  13. The cost of quality: Implementing generalization and suppression for anonymizing biomedical data with minimal information loss.

    Science.gov (United States)

    Kohlmayer, Florian; Prasser, Fabian; Kuhn, Klaus A

    2015-12-01

    With the ARX data anonymization tool structured biomedical data can be de-identified using syntactic privacy models, such as k-anonymity. Data is transformed with two methods: (a) generalization of attribute values, followed by (b) suppression of data records. The former method results in data that is well suited for analyses by epidemiologists, while the latter method significantly reduces loss of information. Our tool uses an optimal anonymization algorithm that maximizes output utility according to a given measure. To achieve scalability, existing optimal anonymization algorithms exclude parts of the search space by predicting the outcome of data transformations regarding privacy and utility without explicitly applying them to the input dataset. These optimizations cannot be used if data is transformed with generalization and suppression. As optimal data utility and scalability are important for anonymizing biomedical data, we had to develop a novel method. In this article, we first confirm experimentally that combining generalization with suppression significantly increases data utility. Next, we proof that, within this coding model, the outcome of data transformations regarding privacy and utility cannot be predicted. As a consequence, existing algorithms fail to deliver optimal data utility. We confirm this finding experimentally. The limitation of previous work can be overcome at the cost of increased computational complexity. However, scalability is important for anonymizing data with user feedback. Consequently, we identify properties of datasets that may be predicted in our context and propose a novel and efficient algorithm. Finally, we evaluate our solution with multiple datasets and privacy models. This work presents the first thorough investigation of which properties of datasets can be predicted when data is anonymized with generalization and suppression. Our novel approach adopts existing optimization strategies to our context and combines different

  14. Crossing the threshold

    Science.gov (United States)

    Bush, John; Tambasco, Lucas

    2017-11-01

    First, we summarize the circumstances in which chaotic pilot-wave dynamics gives rise to quantum-like statistical behavior. For ``closed'' systems, in which the droplet is confined to a finite domain either by boundaries or applied forces, quantum-like features arise when the persistence time of the waves exceeds the time required for the droplet to cross its domain. Second, motivated by the similarities between this hydrodynamic system and stochastic electrodynamics, we examine the behavior of a bouncing droplet above the Faraday threshold, where a stochastic element is introduced into the drop dynamics by virtue of its interaction with a background Faraday wave field. With a view to extending the dynamical range of pilot-wave systems to capture more quantum-like features, we consider a generalized theoretical framework for stochastic pilot-wave dynamics in which the relative magnitudes of the drop-generated pilot-wave field and a stochastic background field may be varied continuously. We gratefully acknowledge the financial support of the NSF through their CMMI and DMS divisions.

  15. BIX Certificates: Cryptographic Tokens for Anonymous Transactions Based on Certificates Public Ledger

    Directory of Open Access Journals (Sweden)

    Sead Muftic

    2016-12-01

    Full Text Available With the widespread use of Internet, Web, and mobile technologies, a new category of applications and transactions that requires anonymity is gaining increased interest and importance. Examples of such new applications are innovative payment systems, digital notaries, electronic voting, documents sharing, electronic auctions, medical applications, and many others. In addition to anonymity, these applications and transactions also require standard security services: identification, authentication, and authorization of users and protection of their transactions. Providing those services in combination with anonymity is an especially challenging issue, because all security services require explicit user identification and authentication. To solve this issue and enable applications with security and also anonymity we introduce a new type of cryptographically encapsulated objects called BIX certificates. “BIX” is an abbreviation for “Blockchain Information Exchange.” Their purpose is equivalent to X.509 certificates: to support security services for users and transactions, but also enhanced with anonymity. This paper describes the structure and attributes of BIX certificate objects and all related protocols for their creation, distribution, and use. The BIX Certification Infrastructure (BCI as a distributed public ledger is also briefly described.

  16. A Lightweight Anonymous Authentication Protocol with Perfect Forward Secrecy for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Ling Xiong

    2017-11-01

    Full Text Available Due to their frequent use in unattended and hostile deployment environments, the security in wireless sensor networks (WSNs has attracted much interest in the past two decades. However, it remains a challenge to design a lightweight authentication protocol for WSNs because the designers are confronted with a series of desirable security requirements, e.g., user anonymity, perfect forward secrecy, resistance to de-synchronization attack. Recently, the authors presented two authentication schemes that attempt to provide user anonymity and to resist various known attacks. Unfortunately, in this work we shall show that user anonymity of the two schemes is achieved at the price of an impractical search operation—the gateway node may search for every possible value. Besides this defect, they are also prone to smart card loss attacks and have no provision for perfect forward secrecy. As our main contribution, a lightweight anonymous authentication scheme with perfect forward secrecy is designed, and what we believe the most interesting feature is that user anonymity, perfect forward secrecy, and resistance to de-synchronization attack can be achieved at the same time. As far as we know, it is extremely difficult to meet these security features simultaneously only using the lightweight operations, such as symmetric encryption/decryption and hash functions.

  17. Anonymization for outputs of population health and health services research conducted via an online data center.

    Science.gov (United States)

    O'Keefe, Christine M; Westcott, Mark; O'Sullivan, Maree; Ickowicz, Adrien; Churches, Tim

    2017-05-01

    Online data centers (ODCs) are becoming increasingly popular for making health-related data available for research. Such centers provide good privacy protection during analysis by trusted researchers, but privacy concerns may still remain if the system outputs are not sufficiently anonymized. In this article, we propose a method for anonymizing analysis outputs from ODCs for publication in academic literature. We use as a model system the Secure Unified Research Environment, an online computing system that allows researchers to access and analyze linked health-related data for approved studies in Australia. This model system suggests realistic assumptions for an ODC that, together with literature and practice reviews, inform our solution design. We propose a two-step approach to anonymizing analysis outputs from an ODC. A data preparation stage requires data custodians to apply some basic treatments to the dataset before making it available. A subsequent output anonymization stage requires researchers to use a checklist at the point of downloading analysis output. The checklist assists researchers with highlighting potential privacy concerns, then applying appropriate anonymization treatments. The checklist can be used more broadly in health care research, not just in ODCs. Ease of online publication as well as encouragement from journals to submit supplementary material are likely to increase both the volume and detail of analysis results publicly available, which in turn will increase the need for approaches such as the one suggested in this paper.

  18. A Lightweight Anonymous Authentication Protocol with Perfect Forward Secrecy for Wireless Sensor Networks.

    Science.gov (United States)

    Xiong, Ling; Peng, Daiyuan; Peng, Tu; Liang, Hongbin; Liu, Zhicai

    2017-11-21

    Due to their frequent use in unattended and hostile deployment environments, the security in wireless sensor networks (WSNs) has attracted much interest in the past two decades. However, it remains a challenge to design a lightweight authentication protocol for WSNs because the designers are confronted with a series of desirable security requirements, e.g., user anonymity, perfect forward secrecy, resistance to de-synchronization attack. Recently, the authors presented two authentication schemes that attempt to provide user anonymity and to resist various known attacks. Unfortunately, in this work we shall show that user anonymity of the two schemes is achieved at the price of an impractical search operation-the gateway node may search for every possible value. Besides this defect, they are also prone to smart card loss attacks and have no provision for perfect forward secrecy. As our main contribution, a lightweight anonymous authentication scheme with perfect forward secrecy is designed, and what we believe the most interesting feature is that user anonymity, perfect forward secrecy, and resistance to de-synchronization attack can be achieved at the same time. As far as we know, it is extremely difficult to meet these security features simultaneously only using the lightweight operations, such as symmetric encryption/decryption and hash functions.

  19. Formal Security-Proved Mobile Anonymous Authentication Protocols with Credit-Based Chargeability and Controllable Privacy

    Directory of Open Access Journals (Sweden)

    Chun-I Fan

    2016-06-01

    Full Text Available Smart mobile phones are widely popularized and advanced mobile communication services are provided increasingly often, such that ubiquitous computing environments will soon be a reality. However, there are many security threats to mobile networks and their impact on security is more serious than that in wireline networks owing to the features of wireless transmissions and the ubiquity property. The secret information which mobile users carry may be stolen by malicious entities. To guarantee the quality of advanced services, security and privacy would be important issues when users roam within various mobile networks. In this manuscript, an anonymous authentication scheme will be proposed to protect the security of the network system and the privacy of users. Not only does the proposed scheme provide mutual authentication between each user and the system, but also each user’s identity is kept secret against anyone else, including the system. Although the system anonymously authenticates the users, it can still generate correct bills to charge these anonymous users via a credit-based solution instead of debit-based ones. Furthermore, our protocols also achieve fair privacy which allows the judge to revoke the anonymity and trace the illegal users when they have misused the anonymity property, for example, if they have committed crimes. Finally, in this paper, we also carry out complete theoretical proofs on each claimed security property.

  20. Albania - Thresholds I and II

    Data.gov (United States)

    Millennium Challenge Corporation — From 2006 to 2011, the government of Albania (GOA) received two Millennium Challenge Corporation (MCC) Threshold Programs totaling $29.6 million. Albania received...

  1. Olfactory threshold in Parkinson's disease.

    Science.gov (United States)

    Quinn, N P; Rossor, M N; Marsden, C D

    1987-01-01

    Olfactory threshold to differing concentrations of amyl acetate was determined in 78 subjects with idiopathic Parkinson's disease and 40 age-matched controls. Impaired olfactory threshold (previously reported by others) was confirmed in Parkinsonian subjects compared with controls. There was no significant correlation between olfactory threshold and age, sex, duration of disease, or current therapy with levodopa or anticholinergic drugs. In a sub-group of 14 levodopa-treated patients with severe "on-off" fluctuations, no change in olfactory threshold between the two states was demonstrable. Olfactory impairment in Parkinson's disease may involve mechanisms that are not influenced by pharmacologic manipulation of dopaminergic or cholinergic status. PMID:3819760

  2. Learning foraging thresholds for lizards

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, L.A. [Univ. of Warwick, Coventry (United Kingdom). Dept. of Computer Science; Hart, W.E. [Sandia National Labs., Albuquerque, NM (United States); Wilson, D.B. [Massachusetts Inst. of Tech., Cambridge, MA (United States)

    1996-01-12

    This work gives a proof of convergence for a randomized learning algorithm that describes how anoles (lizards found in the Carribean) learn a foraging threshold distance. This model assumes that an anole will pursue a prey if and only if it is within this threshold of the anole`s perch. This learning algorithm was proposed by the biologist Roughgarden and his colleagues. They experimentally confirmed that this algorithm quickly converges to the foraging threshold that is predicted by optimal foraging theory our analysis provides an analytic confirmation that the learning algorithm converses to this optimal foraging threshold with high probability.

  3. Cochlear neuropathy and the coding of supra-threshold sound.

    Science.gov (United States)

    Bharadwaj, Hari M; Verhulst, Sarah; Shaheen, Luke; Liberman, M Charles; Shinn-Cunningham, Barbara G

    2014-01-01

    Many listeners with hearing thresholds within the clinically normal range nonetheless complain of difficulty hearing in everyday settings and understanding speech in noise. Converging evidence from human and animal studies points to one potential source of such difficulties: differences in the fidelity with which supra-threshold sound is encoded in the early portions of the auditory pathway. Measures of auditory subcortical steady-state responses (SSSRs) in humans and animals support the idea that the temporal precision of the early auditory representation can be poor even when hearing thresholds are normal. In humans with normal hearing thresholds (NHTs), paradigms that require listeners to make use of the detailed spectro-temporal structure of supra-threshold sound, such as selective attention and discrimination of frequency modulation (FM), reveal individual differences that correlate with subcortical temporal coding precision. Animal studies show that noise exposure and aging can cause a loss of a large percentage of auditory nerve fibers (ANFs) without any significant change in measured audiograms. Here, we argue that cochlear neuropathy may reduce encoding precision of supra-threshold sound, and that this manifests both behaviorally and in SSSRs in humans. Furthermore, recent studies suggest that noise-induced neuropathy may be selective for higher-threshold, lower-spontaneous-rate nerve fibers. Based on our hypothesis, we suggest some approaches that may yield particularly sensitive, objective measures of supra-threshold coding deficits that arise due to neuropathy. Finally, we comment on the potential clinical significance of these ideas and identify areas for future investigation.

  4. Spontaneous compactification to homogeneous spaces

    International Nuclear Information System (INIS)

    Mourao, J.M.

    1988-01-01

    The spontaneous compactification of extra dimensions to compact homogeneous spaces is studied. The methods developed within the framework of coset space dimensional reduction scheme and the most general form of invariant metrics are used to find solutions of spontaneous compactification equations

  5. Screening for spontaneous preterm birth

    NARCIS (Netherlands)

    van Os, M.A.; van Dam, A.J.E.M.

    2015-01-01

    Preterm birth is the most important cause of perinatal morbidity and mortality worldwide. In this thesis studies on spontaneous preterm birth are presented. The main objective was to investigate the predictive capacity of mid-trimester cervical length measurement for spontaneous preterm birth in a

  6. 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.

  7. Between control and hacker activism: the political actions of Anonymous Brasil.

    Science.gov (United States)

    Machado, Murilo Bansi

    2015-12-01

    This paper addresses the political actions of Anonymous, the principal expression of current hacker activism, arguing that hacktivism is a form of political resistance in control societies. To this end, it focuses on studying the Brazilian, hacktivist facet of the collective. In order to stress its political character, it scrutinizes the principal expressions of hacking in the literature. It describes motivations, methods and the ethics of its political actions, based on a comparative analysis of two operations carried out by Brazilian Anonymous adherents in 2012: #OpWeeksPayment and #OpGlobo. And it finishes by identifying four of its main forms of political engagement: promotion of anonymity; "evangelization;" the formation of distributed networks; and the fact that the collective carries out and facilitates several types of political actions.

  8. RSSI-Based User Centric Anonymization for Location Privacy in Vehicular Networks

    Science.gov (United States)

    Wei, Yu-Chih; Chen, Yi-Ming; Shan, Hwai-Ling

    In Vehicular Networks, for enhancing driving safety as well as supporting other applications, vehicles periodically broadcast safety messages with their precise position information to neighbors. However, these broadcast messages make it easy to track specific vehicles and will likely lead to compromise of personal privacy. Unfortunately, current location privacy enhancement methodologies in VANET, including Pseudonymization, K-anonymity, Random silent period, Mix-zones and path confusion, all suffer some shortcomings. In this paper, we propose a RSSI (Received Signal Strength Indicator)-based user centric anonymization model, which can significantly enhance the location privacy and at the same time ensure traffic safety. Simulations are performed to show the advantages of the proposed method. In comparison with traditional random silent period method, our method can increase at least 47% of anonymity in both simple and correlation tracking.

  9. Spontaneous Pneumomediastinum: Hamman Syndrome

    Directory of Open Access Journals (Sweden)

    Tushank Chadha, BS

    2018-04-01

    significant fat stranding. The image also showed an intraluminal stent traversing the gastric antrum and gastric pylorus with no indication of obstruction. Circumferential mural thickening of the gastric antrum and body were consistent with the patient’s history of gastric adenocarcinoma. The shotty perigastric lymph nodes with associated fat stranding, along the greater curvature of the distal gastric body suggested local regional nodal metastases and possible peritoneal carcinomatosis. The thoracic CT scans showed extensive pneumomediastinum that tracked into the soft tissues of the neck, which given the history of vomiting also raised concern for esophageal perforation. There was still no evidence of mediastinal abscess or fat stranding. Additionally, a left subclavian vein port catheter, which terminates with tip at the cavoatrial junction of the superior vena cava can also be seen on the image. Discussion: Spontaneous Pneumomediastinum, also known as Hamman syndrome, is defined by the uncommon incidence of free air in the mediastinum due to the bursting of alveoli, as a result of extended spells of shouting, coughing, or vomiting.1,2 The condition is diagnosed when a clear cause (aerodigestive rupture, barotrauma, infection secondary to gas-forming organisms3 for pneumomediastinum cannot be clearly identified on diagnostic studies. Macklin and Macklin were the first to note the pathogenesis of the syndrome and explained that the common denominator to spontaneous pneumomediastinum was that increased alveolar pressure leads to alveolar rupture.3 Common clinical findings for spontaneous pneumomediastinum include: chest pain, dyspnea, cough, and emesis.4 The condition is not always readily recognized on initial presentation in part for its rare incidence, estimated to be approximately 1 in every 44,500 ED patients3and also because of the non-specific presenting symptoms. For this patient, there was no clear singular cause, and therefore she received care for spontaneous

  10. Recipient screening in IVF: First data from women undergoing anonymous oocyte donation in Dublin

    Directory of Open Access Journals (Sweden)

    Salma Umme

    2011-04-01

    Full Text Available Abstract Background Guidelines for safe gamete donation have emphasised donor screening, although none exist specifically for testing oocyte recipients. Pre-treatment assessment of anonymous donor oocyte IVF treatment in Ireland must comply with the European Union Tissues and Cells Directive (Directive 2004/23/EC. To determine the effectiveness of this Directive when applied to anonymous oocyte recipients in IVF, we reviewed data derived from selected screening tests performed in this clinical setting. Methods Data from tests conducted at baseline for all women enrolling as recipients (n = 225 in the anonymous oocyte donor IVF programme at an urban IVF referral centre during a 24-month period were analysed. Patient age at programme entry and clinical pregnancy rate were also tabulated. All recipients had at least one prior negative test for HIV, Hepatitis B/C, chlamydia, gonorrhoea and syphilis performed by her GP or other primary care provider before reproductive endocrinology consultation. Results Mean (±SD age for donor egg IVF recipients was 40.7 ± 4.2 yrs. No baseline positive chlamydia, gonorrhoea or syphilis screening results were identified among recipients for anonymous oocyte donation IVF during the assessment interval. Mean pregnancy rate (per embryo transfer in this group was 50.5%. Conclusion When tests for HIV, Hepatitis B/C, chlamydia, gonorrhoea and syphilis already have been confirmed to be negative before starting the anonymous donor oocyte IVF sequence, additional (repeat testing on the recipient contributes no new clinical information that would influence treatment in this setting. Patient safety does not appear to be enhanced by application of Directive 2004/23/EC to recipients of anonymous donor oocyte IVF treatment. Given the absence of evidence to quantify risk, this practice is difficult to justify when applied to this low-risk population.

  11. Children from anonymous donors: an inquiry into homosexual and heterosexual parents' attitudes.

    Science.gov (United States)

    Brewaeys, A; Ponjaert-Kristoffersen, I; Van Steirteghem, A C; Devroey, P

    1993-01-01

    This study compared two groups of homosexual and heterosexual parents with respect to their attitudes towards the donor-origin of their children. All couples had applied at the Fertility Clinic for artificial insemination with anonymous donor sperm (AID). Both groups had used anonymous donors in order to conceive. However, the sexual orientation of the parents and the presence or absence of a social father was different in the two groups. By comparing such different families it was hoped to obtain insight into those factors which influence parents' attitudes concerning donor insemination. Twenty-five lesbian and 25 heterosexual parents were interviewed. The open-ended questionnaires solicited information on the following issues: attitudes towards secrecy/disclosure of the use of a donor, views on anonymity/identity registration of the donor, parents' cognitive and emotional representation of the donor. Response rates differed between the groups: all homosexual parents consented to the interview and 44% of the heterosexual parents did so. Parents' attitudes depended on several variables. The different family structures were related to different motivations for AID treatment. For heterosexual couples, the use of a donor offered them the opportunity to become a 'normal family'. For homosexual couples, creating a two-mother family unit meant going one step further in 'being different'. Attitudes towards the use of a donor were consequently different: heterosexual couples chose secrecy and donor anonymity. Homosexual parents intended to inform their children. Of these homosexual parents, 40% would prefer the identity of the donor to be registered. This evolution towards removal of the anonymity seemed to be encouraged by the openness surrounding the use of a donor itself. In both groups it remained difficult to reduce the donor to an anonymous sperm cell, fantasies and questions about the donor continued to exist over the years.

  12. Recipient screening in IVF: First data from women undergoing anonymous oocyte donation in Dublin

    LENUS (Irish Health Repository)

    Walsh, Anthony PH

    2011-04-20

    Abstract Background Guidelines for safe gamete donation have emphasised donor screening, although none exist specifically for testing oocyte recipients. Pre-treatment assessment of anonymous donor oocyte IVF treatment in Ireland must comply with the European Union Tissues and Cells Directive (Directive 2004\\/23\\/EC). To determine the effectiveness of this Directive when applied to anonymous oocyte recipients in IVF, we reviewed data derived from selected screening tests performed in this clinical setting. Methods Data from tests conducted at baseline for all women enrolling as recipients (n = 225) in the anonymous oocyte donor IVF programme at an urban IVF referral centre during a 24-month period were analysed. Patient age at programme entry and clinical pregnancy rate were also tabulated. All recipients had at least one prior negative test for HIV, Hepatitis B\\/C, chlamydia, gonorrhoea and syphilis performed by her GP or other primary care provider before reproductive endocrinology consultation. Results Mean (±SD) age for donor egg IVF recipients was 40.7 ± 4.2 yrs. No baseline positive chlamydia, gonorrhoea or syphilis screening results were identified among recipients for anonymous oocyte donation IVF during the assessment interval. Mean pregnancy rate (per embryo transfer) in this group was 50.5%. Conclusion When tests for HIV, Hepatitis B\\/C, chlamydia, gonorrhoea and syphilis already have been confirmed to be negative before starting the anonymous donor oocyte IVF sequence, additional (repeat) testing on the recipient contributes no new clinical information that would influence treatment in this setting. Patient safety does not appear to be enhanced by application of Directive 2004\\/23\\/EC to recipients of anonymous donor oocyte IVF treatment. Given the absence of evidence to quantify risk, this practice is difficult to justify when applied to this low-risk population.

  13. Threshold Concepts and Information Literacy

    Science.gov (United States)

    Townsend, Lori; Brunetti, Korey; Hofer, Amy R.

    2011-01-01

    What do we teach when we teach information literacy in higher education? This paper describes a pedagogical approach to information literacy that helps instructors focus content around transformative learning thresholds. The threshold concept framework holds promise for librarians because it grounds the instructor in the big ideas and underlying…

  14. Second threshold in weak interactions

    NARCIS (Netherlands)

    Veltman, M.J.G.

    1977-01-01

    The point of view that weak interactions must have a second threshold below 300 – 600 GeV is developed. Above this threshold new physics must come in. This new physics may be the Higgs system, or some other nonperturbative system possibly having some similarities to the Higgs system. The limit of

  15. The Nature of Psychological Thresholds

    Science.gov (United States)

    Rouder, Jeffrey N.; Morey, Richard D.

    2009-01-01

    Following G. T. Fechner (1966), thresholds have been conceptualized as the amount of intensity needed to transition between mental states, such as between a states of unconsciousness and consciousness. With the advent of the theory of signal detection, however, discrete-state theory and the corresponding notion of threshold have been discounted.…

  16. Darknet and bitcoin, the obscure and anonymous side of the internet in healthcare.

    Science.gov (United States)

    Masoni, Marco; Guelfi, Maria Renza; Gensini, Gian Franco

    2016-11-14

    Illegal activities prosecutable by law in the real life can be committed on the internet alike. In the healthcare domain, we refer mainly to selling of illegal and counterfeit drugs, exchange of pedo-pornographic material and marketing of stolen medical records. These illegal activities are made easier by recent developments of the Internet that medical community must be aware of: darknet and bitcoin. The first allows anonymous surfing and the last anonymous financial transactions. After discussing which healthcare areas are affected by these technological developments of the Internet and the deriving consequences, then the Authors express their opinion on what actions can be taken to protect internet community.

  17. An Enhancing Security Research of Tor Anonymous Communication to Against DDos Attacks

    Directory of Open Access Journals (Sweden)

    Feng Tao

    2017-01-01

    Full Text Available Tor (The Second Onion Router is modified by the first generation onion router and known as the most prevalent anonymous communication system. According to the advantage of low latency, high confidentiality of transmission content, high security of communication channels and et al., Tor is widely used in anonymous Web browsing, instant message and so on. However, the vulnerability and blemish of Tor affect system security. An identity and Signcryption-based concurrent signature scheme was used to prevent the behaviors of attackers from inserting controlled nodes and conspiring to make DDos attacks. The integrated security of Tor system was enhanced in our scheme. In addition we have proved the scheme.

  18. Spontaneous breaking of supersymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Zumino, B.

    1981-12-01

    There has been recently a revival of interest in supersymmetric gauge theories, stimulated by the hope that supersymmetry might help in clarifying some of the questions which remain unanswered in the so called Grand Unified Theories and in particular the gauge hierarchy problem. In a Grand Unified Theory one has two widely different mass scales: the unification mass M approx. = 10/sup 15/GeV at which the unification group (e.g. SU(5)) breaks down to SU(3) x SU(2) x U(1) and the mass ..mu.. approx. = 100 GeV at which SU(2) x U(1) is broken down to the U(1) of electromagnetism. There is at present no theoretical understanding of the extreme smallness of the ratio ..mu../M of these two numbers. This is the gauge hierarchy problem. This lecture attempts to review the various mechanisms for spontaneous supersymmetry breaking in gauge theories. Most of the discussions are concerned with the tree approximation, but what is presently known about radiative correction is also reviewed.

  19. Spontaneous intracranial hypotension

    International Nuclear Information System (INIS)

    Haritanti, A.; Karacostas, D.; Drevelengas, A.; Kanellopoulos, V.; Paraskevopoulou, E.; Lefkopoulos, A.; Economou, I.; Dimitriadis, A.S.

    2009-01-01

    Spontaneous intracranial hypotension (SIH) is an uncommon but increasingly recognized syndrome. Orthostatic headache with typical findings on magnetic resonance imaging (MRI) are the key to diagnosis. Delayed diagnosis of this condition may subject patients to unnecessary procedures and prolong morbidity. We describe six patients with SIH and outline the important clinical and neuroimaging findings. They were all relatively young, 20-54 years old, with clearly orthostatic headache, minimal neurological signs (only abducent nerve paresis in two) and diffuse pachymeningeal gadolinium enhancement on brain MRI, while two of them presented subdural hygromas. Spinal MRI was helpful in detecting a cervical cerebrospinal fluid leak in three patients and dilatation of the vertebral venous plexus with extradural fluid collection in another. Conservative management resulted in rapid resolution of symptoms in five patients (10 days-3 weeks) and in one who developed cerebral venous sinus thrombosis, the condition resolved in 2 months. However, this rapid clinical improvement was not accompanied by an analogous regression of the brain MR findings that persisted on a longer follow-up. Along with recent literature data, our patients further point out that SIH, to be correctly diagnosed, necessitates increased alertness by the attending physician, in the evaluation of headaches

  20. Spontaneous lateral temporal encephalocele.

    Science.gov (United States)

    Tuncbilek, Gokhan; Calis, Mert; Akalan, Nejat

    2013-01-01

    A spontaneous encephalocele is one that develops either because of embryological maldevelopment or from a poorly understood postnatal process that permits brain herniation to occur. We here report a rare case of lateral temporal encephalocele extending to the infratemporal fossa under the zygomatic arch. At birth, the infant was noted to have a large cystic mass in the right side of the face. After being operated on initially in another center in the newborn period, the patient was referred to our clinic with a diagnosis of temporal encephalocele. He was 6 months old at the time of admission. Computerized tomography scan and magnetic resonance imaging studies revealed a 8 × 9 cm fluid-filled, multiloculated cystic mass at the right infratemporal fossa. No intracranial pathology or connection is seen. The patient was operated on to reduce the distortion effect of the growing mass. The histopathological examination of the sac revealed well-differentiated mature glial tissue stained with glial fibrillary acid protein. This rare clinical presentation of encephaloceles should be taken into consideration during the evaluation of the lateral facial masses in the infancy period, and possible intracranial connection should be ruled out before surgery to avoid complications.

  1. Bilateral spontaneous carotid artery dissection.

    Science.gov (United States)

    Townend, Bradley Scott; Traves, Laura; Crimmins, Denis

    2005-06-01

    Bilateral internal carotid artery dissections have been reported, but spontaneous bilateral dissections are rare. Internal carotid artery dissection can present with a spectrum of symptoms ranging from headache to completed stroke. Two cases of spontaneous bilateral carotid artery dissection are presented, one with headache and minimal symptoms and the other with a stroke syndrome. No cause could be found in either case, making the dissections completely spontaneous. Bilateral internal carotid artery dissection (ICAD) should be considered in young patients with unexplained head and neck pain with or without focal neurological symptoms and signs. The increasing availability of imaging would sustain the higher index of suspicion.

  2. Compatibility of Adlerian Theory and Practice with the Philosophy and Practices of Alcoholics Anonymous.

    Science.gov (United States)

    Carroll, Jane J.

    1999-01-01

    Tenets of Adlerian theory and practice are compatible with the philosophy and practices of Alcoholics Anonymous. Counselors can expect treatment approaches based on Adlerian counseling theory to be congruent with 12-step practices of individuals who are in recovery from alcohol dependence. (Author)

  3. Bayesian modeling of consumer behavior in the presence of anonymous visits

    Science.gov (United States)

    Novak, Julie Esther

    Tailoring content to consumers has become a hallmark of marketing and digital media, particularly as it has become easier to identify customers across usage or purchase occasions. However, across a wide variety of contexts, companies find that customers do not consistently identify themselves, leaving a substantial fraction of anonymous visits. We develop a Bayesian hierarchical model that allows us to probabilistically assign anonymous sessions to users. These probabilistic assignments take into account a customer's demographic information, frequency of visitation, activities taken when visiting, and times of arrival. We present two studies, one with synthetic and one with real data, where we demonstrate improved performance over two popular practices (nearest-neighbor matching and deleting the anonymous visits) due to increased efficiency and reduced bias driven by the non-ignorability of which types of events are more likely to be anonymous. Using our proposed model, we avoid potential bias in understanding the effect of a firm's marketing on its customers, improve inference about the total number of customers in the dataset, and provide more precise targeted marketing to both previously observed and unobserved customers.

  4. Sexuality Information Needs of Latino and African American Ninth Graders: A Content Analysis of Anonymous Questions

    Science.gov (United States)

    Angulo-Olaiz, Francisca; Goldfarb, Eva S.; Constantine, Norman A.

    2014-01-01

    This study used qualitative content analysis to examine anonymous questions about sex and sexuality submitted by Latino and African American adolescents in Los Angeles, California, classrooms. The majority of questions asked about sexuality and sexual behavior, or anatomy and physiology, with fewer questions about pregnancy and pregnancy…

  5. Anonymous Multi-Receiver Identity-Based Authenticated Encryption with CCA Security

    Directory of Open Access Journals (Sweden)

    Chun-I Fan

    2015-10-01

    Full Text Available In a multi-receiver encryption system, a sender chooses a set of authorized receivers and sends them a message securely and efficiently, as the message is well encrypted and only one ciphertext corresponding to the message is generated no matter how many receivers the sender has chosen. It can be applied to video conferencing systems, pay-per-view channels, remote education, and so forth. Due to privacy considerations, an authorized receiver may not expect that his identity is revealed. In 2010, anonymous multi-receiver identity-based (ID-based encryption was first discussed, and furthermore, many works on the topic have been presented so far. Unfortunately, we find that all of those schemes fail to prove the chosen ciphertext attacks (CCA security in either confidentiality or anonymity. In this manuscript, we propose the first anonymous multi-receiver ID-based authenticated encryption scheme with CCA security in both confidentiality and anonymity. In the proposed scheme, the identity of the sender of a ciphertext can be authenticated by the receivers after a successful decryption. In addition, the proposed scheme also is the first CCA-secure one against insider attacks. Moreover, only one pairing computation is required in decryption.

  6. Security Enhanced Anonymous Multiserver Authenticated Key Agreement Scheme Using Smart Cards and Biometrics

    Science.gov (United States)

    Choi, Younsung; Nam, Junghyun; Lee, Donghoon; Kim, Jiye; Jung, Jaewook; Won, Dongho

    2014-01-01

    An anonymous user authentication scheme allows a user, who wants to access a remote application server, to achieve mutual authentication and session key establishment with the server in an anonymous manner. To enhance the security of such authentication schemes, recent researches combined user's biometrics with a password. However, these authentication schemes are designed for single server environment. So when a user wants to access different application servers, the user has to register many times. To solve this problem, Chuang and Chen proposed an anonymous multiserver authenticated key agreement scheme using smart cards together with passwords and biometrics. Chuang and Chen claimed that their scheme not only supports multiple servers but also achieves various security requirements. However, we show that this scheme is vulnerable to a masquerade attack, a smart card attack, a user impersonation attack, and a DoS attack and does not achieve perfect forward secrecy. We also propose a security enhanced anonymous multiserver authenticated key agreement scheme which addresses all the weaknesses identified in Chuang and Chen's scheme. PMID:25276847

  7. Towards an anonymous access control and accountability scheme for cloud computing

    DEFF Research Database (Denmark)

    Jensen, Meiko; Schäge, Sven; Schwenk, Jörg

    2010-01-01

    An important aspect of trust in cloud computing consists in preventing the cloud provider from misusing the user's data. In this work-in-progress paper, we propose the approach of data anonymization to solve this problem. As this directly leads to problems of cloud usage accounting, we also propose...

  8. Alcoholics anonymous, other 12-step movements and psychotherapy in the US population, 1990.

    Science.gov (United States)

    Room, R; Greenfield, T

    1993-04-01

    Based on the 1990 US National Alcohol Survey, this note provides the first available comprehensive findings on self-reported utilization of a variety of sources of personal support and counselling for alcohol and other problems. Respondents were queried about lifetime attendance and number of times they went to identified sources of help in the prior year. Twelve-step groups included Alcoholics Anonymous, Al-Anon, Adult Children of Alcoholics, and other non-alcohol-oriented groups like Gamblers Anonymous, Narcotics Anonymous, and Overeaters Anonymous; additional questions inquired about support or therapy groups and individual counselling for non-alcohol problems. Of the US adult population, 9% have been to an AA meeting at some time, 3.6% in the prior year, only about one-third of these for problems of their own. About half these percentages, mostly women, have attended Al-Anon. Of the same population, 13.3% indicate ever attending a 12-step meeting (including non-alcohol-oriented groups), 5.3% in the last year. During the prior year a further 2.1% used other support/therapy groups and 5.5% sought individual counselling/therapy for personal problems other than alcohol. In contrast to this high reported utilization, only 4.9% (ever) and 2.3% (12-months) reported going to anyone including AA for a problem (of their own) related to drinking.

  9. Medical Relabeling in Gamblers Anonymous: The Construction of an Ideal Member.

    Science.gov (United States)

    Turner, David N.; Saunders, Danny

    1990-01-01

    Observed 2 Gamblers Anonymous (GA) groups in South Wales over a 12-month period. Determined 2 broad consequences arose from encountering fellow sufferers: acceptance of diagnosis and commitment to recovery and to will of GA, or rejection of the diagnosis with the knowledge that they are returning to the outside world with a reconstituted…

  10. A globally optimal k-anonymity method for the de-identification of health data.

    Science.gov (United States)

    El Emam, Khaled; Dankar, Fida Kamal; Issa, Romeo; Jonker, Elizabeth; Amyot, Daniel; Cogo, Elise; Corriveau, Jean-Pierre; Walker, Mark; Chowdhury, Sadrul; Vaillancourt, Regis; Roffey, Tyson; Bottomley, Jim

    2009-01-01

    Explicit patient consent requirements in privacy laws can have a negative impact on health research, leading to selection bias and reduced recruitment. Often legislative requirements to obtain consent are waived if the information collected or disclosed is de-identified. The authors developed and empirically evaluated a new globally optimal de-identification algorithm that satisfies the k-anonymity criterion and that is suitable for health datasets. Authors compared OLA (Optimal Lattice Anonymization) empirically to three existing k-anonymity algorithms, Datafly, Samarati, and Incognito, on six public, hospital, and registry datasets for different values of k and suppression limits. Measurement Three information loss metrics were used for the comparison: precision, discernability metric, and non-uniform entropy. Each algorithm's performance speed was also evaluated. The Datafly and Samarati algorithms had higher information loss than OLA and Incognito; OLA was consistently faster than Incognito in finding the globally optimal de-identification solution. For the de-identification of health datasets, OLA is an improvement on existing k-anonymity algorithms in terms of information loss and performance.

  11. A context-sensitive approach to anonymizing spatial surveillance data: impact on outbreak detection.

    Science.gov (United States)

    Cassa, Christopher A; Grannis, Shaun J; Overhage, J Marc; Mandl, Kenneth D

    2006-01-01

    The use of spatially based methods and algorithms in epidemiology and surveillance presents privacy challenges for researchers and public health agencies. We describe a novel method for anonymizing individuals in public health data sets by transposing their spatial locations through a process informed by the underlying population density. Further, we measure the impact of the skew on detection of spatial clustering as measured by a spatial scanning statistic. Cases were emergency department (ED) visits for respiratory illness. Baseline ED visit data were injected with artificially created clusters ranging in magnitude, shape, and location. The geocoded locations were then transformed using a de-identification algorithm that accounts for the local underlying population density. A total of 12,600 separate weeks of case data with artificially created clusters were combined with control data and the impact on detection of spatial clustering identified by a spatial scan statistic was measured. The anonymization algorithm produced an expected skew of cases that resulted in high values of data set k-anonymity. De-identification that moves points an average distance of 0.25 km lowers the spatial cluster detection sensitivity by less than 4% and lowers the detection specificity less than 1%. A population-density-based Gaussian spatial blurring markedly decreases the ability to identify individuals in a data set while only slightly decreasing the performance of a standardly used outbreak detection tool. These findings suggest new approaches to anonymizing data for spatial epidemiology and surveillance.

  12. HOP: Achieving Efficient Anonymity in MANETs by Combining HIP, OLSR, and Pseudonyms

    Directory of Open Access Journals (Sweden)

    Campos Javier

    2011-01-01

    Full Text Available Offering secure and anonymous communications in mobile ad hoc networking environments is essential to achieve confidence and privacy, thus promoting widespread adoption of this kind of networks. In addition, some minimum performance levels must be achieved for any solution to be practical and become widely adopted. In this paper, we propose and implement HOP, a novel solution based on cryptographic Host Identity Protocol (HIP that offers security and user-level anonymity in MANET environments while maintaining good performance levels. In particular, we introduce enhancements to the authentication process to achieve Host Identity Tag (HIT relationship anonymity, along with source/destination HIT anonymity when combined with multihoming. Afterward we detail how we integrate our improved version of HIP with the OLSR routing protocol to achieve efficient support for pseudonyms. We implemented our proposal in an experimental testbed, and the results obtained show that performance levels achieved are quite good, and that the integration with OLSR is achieved with a low overhead.

  13. Security Enhanced Anonymous Multiserver Authenticated Key Agreement Scheme Using Smart Cards and Biometrics

    Directory of Open Access Journals (Sweden)

    Younsung Choi

    2014-01-01

    Full Text Available An anonymous user authentication scheme allows a user, who wants to access a remote application server, to achieve mutual authentication and session key establishment with the server in an anonymous manner. To enhance the security of such authentication schemes, recent researches combined user’s biometrics with a password. However, these authentication schemes are designed for single server environment. So when a user wants to access different application servers, the user has to register many times. To solve this problem, Chuang and Chen proposed an anonymous multiserver authenticated key agreement scheme using smart cards together with passwords and biometrics. Chuang and Chen claimed that their scheme not only supports multiple servers but also achieves various security requirements. However, we show that this scheme is vulnerable to a masquerade attack, a smart card attack, a user impersonation attack, and a DoS attack and does not achieve perfect forward secrecy. We also propose a security enhanced anonymous multiserver authenticated key agreement scheme which addresses all the weaknesses identified in Chuang and Chen’s scheme.

  14. Security enhanced anonymous multiserver authenticated key agreement scheme using smart cards and biometrics.

    Science.gov (United States)

    Choi, Younsung; Nam, Junghyun; Lee, Donghoon; Kim, Jiye; Jung, Jaewook; Won, Dongho

    2014-01-01

    An anonymous user authentication scheme allows a user, who wants to access a remote application server, to achieve mutual authentication and session key establishment with the server in an anonymous manner. To enhance the security of such authentication schemes, recent researches combined user's biometrics with a password. However, these authentication schemes are designed for single server environment. So when a user wants to access different application servers, the user has to register many times. To solve this problem, Chuang and Chen proposed an anonymous multiserver authenticated key agreement scheme using smart cards together with passwords and biometrics. Chuang and Chen claimed that their scheme not only supports multiple servers but also achieves various security requirements. However, we show that this scheme is vulnerable to a masquerade attack, a smart card attack, a user impersonation attack, and a DoS attack and does not achieve perfect forward secrecy. We also propose a security enhanced anonymous multiserver authenticated key agreement scheme which addresses all the weaknesses identified in Chuang and Chen's scheme.

  15. A Quantitative Study on Anonymity and Professionalism within an Online Free Open Access Medical Education Community.

    Science.gov (United States)

    Dimitri, Daneilla; Gubert, Andrea; Miller, Amanda B; Thoma, Brent; Chan, Teresa

    2016-09-18

    The increasing use of social media to share knowledge in medical education has led to concerns about the professionalism of online medical learners and physicians. However, there is a lack of research on the behavior of professionals within open online discussions. In 2013, the Academic Life in Emergency Medicine website (ALiEM.com) launched a series of moderated online case discussions that provided an opportunity to explore the relationship between anonymity and professionalism. Comments from 12 case discussions conducted over a one-year period were analyzed using modified scales of anonymity and professionalism derived by Kilner and Hoadley. Descriptive statistics and Spearman calculations were conducted for the professionalism score, anonymity score, and level of participation. No correlation was found between professionalism and anonymity scores (rho = -0.004, p = 0.97). However, the number of comments (rho = 0.35, p professional environment through the use of a website with a positive reputation, the modelling of respectful behaviour by the moderators, the norms of the broader online community, and the pre-specified objectives for each discussion.

  16. Open and Anonymous Peer Review in a Digital Online Environment Compared in Academic Writing Context

    Science.gov (United States)

    Razi, Salim

    2016-01-01

    This study compares the impact of "open" and "anonymous" peer feedback as an adjunct to teacher-mediated feedback in a digital online environment utilising data gathered on an academic writing course at a Turkish university. Students were divided into two groups with similar writing proficiencies. Students peer reviewed papers…

  17. Brother-Sister Incest: Data from Anonymous Computer-Assisted Self Interviews

    Science.gov (United States)

    Stroebel, Sandra S.; O'Keefe, Stephen L.; Beard, Keith W.; Kuo, Shih-Ya; Swindell, Samuel; Stroupe, Walter

    2013-01-01

    Retrospective data were entered anonymously by 1,521 adult women using computer-assisted self interview. Forty were classified as victims of brother-sister incest, 19 were classified as victims of father-daughter incest, and 232 were classified as victims of sexual abuse by an adult other than their father before reaching 18 years of age. The…

  18. Peer Feedback in Anonymous Peer Review in an EFL Writing Class in Spain

    Science.gov (United States)

    Coté, Robert A.

    2014-01-01

    The present study reports the results of a process of peer feedback through anonymous peer review in an EFL writing class. Numerous studies have reported on the benefits of peer review (PR) in the ESL/EFL writing classroom. However, the literature also identifies social issues that can negatively affect the outcome of face-to-face PR. In this…

  19. Romantic Relationship Advice from Anonymous Online Helpers: The Peer Support Adolescents Exchange

    Science.gov (United States)

    Kim, Jung-Eun; Weinstein, Emily C.; Selman, Robert L.

    2017-01-01

    This empirical study investigates adolescents' responses to peers' personal accounts of romantic relationship difficulties posted to an online forum. We analyze 440 anonymous responses to personal accounts of four romantic relationship issues: controlling partners, break-ups, trust issues, and partner cruelty. Responses were categorized, in order…

  20. Photoproduction of Charm Near Threshold

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.

    2000-10-31

    Charm and bottom production near threshold is sensitive to the multi-quark, gluonic, and hidden-color correlations of hadronic and nuclear wavefunctions in QCD since all of the target's constituents must act coherently within the small interaction volume of the heavy quark production subprocess. Although such multi-parton subprocess cross sections are suppressed by powers of 1=m{sub Q}{sup 2}, they have less phase-space suppression and can dominate the contributions of the leading-twist single-gluon subprocesses in the threshold regime. The small rates for open and hidden charm photoproduction at threshold call for a dedicated facility.

  1. Spontaneous intraorbital hematoma: case report

    Directory of Open Access Journals (Sweden)

    Vinodan Paramanathan

    2010-12-01

    Full Text Available Vinodan Paramanathan, Ardalan ZolnourianQueen's Hospital NHS Foundation Trust, Burton on Trent, Staffordshire DE13 0RB, UKAbstract: Spontaneous intraorbital hematoma is an uncommon clinical entity seen in ophthalmology practice. It is poorly represented in the literature. Current evidence attributes it to orbital trauma, neoplasm, vascular malformations, acute sinusitis, and systemic abnormalities. A 65-year-old female presented with spontaneous intraorbital hematoma manifesting as severe ocular pains, eyelid edema, proptosis, and diplopia, without a history of trauma. Computer tomography demonstrated a fairly well defined extraconal lesion with opacification of the paranasal sinuses. The principal differential based on all findings was that of a spreading sinus infection and an extraconal tumor. An unprecedented finding of a spontaneous orbital hematoma was discovered when the patient was taken to theater. We discuss the rarity of this condition and its management.Keywords: hemorrhage, ophthalmology, spontaneous, intra-orbital, hematoma

  2. Spontaneous ischaemic stroke in dogs

    DEFF Research Database (Denmark)

    Gredal, Hanne Birgit; Skerritt, G. C.; Gideon, P.

    2013-01-01

    Translation of experimental stroke research into the clinical setting is often unsuccessful. Novel approaches are therefore desirable. As humans, pet dogs suffer from spontaneous ischaemic stroke and may hence offer new ways of studying genuine stroke injury mechanisms.......Translation of experimental stroke research into the clinical setting is often unsuccessful. Novel approaches are therefore desirable. As humans, pet dogs suffer from spontaneous ischaemic stroke and may hence offer new ways of studying genuine stroke injury mechanisms....

  3. Spontaneity and international marketing performance

    OpenAIRE

    Souchon, Anne L.; Hughes, Paul; Farrell, Andrew M.; Nemkova, Ekaterina; Oliveira, Joao S.

    2016-01-01

    The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. Purpose – The purpose of this paper is to ascertain how today’s international marketers can perform better on the global scene by harnessing spontaneity. Design/methodology/approach – The authors draw on contingency theory to develop a model of the spontaneity – international marketing performance relationship, and identify three potential m...

  4. Parton distributions with threshold resummation

    CERN Document Server

    Bonvini, Marco; Rojo, Juan; Rottoli, Luca; Ubiali, Maria; Ball, Richard D.; Bertone, Valerio; Carrazza, Stefano; Hartland, Nathan P.

    2015-01-01

    We construct a set of parton distribution functions (PDFs) in which fixed-order NLO and NNLO calculations are supplemented with soft-gluon (threshold) resummation up to NLL and NNLL accuracy respectively, suitable for use in conjunction with any QCD calculation in which threshold resummation is included at the level of partonic cross sections. These resummed PDF sets, based on the NNPDF3.0 analysis, are extracted from deep-inelastic scattering, Drell-Yan, and top quark pair production data, for which resummed calculations can be consistently used. We find that, close to threshold, the inclusion of resummed PDFs can partially compensate the enhancement in resummed matrix elements, leading to resummed hadronic cross-sections closer to the fixed-order calculation. On the other hand, far from threshold, resummed PDFs reduce to their fixed-order counterparts. Our results demonstrate the need for a consistent use of resummed PDFs in resummed calculations.

  5. Conceptions of nuclear threshold status

    International Nuclear Information System (INIS)

    Quester, G.H.

    1991-01-01

    This paper reviews some alternative definitions of nuclear threshold status. Each of them is important, and major analytical confusions would result if one sense of the term is mistaken for another. The motives for nations entering into such threshold status are a blend of civilian and military gains, and of national interests versus parochial or bureaucratic interests. A portion of the rationale for threshold status emerges inevitably from the pursuit of economic goals, and another portion is made more attraction by the derives of the domestic political process. Yet the impact on international security cannot be dismissed, especially where conflicts among the states remain real. Among the military or national security motives are basic deterrence, psychological warfare, war-fighting and, more generally, national prestige. In the end, as the threshold phenomenon is assayed for lessons concerning the role of nuclear weapons more generally in international relations and security, one might conclude that threshold status and outright proliferation coverage to a degree in the motives for all of the states involved and in the advantages attained. As this paper has illustrated, nuclear threshold status is more subtle and more ambiguous than outright proliferation, and it takes considerable time to sort out the complexities. Yet the world has now had a substantial amount of time to deal with this ambiguous status, and this may tempt more states to exploit it

  6. Threshold models in radiation carcinogenesis

    International Nuclear Information System (INIS)

    Hoel, D.G.; Li, P.

    1998-01-01

    Cancer incidence and mortality data from the atomic bomb survivors cohort has been analyzed to allow for the possibility of a threshold dose response. The same dose-response models as used in the original papers were fit to the data. The estimated cancer incidence from the fitted models over-predicted the observed cancer incidence in the lowest exposure group. This is consistent with a threshold or nonlinear dose-response at low-doses. Thresholds were added to the dose-response models and the range of possible thresholds is shown for both solid tumor cancers as well as the different leukemia types. This analysis suggests that the A-bomb cancer incidence data agree more with a threshold or nonlinear dose-response model than a purely linear model although the linear model is statistically equivalent. This observation is not found with the mortality data. For both the incidence data and the mortality data the addition of a threshold term significantly improves the fit to the linear or linear-quadratic dose response for both total leukemias and also for the leukemia subtypes of ALL, AML, and CML

  7. Tactile thresholds in healthy subjects

    Directory of Open Access Journals (Sweden)

    Metka Moharić

    2014-10-01

    Full Text Available Background: The assessment of sensory thresholds provides a method of examining the function of peripheral nerve fibers and their central connections. Quantitative sensory testing is a variant of conventional sensory testing wherein the goal is the quantification of the level of stimulation needed to produce a particular sensation. While thermal and vibratory testing are established methods in assessment of sensory thresholds, assessment of tactile thresholds with monofilaments is not used routinely. The purpose of this study was to assess the tactile thresholds in normal healthy population.Methods: In 39 healthy volunteers (19 men aged 21 to 71 years, tactile thresholds were assessed with von Frey’s hair in 7 parts of the body bilaterally.Results: We found touch sensitivity not to be dependent on age or gender. The right side was significantly more sensitive in the lateral part of the leg (p=0.011 and the left side in the medial part of the arm (p=0.022. There were also significant differences between sites (p<0.001, whereby distal parts of the body were more sensitive.Conclusions: Von Frey filaments allow the estimation of tactile thresholds without the need for complicated instrumentation.

  8. Alcoholics Anonymous

    Science.gov (United States)

    ... China Colombia Costa Rica Cuba Cyprus Czech Republic Denmark Dominican Republic Ecuador Egypt El Salvador Estonia Faroe ... Make a contribution | Self-Support Press/Media | Archives & History | A.A. General Service Board Calendar | G.S.O. ...

  9. Adolescent Substance Abuse in Mexico, Puerto Rico and The United States: Effect of Anonymous versus Confidential Survey Formats

    Science.gov (United States)

    Latimer, William W.; O'Brien, Megan S.; Vasquez, Marco A.; Medina-Mora, Maria Elena; Rios-Bedoya, Carlos F.; Floyd, Leah J.

    2006-01-01

    Anonymous surveys have been widely used worldwide to describe adolescent substance use yet cannot elucidate causal drug abuse predictors. Studies in the U.S. have generally found that anonymous and confidential surveys yield comparable levels of self-reported substance use, yet the effect of survey format on youth self-report has not been…

  10. Emergence of Informal Educative Space out of an Anonymous Online Bulletin Board in Korea during the Global Economic Crisis

    Science.gov (United States)

    Kang, Dae Joong; Choi, Seon Joo; Lee, SeungHyeop

    2013-01-01

    This study aimed to understand how people learn and teach informally in an anonymous online bulletin board, the primary purpose of which is not learning and teaching. We conducted a qualitative analysis of comments and replies tagged to the most popular postings of an anonymous online bulletin board, during the global economic crisis in 2008-2009.…

  11. Comparison of the prognosis of spontaneous and percutaneous coronary intervention-related myocardial infarction.

    Science.gov (United States)

    Leonardi, Sergio; Thomas, Laine; Neely, Megan L; Tricoci, Pierluigi; Lopes, Renato D; White, Harvey D; Armstrong, Paul W; Giugliano, Robert P; Antman, Elliott M; Califf, Robert M; Newby, L Kristin; Mahaffey, Kenneth W

    2012-12-04

    This study compared prognoses of myocardial infarction related to percutaneous coronary intervention (PCI, procedural MI) using increasing creatine kinase-myocardial band (CK-MB) thresholds with spontaneous MI. Procedural MI usually is defined by a CK-MB elevation of more than 3 times the upper limit of normal (ULN), but higher thresholds have been proposed. Patients from the EARLY-ACS (Early Glycoprotein IIb/IIIa Inhibition in Non-ST-Segment Elevation Acute Coronary Syndrome) study and the SYNERGY (Superior Yield of the New strategy of Enoxaparin, Revascularization and GlYcoprotein IIb/IIIa inhibitors) study treated with PCI were included. The primary end point was 1-year all-cause mortality from 24 h after PCI. To determine an enzymatic threshold for procedural MI with a prognosis similar to that of spontaneous MI, we redefined procedural MI using increasing CK-MB thresholds and compared corresponding hazard ratios with those of spontaneous MI (CK-MB more than twice the ULN). Hazard ratios for mortality for procedural and spontaneous MI were calculated using Cox proportional hazards regression and Global Registry of Acute Cardiac Events covariates for risk adjustment. Nine thousand eighty-seven patients who underwent PCI (46.8%) were included; 773 procedural MI and 239 spontaneous MI occurred within 30 days. Adjusted hazard ratios for 1-year death were 1.39 (95% confidence interval [CI]: 1.01 to 1.89) for procedural MI and 5.37 (95% CI: 3.90 to 7.38) for spontaneous MI. The CK-MB threshold for procedural MI that achieved the same prognosis as spontaneous MI was 27.7 times the ULN (95% CI: 13.9 to 58.4), but this differed between the SYNERGY study (57.9 times the ULN, 95% CI: 17.9 to 63.6) and the EARLY-ACS study (20.4 times the ULN, 95% CI: 5.16 to 24.2). Of all procedural MI, 49 (6%) had CK-MB elevations of 27.7 or more times the ULN. The current enzymatic definition of procedural MI (CK-MB more than 3 times the ULN) used in clinical trials is less strongly

  12. Pauses in spontaneous written communication: a keystroke logging study

    Directory of Open Access Journals (Sweden)

    Evgeny Chukharev-Hudilainen

    2014-06-01

    Full Text Available Spontaneous writing observed in chats, instant messengers, and social media has become established as productive modes of communication and discourse genres. However, they remain understudied from the perspective of writing process research. In this paper, we present an empirical study wherein keystrokes made by chat users in a game were recorded. The distributions of the inter-key intervals were analyzed and fitted with ex-Gaussian distribution equation, and an argument for psycholinguistic interpretation of the distribution parameters is presented. This analysis leads to establishing a threshold of 500 ms for the identification of pauses in spontaneous writing. Furthermore, we demonstrate that pauses longer than 1.2 s may correspond to higher-level linguistic processing beyond a single propositional expression (functional element of the discourse.

  13. A case of spontaneous ventriculocisternostomy

    International Nuclear Information System (INIS)

    Yamane, Kanji; Yoshimoto, Hisanori; Harada, Kiyoshi; Uozumi, Tohru; Kuwabara, Satoshi.

    1983-01-01

    The authors experienced a case of spontaneous ventriculocisternostomy diagnosed by CT scan with metrizamide and Conray. Patient was 23-year-old male who had been in good health until one month before admission, when he began to have headache and tinnitus. He noticed bilateral visual acuity was decreased about one week before admission and vomiting appeared two days before admission. He was admitted to our hospital because of bilateral papilledema and remarkable hydrocephalus diagnosed by CT scan. On admission, no abnormal neurological signs except for bilateral papilledema were noted. Immediately, right ventricular drainage was performed. Pressure of the ventricle was over 300mmH 2 O and CSF was clear. PVG and PEG disclosed an another cavity behind the third ventricle, which was communicated with the third ventricle, and occlusion of aqueduct of Sylvius. Metrizamide CT scan and Conray CT scan showed a communication between this cavity and quadrigeminal and supracerebellar cisterns. On these neuroradiological findings, the diagnosis of obstructive hydrocephalus due to benign aqueduct stenosis accompanied with spontaneous ventriculocisternostomy was obtained. Spontaneous ventriculocisternostomy was noticed to produce arrest of hydrocephalus, but with our case, spontaneous regression of such symptoms did not appeared. By surgical ventriculocisternostomy (method by Torkildsen, Dandy, or Scarff), arrest of hydrocephalus was seen in about 50 to 70 per cent, which was the same results as those of spontaneous ventriculocisternostomy. It is concluded that VP shunt or VA shunt is thought to be better treatment of obstructive hydrocephalus than the various kinds of surgical ventriculocisternostomy. (J.P.N.)

  14. Optical antenna enhanced spontaneous emission.

    Science.gov (United States)

    Eggleston, Michael S; Messer, Kevin; Zhang, Liming; Yablonovitch, Eli; Wu, Ming C

    2015-02-10

    Atoms and molecules are too small to act as efficient antennas for their own emission wavelengths. By providing an external optical antenna, the balance can be shifted; spontaneous emission could become faster than stimulated emission, which is handicapped by practically achievable pump intensities. In our experiments, InGaAsP nanorods emitting at ∼ 200 THz optical frequency show a spontaneous emission intensity enhancement of 35 × corresponding to a spontaneous emission rate speedup ∼ 115 ×, for antenna gap spacing, d = 40 nm. Classical antenna theory predicts ∼ 2,500 × spontaneous emission speedup at d ∼ 10 nm, proportional to 1/d(2). Unfortunately, at d antenna efficiency drops below 50%, owing to optical spreading resistance, exacerbated by the anomalous skin effect (electron surface collisions). Quantum dipole oscillations in the emitter excited state produce an optical ac equivalent circuit current, I(o) = qω|x(o)|/d, feeding the antenna-enhanced spontaneous emission, where q|x(o)| is the dipole matrix element. Despite the quantum-mechanical origin of the drive current, antenna theory makes no reference to the Purcell effect nor to local density of states models. Moreover, plasmonic effects are minor at 200 THz, producing only a small shift of antenna resonance frequency.

  15. Three-factor anonymous authentication and key agreement scheme for Telecare Medicine Information Systems.

    Science.gov (United States)

    Arshad, Hamed; Nikooghadam, Morteza

    2014-12-01

    Nowadays, with comprehensive employment of the internet, healthcare delivery services is provided remotely by telecare medicine information systems (TMISs). A secure mechanism for authentication and key agreement is one of the most important security requirements for TMISs. Recently, Tan proposed a user anonymity preserving three-factor authentication scheme for TMIS. The present paper shows that Tan's scheme is vulnerable to replay attacks and Denial-of-Service attacks. In order to overcome these security flaws, a new and efficient three-factor anonymous authentication and key agreement scheme for TMIS is proposed. Security and performance analysis shows superiority of the proposed scheme in comparison with previously proposed schemes that are related to security of TMISs.

  16. THE WIKILEAKS´S CASE AND ANONYMITY: EFFECTS ON THE INFORMATION FREEDOM

    Directory of Open Access Journals (Sweden)

    Marlus Heriberto Arns de Oliveira

    2015-10-01

    Full Text Available The Constitution of the Federative Republic of Brazil, enacted in 1988 during the democratization process of the country after the end of an authoritarian regime preceded by several others that show a non-democratic tradition in the Brazilian Republic, remained still remnants an authoritarian Patronizing and Paternalist state, the example of the final part of the Article 5, item IV, which claims to be the free expression of thought, but forbids anonymity, prohibition which deserves to be rethought, especially on the internet, where the navigation data of people deserve protection, as well as their rights to remain anonymous, a fact which entails the need for reflection on the scope and how best to interpret the constitutional provision cited, a debate that, in the proposed article will deal think the ideas of paternalism, authoritarianism and freedom, whose focus will be about within the Internet, social networks and the Knowledge Society.

  17. An efficient anonymous authentication scheme for wireless body area networks using elliptic curve cryptosystem.

    Science.gov (United States)

    Zhao, Zhenguo

    2014-02-01

    With the development of wireless networks and medical sensors, wireless body area networks are playing more and more important role in the field of healthcare service. The data transmitted in WBANs is very sensitive since it will be used in clinical diagnoses or measurements. Therefore, security and privacy of communication in WBANs derive increasing attentions from the academia and industry. In this paper, we propose an identity (ID)-based efficient anonymous authentication scheme for WBANs using elliptic curve cryptosystem (ECC). Due to the ID-based concept, there is no certificate is needed in the proposed scheme. Moreover, the proposed scheme not only provides mutual authentication between the client and the application provider but also provides client anonymity. Performance analysis shows that improvements of 50.58% and 3.87% in the client side and the application provider side separately. Then the proposed scheme is more suitable for WBANs.

  18. Anonymous three-party password-authenticated key exchange scheme for Telecare Medical Information Systems.

    Science.gov (United States)

    Xie, Qi; Hu, Bin; Dong, Na; Wong, Duncan S

    2014-01-01

    Telecare Medical Information Systems (TMIS) provide an effective way to enhance the medical process between doctors, nurses and patients. For enhancing the security and privacy of TMIS, it is important while challenging to enhance the TMIS so that a patient and a doctor can perform mutual authentication and session key establishment using a third-party medical server while the privacy of the patient can be ensured. In this paper, we propose an anonymous three-party password-authenticated key exchange (3PAKE) protocol for TMIS. The protocol is based on the efficient elliptic curve cryptosystem. For security, we apply the pi calculus based formal verification tool ProVerif to show that our 3PAKE protocol for TMIS can provide anonymity for patient and doctor while at the same time achieves mutual authentication and session key security. The proposed scheme is secure and efficient, and can be used in TMIS.

  19. A Semantic-Based K-Anonymity Scheme for Health Record Linkage.

    Science.gov (United States)

    Lu, Yang; Sinnott, Richard O; Verspoor, Karin

    2017-01-01

    Record linkage is a technique for integrating data from sources or providers where direct access to the data is not possible due to security and privacy considerations. This is a very common scenario for medical data, as patient privacy is a significant concern. To avoid privacy leakage, researchers have adopted k-anonymity to protect raw data from re-identification however they cannot avoid associated information loss, e.g. due to generalisation. Given that individual-level data is often not disclosed in the linkage cases, but yet remains potentially re-discoverable, we propose semantic-based linkage k-anonymity to de-identify record linkage with fewer generalisations and eliminate inference disclosure through semantic reasoning.

  20. A Framework For Enhancing Privacy In Location Based Services Using K-Anonymity Model

    Directory of Open Access Journals (Sweden)

    Jane Mugi

    2015-08-01

    Full Text Available Abstract This paper presents a framework for enhancing privacy in Location Based Services using K-anonymity model. Users of location based services have to reveal their location information in order to use these services however this has threatened the user privacy. K-anonymity approach has been studied extensively in various forms. However it is only effective when the user location is fixed. When a user moves and continuously sends their location information the location service provider can approximate user trajectory which poses a threat to the trajectory privacy of the user. This framework will ensure that user privacy is enhanced for both snapshot and continuous queries. The efficiency and effectiveness of the proposed framework was evaluated the results indicate that the proposed framework has high success rate and good run time performance.

  1. Applying LU Decomposition of Matrices to Design Anonymity Bilateral Remote User Authentication Scheme

    Directory of Open Access Journals (Sweden)

    Xiong Li

    2013-01-01

    Full Text Available We apply LU decomposition of matrices to present an anonymous bilateral authentication scheme. This paper aims at improving security and providing more excellent performances for remote user authentication scheme. The proposed scheme can provide bilateral authentication and session key agreement, can quickly check the validity of the input password, and can really protect the user anonymity. The security of the proposed scheme is based on the discrete logarithm problem (DLP, Diffie-Hellman problem (DHP, and the one-way hash function. It can resist various attacks such as insider attack, impersonation attack, server spoofing attack, and stolen smart card attack. Moreover, the presented scheme is computationally efficient for real-life implementation.

  2. Anonymous three-party password-authenticated key exchange scheme for Telecare Medical Information Systems.

    Directory of Open Access Journals (Sweden)

    Qi Xie

    Full Text Available Telecare Medical Information Systems (TMIS provide an effective way to enhance the medical process between doctors, nurses and patients. For enhancing the security and privacy of TMIS, it is important while challenging to enhance the TMIS so that a patient and a doctor can perform mutual authentication and session key establishment using a third-party medical server while the privacy of the patient can be ensured. In this paper, we propose an anonymous three-party password-authenticated key exchange (3PAKE protocol for TMIS. The protocol is based on the efficient elliptic curve cryptosystem. For security, we apply the pi calculus based formal verification tool ProVerif to show that our 3PAKE protocol for TMIS can provide anonymity for patient and doctor while at the same time achieves mutual authentication and session key security. The proposed scheme is secure and efficient, and can be used in TMIS.

  3. Practical m-k-Anonymization for Collaborative Data Publishing without Trusted Third Party

    Directory of Open Access Journals (Sweden)

    Jingyu Hua

    2017-01-01

    Full Text Available In collaborative data publishing (CDP, an m-adversary attack refers to a scenario where up to m malicious data providers collude to infer data records contributed by other providers. Existing solutions either rely on a trusted third party (TTP or introduce expensive computation and communication overheads. In this paper, we present a practical distributed k-anonymization scheme, m-k-anonymization, designed to defend against m-adversary attacks without relying on any TTPs. We then prove its security in the semihonest adversary model and demonstrate how an extension of the scheme can also be proven secure in a stronger adversary model. We also evaluate its efficiency using a commonly used dataset.

  4. Airplane pilot mental health and suicidal thoughts: a cross-sectional descriptive study via anonymous web-based survey.

    Science.gov (United States)

    Wu, Alexander C; Donnelly-McLay, Deborah; Weisskopf, Marc G; McNeely, Eileen; Betancourt, Theresa S; Allen, Joseph G

    2016-12-15

    The Germanwings Flight 9525 crash has brought the sensitive subject of airline pilot mental health to the forefront in aviation. Globally, 350 million people suffer from depression-a common mental disorder. This study provides further information on this important topic regarding mental health especially among female airline pilots. This is the first study to describe airline pilot mental health-with a focus on depression and suicidal thoughts-outside of the information derived from aircraft accident investigations, regulated health examinations, or identifiable self-reports, which are records protected by civil aviation authorities and airline companies. This is a descriptive cross-sectional study via an anonymous web-based survey administered between April and December 2015. Pilots were recruited from unions, airline companies, and airports via convenience sampling. Data analysis included calculating absolute number and prevalence of health characteristics and depression scores. One thousand eight hundred thirty seven (52.7%) of the 3485 surveyed pilots completed the survey, with 1866 (53.5%) completing at least half of the survey. 233 (12.6%) of 1848 airline pilots responding to the Patient Health Questionnaire 9 (PHQ-9), and 193 (13.5%) of 1430 pilots who reported working as an airline pilot in the last seven days at time of survey, met depression threshold-PHQ-9 total score ≥ 10. Seventy-five participants (4.1%) reported having suicidal thoughts within the past two weeks. We found a significant trend in proportions of depression at higher levels of use of sleep-aid medication (trend test z = 6.74, p < 0.001) and among those experiencing sexual harassment (z = 3.18, p = 0.001) or verbal harassment (z = 6.13, p < 0.001). Hundreds of pilots currently flying are managing depressive symptoms perhaps without the possibility of treatment due to the fear of negative career impacts. This study found 233 (12.6%) airline pilots meeting

  5. Un algorithme probabiliste d'election et d'arbre couvrant sur des reseaux anonymes

    OpenAIRE

    Lavallee, Ivan; Lavault, C.

    1989-01-01

    Dans le present rapport, nous proposons deux variantes d'un algorithme distribue, probabiliste, asynchrone d'election et de construction d'arbre couvrant dans des reseaux anonymes a topologie quelconque. A notre connaissance, cet algorithme est le premier du genre, a etre totalement et rigoureusement specifie. Il est fonde sur un precedent algorithme deterministe d'election pour reseaux de processus a identites distinctes. Nous montrons ici comment construire les deux variantes, suivant deux ...

  6. Facebook’s Ugly Sisters: Anonymity and Abuse on Formspring and Ask.fm

    OpenAIRE

    Binns, Amy

    2013-01-01

    New question and answer websites Ask.fm and Formspring have brought highly specific and personal abuse to a new level amongst young people by providing easy anonymity to users within a circle of offline friendship groups culled from Facebook. Relatively unknown due to their unattractiveness to adults, these sites are growing rapidly and have already been associated with at least eight suicides amongst teenagers. \\ud \\ud Media educators at school level encouraging self-awareness of social medi...

  7. Nursing lives in the blogosphere: A thematic analysis of anonymous online nursing narratives.

    Science.gov (United States)

    Castro, Aimee; Andrews, Gavin

    2018-02-01

    The aim of this study was to explore the work-life narratives of nurses through a thematic analysis of the nursing accounts they post in their publicly accessible, anonymous blogs. Many nurses participate on social media. Blogs have been advocated as a self-reflective tool in nursing practice, yet as far as the authors are aware, no previous studies have explored nurses' individual blogs for their potential to reveal nurses' perceptions of nursing work. The research design was qualitative description. Between May-August 2015, Internet search engines were used to discover lists of nursing blogs recommended by organizations representing nurses' interests. Recommended blogs were purposively sampled. Four anonymous blogs written by nurses from different nursing specialties met the sampling criteria. All 520 of their entries from 2014 were read and copied into NVivo 10, where an inductive coding process was followed. Three major themes arose in these nurses' online discussions of their work lives: they truly care about and value their nursing work, but they are feeling stressed and burnt out and they are using their anonymous blogs to share factors that frustrate them in their nursing work. Three main areas of frustration were revealed: teamwork problems, challenging patients and families, and management issues. Anonymous nursing blogs offer valuable, longitudinal insights into nurses' perceptions of their work lives. Nursing blogs should be further explored for ongoing insights into nurses' experiences of nursing work, as well as nurses' recommendations for addressing issues causing them to feel frustrated in their work environments. © 2017 John Wiley & Sons Ltd.

  8. Use of anonymous Web communities and websites by medical consumers in Japan to research drug information.

    Science.gov (United States)

    Kishimoto, Keiko; Fukushima, Noriko

    2011-01-01

    In this study, we investigated the status of researching drug information online, and the type of Internet user who uses anonymous Web communities and websites. A Web-based cross-sectional survey of 10875 male and female Internet users aged 16 and over was conducted in March 2010. Of 10282 analyzed respondents, excluding medical professionals, about 47% reported that they had previously searched the Internet for drug information and had used online resources ranging from drug information search engines and pharmaceutical industry websites to social networking sites and Twitter. Respondents who had researched drug information online (n=4861) were analyzed by two multivariable logistic regressions. In Model 1, the use of anonymous websites associated with age (OR, 0.778; 95% CI, 0.742-0.816), referring to the reputation and the narrative of other Internet users on shopping (OR, 1.640; 95% CI, 1.450-1.855), taking a prescription drug (OR, 0.806; 95% CI, 0.705-0.922), and frequent consulting with non-professionals about medical care and health (OR, 1.613; 95% CI, 1.396-1.865). In Model 2, use of only anonymous websites was associated with age (OR, 0.753; 95% CI, 0.705-0.805), using the Internet daily (OR, 0.611; 95% CI, 0.462-0.808), taking a prescription drug (OR, 0.614; 95% CI, 0.505-0.747), and experience a side effect (OR, 0.526; 95% CI, 0.421-0.658). The analysis revealed the profiles of Internet users who researched drug information on social media sites where the information providers are anonymous and do not necessarily have adequate knowledge of medicine and online information literacy.

  9. Gamblers Anonymous in Israel: a participant observation study of a self-help group.

    Science.gov (United States)

    Cromer, G

    1978-10-01

    This participant observation study of the first Gamblers Anonymous group in Israel is designed to show (1) the ways in which the group helps it members rehabilitate themselves, (2) the three stages through which they must go in order to ensure success, and (3) the reason why some participants fail to do so. The article concludes with a number of observations concerning the extent of gambling in Israel and the different ways that should be developed for dealing with the problem.

  10. [Examination of the Young maladaptive schemes in a group of Gamblers Anonymous].

    Science.gov (United States)

    Katona, Zsuzsa; Körmendi, Attila

    2012-01-01

    Literature of gambling addiction has become widespread in last years. Many studies were written about the vulnerability factors helping the development of addiction, theoretical models, comorbid problems and therapy possibilities. Currently there is no integrated theoretical model that could explain sufficiently the development and maintenance of pathological gambling. The treatment issue is also unresolved. Cognitive psychology is a dynamically developing field of psychology and good results are achieved in gambling treatment with applying cognitive techniques. Jeffrey Young's schema-focused therapy is a recent theoretical and therapeutic direction within cognitive psychology which emphasizes the necessity of emotional changes beside rational ones in the interest of efficiency. The purpose of our research is to examine and analyse active maladaptive schemas among gamblers who are members of Gamblers Anonymous self-help group. 23 control persons and 23 gamblers associated with support group of Gamblers Anonymous took part in our research. The severity of gambling behaviour was measured by Gamblers Anonymous Twenty Questions. For exploring maladaptive schemas we used the shorter 114-item version of the Young Schema Questionnaire (YSQ-S3). All the examined gamblers were considered as problem gamblers based on Gamblers Anonymous Twenty Questions. In the control group there where no active schemas while in the group of gamblers several schemas (Emotional deprivation, Self-sacrifice, Recognition seeking, Emotional inhibition, Unrelenting standards, Self-punitiveness, Insufficient self-control) showed activity. Active schemas show similarity in their matter with main establishments of researches about gamblers and support the role of impulsivity, narcissistic traits, self-medicalization and emotional deprivation in the development and maintenance of pathological gambling.

  11. Mirroring the videos of Anonymous:cloud activism, living networks, and political mimesis

    OpenAIRE

    Fish, Adam Richard

    2016-01-01

    Mirrors describe the multiplication of data across a network. In this article, I examine the politics of mirroring as practiced on videos by the hacktivist network Anonymous. Mirrors are designed to retain visibility on social media platforms and motivate viewers towards activism. They emerge from a particular social structure and propagate a specific symbolic system. Furthermore, mirrors are not exact replicas nor postmodern representations. Rather, mirroring maps a contestation over visibil...

  12. Mutual support and recovery in the Russian Alcoholics Anonymous online community

    Directory of Open Access Journals (Sweden)

    Lyytikäinen Laura

    2016-04-01

    Full Text Available AIMS – In Russia the paradigm of alcoholism as a disease is still in contrast to the general perception of alcoholics as weak-willed. This article studies alcoholism and recovery in Russia through the case study of the Russian Alcoholics Anonymous online group. It studies how people who are seeking help for their drinking problems in this online community come to incorporate a new self-understanding of being ill with alcoholism.

  13. Anonymous As a Cyber Tribe: A New Model for Complex, Non-State Cyber Actors

    Science.gov (United States)

    2015-05-01

    non- state cyber actors. The Air Force values a professional workplace that strictly prohibits racism , sexism, lewd material, and most forms of...AU/ACSC/LIDOWSKI, R/AY15 AIR COMMAND AND STAFF COLLEGE AIR UNIVERSITY ANONYMOUS AS A CYBER TRIBE: A NEW MODEL FOR COMPLEX, NON- STATE ...government or the Department of Defense. In accordance with Air Force Instruction 51-303, it is not copyrighted, but is the property of the United

  14. Local and global recoding methods for anonymizing set-valued data

    KAUST Repository

    Terrovitis, Manolis

    2010-06-10

    In this paper, we study the problem of protecting privacy in the publication of set-valued data. Consider a collection of supermarket transactions that contains detailed information about items bought together by individuals. Even after removing all personal characteristics of the buyer, which can serve as links to his identity, the publication of such data is still subject to privacy attacks from adversaries who have partial knowledge about the set. Unlike most previous works, we do not distinguish data as sensitive and non-sensitive, but we consider them both as potential quasi-identifiers and potential sensitive data, depending on the knowledge of the adversary. We define a new version of the k-anonymity guarantee, the k m-anonymity, to limit the effects of the data dimensionality, and we propose efficient algorithms to transform the database. Our anonymization model relies on generalization instead of suppression, which is the most common practice in related works on such data. We develop an algorithm that finds the optimal solution, however, at a high cost that makes it inapplicable for large, realistic problems. Then, we propose a greedy heuristic, which performs generalizations in an Apriori, level-wise fashion. The heuristic scales much better and in most of the cases finds a solution close to the optimal. Finally, we investigate the application of techniques that partition the database and perform anonymization locally, aiming at the reduction of the memory consumption and further scalability. A thorough experimental evaluation with real datasets shows that a vertical partitioning approach achieves excellent results in practice. © 2010 Springer-Verlag.

  15. Spontaneous subcapsular and perirrenal hemorrhage

    International Nuclear Information System (INIS)

    Fuster, M.J.; Saez, J.; Perez-Paya, F.J.; Fernandez, F.

    1997-01-01

    To assess the role of CT in the etiologic diagnosis of spontaneous subcapsular and perirrenal hemorrhage. The CT findings are described in 13 patients presenting subcapsular and perirrenal hemorrhage. Those patients in whom the bleeding was not spontaneous were excluded. Surgical confirmation was obtained in nine cases. In 11 of the 13 cases (84.6%), involving five adenocarcinomas, five angiomyolipoma, two complicated cysts and one case of panarterities nodosa, CT disclosed the underlying pathology. In two cases (15.4%), it only revealed the extension of the hematoma, but gave no clue to its origin. CT is the technique of choice when spontaneous subcapsular and perirrenal hemorrhage is suspected since, in most cases, it reveals the underlying pathology. (Author)

  16. DOE approach to threshold quantities

    International Nuclear Information System (INIS)

    Wickham, L.E.; Kluk, A.F.; Department of Energy, Washington, DC)

    1985-01-01

    The Department of Energy (DOE) is developing the concept of threshold quantities for use in determining which waste materials must be handled as radioactive waste and which may be disposed of as nonradioactive waste at its sites. Waste above this concentration level would be managed as radioactive or mixed waste (if hazardous chemicals are present); waste below this level would be handled as sanitary waste. Ideally, the threshold must be set high enough to significantly reduce the amount of waste requiring special handling. It must also be low enough so that waste at the threshold quantity poses a very small health risk and multiple exposures to such waste would still constitute a small health risk. It should also be practical to segregate waste above or below the threshold quantity using available instrumentation. Guidance is being prepared to aid DOE sites in establishing threshold quantity values based on pathways analysis using site-specific parameters (waste stream characteristics, maximum exposed individual, population considerations, and site specific parameters such as rainfall, etc.). A guidance dose of between 0.001 to 1.0 mSv/y (0.1 to 100 mrem/y) was recommended with 0.3 mSv/y (30 mrem/y) selected as the guidance dose upon which to base calculations. Several tasks were identified, beginning with the selection of a suitable pathway model for relating dose to the concentration of radioactivity in the waste. Threshold concentrations corresponding to the guidance dose were determined for waste disposal sites at a selected humid and arid site. Finally, cost-benefit considerations at the example sites were addressed. The results of the various tasks are summarized and the relationship of this effort with related developments at other agencies discussed

  17. There is no ``I'' in referee: Why referees should be anonymous

    Science.gov (United States)

    Ucko, Daniel

    2015-03-01

    From the early days of modern science, it has been recognized that scientific claims must be verified by someone who is not the maker of those claims, and who furthermore has no stake in the matter. In other words, claims need to be evaluated objectively, by the community. The way in which this tends to be done is by peer review conducted by journals. Peer review as currently practiced touches on the themes of trust, where the trust is in institutions and procedures that emerge from expert communities. The practice of peer review is viewed as a citizenly duty of scientists in the scientific community, because all scientists take turns serving either as authors, referees, and editors in the peer review process We lack the resources to have a work evaluated by the entire community, so we substitute with a representative. Yet, in most examples of scientific review, the referee or referees are anonymous. This question is particularly important when the peer review process is brought to bear in order to evaluate matters beyond scientific validity, more ``subjective'' criteria such as relative importance, broadness of interest - criteria that do not appear to have an objective standard of comparison and validation. I will show that the anonymity of referees, far from endangering this trust, actually strengthens it. I will show that this anonymity is crucial in order to maintain any objectivity in scientific peer review, and why authors should not try to unmask the referee. Also at American Physical Society (APS).

  18. Provably Secure Anonymous-yet-Accountable Crowdsensing with Scalable Sublinear Revocation

    Directory of Open Access Journals (Sweden)

    Rahaman Sazzadur

    2017-10-01

    Full Text Available Group signature schemes enable anonymous-yet-accountable communications. Such a capability is extremely useful for applications, such as smartphone-based crowdsensing and citizen science. However, the performance of modern group signature schemes is still inadequate to manage large dynamic groups. In this paper, we design the first provably secure verifier-local revocation (VLR - based group signature scheme that supports sublinear revocation, named Sublinear Revocation with Backward unlinkability and Exculpability (SRBE. To achieve this performance gain, SRBE introduces time bound pseudonyms for the signer. By introducing low-cost short-lived pseudonyms with sublinear revocation checking, SRBE drastically improves the efficiency of the group-signature primitive. The backward-unlinkable anonymity of SRBE guarantees that even after the revocation of a signer, her previously generated signatures remain unlinkable across epochs. This behavior favors the dynamic nature of real-world crowdsensing settings. We prove its security and discuss parameters that influence its scalability. Using SRBE, we also implement a prototype named GroupSense for anonymous-yet-accountable crowdsensing, where our experimental findings confirm GroupSense’s scalability. We point out the open problems remaining in this space.

  19. kACTUS 2: Privacy Preserving in Classification Tasks Using k-Anonymity

    Science.gov (United States)

    Kisilevich, Slava; Elovici, Yuval; Shapira, Bracha; Rokach, Lior

    k-anonymity is the method used for masking sensitive data which successfully solves the problem of re-linking of data with an external source and makes it difficult to re-identify the individual. Thus k-anonymity works on a set of quasi-identifiers (public sensitive attributes), whose possible availability and linking is anticipated from external dataset, and demands that the released dataset will contain at least k records for every possible quasi-identifier value. Another aspect of k is its capability of maintaining the truthfulness of the released data (unlike other existing methods). This is achieved by generalization, a primary technique in k-anonymity. Generalization consists of generalizing attribute values and substituting them with semantically consistent but less precise values. When the substituted value doesn’t preserve semantic validity the technique is called suppression which is a private case of generalization. We present a hybrid approach called compensation which is based on suppression and swapping for achieving privacy. Since swapping decreases the truthfulness of attribute values there is a tradeoff between level of swapping (information truthfulness) and suppression (information loss) incorporated in our algorithm.

  20. Potential harms, anonymization, and the right to withdraw consent to biobank research.

    Science.gov (United States)

    Eriksson, Stefan; Helgesson, Gert

    2005-09-01

    This paper discusses the potential harms involved in biobank research and how ethical review, informed consent, withdrawals, and anonymization of samples should be handled in the light of these harms. There is less risk involved in biobank research than in human subject research; it should therefore be treated differently. In our view, anonymization should not be an automatically permissible response to requests for withdrawal. Nor should a request for withdrawal necessarily stop research on identifiable samples. Apart from not being particularly appropriate for protecting the interests of individuals, anonymization of samples has a negative impact on research. We suggest that the current view on withdrawal from research, supported by the Declaration of Helsinki and subsequent ethical guidelines, be abandoned in the context of biobank research and be replaced by an approach inspired by the Nuremberg Code. This approach requires those wishing to withdraw their samples from research to present sufficient reason for doing so. Our interpretation of 'sufficient reason' includes all those involving genuine, deeply felt concerns that are not based on misconceptions. Still, this underlines the fact that we all share a responsibility for health research and that no one should take withdrawal from biobank research lightly.

  1. Does the type of anonymity matter? The impact of visualization on information sharing in online groups.

    Science.gov (United States)

    Wodzicki, Katrin; Schwämmlein, Eva; Cress, Ulrike; Kimmerle, Joachim

    2011-03-01

    Groups who share information in computer-mediated settings often have to deal with the issue of anonymity. Previous research has shown that only people with a prosocial orientation--that is, those whose main interest is to add to the benefit of the group as a whole--are willing to share information in anonymous situations. The willingness to share information by those people with a proself orientation--that is, those who put more emphasis on their personal benefit--can be increased by providing photographs of the other group members. The information-sharing behavior of prosocials, however, suffers from such a deletion of anonymity. In an online experiment, we examined how information-sharing behavior of proselfs may be increased without negatively influencing the information-sharing behavior of prosocials in an online setting. It was shown that even proselfs share information if the group members are visualized in a homogeneous way, while prosocials' information-sharing behavior is not impaired by this visualization. In addition, the results suggest that people's perceived homogeneity of the online group, as well as the importance of the collective goal, are the underlying processes of this effect. These results have important practical implications for the design of online information-sharing settings.

  2. Fortified Anonymous Communication Protocol for Location Privacy in WSN: A Modular Approach

    Directory of Open Access Journals (Sweden)

    Abdel-Shakour Abuzneid

    2015-03-01

    Full Text Available Wireless sensor network (WSN consists of many hosts called sensors. These sensors can sense a phenomenon (motion, temperature, humidity, average, max, min, etc. and represent what they sense in a form of data. There are many applications for WSNs including object tracking and monitoring where in most of the cases these objects need protection. In these applications, data privacy itself might not be as important as the privacy of source location. In addition to the source location privacy, sink location privacy should also be provided. Providing an efficient end-to-end privacy solution would be a challenging task to achieve due to the open nature of the WSN. The key schemes needed for end-to-end location privacy are anonymity, observability, capture likelihood, and safety period. We extend this work to allow for countermeasures against multi-local and global adversaries. We present a network model protected against a sophisticated threat model: passive /active and local/multi-local/global attacks. This work provides a solution for end-to-end anonymity and location privacy as well. We will introduce a framework called fortified anonymous communication (FAC protocol for WSN.

  3. Thresholds in chemical respiratory sensitisation.

    Science.gov (United States)

    Cochrane, Stella A; Arts, Josje H E; Ehnes, Colin; Hindle, Stuart; Hollnagel, Heli M; Poole, Alan; Suto, Hidenori; Kimber, Ian

    2015-07-03

    There is a continuing interest in determining whether it is possible to identify thresholds for chemical allergy. Here allergic sensitisation of the respiratory tract by chemicals is considered in this context. This is an important occupational health problem, being associated with rhinitis and asthma, and in addition provides toxicologists and risk assessors with a number of challenges. In common with all forms of allergic disease chemical respiratory allergy develops in two phases. In the first (induction) phase exposure to a chemical allergen (by an appropriate route of exposure) causes immunological priming and sensitisation of the respiratory tract. The second (elicitation) phase is triggered if a sensitised subject is exposed subsequently to the same chemical allergen via inhalation. A secondary immune response will be provoked in the respiratory tract resulting in inflammation and the signs and symptoms of a respiratory hypersensitivity reaction. In this article attention has focused on the identification of threshold values during the acquisition of sensitisation. Current mechanistic understanding of allergy is such that it can be assumed that the development of sensitisation (and also the elicitation of an allergic reaction) is a threshold phenomenon; there will be levels of exposure below which sensitisation will not be acquired. That is, all immune responses, including allergic sensitisation, have threshold requirement for the availability of antigen/allergen, below which a response will fail to develop. The issue addressed here is whether there are methods available or clinical/epidemiological data that permit the identification of such thresholds. This document reviews briefly relevant human studies of occupational asthma, and experimental models that have been developed (or are being developed) for the identification and characterisation of chemical respiratory allergens. The main conclusion drawn is that although there is evidence that the

  4. On computational Gestalt detection thresholds.

    Science.gov (United States)

    Grompone von Gioi, Rafael; Jakubowicz, Jérémie

    2009-01-01

    The aim of this paper is to show some recent developments of computational Gestalt theory, as pioneered by Desolneux, Moisan and Morel. The new results allow to predict much more accurately the detection thresholds. This step is unavoidable if one wants to analyze visual detection thresholds in the light of computational Gestalt theory. The paper first recalls the main elements of computational Gestalt theory. It points out a precision issue in this theory, essentially due to the use of discrete probability distributions. It then proposes to overcome this issue by using continuous probability distributions and illustrates it on the meaningful alignment detector of Desolneux et al.

  5. Nuclear threshold effects and neutron strength function

    International Nuclear Information System (INIS)

    Hategan, Cornel; Comisel, Horia

    2003-01-01

    One proves that a Nuclear Threshold Effect is dependent, via Neutron Strength Function, on Spectroscopy of Ancestral Neutron Threshold State. The magnitude of the Nuclear Threshold Effect is proportional to the Neutron Strength Function. Evidence for relation of Nuclear Threshold Effects to Neutron Strength Functions is obtained from Isotopic Threshold Effect and Deuteron Stripping Threshold Anomaly. The empirical and computational analysis of the Isotopic Threshold Effect and of the Deuteron Stripping Threshold Anomaly demonstrate their close relationship to Neutron Strength Functions. It was established that the Nuclear Threshold Effects depend, in addition to genuine Nuclear Reaction Mechanisms, on Spectroscopy of (Ancestral) Neutron Threshold State. The magnitude of the effect is proportional to the Neutron Strength Function, in their dependence on mass number. This result constitutes also a proof that the origins of these threshold effects are Neutron Single Particle States at zero energy. (author)

  6. Spontaneous isolated celiac artery dissection

    Directory of Open Access Journals (Sweden)

    Tuba Cimilli Ozturk

    2011-01-01

    Full Text Available Dyspepsia with mild, stabbing epigastric discomfort without history of trauma is a very common symptom that emergency physicians see in their daily practice. Vascular emergencies, mostly the aortic dissection and aneurysm, are always described in the differential diagnosis with persistent symptoms. Isolated celiac artery dissection occurring spontaneously is a very rare diagnosis. The involvement of branch vessels is generally observed and patients show various clinical signs and symptoms according to the involved branch vessel. Here we are presenting a case with spontaneous isolated celiac artery dissection, without any branch vessel involvement or visceral damage, detected by computed tomography scans taken on admission.

  7. Spontaneous waves in muscle fibres

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, Stefan; Kruse, Karsten [Department of Theoretical Physics, Saarland University, 66041 Saarbruecken (Germany); Max Planck Institute for the Physics of Complex Systems, Noethnitzer Street 38, 01187 Dresden (Germany)

    2007-11-15

    Mechanical oscillations are important for many cellular processes, e.g. the beating of cilia and flagella or the sensation of sound by hair cells. These dynamic states originate from spontaneous oscillations of molecular motors. A particularly clear example of such oscillations has been observed in muscle fibers under non-physiological conditions. In that case, motor oscillations lead to contraction waves along the fiber. By a macroscopic analysis of muscle fiber dynamics we find that the spontaneous waves involve non-hydrodynamic modes. A simple microscopic model of sarcomere dynamics highlights mechanical aspects of the motor dynamics and fits with the experimental observations.

  8. The long path to pregnancy: early experience with dual anonymous gamete donation in a European in vitro fertilisation referral centre

    Directory of Open Access Journals (Sweden)

    Sills Eric

    2010-08-01

    Full Text Available Abstract Background This investigation describes features of patients undergoing in vitro fertilisation (IVF and embryo transfer (ET where both gametes were obtained from anonymous donors. Methods Gamete unsuitability or loss was confirmed in both members of seven otherwise healthy couples presenting for reproductive endocrinology consultation over a 12-month interval in Ireland. IVF was undertaken with fresh oocytes provided by anonymous donors in Ukraine; frozen sperm (anonymous donor was obtained from a licensed tissue establishment. For recipients, saline-enhanced sonography was used to assess intrauterine contour with endometrial preparation via transdermal estrogen. Results Among commissioning couples, mean±SD female and male age was 41.9 ± 3.7 and 44.6 ± 3.5 yrs, respectively. During this period, female age for non dual anonymous gamete donation IVF patients was 37.9 ± 3 yrs (p Conclusions Mean age of females undergoing dual anonymous donor gamete donation with IVF is significantly higher than the background IVF patient population. Even when neither partner is able to contribute any gametes for IVF, the clinical pregnancy rate per transfer can be satisfactory if both anonymous egg and sperm donation are used concurrently. Our report emphasises the role of pre-treatment counselling in dual anonymous gamete donation, and presents a coordinated screening and treatment approach in IVF where this option may be contemplated.

  9. (a,k)-Anonymous Scheme for Privacy-Preserving Data Collection in IoT-based Healthcare Services Systems.

    Science.gov (United States)

    Li, Hongtao; Guo, Feng; Zhang, Wenyin; Wang, Jie; Xing, Jinsheng

    2018-02-14

    The widely use of IoT technologies in healthcare services has pushed forward medical intelligence level of services. However, it also brings potential privacy threat to the data collection. In healthcare services system, health and medical data that contains privacy information are often transmitted among networks, and such privacy information should be protected. Therefore, there is a need for privacy-preserving data collection (PPDC) scheme to protect clients (patients) data. We adopt (a,k)-anonymity model as privacy pretection scheme for data collection, and propose a novel anonymity-based PPDC method for healthcare services in this paper. The threat model is analyzed in the client-server-to-user (CS2U) model. On client-side, we utilize (a,k)-anonymity notion to generate anonymous tuples which can resist possible attack, and adopt a bottom-up clustering method to create clusters that satisfy a base privacy level of (a 1 ,k 1 )-anonymity. On server-side, we reduce the communication cost through generalization technology, and compress (a 1 ,k 1 )-anonymous data through an UPGMA-based cluster combination method to make the data meet the deeper level of privacy (a 2 ,k 2 )-anonymity (a 1  ≥ a 2 , k 2  ≥ k 1 ). Theoretical analysis and experimental results prove that our scheme is effective in privacy-preserving and data quality.

  10. Secure anonymous mutual authentication for star two-tier wireless body area networks.

    Science.gov (United States)

    Ibrahim, Maged Hamada; Kumari, Saru; Das, Ashok Kumar; Wazid, Mohammad; Odelu, Vanga

    2016-10-01

    Mutual authentication is a very important service that must be established between sensor nodes in wireless body area network (WBAN) to ensure the originality and integrity of the patient's data sent by sensors distributed on different parts of the body. However, mutual authentication service is not enough. An adversary can benefit from monitoring the traffic and knowing which sensor is in transmission of patient's data. Observing the traffic (even without disclosing the context) and knowing its origin, it can reveal to the adversary information about the patient's medical conditions. Therefore, anonymity of the communicating sensors is an important service as well. Few works have been conducted in the area of mutual authentication among sensor nodes in WBAN. However, none of them has considered anonymity among body sensor nodes. Up to our knowledge, our protocol is the first attempt to consider this service in a two-tier WBAN. We propose a new secure protocol to realize anonymous mutual authentication and confidential transmission for star two-tier WBAN topology. The proposed protocol uses simple cryptographic primitives. We prove the security of the proposed protocol using the widely-accepted Burrows-Abadi-Needham (BAN) logic, and also through rigorous informal security analysis. In addition, to demonstrate the practicality of our protocol, we evaluate it using NS-2 simulator. BAN logic and informal security analysis prove that our proposed protocol achieves the necessary security requirements and goals of an authentication service. The simulation results show the impact on the various network parameters, such as end-to-end delay and throughput. The nodes in the network require to store few hundred bits. Nodes require to perform very few hash invocations, which are computationally very efficient. The communication cost of the proposed protocol is few hundred bits in one round of communication. Due to the low computation cost, the energy consumed by the nodes is

  11. Human Papillomavirus Infection as a Possible Cause of Spontaneous Abortion and Spontaneous Preterm Delivery

    DEFF Research Database (Denmark)

    Ambühl, Lea Maria Margareta; Baandrup, Ulrik; Dybkær, Karen

    2016-01-01

    , and 10.9% (95% CI; 10.1–11.7) for umbilical cord blood. Summary estimates for HPV prevalence of spontaneous abortions and spontaneous preterm deliveries, in cervix (spontaneous abortions: 24.5%, and pretermdeliveries: 47%, resp.) and placenta (spontaneous abortions: 24.9%, and preterm deliveries: 50......%, resp.), were identified to be higher compared to normal full-term pregnancies (푃 spontaneous abortion, spontaneous preterm...

  12. Thresholds models of technological transitions

    NARCIS (Netherlands)

    Zeppini, P.; Frenken, K.; Kupers, R.

    2014-01-01

    We present a systematic review of seven threshold models of technological transitions from physics, biology, economics and sociology. The very same phenomenon of a technological transition can be explained by very different logics, ranging from economic explanations based on price, performance and

  13. Risk thresholds for alcohol consumption

    DEFF Research Database (Denmark)

    Wood, Angela M; Kaptoge, Stephen; Butterworth, Adam S

    2018-01-01

    BACKGROUND: Low-risk limits recommended for alcohol consumption vary substantially across different national guidelines. To define thresholds associated with lowest risk for all-cause mortality and cardiovascular disease, we studied individual-participant data from 599 912 current drinkers withou...

  14. Weights of Exact Threshold Functions

    DEFF Research Database (Denmark)

    Babai, László; Hansen, Kristoffer Arnsfelt; Podolskii, Vladimir V.

    2010-01-01

    We consider Boolean exact threshold functions defined by linear equations, and in general degree d polynomials. We give upper and lower bounds on the maximum magnitude (absolute value) of the coefficients required to represent such functions. These bounds are very close and in the linear case in ...... leave a substantial gap, a challenge for future work....

  15. Threshold quantities for helminth infections

    NARCIS (Netherlands)

    Heesterbeek, J.A.P.; Roberts, M.G.

    1995-01-01

    For parasites with a clearly defined life-cycle we give threshold quantities that determine the stability of the parasite-free steady state for autonomous and periodic deterministic systems formulated in terms of mean parasite burdens. We discuss the biological interpretations of the quantities, how

  16. Percolation Threshold Parameters of Fluids

    Czech Academy of Sciences Publication Activity Database

    Škvor, J.; Nezbeda, Ivo

    2009-01-01

    Roč. 79, č. 4 (2009), 041141-041147 ISSN 1539-3755 Institutional research plan: CEZ:AV0Z40720504 Keywords : percolation threshold * universality * infinite cluster Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.400, year: 2009

  17. Threshold enhancement of diphoton resonances

    Directory of Open Access Journals (Sweden)

    Aoife Bharucha

    2016-10-01

    Full Text Available We revisit a mechanism to enhance the decay width of (pseudo-scalar resonances to photon pairs when the process is mediated by loops of charged fermions produced near threshold. Motivated by the recent LHC data, indicating the presence of an excess in the diphoton spectrum at approximately 750 GeV, we illustrate this threshold enhancement mechanism in the case of a 750 GeV pseudoscalar boson A with a two-photon decay mediated by a charged and uncolored fermion having a mass at the 12MA threshold and a small decay width, <1 MeV. The implications of such a threshold enhancement are discussed in two explicit scenarios: i the Minimal Supersymmetric Standard Model in which the A state is produced via the top quark mediated gluon fusion process and decays into photons predominantly through loops of charginos with masses close to 12MA and ii a two Higgs doublet model in which A is again produced by gluon fusion but decays into photons through loops of vector-like charged heavy leptons. In both these scenarios, while the mass of the charged fermion has to be adjusted to be extremely close to half of the A resonance mass, the small total widths are naturally obtained if only suppressed three-body decay channels occur. Finally, the implications of some of these scenarios for dark matter are discussed.

  18. Crossing Thresholds in Academic Reading

    Science.gov (United States)

    Abbott, Rob

    2013-01-01

    This paper looks at the conceptual thresholds in relation to academic reading which might be crossed by undergraduate English Literature students. It is part of a wider study following 16 students through three years of undergraduate study. It uses theoretical ideas from Bakhtin and Foucault to analyse interviews with English lecturers. It…

  19. Quantifying ecological thresholds from response surfaces

    Science.gov (United States)

    Heather E. Lintz; Bruce McCune; Andrew N. Gray; Katherine A. McCulloh

    2011-01-01

    Ecological thresholds are abrupt changes of ecological state. While an ecological threshold is a widely accepted concept, most empirical methods detect them in time or across geographic space. Although useful, these approaches do not quantify the direct drivers of threshold response. Causal understanding of thresholds detected empirically requires their investigation...

  20. Spontaneous emission by moving atoms

    International Nuclear Information System (INIS)

    Meystre, P.; Wilkens, M.

    1994-01-01

    It is well known that spontaneous emission is not an intrinsic atomic property, but rather results from the coupling of the atom to the vacuum modes of the electromagnetic field. As such, it can be modified by tailoring the electromagnetic environment into which the atom can radiate. This was already realized by Purcell, who noted that the spontaneous emission rate can be enhanced if the atom placed inside a cavity is resonant with one of the cavity is resonant with one of the cavity modes, and by Kleppner, who discussed the opposite case of inhibited spontaneous emission. It has also been recognized that spontaneous emission need not be an irreversible process. Indeed, a system consisting of a single atom coupled to a single mode of the electromagnetic field undergoes a periodic exchange of excitation between the atom and the field. This periodic exchange remains dominant as long as the strength of the coupling between the atom and a cavity mode is itself dominant. 23 refs., 6 figs

  1. Spontaneous Development of Moral Concepts

    Science.gov (United States)

    Siegal, M.

    1975-01-01

    Moral competence is more difficult to attain than scientific competence. Since language comprehension plays a central role in conceptual development, and moral language is difficult to learn, there is a common deficiency in moral conceptual development. This suggests a theory of non-spontaneous solutions to moral problems. (Author/MS)

  2. Shell theorem for spontaneous emission

    DEFF Research Database (Denmark)

    Kristensen, Philip Trøst; Mortensen, Jakob Egeberg; Lodahl, Peter

    2013-01-01

    and therefore is given exactly by the dipole approximation theory. This surprising result is a spontaneous emission counterpart to the shell theorems of classical mechanics and electrostatics and provides insights into the physics of mesoscopic emitters as well as great simplifications in practical calculations....

  3. Prediction of Spontaneous Preterm Birth

    NARCIS (Netherlands)

    Dijkstra, Karolien

    2002-01-01

    Preterm birth is a leading cause of neonatal morbidity and mortality. It is a major goal in obstetrics to lower the incidence of spontaneous preterm birth (SPB) and related neonatal morbidity and mortality. One of the principal objectives is to discover early markers that would allow us to identify

  4. EAMJ Dec. Spontaneous.indd

    African Journals Online (AJOL)

    2008-12-12

    Dec 12, 2008 ... surgical abortion at one month gestation without any complication. The second pregnancy which was a year prior resulted in a spontaneous miscarriage at two months followed by evacuation of retained products of conception with no post abortion complications. Antibiotics were taken following both.

  5. Spontaneous fission of superheavy nuclei

    Indian Academy of Sciences (India)

    the Yukawa-plus-exponential potential. The microscopic shell and pairing corrections are obtained using the Strutinsky and BCS approaches and the cranking formulae yield the inertia tensor. Finally, the WKB method is used to calculate penetrabilities and spontaneous fission half-lives. Calculations are performed for the ...

  6. Anonymity as an Instructional Scaffold in Peer Assessment: Its Effects on Peer Feedback Quality and Evolution in Students' Perceptions about Peer Assessment Skills

    Science.gov (United States)

    Rotsaert, Tijs; Panadero, Ernesto; Schellens, Tammy

    2018-01-01

    Although previous research has indicated that providing anonymity is an effective way to create a safe peer assessment setting, continuously ensuring anonymity prevents students from experiencing genuine two-way interactive feedback dialogues. The present study investigated how installing a transitional approach from an anonymous to a…

  7. (In)visible Ghosts in the Machine and the Powers that Bind: The Relational Securitization of Anonymous

    DEFF Research Database (Denmark)

    Dunn Cavelty, Myriam; Jaeger, Mark Daniel

    2015-01-01

    This paper analyzes the formation and subsequent securitization of the digital protest movement Anonymous, highlighting the emergence of social antagonists from communication itself. In contrast to existing approaches that implicitly or explicitly conceptualize Othering (and securitization) as un...

  8. Spontaneous Retropharyngeal Emphysema: A Case Report | Chi ...

    African Journals Online (AJOL)

    ... is a rare clinical condition in pediatric otolaryngology. The predominant symptoms are sore throat, odynophagia, dysphagia, and neck pain. Here, we report a case of spontaneous retropharyngeal emphysema. Keywords: Iatrogenic injury, retropharyngeal emphysema, spontaneous retropharyngeal emphysem, trauma ...

  9. La maladie de Grisel : Spontaneous atlantoaxial subluxation

    NARCIS (Netherlands)

    Meek, MF; Robinson, PH; Hermens, RAEC

    Objective: "La maladie de Grisel" (Grisel's syndrome) is a spontaneously occurring atlantoaxial subluxation with torticollis. We present a case of atlantoaxial subluxation occurring in a 20-year period of pharyngoplasty surgery. The occurrence of a "spontaneous" atlantoaxial subluxation after oral

  10. Spontaneous swallowing frequency has potential to identify dysphagia in acute stroke.

    Science.gov (United States)

    Crary, Michael A; Carnaby, Giselle D; Sia, Isaac; Khanna, Anna; Waters, Michael F

    2013-12-01

    Spontaneous swallowing frequency has been described as an index of dysphagia in various health conditions. This study evaluated the potential of spontaneous swallow frequency analysis as a screening protocol for dysphagia in acute stroke. In a cohort of 63 acute stroke cases, swallow frequency rates (swallows per minute [SPM]) were compared with stroke and swallow severity indices, age, time from stroke to assessment, and consciousness level. Mean differences in SPM were compared between patients with versus without clinically significant dysphagia. Receiver operating characteristic curve analysis was used to identify the optimal threshold in SPM, which was compared with a validated clinical dysphagia examination for identification of dysphagia cases. Time series analysis was used to identify the minimally adequate time period to complete spontaneous swallow frequency analysis. SPM correlated significantly with stroke and swallow severity indices but not with age, time from stroke onset, or consciousness level. Patients with dysphagia demonstrated significantly lower SPM rates. SPM differed by dysphagia severity. Receiver operating characteristic curve analysis yielded a threshold of SPM≤0.40 that identified dysphagia (per the criterion referent) with 0.96 sensitivity, 0.68 specificity, and 0.96 negative predictive value. Time series analysis indicated that a 5- to 10-minute sampling window was sufficient to calculate spontaneous swallow frequency to identify dysphagia cases in acute stroke. Spontaneous swallowing frequency presents high potential to screen for dysphagia in acute stroke without the need for trained, available personnel.

  11. Spontaneous Swallowing Frequency [Has Potential to] Identify Dysphagia in Acute Stroke

    Science.gov (United States)

    Carnaby, Giselle D; Sia, Isaac; Khanna, Anna; Waters, Michael

    2014-01-01

    Background and Purpose Spontaneous swallowing frequency has been described as an index of dysphagia in various health conditions. This study evaluated the potential of spontaneous swallow frequency analysis as a screening protocol for dysphagia in acute stroke. Methods In a cohort of 63 acute stroke cases swallow frequency rates (swallows per minute: SPM) were compared to stroke and swallow severity indices, age, time from stroke to assessment, and consciousness level. Mean differences in SPM were compared between patients with vs. without clinically significant dysphagia. ROC analysis was used to identify the optimal threshold in SPM which was compared to a validated clinical dysphagia examination for identification of dysphagia cases. Time series analysis was employed to identify the minimally adequate time period to complete spontaneous swallow frequency analysis. Results SPM correlated significantly with stroke and swallow severity indices but not with age, time from stroke onset, or consciousness level. Patients with dysphagia demonstrated significantly lower SPM rates. SPM differed by dysphagia severity. ROC analysis yielded a threshold of SPM ≤ 0.40 which identified dysphagia (per the criterion referent) with 0.96 sensitivity, 0.68 specificity, and 0.96 negative predictive value. Time series analysis indicated that a 5 to 10 minute sampling window was sufficient to calculate spontaneous swallow frequency to identify dysphagia cases in acute stroke. Conclusions Spontaneous swallowing frequency presents high potential to screen for dysphagia in acute stroke without the need for trained, available personnel. PMID:24149008

  12. Elicitation threshold of cobalt chloride

    DEFF Research Database (Denmark)

    Fischer, Louise A; Johansen, Jeanne D; Voelund, Aage

    2016-01-01

    BACKGROUND: Cobalt is a strong skin sensitizer (grade 5 of 5 in the guinea-pig maximization test) that is used in various industrial and consumer applications. To prevent sensitization to cobalt and elicitation of allergic cobalt dermatitis, information about the elicitation threshold level...... of cobalt is important. OBJECTIVE: To identify the dermatitis elicitation threshold levels in cobalt-allergic individuals. MATERIALS AND METHODS: Published patch test dose-response studies were reviewed to determine the elicitation dose (ED) levels in dermatitis patients with a previous positive patch test...... reaction to cobalt. A logistic dose-response model was applied to data collected from the published literature to estimate ED values. The 95% confidence interval (CI) for the ratio of mean doses that can elicit a reaction in 10% (ED(10)) of a population was calculated with Fieller's method. RESULTS...

  13. Scaling behavior of threshold epidemics

    Science.gov (United States)

    Ben-Naim, E.; Krapivsky, P. L.

    2012-05-01

    We study the classic Susceptible-Infected-Recovered (SIR) model for the spread of an infectious disease. In this stochastic process, there are two competing mechanism: infection and recovery. Susceptible individuals may contract the disease from infected individuals, while infected ones recover from the disease at a constant rate and are never infected again. Our focus is the behavior at the epidemic threshold where the rates of the infection and recovery processes balance. In the infinite population limit, we establish analytically scaling rules for the time-dependent distribution functions that characterize the sizes of the infected and the recovered sub-populations. Using heuristic arguments, we also obtain scaling laws for the size and duration of the epidemic outbreaks as a function of the total population. We perform numerical simulations to verify the scaling predictions and discuss the consequences of these scaling laws for near-threshold epidemic outbreaks.

  14. Feedback from recently returned veterans on an anonymous web-based brief alcohol intervention.

    Science.gov (United States)

    Lapham, Gwen T; Hawkins, Eric J; Chavez, Laura J; Achtmeyer, Carol E; Williams, Emily C; Thomas, Rachel M; Ludman, Evette J; Kypri, Kypros; Hunt, Stephen C; Bradley, Katharine A

    2012-08-28

    Veterans of Operation Enduring Freedom and Operation Iraqi Freedom (OEF/OIF) are at increased risk for alcohol misuse, and innovative methods are needed to improve their access to alcohol screening and brief interventions (SBI). This study adapted an electronic SBI (e-SBI) website shown to be efficacious in college students for OEF/OIF veterans and reported findings from interviews with OEF/OIF veterans about their impressions of the e-SBI. Outpatient veterans of OEF/OIF who drank ≥3 days in the past week were recruited from a US Department of Veterans Affairs (VA) Deployment Health Clinic waiting room. Veterans privately pretested the anonymous e-SBI then completed individual semistructured audio-recorded interviews. Their responses were analyzed using template analysis to explore domains identified a priori as well as emergent domains. During interviews, all nine OEF/OIF veterans (1 woman and 8 men) indicated they had received feedback for risky alcohol consumption. Participants generally liked the standard-drinks image, alcohol-related caloric and monetary feedback, and the website's brevity and anonymity (a priori domains). They also experienced challenges with portions of the e-SBI assessment and viewed feedback regarding alcohol risk and normative drinking as problematic, but described potential benefits derived from the e-SBI (emergent domains). The most appealing e-SBIs would ensure anonymity and provide personalized transparent feedback about alcohol-related risk, consideration of the context for drinking, strategies to reduce drinking, and additional resources for veterans with more severe alcohol misuse. Results of this qualitative exploratory study suggest e-SBI may be an acceptable strategy for increasing OEF/OIF veteran access to evidenced-based alcohol SBI.

  15. Blinded Anonymization: a method for evaluating cancer prevention programs under restrictive data protection regulations.

    Science.gov (United States)

    Bartholomäus, Sebastian; Hense, Hans Werner; Heidinger, Oliver

    2015-01-01

    Evaluating cancer prevention programs requires collecting and linking data on a case specific level from multiple sources of the healthcare system. Therefore, one has to comply with data protection regulations which are restrictive in Germany and will likely become stricter in Europe in general. To facilitate the mortality evaluation of the German mammography screening program, with more than 10 Million eligible women, we developed a method that does not require written individual consent and is compliant to existing privacy regulations. Our setup is composed of different data owners, a data collection center (DCC) and an evaluation center (EC). Each data owner uses a dedicated software that preprocesses plain-text personal identifiers (IDAT) and plaintext evaluation data (EDAT) in such a way that only irreversibly encrypted record assignment numbers (RAN) and pre-aggregated, reversibly encrypted EDAT are transmitted to the DCC. The DCC uses the RANs to perform a probabilistic record linkage which is based on an established and evaluated algorithm. For potentially identifying attributes within the EDAT ('quasi-identifiers'), we developed a novel process, named 'blinded anonymization'. It allows selecting a specific generalization from the pre-processed and encrypted attribute aggregations, to create a new data set with assured k-anonymity, without using any plain-text information. The anonymized data is transferred to the EC where the EDAT is decrypted and used for evaluation. Our concept was approved by German data protection authorities. We implemented a prototype and tested it with more than 1.5 Million simulated records, containing realistically distributed IDAT. The core processes worked well with regard to performance parameters. We created different generalizations and calculated the respective suppression rates. We discuss modalities, implications and limitations for large data sets in the cancer registry domain, as well as approaches for further

  16. Spontaneous emission effects in optically pumped x-ray FEL

    Energy Technology Data Exchange (ETDEWEB)

    Smetanin, I.V.; Grigor`ev, S.V. [P.N. Lebedev Physics Institute, Moscow (Russian Federation)

    1995-12-31

    An effect of spontaneous emission in both quantum and classical regimes of the optically pumped X-ray free electron laser (FEL) in investigated. The quantum properties of an FEL are determined by the ratio of the separation {h_bar} between the absorption and emission lines (i.e. the quanta emitted) and their effective width {Delta}{epsilon} {eta}={h_bar}/{Delta}{epsilon}. In the conventional classical regime {eta} {much_lt} 1 an electron emits and absorbes a great number of shortwavelength photons over the interaction region, the gain in FEL being the result of these competitive processes. In the quantum limit {eta} {much_gt} 1 the emission and absorption lines are completely separated and thus the FEL becomes a two-level quantum oscillator with a completely inverted active medium. Spontaneous emission causes the electron to leave the range of energies where resonant interaction with the laser field occurs, thus effectively reducing the number of particles that take part in generating the induced X-ray signal. This effect is found to be crucial for lasing in optically pumped X-ray FEL. The characteristic relaxation times are calculated for both classical and quantum FEL regimes. It is shown that spontaneous emission results in FEL electron beam threshold current, which is of rather high value. An optimal range of pumping laser intensities is determined.

  17. Neutron angular distribution in plutonium-240 spontaneous fission

    Energy Technology Data Exchange (ETDEWEB)

    Marcath, Matthew J., E-mail: mmarcath@umich.edu [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109 (United States); Shin, Tony H.; Clarke, Shaun D. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109 (United States); Peerani, Paolo [European Commission at the Joint Research Centre, Ispra (Italy); Pozzi, Sara A. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109 (United States)

    2016-09-11

    Nuclear safeguards applications require accurate fission models that exhibit prompt neutron anisotropy. In the laboratory reference frame, an anisotropic neutron angular distribution is observed because prompt fission neutrons carry momentum from fully accelerated fission fragments. A liquid organic scintillation detector array was used with pulse shape discrimination techniques to produce neutron-neutron cross-correlation time distributions and angular distributions from spontaneous fission in a {sup 252}Cf, a 0.84 g {sup 240}Pu{sub eff} metal, and a 1.63 g {sup 240}Pu{sub eff} metal sample. The effect of cross-talk, estimated with MCNPX-PoliMi simulations, is removed from neutron-neutron coincidences as a function of the angle between detector pairs. Fewer coincidences were observed at detector angles near 90°, relative to higher and lower detector angles. As light output threshold increases, the observed anisotropy increases due to spectral effects arising from fission fragment momentum transfer to emitted neutrons. Stronger anisotropy was observed in Cf-252 spontaneous fission prompt neutrons than in Pu-240 neutrons. - Highlights: • Pu-240 prompt fission fast-neutron anisotropy was quantified for the first time. • MCNPX-PoliMi and MPPost codes were used to remove cross-talk neutron detections from experiment results. • Cf-252 spontaneous fission neutrons were found to be more anisotropic than Pu-240 neutrons.

  18. Roots at the Percolation Threshold

    Science.gov (United States)

    Kroener, E.; Ahmed, M. A.; Kaestner, A.; Vontobel, P.; Zarebanadkouki, M.; Carminati, A.

    2014-12-01

    Much of the carbon assimilated by plants during photosynthesis is lost to the soil via rhizodepositions. One component of rhizopdeposition is mucilage, a hydrogel that dramatically alters the soil physical properties. Mucilage was assumed to explain unexpectedly low rhizosphere rewetting rates during irrigation (Carminati et al. 2010) and temporarily water repellency in the rhizosphere after severe drying (Moradi et al. 2012).Here, we present an experimental and theoretical study for the rewetting behaviour of a soil mixed with mucilage, which was used as an analogue of the rhizosphere. Our samples were made of two layers of untreated soils separated by a thin layer (ca. 1 mm) of soil treated with mucilage. We prepared soil columns of varying particle size, mucilage concentration and height of the middle layer above the water table. The dry soil columns were re-wetted by capillary rise from the bottom.The rewetting of the middle layer showed a distinct dual behavior. For mucilage concentrations lower than a certain threshold, water could cross the thin layer almost immediately after rewetting of bulk soil. At slightly higher mucilage concentrations, the thin layer was almost impermeable. The mucilage concentration at the threshold strongly depended on particle size: the smaller the particle size the larger the soil specific surface and the more mucilage was needed to cover the entire particle surface and to induce water repellency.We applied a classic pore network model to simulate the experimental observations. In the model a certain fraction of nodes were randomly disconnected to reproduce the effect of mucilage in temporarily blocking the flow. The percolation model could qualitatively reproduce well the threshold characteristics of the experiments. Our experiments, together with former observations of water dynamics in the rhizosphere, suggest that the rhizosphere is near the percolation threshold, where small variations in mucilage concentration sensitively

  19. Realistic Realizations Of Threshold Circuits

    Science.gov (United States)

    Razavi, Hassan M.

    1987-08-01

    Threshold logic, in which each input is weighted, has many theoretical advantages over the standard gate realization, such as reducing the number of gates, interconnections, and power dissipation. However, because of the difficult synthesis procedure and complicated circuit implementation, their use in the design of digital systems is almost nonexistant. In this study, three methods of NMOS realizations are discussed, and their advantages and shortcomings are explored. Also, the possibility of using the methods to realize multi-valued logic is examined.

  20. Root finding with threshold circuits

    Czech Academy of Sciences Publication Activity Database

    Jeřábek, Emil

    2012-01-01

    Roč. 462, Nov 30 (2012), s. 59-69 ISSN 0304-3975 R&D Projects: GA AV ČR IAA100190902; GA MŠk(CZ) 1M0545 Institutional support: RVO:67985840 Keywords : root finding * threshold circuit * power series Subject RIV: BA - General Mathematics Impact factor: 0.489, year: 2012 http://www.sciencedirect.com/science/article/pii/S0304397512008006#

  1. An improved biometrics-based remote user authentication scheme with user anonymity.

    Science.gov (United States)

    Khan, Muhammad Khurram; Kumari, Saru

    2013-01-01

    The authors review the biometrics-based user authentication scheme proposed by An in 2012. The authors show that there exist loopholes in the scheme which are detrimental for its security. Therefore the authors propose an improved scheme eradicating the flaws of An's scheme. Then a detailed security analysis of the proposed scheme is presented followed by its efficiency comparison. The proposed scheme not only withstands security problems found in An's scheme but also provides some extra features with mere addition of only two hash operations. The proposed scheme allows user to freely change his password and also provides user anonymity with untraceability.

  2. Applying Semigroup Property of Enhanced Chebyshev Polynomials to Anonymous Authentication Protocol

    Directory of Open Access Journals (Sweden)

    Hong Lai

    2012-01-01

    Full Text Available We apply semigroup property of enhanced Chebyshev polynomials to present an anonymous authentication protocol. This paper aims at improving security and reducing computational and storage overhead. The proposed scheme not only has much lower computational complexity and cost in the initialization phase but also allows the users to choose their passwords freely. Moreover, it can provide revocation of lost or stolen smart card, which can resist man-in-the-middle attack and off-line dictionary attack together with various known attacks.

  3. An Improved Biometrics-Based Remote User Authentication Scheme with User Anonymity

    Directory of Open Access Journals (Sweden)

    Muhammad Khurram Khan

    2013-01-01

    Full Text Available The authors review the biometrics-based user authentication scheme proposed by An in 2012. The authors show that there exist loopholes in the scheme which are detrimental for its security. Therefore the authors propose an improved scheme eradicating the flaws of An’s scheme. Then a detailed security analysis of the proposed scheme is presented followed by its efficiency comparison. The proposed scheme not only withstands security problems found in An’s scheme but also provides some extra features with mere addition of only two hash operations. The proposed scheme allows user to freely change his password and also provides user anonymity with untraceability.

  4. Generalised universality of gauge thresholds in heterotic vacua with and without supersymmetry

    CERN Document Server

    Angelantonj, Carlo; Tsulaia, Mirian

    2015-01-01

    We study one-loop quantum corrections to gauge couplings in heterotic vacua with spontaneous supersymmetry breaking. Although in non-supersymmetric constructions these corrections are not protected and are typically model dependent, we show how a universal behaviour of threshold differences, typical of supersymmetric vacua, may still persist. We formulate specific conditions on the way supersymmetry should be broken for this to occur. Our analysis implies a generalised notion of threshold universality even in the case of unbroken supersymmetry, whenever extra charged massless states appear at enhancement points in the bulk of moduli space. Several examples with universality, including non-supersymmetric chiral models in four dimensions, are presented.

  5. Systematics of spontaneous positron lines

    International Nuclear Information System (INIS)

    Mueller, U.; Reus, T. de; Reinhardt, J.; Mueller, B.; Greiner, W.

    1985-08-01

    Dynamical and spontaneous positron emission are investigated for heavy-ion collisions with long time delay using a semiclassical description. Numerical results and analytical expressions for the characteristic quantities of the resulting spontaneous positron line, i.e., its position, width, and cross section, are compared. The expected behaviour of the line position and cross section and its visibility against the spectrum of dynamically created positrons is discussed in dependence of the united charge Zsub(u) of projectile and target nucleus in a range of systems from Zsub(u)=180 up to Zsub(u)=188. The results are confronted with presently available experimental data, and possible implications on further experiments are worked out. (orig.)

  6. Spontaneous Rotational Inversion in Phycomyces

    KAUST Repository

    Goriely, Alain

    2011-03-01

    The filamentary fungus Phycomyces blakesleeanus undergoes a series of remarkable transitions during aerial growth. During what is known as the stagea IV growth phase, the fungus extends while rotating in a counterclockwise manner when viewed from above (stagea IVa) and then, while continuing to grow, spontaneously reverses to a clockwise rotation (stagea IVb). This phase lasts for 24-48Ah and is sometimes followed by yet another reversal (stageAIVc) before the overall growth ends. Here, we propose a continuum mechanical model of this entire process using nonlinear, anisotropic, elasticity and show how helical anisotropy associated with the cell wall structure can induce spontaneous rotation and, under appropriate circumstances, the observed reversal of rotational handedness. © 2011 American Physical Society.

  7. Spontaneous regression of colon cancer.

    Science.gov (United States)

    Kihara, Kyoichi; Fujita, Shin; Ohshiro, Taihei; Yamamoto, Seiichiro; Sekine, Shigeki

    2015-01-01

    A case of spontaneous regression of transverse colon cancer is reported. A 64-year-old man was diagnosed as having cancer of the transverse colon at a local hospital. Initial and second colonoscopy examinations revealed a typical cancer of the transverse colon, which was diagnosed as moderately differentiated adenocarcinoma. The patient underwent right hemicolectomy 6 weeks after the initial colonoscopy. The resected specimen showed only a scar at the tumor site, and no cancerous tissue was proven histologically. The patient is alive with no evidence of recurrence 1 year after surgery. Although an antitumor immune response is the most likely explanation, the exact nature of the phenomenon was unclear. We describe this rare case and review the literature pertaining to spontaneous regression of colorectal cancer. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Management of intractable spontaneous epistaxis

    Science.gov (United States)

    Rudmik, Luke

    2012-01-01

    Background: Epistaxis is a common otolaryngology emergency and is often controlled with first-line interventions such as cautery, hemostatic agents, or anterior nasal packing. A subset of patients will continue to bleed and require more aggressive therapy. Methods: Intractable spontaneous epistaxis was traditionally managed with posterior nasal packing and prolonged hospital admission. In an effort to reduce patient morbidity and shorten hospital stay, surgical and endovascular techniques have gained popularity. A literature review was conducted. Results: Transnasal endoscopic sphenopalatine artery ligation and arterial embolization provide excellent control rates but the decision to choose one over the other can be challenging. The role of transnasal endoscopic anterior ethmoid artery ligation is unclear but may be considered in certain cases when bleeding localizes to the ethmoid region. Conclusion: This article will focus on the management of intractable spontaneous epistaxis and discuss the role of endoscopic arterial ligation and embolization as it pertains to this challenging clinical scenario. PMID:22391084

  9. Color difference thresholds in dentistry.

    Science.gov (United States)

    Paravina, Rade D; Ghinea, Razvan; Herrera, Luis J; Bona, Alvaro D; Igiel, Christopher; Linninger, Mercedes; Sakai, Maiko; Takahashi, Hidekazu; Tashkandi, Esam; Perez, Maria del Mar

    2015-01-01

    The aim of this prospective multicenter study was to determine 50:50% perceptibility threshold (PT) and 50:50% acceptability threshold (AT) of dental ceramic under simulated clinical settings. The spectral radiance of 63 monochromatic ceramic specimens was determined using a non-contact spectroradiometer. A total of 60 specimen pairs, divided into 3 sets of 20 specimen pairs (medium to light shades, medium to dark shades, and dark shades), were selected for psychophysical experiment. The coordinating center and seven research sites obtained the Institutional Review Board (IRB) approvals prior the beginning of the experiment. Each research site had 25 observers, divided into five groups of five observers: dentists-D, dental students-S, dental auxiliaries-A, dental technicians-T, and lay persons-L. There were 35 observers per group (five observers per group at each site ×7 sites), for a total of 175 observers. Visual color comparisons were performed using a viewing booth. Takagi-Sugeno-Kang (TSK) fuzzy approximation was used for fitting the data points. The 50:50% PT and 50:50% AT were determined in CIELAB and CIEDE2000. The t-test was used to evaluate the statistical significance in thresholds differences. The CIELAB 50:50% PT was ΔEab  = 1.2, whereas 50:50% AT was ΔEab  = 2.7. Corresponding CIEDE2000 (ΔE00 ) values were 0.8 and 1.8, respectively. 50:50% PT by the observer group revealed differences among groups D, A, T, and L as compared with 50:50% PT for all observers. The 50:50% AT for all observers was statistically different than 50:50% AT in groups T and L. A 50:50% perceptibility and ATs were significantly different. The same is true for differences between two color difference formulas ΔE00 /ΔEab . Observer groups and sites showed high level of statistical difference in all thresholds. Visual color difference thresholds can serve as a quality control tool to guide the selection of esthetic dental materials, evaluate clinical performance, and

  10. Spontaneous baryogenesis in warm inflation

    OpenAIRE

    Brandenberger, Robert H.; Yamaguchi, Masahide

    2003-01-01

    We discuss spontaneous baryogenesis in the warm inflation scenario. In contrast with standard inflation models, radiation always exists in the warm inflation scenario, and the inflaton must be directly coupled to it. Also, the transition to the post-inflationary radiation dominated phase is smooth and the entropy is not significantly increased at the end of the period of inflation. In addition, after the period of warm inflation ends, the inflaton does not oscillate coherently but slowly roll...

  11. Voting on Thresholds for Public Goods

    DEFF Research Database (Denmark)

    Rauchdobler, Julian; Sausgruber, Rupert; Tyran, Jean-Robert

    Introducing a threshold in the sense of a minimal project size transforms a public goods game with an inefficient equilibrium into a coordination game with a set of Pareto-superior equilibria. Thresholds may therefore improve efficiency in the voluntary provision of public goods. In our one......-shot experiment, we find that coordination often fails and exogenously imposed thresholds are ineffective at best and often counter-productive. This holds under a range of threshold levels and refund rates. We test if thresholds perform better if they are endogenously chosen, i.e. if a threshold is approved...

  12. Spontaneous Splenic Rupture in Melanoma

    Directory of Open Access Journals (Sweden)

    Hadi Mirfazaelian

    2014-01-01

    Full Text Available Spontaneous rupture of spleen due to malignant melanoma is a rare situation, with only a few case reports in the literature. This study reports a previously healthy, 30-year-old man who came with chief complaint of acute abdominal pain to emergency room. On physical examination, abdominal tenderness and guarding were detected to be coincident with hypotension. Ultrasonography revealed mild splenomegaly with moderate free fluid in abdominopelvic cavity. Considering acute abdominal pain and hemodynamic instability, he underwent splenectomy with splenic rupture as the source of bleeding. Histologic examination showed diffuse infiltration by tumor. Immunohistochemical study (positive for S100, HMB45, and vimentin and negative for CK, CD10, CK20, CK7, CD30, LCA, EMA, and chromogranin confirmed metastatic malignant melanoma. On further questioning, there was a past history of a nasal dark skin lesion which was removed two years ago with no pathologic examination. Spontaneous (nontraumatic rupture of spleen is an uncommon situation and it happens very rarely due to neoplastic metastasis. Metastasis of malignant melanoma is one of the rare causes of the spontaneous rupture of spleen.

  13. Sexual practices among men attending an anonymous HIV testing site in Singapore.

    Science.gov (United States)

    Bishop, G D; Kok, A J; Chan, R K

    1998-06-01

    This study was undertaken to provide an empirical basis for planning safer sex interventions in Singapore by examining the sexual practices of men attending an anonymous HIV testing site. All male clients attending the testing site from January, 1996 to January 1997 were asked to complete an anonymous questionnaire concerning oral and anal sex with men as well as vaginal, oral and anal sex with women within the past year. Questionnaires were obtained from 251 male clients, ranging in age from 17 to 70 years (mean = 30.3). Of these 50.6% reported sex with women only, 39% with men only, 7.2% with both men and women and 3.2% with no one. Condom use was moderately high for anal and vaginal sex but low for oral sex. A risk index based on the riskiness of specific activities showed that bisexuals were the most likely to engage in high risk behaviour whereas homosexuals were the least likely. One factor in the greater riskiness of bisexuals' behaviour appeared to be a higher frequency of unprotected sex with women. These findings provide a preliminary portrait of sexual risk-taking among men in Singapore and suggest the need for continued emphasis on consistent condom use for penetrative sex as well as appropriate precautions for oral sex. The results also suggest the need to develop targeted interventions for bisexuals, particularly with respect to unprotected sex with women.

  14. Privacy preserving data publishing of categorical data through k-anonymity and feature selection.

    Science.gov (United States)

    Aristodimou, Aristos; Antoniades, Athos; Pattichis, Constantinos S

    2016-03-01

    In healthcare, there is a vast amount of patients' data, which can lead to important discoveries if combined. Due to legal and ethical issues, such data cannot be shared and hence such information is underused. A new area of research has emerged, called privacy preserving data publishing (PPDP), which aims in sharing data in a way that privacy is preserved while the information lost is kept at a minimum. In this Letter, a new anonymisation algorithm for PPDP is proposed, which is based on k-anonymity through pattern-based multidimensional suppression (kPB-MS). The algorithm uses feature selection for reducing the data dimensionality and then combines attribute and record suppression for obtaining k-anonymity. Five datasets from different areas of life sciences [RETINOPATHY, Single Proton Emission Computed Tomography imaging, gene sequencing and drug discovery (two datasets)], were anonymised with kPB-MS. The produced anonymised datasets were evaluated using four different classifiers and in 74% of the test cases, they produced similar or better accuracies than using the full datasets.

  15. A robust uniqueness-and-anonymity-preserving remote user authentication scheme for connected health care.

    Science.gov (United States)

    Wen, Fengtong

    2013-12-01

    User authentication plays an important role to protect resources or services from being accessed by unauthorized users. In a recent paper, Das et al. proposed a secure and efficient uniqueness-and-anonymity-preserving remote user authentication scheme for connected health care. This scheme uses three factors, e.g. biometrics, password, and smart card, to protect the security. It protects user privacy and is believed to have many abilities to resist a range of network attacks, even if the secret information stored in the smart card is compromised. In this paper, we analyze the security of Das et al.'s scheme, and show that the scheme is in fact insecure against the replay attack, user impersonation attacks and off-line guessing attacks. Then, we also propose a robust uniqueness-and-anonymity-preserving remote user authentication scheme for connected health care. Compared with the existing schemes, our protocol uses a different user authentication mechanism to resist replay attack. We show that our proposed scheme can provide stronger security than previous protocols. Furthermore, we demonstrate the validity of the proposed scheme through the BAN (Burrows, Abadi, and Needham) logic.

  16. CRYPTOGRAPHIC SECURE CLOUD STORAGE MODEL WITH ANONYMOUS AUTHENTICATION AND AUTOMATIC FILE RECOVERY

    Directory of Open Access Journals (Sweden)

    Sowmiya Murthy

    2014-10-01

    Full Text Available We propose a secure cloud storage model that addresses security and storage issues for cloud computing environments. Security is achieved by anonymous authentication which ensures that cloud users remain anonymous while getting duly authenticated. For achieving this goal, we propose a digital signature based authentication scheme with a decentralized architecture for distributed key management with multiple Key Distribution Centers. Homomorphic encryption scheme using Paillier public key cryptosystem is used for encrypting the data that is stored in the cloud. We incorporate a query driven approach for validating the access policies defined by an individual user for his/her data i.e. the access is granted to a requester only if his credentials matches with the hidden access policy. Further, since data is vulnerable to losses or damages due to the vagaries of the network, we propose an automatic retrieval mechanism where lost data is recovered by data replication and file replacement with string matching algorithm. We describe a prototype implementation of our proposed model.

  17. Moves on the Street: Classifying Crime Hotspots Using Aggregated Anonymized Data on People Dynamics.

    Science.gov (United States)

    Bogomolov, Andrey; Lepri, Bruno; Staiano, Jacopo; Letouzé, Emmanuel; Oliver, Nuria; Pianesi, Fabio; Pentland, Alex

    2015-09-01

    The wealth of information provided by real-time streams of data has paved the way for life-changing technological advancements, improving the quality of life of people in many ways, from facilitating knowledge exchange to self-understanding and self-monitoring. Moreover, the analysis of anonymized and aggregated large-scale human behavioral data offers new possibilities to understand global patterns of human behavior and helps decision makers tackle problems of societal importance. In this article, we highlight the potential societal benefits derived from big data applications with a focus on citizen safety and crime prevention. First, we introduce the emergent new research area of big data for social good. Next, we detail a case study tackling the problem of crime hotspot classification, that is, the classification of which areas in a city are more likely to witness crimes based on past data. In the proposed approach we use demographic information along with human mobility characteristics as derived from anonymized and aggregated mobile network data. The hypothesis that aggregated human behavioral data captured from the mobile network infrastructure, in combination with basic demographic information, can be used to predict crime is supported by our findings. Our models, built on and evaluated against real crime data from London, obtain accuracy of almost 70% when classifying whether a specific area in the city will be a crime hotspot or not in the following month.

  18. Optimizing Systems of Threshold Detection Sensors

    National Research Council Canada - National Science Library

    Banschbach, David C

    2008-01-01

    .... Below the threshold all signals are ignored. We develop a mathematical model for setting individual sensor thresholds to obtain optimal probability of detecting a significant event, given a limit on the total number of false positives allowed...

  19. Nuclear thermodynamics below particle threshold

    International Nuclear Information System (INIS)

    Schiller, A.; Agvaanluvsan, U.; Algin, E.; Bagheri, A.; Chankova, R.; Guttormsen, M.; Hjorth-Jensen, M.; Rekstad, J.; Siem, S.; Sunde, A. C.; Voinov, A.

    2005-01-01

    From a starting point of experimentally measured nuclear level densities, we discuss thermodynamical properties of nuclei below the particle emission threshold. Since nuclei are essentially mesoscopic systems, a straightforward generalization of macroscopic ensemble theory often yields unphysical results. A careful critique of traditional thermodynamical concepts reveals problems commonly encountered in mesoscopic systems. One of which is the fact that microcanonical and canonical ensemble theory yield different results, another concerns the introduction of temperature for small, closed systems. Finally, the concept of phase transitions is investigated for mesoscopic systems

  20. The long path to pregnancy: early experience with dual anonymous gamete donation in a European in vitro fertilisation referral centre.

    Science.gov (United States)

    Sills, Eric Scott; Mykhaylyshyn, Lyubov O; Dorofeyeva, Ulyana S; Walsh, David J; Salma, Umme; Omar, Ahmed B; Coull, Graham D; David, Ileana A; Brickell, Kathy M; Tsar, Olga M; Walsh, Anthony Ph

    2010-08-11

    This investigation describes features of patients undergoing in vitro fertilisation (IVF) and embryo transfer (ET) where both gametes were obtained from anonymous donors. Gamete unsuitability or loss was confirmed in both members of seven otherwise healthy couples presenting for reproductive endocrinology consultation over a 12-month interval in Ireland. IVF was undertaken with fresh oocytes provided by anonymous donors in Ukraine; frozen sperm (anonymous donor) was obtained from a licensed tissue establishment. For recipients, saline-enhanced sonography was used to assess intrauterine contour with endometrial preparation via transdermal estrogen. Among commissioning couples, mean+/-SD female and male age was 41.9 +/- 3.7 and 44.6 +/- 3.5 yrs, respectively. During this period, female age for non dual anonymous gamete donation IVF patients was 37.9 +/- 3 yrs (p /=3 yrs for couples enrolling in dual gamete donation, and each had >/=2 prior failed fertility treatments using native oocytes. All seven recipient couples proceeded to embryo transfer, although one patient had two transfers. Clinical pregnancy was achieved for 5/7 (71.4%) patients. Non-transferred cryopreserved embryos were available for all seven couples. Mean age of females undergoing dual anonymous donor gamete donation with IVF is significantly higher than the background IVF patient population. Even when neither partner is able to contribute any gametes for IVF, the clinical pregnancy rate per transfer can be satisfactory if both anonymous egg and sperm donation are used concurrently. Our report emphasises the role of pre-treatment counselling in dual anonymous gamete donation, and presents a coordinated screening and treatment approach in IVF where this option may be contemplated.

  1. The long path to pregnancy: early experience with dual anonymous gamete donation in a European in vitro fertilisation referral centre

    LENUS (Irish Health Repository)

    Sills, Eric Scott

    2010-08-11

    Abstract Background This investigation describes features of patients undergoing in vitro fertilisation (IVF) and embryo transfer (ET) where both gametes were obtained from anonymous donors. Methods Gamete unsuitability or loss was confirmed in both members of seven otherwise healthy couples presenting for reproductive endocrinology consultation over a 12-month interval in Ireland. IVF was undertaken with fresh oocytes provided by anonymous donors in Ukraine; frozen sperm (anonymous donor) was obtained from a licensed tissue establishment. For recipients, saline-enhanced sonography was used to assess intrauterine contour with endometrial preparation via transdermal estrogen. Results Among commissioning couples, mean±SD female and male age was 41.9 ± 3.7 and 44.6 ± 3.5 yrs, respectively. During this period, female age for non dual anonymous gamete donation IVF patients was 37.9 ± 3 yrs (p < 0.001). Infertility duration was ≥3 yrs for couples enrolling in dual gamete donation, and each had ≥2 prior failed fertility treatments using native oocytes. All seven recipient couples proceeded to embryo transfer, although one patient had two transfers. Clinical pregnancy was achieved for 5\\/7 (71.4%) patients. Non-transferred cryopreserved embryos were available for all seven couples. Conclusions Mean age of females undergoing dual anonymous donor gamete donation with IVF is significantly higher than the background IVF patient population. Even when neither partner is able to contribute any gametes for IVF, the clinical pregnancy rate per transfer can be satisfactory if both anonymous egg and sperm donation are used concurrently. Our report emphasises the role of pre-treatment counselling in dual anonymous gamete donation, and presents a coordinated screening and treatment approach in IVF where this option may be contemplated.

  2. Threshold Concepts in Finance: Student Perspectives

    Science.gov (United States)

    Hoadley, Susan; Kyng, Tim; Tickle, Leonie; Wood, Leigh N.

    2015-01-01

    Finance threshold concepts are the essential conceptual knowledge that underpin well-developed financial capabilities and are central to the mastery of finance. In this paper we investigate threshold concepts in finance from the point of view of students, by establishing the extent to which students are aware of threshold concepts identified by…

  3. METAL DELM - metal avrelianis contribution to the study of mining coins and anonymous quadrantes

    Directory of Open Access Journals (Sweden)

    Vojvoda Mirjana D.

    2016-01-01

    Full Text Available In the course of rescue archaeological investigations at the Viminacium necropolis of Vi{e Grobalja in 1984, one anonymous quadrans of the VIII Apollo group was discovered (cat. 1. It was discovered in trench 63 in the immediate vicinity of a grave with an inhumation (G 343 that, besides two pottery vessels, also yielded as grave offerings one as of Faustina the Elder, minted after her death, in AD 141. Other finds presented here are four specimens of Roman mining coins from the private collection of Petar Fajfri} from [abac (cat. 2-5. All specimens come from the well known site of Duge Njive in the area of the village of Banatsko Polje (Bogati} borough where, by all appearances, are the remains of a vicus or smaller settlement. Five specimens of mining coins from that site have already been published. Both mining coins and anonymous quadrantes represent, in general, rare types of numismatic finds. Nine anonymous quadrantes are known so far from the territory of Serbia (Table 1 and the provenance is known for three specimens from the region of Guberevac-Babe (Kosmaj, housed in the National Museum in Belgrade. All three belong to the Minerva group with an owl facing to the right represented on the reverse. For two more anonymous quadrantes the place of discovery is known: one specimen comes from Singidunum and belongs to the Mercury group and the other that was found at Viminacium and is the subject of this paper is of the Apollo group. There are four more specimens from unknown sites for which it is assumed that they come from the Upper Moesia territory. Two of them are from the Vajfert collection and two from the Kovačević collection in the National Museum in Belgrade, There has, however, been a somewhat greater number (38 of Roman mining coins discovered in Serbia (Table 1. We know the finding locations of 25 of them: from the Kosmaj area (Babe, Guberevac and Stojnik, the Ibar valley (from the vicinity of Trepča and So~anica, Ritopek

  4. Threshold enhancement of diphoton resonances

    CERN Document Server

    Bharucha, Aoife; Goudelis, Andreas

    2016-10-10

    The data collected by the LHC collaborations at an energy of 13 TeV indicates the presence of an excess in the diphoton spectrum that would correspond to a resonance of a 750 GeV mass. The apparently large production cross section is nevertheless very difficult to explain in minimal models. We consider the possibility that the resonance is a pseudoscalar boson $A$ with a two--photon decay mediated by a charged and uncolored fermion having a mass at the $\\frac12 M_A$ threshold and a very small decay width, $\\ll 1$ MeV; one can then generate a large enhancement of the $A\\gamma\\gamma$ amplitude which explains the excess without invoking a large multiplicity of particles propagating in the loop, large electric charges and/or very strong Yukawa couplings. The implications of such a threshold enhancement are discussed in two explicit scenarios: i) the Minimal Supersymmetric Standard Model in which the $A$ state is produced via the top quark mediated gluon fusion process and decays into photons predominantly through...

  5. Perturbation analysis of spontaneous action potential initiation by stochastic ion channels

    KAUST Repository

    Keener, James P.

    2011-07-01

    A stochastic interpretation of spontaneous action potential initiation is developed for the Morris-Lecar equations. Initiation of a spontaneous action potential can be interpreted as the escape from one of the wells of a double well potential, and we develop an asymptotic approximation of the mean exit time using a recently developed quasistationary perturbation method. Using the fact that the activating ionic channel\\'s random openings and closings are fast relative to other processes, we derive an accurate estimate for the mean time to fire an action potential (MFT), which is valid for a below-threshold applied current. Previous studies have found that for above-threshold applied current, where there is only a single stable fixed point, a diffusion approximation can be used. We also explore why different diffusion approximation techniques fail to estimate the MFT. © 2011 American Physical Society.

  6. Anonymous sex and HIV risk practices among men using the Internet specifically to find male partners for unprotected sex.

    Science.gov (United States)

    Klein, H

    2012-06-01

    To examine the popularity of anonymous sex practices among men using the Internet to find male partners for unprotected sex, and how anonymous sex relates to involvement in other HIV-related risk behaviours, and to investigate the factors associated with engaging in anonymous sex. Structured telephone interviews were conducted with men who used the Internet specifically to find male partners for unprotected sex. Random sampling from 16 websites was used to obtain a national sample. The data reported in this paper were based on quantitative interviews collected with a cross-sectional study design. Between January 2008 and May 2009, confidential telephone interviews lasting approximately 1-2 h were completed with 332 men. Participants were paid $35 for their participation. Most of the men (67.4%) liked anonymous sex, and slightly more than half (51.2%) had engaged in the behaviour during the month prior to interview. Involvement in anonymous sex was associated with greater involvement in a variety of human immunodeficiency virus (HIV)-related risk practices, such as illegal drug use, number of sex partners, and amount of unprotected sex. Four factors were associated with having vs not having anonymous sex: (1) being HIV positive; (2) answering all of the HIV-related knowledge questions correctly; (3) deriving greater enjoyment from having sex in public places, such as parks, public toilets, or adult book shops; and (4) greater impulsivity. Seven factors were associated with greater vs lesser involvement in anonymous sex among those practising the behaviour: (1) being involved in a relationship with a long-term partner; (2) liking to have sex in public places; (3) using bareback-oriented websites to identify sex partners; (4) greater impulsivity; (5) low level of condom use self-efficacy; (6) greater knowledge about HIV/acquired immunodeficiency syndrome; and either (7a) severe childhood maltreatment or (7b) Caucasian race. Men in this population often sought

  7. Spontaneous oscillations in microfluidic networks

    Science.gov (United States)

    Case, Daniel; Angilella, Jean-Regis; Motter, Adilson

    2017-11-01

    Precisely controlling flows within microfluidic systems is often difficult which typically results in systems being heavily reliant on numerous external pumps and computers. Here, I present a simple microfluidic network that exhibits flow rate switching, bistablity, and spontaneous oscillations controlled by a single pressure. That is, by solely changing the driving pressure, it is possible to switch between an oscillating and steady flow state. Such functionality does not rely on external hardware and may even serve as an on-chip memory or timing mechanism. I use an analytic model and rigorous fluid dynamics simulations to show these results.

  8. General features of spontaneous baryogenesis

    Science.gov (United States)

    Arbuzova, Elena

    2017-04-01

    The classical version of spontaneous baryogenesis is studied in details. It is shown that the relation between the time derivative of the (pseudo)goldstone field and the baryonic chemical potential essentially depends upon the representation chosen for the fermionic fields with non-zero baryonic number (quarks). The kinetic equation, used for the calculations of the cosmological baryon asymmetry, is generalized to the case of non-stationary background. The effects of the finite interval of the integration over time are also included into consideration.

  9. Spontaneous osteonecrosis of the knee

    Energy Technology Data Exchange (ETDEWEB)

    Kattapuram, Taj M. [Department of Radiology, Massachusetts General Hospital (United States); Kattapuram, Susan V. [Department of Radiology, Massachusetts General Hospital (United States)], E-mail: skattapuram@partners.org

    2008-07-15

    Spontaneous osteonecrosis of the knee presents with acute onset of severe, pain in elderly patients, usually female and usually without a history of trauma. Originally described as idiopathic osteonecrosis, the exact etiology is still debated. Evidence suggests that an acute fracture occurs as a result of chronic stress or minor trauma to a weakened subchondral bone plate. The imaging characteristics on MR reflect the age of the lesion and the symptoms. More appropriate terminology may be ' subchondral insufficiency fracture of the knee' or 'focal subchondral osteonecrosis'.

  10. Anonymity versus privacy in the dictator game: revealing donor decisions to recipients does not substantially impact donor behavior.

    Directory of Open Access Journals (Sweden)

    Jeffrey Winking

    Full Text Available Anonymity is often offered in economic experiments in order to eliminate observer effects and induce behavior that would be exhibited under private circumstances. However, anonymity differs from privacy in that interactants are only unaware of each others' identities, while having full knowledge of each others' actions. Such situations are rare outside the laboratory and anonymity might not meet the requirements of some participants to psychologically engage as if their actions were private. In order to explore the impact of a lack of privacy on prosocial behaviors, I expand on a study reported in Dana et al. (2006 in which recipients were left unaware of the Dictator Game and given donations as "bonuses" to their show-up fees for other tasks. In the current study, I explore whether differences between a private Dictator Game (sensu Dana et al. (2006 and a standard anonymous one are due to a desire by dictators to avoid shame or to pursue prestige. Participants of a Dictator Game were randomly assigned to one of four categories-one in which the recipient knew of (1 any donation by an anonymous donor (including zero donations, (2 nothing at all, (3 only zero donations, and (4 and only non-zero donations. The results suggest that a lack of privacy increases the shame that selfish-acting participants experience, but that removing such a cost has only minimal effects on actual behavior.

  11. A robust anonymous biometric-based authenticated key agreement scheme for multi-server environments.

    Science.gov (United States)

    Guo, Hua; Wang, Pei; Zhang, Xiyong; Huang, Yuanfei; Ma, Fangchao

    2017-01-01

    In order to improve the security in remote authentication systems, numerous biometric-based authentication schemes using smart cards have been proposed. Recently, Moon et al. presented an authentication scheme to remedy the flaws of Lu et al.'s scheme, and claimed that their improved protocol supports the required security properties. Unfortunately, we found that Moon et al.'s scheme still has weaknesses. In this paper, we show that Moon et al.'s scheme is vulnerable to insider attack, server spoofing attack, user impersonation attack and guessing attack. Furthermore, we propose a robust anonymous multi-server authentication scheme using public key encryption to remove the aforementioned problems. From the subsequent formal and informal security analysis, we demonstrate that our proposed scheme provides strong mutual authentication and satisfies the desirable security requirements. The functional and performance analysis shows that the improved scheme has the best secure functionality and is computational efficient.

  12. Improving an Anonymous and Provably Secure Authentication Protocol for a Mobile User

    Directory of Open Access Journals (Sweden)

    Jongho Moon

    2017-01-01

    Full Text Available Recently many authentication protocols using an extended chaotic map were suggested for a mobile user. Many researchers demonstrated that authentication protocol needs to provide key agreement, mutual authentication, and user anonymity between mobile user and server and resilience to many possible attacks. In this paper, we cautiously analyzed chaotic-map-based authentication scheme and proved that it is still insecure to off-line identity guessing, user and server impersonation, and on-line identity guessing attacks. To address these vulnerabilities, we proposed an improved protocol based on an extended chaotic map and a fuzzy extractor. We proved the security of the proposed protocol using a random oracle and AVISPA (Automated Validation of Internet Security Protocols and Applications tool. Furthermore, we present an informal security analysis to make sure that the improved protocol is invulnerable to possible attacks. The proposed protocol is also computationally efficient when compared to other previous protocols.

  13. Female and male life stories published in the Finnish Alcoholics Anonymous journal.

    Science.gov (United States)

    Aaltonen, I; Mäkelä, K

    1994-03-01

    To study differences in how women and men describe their drinking problems, key expressions were recorded in 50 female and 50 male stories published in the Finnish A.A. (Alcoholics Anonymous) journal. Men show more interest in the past and try to understand their lives in causal terms. Women focus on the present and on experiences in A.A. Men more frequently mention narcotics and alcohol substitutes; medical drugs are more common in female stories. Men's stories more frequently contain social deviance. Women pay more attention to social relationships. The phrase Higher Power is used with equal frequency, but women more commonly use the word God. Women express more positive emotions. Registers of negative emotions differ. The drinking man is threatened by feelings of inferiority; the drinking woman by shame and guilt.

  14. A Clustering K-Anonymity Privacy-Preserving Method for Wearable IoT Devices

    Directory of Open Access Journals (Sweden)

    Fang Liu

    2018-01-01

    Full Text Available Wearable technology is one of the greatest applications of the Internet of Things. The popularity of wearable devices has led to a massive scale of personal (user-specific data. Generally, data holders (manufacturers of wearable devices are willing to share these data with others to get benefits. However, significant privacy concerns would arise when sharing the data with the third party in an improper manner. In this paper, we first propose a specific threat model about the data sharing process of wearable devices’ data. Then we propose a K-anonymity method based on clustering to preserve privacy of wearable IoT devices’ data and guarantee the usability of the collected data. Experiment results demonstrate the effectiveness of the proposed method.

  15. Safe2Tell® : an anonymous, 24/7 reporting system for preventing school violence.

    Science.gov (United States)

    Payne, Susan R T; Elliott, Delbert S

    2011-01-01

    There is widespread agreement that many school shootings could be prevented if authorities were informed that a student was planning or preparing to carry out an attack. A universal problem is that young people are highly reluctant to report on their peers. This code of silence represents a major barrier to prevention efforts. In response to the Columbine shooting, the state of Colorado established the Safe2Tell® anonymous, 24/7 reporting system for receiving and forwarding threats of violence, bullying, and other concerns. This article describes how the program has grown to the point that it now receives more than 100 calls per month. A series of case examples illustrates its success in responding to threatening situations, including twenty-eight potential school attacks. Copyright © 2011 Wiley Periodicals, Inc., A Wiley Company.

  16. Improvement of a uniqueness-and-anonymity-preserving user authentication scheme for connected health care.

    Science.gov (United States)

    Xie, Qi; Liu, Wenhao; Wang, Shengbao; Han, Lidong; Hu, Bin; Wu, Ting

    2014-09-01

    Patient's privacy-preserving, security and mutual authentication between patient and the medical server are the important mechanism in connected health care applications, such as telecare medical information systems and personally controlled health records systems. In 2013, Wen showed that Das et al.'s scheme is vulnerable to the replay attack, user impersonation attacks and off-line guessing attacks, and then proposed an improved scheme using biometrics, password and smart card to overcome these weaknesses. However, we show that Wen's scheme is still vulnerable to off-line password guessing attacks, does not provide user's anonymity and perfect forward secrecy. Further, we propose an improved scheme to fix these weaknesses, and use the applied pi calculus based formal verification tool ProVerif to prove the security and authentication.

  17. Quality of life changes in an alcoholics anonymous self-help group

    Directory of Open Access Journals (Sweden)

    INDRĖ DIRGĖLIENĖ

    2017-09-01

    Full Text Available The issue of alcohol addiction is one of the most pressing in contemporary society as it causes an effect in the context of poverty, violence and suicidal behaviour. After the restoration of Lithuania‘s Independence a new helping profession such as social worker appeared: they were expected to provide professional help to people in order to help them find inner motivation for positive socialization or re-socialization. The issue of alcohol addiction/dependence was first viewed systemically, with the understanding of the need for systemic help: social, psychological, spiritual and medical. Long-term rehabilitation centres have been created and self-help groups formed: those of Alcoholics Anonymous (AA, Al-anon (self – help groups for friends and families who have relatives suffering from alcohol and ACA (Adult Children of Alcoholics self-help group. The article analyzes the quality of life changes in an Alcoholics Anonymous self-help group. Qualitative survey data are presented in this article. Six life stories of people attending Alcoholics Anonymous (AA self-help groups are provided. The age of the participants ranges from 31 to 58. The main criterion to participate in the research is: people who have or have had problems because of alcohol usage and who are Alcoholics Anonymous self-help group (AA participants that have reached Step 12. This means they are ready to spread the message about recovering from this abuse to people who suffer from it. Deep analysis interview has been used to collect the data. Interview notional blocks are: 1 childhood experiences; 2 addiction to alcohol period and crisis; 3 changes of life quality when attending AA groups. The study data have been provided using content analysis through the deduction method. The theoretical basis is a systematic approach to a person in the course of his life‘ spiritual concepts and stages of recovery (May, 2004; Linn, Linn, 2003; Kubler-Ross, 2008 and the theory of integrated

  18. A robust anonymous biometric-based authenticated key agreement scheme for multi-server environments

    Science.gov (United States)

    Huang, Yuanfei; Ma, Fangchao

    2017-01-01

    In order to improve the security in remote authentication systems, numerous biometric-based authentication schemes using smart cards have been proposed. Recently, Moon et al. presented an authentication scheme to remedy the flaws of Lu et al.’s scheme, and claimed that their improved protocol supports the required security properties. Unfortunately, we found that Moon et al.’s scheme still has weaknesses. In this paper, we show that Moon et al.’s scheme is vulnerable to insider attack, server spoofing attack, user impersonation attack and guessing attack. Furthermore, we propose a robust anonymous multi-server authentication scheme using public key encryption to remove the aforementioned problems. From the subsequent formal and informal security analysis, we demonstrate that our proposed scheme provides strong mutual authentication and satisfies the desirable security requirements. The functional and performance analysis shows that the improved scheme has the best secure functionality and is computational efficient. PMID:29121050

  19. A robust anonymous biometric-based authenticated key agreement scheme for multi-server environments.

    Directory of Open Access Journals (Sweden)

    Hua Guo

    Full Text Available In order to improve the security in remote authentication systems, numerous biometric-based authentication schemes using smart cards have been proposed. Recently, Moon et al. presented an authentication scheme to remedy the flaws of Lu et al.'s scheme, and claimed that their improved protocol supports the required security properties. Unfortunately, we found that Moon et al.'s scheme still has weaknesses. In this paper, we show that Moon et al.'s scheme is vulnerable to insider attack, server spoofing attack, user impersonation attack and guessing attack. Furthermore, we propose a robust anonymous multi-server authentication scheme using public key encryption to remove the aforementioned problems. From the subsequent formal and informal security analysis, we demonstrate that our proposed scheme provides strong mutual authentication and satisfies the desirable security requirements. The functional and performance analysis shows that the improved scheme has the best secure functionality and is computational efficient.

  20. An integrative perspective of the anaerobic threshold.

    Science.gov (United States)

    Sales, Marcelo Magalhães; Sousa, Caio Victor; da Silva Aguiar, Samuel; Knechtle, Beat; Nikolaidis, Pantelis Theodoros; Alves, Polissandro Mortoza; Simões, Herbert Gustavo

    2017-12-14

    The concept of anaerobic threshold (AT) was introduced during the nineteen sixties. Since then, several methods to identify the anaerobic threshold (AT) have been studied and suggested as novel 'thresholds' based upon the variable used for its detection (i.e. lactate threshold, ventilatory threshold, glucose threshold). These different techniques have brought some confusion about how we should name this parameter, for instance, anaerobic threshold or the physiological measure used (i.e. lactate, ventilation). On the other hand, the modernization of scientific methods and apparatus to detect AT, as well as the body of literature formed in the past decades, could provide a more cohesive understanding over the AT and the multiple physiological systems involved. Thus, the purpose of this review was to provide an integrative perspective of the methods to determine AT. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. What affects your MS? Responses to an anonymous, Internet-based epidemiological survey.

    Science.gov (United States)

    Simmons, Rex D; Ponsonby, Anne-Louise; van der Mei, Ingrid A F; Sheridan, Peter

    2004-04-01

    Evolving information technology has raised the possibility of new methods of data collection in multiple sclerosis (MS) research. An anonymous, self-report, Internet-based survey was developed, which asked people with MS their opinion on how various extrinsic factors affected their condition. From September 2001 to July 2002, a total of 2529 people completed the questionnaire. The demographic and clinical profiles of the anonymous respondents indicated that most were likely to have MS. Common factors reported as beneficial were cannabis, cold baths, meditation and dietary factors. Common adverse factors reported were high stress, exposure to high temperatures and viral infections. There was an increasing report of high temperatures as being adverse with increasing respondent age (test for trend, P < 0.001). The adverse report of high temperatures correlated significantly with the report of strong sunlight apparently making MS worse (r = 0.35, P < 0.0001). In Australia, high temperatures were more likely to be reported as adverse in warmer, lower latitude regions. The association between strong sunlight as adverse and age or region did not persist after adjustment for high temperatures. Thus, this apparent adverse factor appeared to relate to solar heat, not solar light. People with MS may risk vitamin D deficiency because of sun avoidance due to heat-related fatigue or intolerance. This is of clinical significance not only for bone health but because vitamin D may have beneficial immunomodulatory properties. The present study provides new information from people with MS on factors that may influence symptoms or clinical course. This information will now be used in the design of formal epidemiological cohort studies.

  2. Radiological evaluation of spontaneous pneumoperitoneum

    International Nuclear Information System (INIS)

    Kim, H. S.; Kim, J. D.; Rhee, H. S.

    1982-01-01

    112 cases of spontaneous penumoperitoneum, the causes of which were confirmed by clinical and surgical procedure at Presbyterian Medical Center from January, 1977 to July, 1981 were reviewed radiologically. The results were as follows: 1. Perforation of duodenal ulcer (46/112: 41.1%), stomach ulcer (22/112: 19.6%), and stomach cancer (11/112: 9.8%) were the three most common causes of spontaneous penumoperitoneum. These were 70.5% of all causes. 2. The most common site of free gas was both subdiaphragmatic areas (46: 41.1%). Others were Rt. subdiaphragmatic only (31: 27.7%), both subdiaphragmatic with subhepatic (16: 14.3%), Rt. subdiaphragmatic with subhepatic (7: 6.2%), Rt. subdiaphragmatic only (5: 4.4%), diffuse in abdomen (4: 3.6%), and subhepatic only (3: 2.7%). So 92.0% (103/112) were located in RUQ. 3. The radiological shape of free gas was classified: crescent (52: 46.4%) of small amount; half-moon (21: 18.8%) of moderate amount; large or diffuse (39: 34.8%) of large amount.4. The age between 31 and 60 occupied 69.1% (77/112), and male was predominant (5.2 times). 5. The patient's position showing free air most frequently was erect

  3. Epidemic thresholds for bipartite networks

    Science.gov (United States)

    Hernández, D. G.; Risau-Gusman, S.

    2013-11-01

    It is well known that sexually transmitted diseases (STD) spread across a network of human sexual contacts. This network is most often bipartite, as most STD are transmitted between men and women. Even though network models in epidemiology have quite a long history now, there are few general results about bipartite networks. One of them is the simple dependence, predicted using the mean field approximation, between the epidemic threshold and the average and variance of the degree distribution of the network. Here we show that going beyond this approximation can lead to qualitatively different results that are supported by numerical simulations. One of the new features, that can be relevant for applications, is the existence of a critical value for the infectivity of each population, below which no epidemics can arise, regardless of the value of the infectivity of the other population.

  4. A Case of Multiple Spontaneous Keloid Scars

    Directory of Open Access Journals (Sweden)

    Abdulhadi Jfri

    2015-07-01

    Full Text Available Keloid scars result from an abnormal healing response to cutaneous injury or inflammation that extends beyond the borders of the original wound. Spontaneous keloid scars forming in the absence of any previous trauma or surgical procedure are rare. Certain syndromes have been associated with this phenomenon, and few reports have discussed the evidence of single spontaneous keloid scar, which raises the question whether they are really spontaneous. Here, we present a 27-year-old mentally retarded single female with orbital hypertelorism, broad nasal bridge, repaired cleft lip and high-arched palate who presented with progressive multiple spontaneous keloid scars in different parts of her body which were confirmed histologically by the presence of typical keloidal collagen. This report supports the fact that keloid scars can appear spontaneously and are possibly linked to a genetic factor. Furthermore, it describes a new presentation of spontaneous keloid scars in the form of multiple large lesions in different sites of the body.

  5. Spontaneity of communication in individuals with autism.

    Science.gov (United States)

    Chiang, Hsu-Min; Carter, Mark

    2008-04-01

    This article provides an examination of issues related to spontaneity of communication in children with autism. Deficits relating to spontaneity or initiation are frequently reported in individuals with autism, particularly in relation to communication and social behavior. Nevertheless, spontaneity is not necessarily clearly conceptualized or measured. Several approaches to conceptualization of communicative spontaneity are examined with a particular focus on the continuum model and how it might be practically applied. A range of possible explanations for deficits in spontaneity of communication in children with autism is subsequently explored, including external factors (highly structured teaching programs, failure to systematically instruct for spontaneity) and intrinsic characteristics (intellectual disability, stimulus overselectivity, weak central coherence). Possible implications for future research are presented.

  6. Spontaneous cryptococcal peritonitis in cirrhotic patients.

    Directory of Open Access Journals (Sweden)

    Sungkanuparph S

    2002-07-01

    Full Text Available Spontaneous bacterial peritonitis is a common complication in patients with cirrhosis and ascites. However, spontaneous peritonitis caused by Cryptococcus neoformans is uncommon. Delayed diagnosis of cryptococcal peritonitis often results in death. We describe three cases of spontaneous cryptococcal peritonitis in patients with decompensated cirrhosis. One case had associated symptomatic human immunodeficiency virus infection. Clinical awareness of this entity may lead to the early diagnosis and proper treatment.

  7. Spontaneous Intracranial Hypotension without Orthostatic Headache

    Directory of Open Access Journals (Sweden)

    Tülay Kansu

    2009-03-01

    Full Text Available We report 2 cases of spontaneous intracranial hypotension that presented with unilateral abducens nerve palsy, without orthostatic headache. While sixth nerve palsies improved without any intervention, subdural hematoma was detected with magnetic resonance imaging. We conclude that headache may be absent in spontaneous intracranial hypotension and spontaneous improvement of sixth nerve palsy can occur, even after the development of a subdural hematoma

  8. Spontaneous renal hematoma - a case report

    International Nuclear Information System (INIS)

    Obrzut, M.; Obrzut, M.; Homa, J.; Obrzut, B.

    2006-01-01

    Spontaneous pararenal hematoma is a rare pathology most frequently coexisting with renal tumours, vascular anomalies and inflammatory processes. In some cases one cannot establish its etiology. The paper describes a case of a 58-year-old man with a spontaneous pararenal hematoma and presents a diagnostic algorithm. Ultrasonography and CT play an important role in diagnostics of spontaneous pararenal haemorrhages. These methods enable a precise evaluation of size and location of hematoma and its evolution. (author)

  9. Is the introduction of anonymous delivery associated with a reduction of high neonaticide rates in Austria? A retrospective study.

    Science.gov (United States)

    Klier, C M; Grylli, C; Amon, S; Fiala, C; Weizmann-Henelius, G; Pruitt, S L; Putkonen, H

    2013-03-01

    To assess rates of neonaticide after the implementation of a preventative 'anonymous delivery' law in mid-2001 in Austria. Women are allowed to access antenatal care and give birth in a hospital anonymously, without showing any ID and free of charge. Retrospective study. A complete census of police-reported neonaticides was obtained from the police statistics of Austria, Sweden and Finland. All neonaticides reported to the police, 1991-2009. Neonaticide rates before (1991-2001) and after (2002-2009) the introduction of anonymous delivery legislation per 100 000 births. The Mann-Whitney U-test for two independent samples was used to compare neonaticide rates in the period before the new law was introduced with the rates observed after the implementation of the new law for each country. On average the rate of police-reported neonaticides was 7.2 per 100 000 births (SD 3.5, median 7.1) in Austria prior to the new law being passed, and 3.1 per 100 000 births (SD 2.1, median 2.6) after the law was passed. A significant decrease in neonaticide was observed in Austria after the implementation of anonymous delivery (Mann-Whitney U-test P = 0.017). Whereas the Finnish and Swedish rates were lower than the Austrian rates before and after the implementation of the Austrian law, they remained unchanged over the study period. Our data demonstrate a significant decrease in the number of police-reported neonaticides in Austria after the implementation of anonymous delivery. Even though underlying factors associated with neonaticide are complex, the findings could indicate an effect of anonymous delivery in the prevention of this crime. © 2012 The Authors BJOG An International Journal of Obstetrics and Gynaecology © 2012 RCOG.

  10. “The Question Exists, but You Don’t Exist With It”: Strategic Anonymity in the Social Lives of Adolescents

    OpenAIRE

    Nicole B. Ellison; Lindsay Blackwell; Cliff Lampe; Penny Trieu

    2016-01-01

    Anonymous interactions may have important implications for adolescents’ social and psychological development. In this article, we use semi-structured interview data collected from US adolescents aged 13–18 years ( N  = 22) to explore how the specific affordances of an online platform that enables selective anonymity shape adolescents’ practices and perceptions. We contribute to scholarship on the effects of anonymous interaction online by surfacing positive outcomes for young adults who choos...

  11. Biomarkers of spontaneous preterm birth

    DEFF Research Database (Denmark)

    Polettini, Jossimara; Cobo, Teresa; Kacerovsky, Marian

    2017-01-01

    predictors of pregnancy outcome. This systematic review was conducted to synthesize the knowledge on PTB biomarkers identified using multiplex analysis. Three electronic databases (PubMed, EMBASE and Web of Science) were searched for studies in any language reporting the use of multiplex assays for maternal......Despite decades of research on risk indicators of spontaneous preterm birth (PTB), reliable biomarkers are still not available to screen or diagnose high-risk pregnancies. Several biomarkers in maternal and fetal compartments have been mechanistically linked to PTB, but none of them are reliable......) followed by MIP-1β, GM-CSF, Eotaxin, and TNF-RI (two studies) were reported more than once in maternal serum. However, results could not be combined due to heterogeneity in type of sample, study population, assay, and analysis methods. By this systematic review, we conclude that multiplex assays...

  12. Spontaneous Strategies in Innovation Networks

    DEFF Research Database (Denmark)

    Plesner, Ursula; Husted, Emil Krastrup

    and a site ontology, we show how physical sites and objects become constitutive of the inside of virtual worlds through innovation processes. This argument is in line with ANT’s perspective on strategy, where sites and objects are considered a strategically relevant resource in the innovation process...... of materiality in relation to the organization and structuring of virtual worlds. We examine various innovation processes in five Danish entrepreneurial companies where actors continuously struggle to stabilize virtual worlds as platforms for professional communication. With inspiration from actor-network theory....... Empirically, the analysis is founded on descriptive accounts from the five entrepreneurs. By highlighting the spontaneous strategies described by actors, we show how sites and objects are actively used as an element in their strategy, and also how the sites and objects end up facilitating new ways of thinking...

  13. Recurrent spontaneous attacks of dizziness.

    Science.gov (United States)

    Lempert, Thomas

    2012-10-01

    This article describes the common causes of recurrent vertigo and dizziness that can be diagnosed largely on the basis of history. Ninety percent of spontaneous recurrent vertigo and dizziness can be explained by six disorders: (1) Ménière disease is characterized by vertigo attacks, lasting 20 minutes to several hours, with concomitant hearing loss, tinnitus, and aural fullness. Aural symptoms become permanent during the course of the disease. (2) Attacks of vestibular migraine may last anywhere from minutes to days. Most patients have a previous history of migraine headaches, and many experience migraine symptoms during the attack. (3) Vertebrobasilar TIAs affect older adults with vascular risk factors. Most attacks last less than 1 hour and are accompanied by other symptoms from the posterior circulation territory. (4) Vestibular paroxysmia is caused by vascular compression of the eighth cranial nerve. It manifests itself with brief attacks of vertigo that recur many times per day, sometimes with concomitant cochlear symptoms. (5) Orthostatic hypotension causes brief episodes of dizziness lasting seconds to a few minutes after standing up and is relieved by sitting or lying down. In older adults, it may be accompanied by supine hypertension. (6) Panic attacks usually last minutes, occur in specific situations, and are accompanied by choking, palpitations, tremor, heat, and anxiety. Less common causes of spontaneous recurrent vertigo and dizziness include perilymph fistula, superior canal dehiscence, autoimmune inner ear disease, otosclerosis, cardiac arrhythmia, and medication side effects. Neurologists need to venture into otolaryngology, internal medicine, and psychiatry to master the differential diagnosis of recurrent dizziness.

  14. Crows spontaneously exhibit analogical reasoning.

    Science.gov (United States)

    Smirnova, Anna; Zorina, Zoya; Obozova, Tanya; Wasserman, Edward

    2015-01-19

    Analogical reasoning is vital to advanced cognition and behavioral adaptation. Many theorists deem analogical thinking to be uniquely human and to be foundational to categorization, creative problem solving, and scientific discovery. Comparative psychologists have long been interested in the species generality of analogical reasoning, but they initially found it difficult to obtain empirical support for such thinking in nonhuman animals (for pioneering efforts, see [2, 3]). Researchers have since mustered considerable evidence and argument that relational matching-to-sample (RMTS) effectively captures the essence of analogy, in which the relevant logical arguments are presented visually. In RMTS, choice of test pair BB would be correct if the sample pair were AA, whereas choice of test pair EF would be correct if the sample pair were CD. Critically, no items in the correct test pair physically match items in the sample pair, thus demanding that only relational sameness or differentness is available to support accurate choice responding. Initial evidence suggested that only humans and apes can successfully learn RMTS with pairs of sample and test items; however, monkeys have subsequently done so. Here, we report that crows too exhibit relational matching behavior. Even more importantly, crows spontaneously display relational responding without ever having been trained on RMTS; they had only been trained on identity matching-to-sample (IMTS). Such robust and uninstructed relational matching behavior represents the most convincing evidence yet of analogical reasoning in a nonprimate species, as apes alone have spontaneously exhibited RMTS behavior after only IMTS training. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Threshold behavior in electron-atom scattering

    International Nuclear Information System (INIS)

    Sadeghpour, H.R.; Greene, C.H.

    1996-01-01

    Ever since the classic work of Wannier in 1953, the process of treating two threshold electrons in the continuum of a positively charged ion has been an active field of study. The authors have developed a treatment motivated by the physics below the double ionization threshold. By modeling the double ionization as a series of Landau-Zener transitions, they obtain an analytical formulation of the absolute threshold probability which has a leading power law behavior, akin to Wannier's law. Some of the noteworthy aspects of this derivation are that the derivation can be conveniently continued below threshold giving rise to a open-quotes cuspclose quotes at threshold, and that on both sides of the threshold, absolute values of the cross sections are obtained

  16. Iran: the next nuclear threshold state?

    OpenAIRE

    Maurer, Christopher L.

    2014-01-01

    Approved for public release; distribution is unlimited A nuclear threshold state is one that could quickly operationalize its peaceful nuclear program into one capable of producing a nuclear weapon. This thesis compares two known threshold states, Japan and Brazil, with Iran to determine if the Islamic Republic could also be labeled a threshold state. Furthermore, it highlights the implications such a status could have on U.S. nonproliferation policy. Although Iran's nuclear program is mir...

  17. Neutron angular distribution in plutonium-240 spontaneous fission

    Science.gov (United States)

    Marcath, Matthew J.; Shin, Tony H.; Clarke, Shaun D.; Peerani, Paolo; Pozzi, Sara A.

    2016-09-01

    Nuclear safeguards applications require accurate fission models that exhibit prompt neutron anisotropy. In the laboratory reference frame, an anisotropic neutron angular distribution is observed because prompt fission neutrons carry momentum from fully accelerated fission fragments. A liquid organic scintillation detector array was used with pulse shape discrimination techniques to produce neutron-neutron cross-correlation time distributions and angular distributions from spontaneous fission in a 252Cf, a 0.84 g 240Pueff metal, and a 1.63 g 240Pueff metal sample. The effect of cross-talk, estimated with MCNPX-PoliMi simulations, is removed from neutron-neutron coincidences as a function of the angle between detector pairs. Fewer coincidences were observed at detector angles near 90°, relative to higher and lower detector angles. As light output threshold increases, the observed anisotropy increases due to spectral effects arising from fission fragment momentum transfer to emitted neutrons. Stronger anisotropy was observed in Cf-252 spontaneous fission prompt neutrons than in Pu-240 neutrons.

  18. Roots at the percolation threshold.

    Science.gov (United States)

    Kroener, Eva; Ahmed, Mutez Ali; Carminati, Andrea

    2015-04-01

    The rhizosphere is the layer of soil around the roots where complex and dynamic interactions between plants and soil affect the capacity of plants to take up water. The physical properties of the rhizosphere are affected by mucilage, a gel exuded by roots. Mucilage can absorb large volumes of water, but it becomes hydrophobic after drying. We use a percolation model to describe the rewetting of dry rhizosphere. We find that at a critical mucilage concentration the rhizosphere becomes impermeable. The critical mucilage concentration depends on the radius of the soil particle size. Capillary rise experiments with neutron radiography prove that for concentrations below the critical mucilage concentration water could easily cross the rhizosphere, while above the critical concentration water could no longer percolate through it. Our studies, together with former observations of water dynamics in the rhizosphere, suggest that the rhizosphere is near the percolation threshold, where small variations in mucilage concentration sensitively alter the soil hydraulic conductivity. Is mucilage exudation a plant mechanism to efficiently control the rhizosphere conductivity and the access to water?

  19. Percolation Threshold in Polycarbonate Nanocomposites

    Science.gov (United States)

    Ahuja, Suresh

    2014-03-01

    Nanocomposites have unique mechanical, electrical, magnetic, optical and thermal properties. Many methods could be applied to prepare polymer-inorganic nanocomposites, such as sol-gel processing, in-situ polymerization, particle in-situ formation, blending, and radiation synthesis. The analytical composite models that have been put forth include Voigt and Reuss bounds, Polymer nanocomposites offer the possibility of substantial improvements in material properties such as shear and bulk modulus, yield strength, toughness, film scratch resistance, optical properties, electrical conductivity, gas and solvent transport, with only very small amounts of nanoparticles Experimental results are compared against composite models of Hashin and Shtrikman bounds, Halpin-Tsai model, Cox model, and various Mori and Tanaka models. Examples of numerical modeling are molecular dynamics modeling and finite element modeling of reduced modulus and hardness that takes into account the modulus of the components and the effect of the interface between the hard filler and relatively soft polymer, polycarbonate. Higher nanoparticle concentration results in poor dispersion and adhesion to polymer matrix which results in lower modulus and hardness and departure from the existing composite models. As the level of silica increases beyond a threshold level, aggregates form which results in weakening of the structure. Polymer silica interface is found to be weak as silica is non-interacting promoting interfacial slip at silica-matrix junctions. Our experimental results compare favorably with those of nanocomposites of polyesters where the effect of nanoclay on composite hardness and modulus depended on dispersion of nanoclay in polyester.

  20. Dynamical thresholds for complete fusion

    International Nuclear Information System (INIS)

    Davies, K.T.R.; Sierk, A.J.; Nix, J.R.

    1983-01-01

    It is our purpose here to study the effect of nuclear dissipation and shape parametrization on dynamical thresholds for compound-nucleus formation in symmetric heavy-ion reactions. This is done by solving numerically classical equations of motion for head-on collisions to determine whether the dynamical trajectory in a multidimensional deformation space passes inside the fission saddle point and forms a compound nucleus, or whether it passes outside the fission saddle point and reseparates in a fast-fission or deep-inelastic reaction. Specifying the nuclear shape in terms of smoothly joined portions of three quadratic surfaces of revolution, we take into account three symmetric deformation coordinates. However, in some cases we reduce the number of coordinates to two by requiring the ends of the fusing system to be spherical in shape. The nuclear potential energy of deformation is determined in terms of a Coulomb energy and a double volume energy of a Yukawa-plus-exponential folding function. The collective kinetic energy is calculated for incompressible, nearly irrotational flow by means of the Werner-Wheeler approximation. Four possibilities are studied for the transfer of collective kinetic energy into internal single-particle excitation energy: zero dissipation, ordinary two body viscosity, one-body wall-formula dissipation, and one-body wall-and-window dissipation

  1. Efficient threshold for volumetric segmentation

    Science.gov (United States)

    Burdescu, Dumitru D.; Brezovan, Marius; Stanescu, Liana; Stoica Spahiu, Cosmin; Ebanca, Daniel

    2015-07-01

    Image segmentation plays a crucial role in effective understanding of digital images. However, the research on the existence of general purpose segmentation algorithm that suits for variety of applications is still very much active. Among the many approaches in performing image segmentation, graph based approach is gaining popularity primarily due to its ability in reflecting global image properties. Volumetric image segmentation can simply result an image partition composed by relevant regions, but the most fundamental challenge in segmentation algorithm is to precisely define the volumetric extent of some object, which may be represented by the union of multiple regions. The aim in this paper is to present a new method to detect visual objects from color volumetric images and efficient threshold. We present a unified framework for volumetric image segmentation and contour extraction that uses a virtual tree-hexagonal structure defined on the set of the image voxels. The advantage of using a virtual tree-hexagonal network superposed over the initial image voxels is that it reduces the execution time and the memory space used, without losing the initial resolution of the image.

  2. Ongoing spontaneous activity controls access to consciousness: a neuronal model for inattentional blindness.

    Directory of Open Access Journals (Sweden)

    Stanislas Dehaene

    2005-05-01

    Full Text Available Even in the absence of sensory inputs, cortical and thalamic neurons can show structured patterns of ongoing spontaneous activity, whose origins and functional significance are not well understood. We use computer simulations to explore the conditions under which spontaneous activity emerges from a simplified model of multiple interconnected thalamocortical columns linked by long-range, top-down excitatory axons, and to examine its interactions with stimulus-induced activation. Simulations help characterize two main states of activity. First, spontaneous gamma-band oscillations emerge at a precise threshold controlled by ascending neuromodulator systems. Second, within a spontaneously active network, we observe the sudden "ignition" of one out of many possible coherent states of high-level activity amidst cortical neurons with long-distance projections. During such an ignited state, spontaneous activity can block external sensory processing. We relate those properties to experimental observations on the neural bases of endogenous states of consciousness, and particularly the blocking of access to consciousness that occurs in the psychophysical phenomenon of "inattentional blindness," in which normal subjects intensely engaged in mental activity fail to notice salient but irrelevant sensory stimuli. Although highly simplified, the generic properties of a minimal network may help clarify some of the basic cerebral phenomena underlying the autonomy of consciousness.

  3. Ongoing spontaneous activity controls access to consciousness: a neuronal model for inattentional blindness.

    Science.gov (United States)

    Dehaene, Stanislas; Changeux, Jean-Pierre

    2005-05-01

    Even in the absence of sensory inputs, cortical and thalamic neurons can show structured patterns of ongoing spontaneous activity, whose origins and functional significance are not well understood. We use computer simulations to explore the conditions under which spontaneous activity emerges from a simplified model of multiple interconnected thalamocortical columns linked by long-range, top-down excitatory axons, and to examine its interactions with stimulus-induced activation. Simulations help characterize two main states of activity. First, spontaneous gamma-band oscillations emerge at a precise threshold controlled by ascending neuromodulator systems. Second, within a spontaneously active network, we observe the sudden "ignition" of one out of many possible coherent states of high-level activity amidst cortical neurons with long-distance projections. During such an ignited state, spontaneous activity can block external sensory processing. We relate those properties to experimental observations on the neural bases of endogenous states of consciousness, and particularly the blocking of access to consciousness that occurs in the psychophysical phenomenon of "inattentional blindness," in which normal subjects intensely engaged in mental activity fail to notice salient but irrelevant sensory stimuli. Although highly simplified, the generic properties of a minimal network may help clarify some of the basic cerebral phenomena underlying the autonomy of consciousness.

  4. Variation among internet based calculators in predicting spontaneous resolution of vesicoureteral reflux.

    Science.gov (United States)

    Routh, Jonathan C; Gong, Edward M; Cannon, Glenn M; Yu, Richard N; Gargollo, Patricio C; Nelson, Caleb P

    2010-04-01

    An increasing number of parents and practitioners use the Internet for health related purposes, and an increasing number of models are available on the Internet for predicting spontaneous resolution rates for children with vesicoureteral reflux. We sought to determine whether currently available Internet based calculators for vesicoureteral reflux resolution produce systematically different results. Following a systematic Internet search we identified 3 Internet based calculators of spontaneous resolution rates for children with vesicoureteral reflux, of which 2 were academic affiliated and 1 was industry affiliated. We generated a random cohort of 100 hypothetical patients with a wide range of clinical characteristics and entered the data on each patient into each calculator. We then compared the results from the calculators in terms of mean predicted resolution probability and number of cases deemed likely to resolve at various cutoff probabilities. Mean predicted resolution probabilities were 41% and 36% (range 31% to 41%) for the 2 academic affiliated calculators and 33% for the industry affiliated calculator (p = 0.02). For some patients the calculators produced markedly different probabilities of spontaneous resolution, in some instances ranging from 24% to 89% for the same patient. At thresholds greater than 5%, 10% and 25% probability of spontaneous resolution the calculators differed significantly regarding whether cases would resolve (all p calculators. For certain patients, particularly those with a lower probability of spontaneous resolution, these differences can significantly influence clinical decision making. Copyright (c) 2010 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  5. Optical bistability via quantum interference from incoherent pumping and spontaneous emission

    International Nuclear Information System (INIS)

    Sahrai, M.; Asadpour, S.H.; Sadighi-Bonabi, R.

    2011-01-01

    We theoretically investigate the optical bistability (OB) in a V-type three-level atomic system confined in a unidirectional ring cavity via incoherent pumping field. It is shown that the threshold of optical bistability can be controlled by the rate of an incoherent pumping field and by interference mechanism arising from the spontaneous emission and incoherent pumping field. We demonstrate that the optical bistability converts to optical multi-stability (OM) by the quantum interference mechanism. - Highlights: → We modulate the optical bistability (OB) in a four-level N-type atomic system. → The threshold of optical bistability can be controlled by the quantum interferences. → OB converts to optical multi-stability (OM) by the quantum interferences. → We discuss the effect of an incoherent pumping field on reduction of OB threshold.

  6. Error Thresholds on Dynamic Fittness-Landscapes

    OpenAIRE

    Nilsson, Martin; Snoad, Nigel

    1999-01-01

    In this paper we investigate error-thresholds on dynamics fitness-landscapes. We show that there exists both lower and an upper threshold, representing limits to the copying fidelity of simple replicators. The lower bound can be expressed as a correction term to the error-threshold present on a static landscape. The upper error-threshold is a new limit that only exists on dynamic fitness-landscapes. We also show that for long genomes on highly dynamic fitness-landscapes there exists a lower b...

  7. Stabiliteit spontane taal bij chronische milde afasie

    NARCIS (Netherlands)

    Wolthuis, Nienke; Mendez Orellana, Carolina; Nouwens, Femke; Jonkers, Roel; Visch-Brink, Evy; Bastiaanse, Roelien

    2014-01-01

    In aphasia, an analysis of spontaneous speech provides opportunities to establish the linguistic and communicative abilities, to create suitable therapy plans and to measure language progress. The current study investigated the stability of spontaneous speech within an interview of ten mild aphasic

  8. Spontaneously broken abelian gauge invariant supersymmetric model

    International Nuclear Information System (INIS)

    Mainland, G.B.; Tanaka, K.

    A model is presented that is invariant under an Abelian gauge transformation and a modified supersymmetry transformation. This model is broken spontaneously, and the interplay between symmetry breaking, Goldstone particles, and mass breaking is studied. In the present model, spontaneously breaking the Abelian symmetry of the vacuum restores the invariance of the vacuum under a modified supersymmetry transformation. (U.S.)

  9. Spontaneous Achilles tendon rupture in alkaptonuria | Mohammed ...

    African Journals Online (AJOL)

    Spontaneous Achilles tendon ruptures are uncommon. We present a 46-year-old man with spontaneous Achilles tendon rupture due to ochronosis. To our knowledge, this has not been previously reported in Sudan literature. The tendon of the reported patient healed well after debridement and primary repairs.

  10. Spontaneous rupture of choledochal cyst: case report

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Ho Seob; Nam, Kyung Jin; Lee, Jin Hwa; Kim, Chan Sung; Choi, Jong Cheol; Oh, Jong Young [Dong-a University College of Medicine, Pusan (Korea, Republic of)

    2002-11-01

    Spontaneous rupture of a choledochal cyst leading to biliary peritonitis is a rare complication which can be fatal if not promptly diagnosed. The authors report the ultrasound and CT findings of two cases of spontaneous choledochal cystic rupture and the biliary peritonitis which ensued.

  11. Spontaneity and Equilibrium II: Multireaction Systems

    Science.gov (United States)

    Raff, Lionel M.

    2014-01-01

    The thermodynamic criteria for spontaneity and equilibrium in multireaction systems are developed and discussed. When N reactions are occurring simultaneously, it is shown that G and A will depend upon N independent reaction coordinates, ?a (a = 1,2, ..., N), in addition to T and p for G or T and V for A. The general criteria for spontaneity and…

  12. Alcoholics Anonymous and Relapse Prevention as Maintenance Strategies After Conjoint Behavioral Alcohol Treatment for Men: 18-Month Outcomes

    Science.gov (United States)

    McCrady, Barbara S.; Epstein, Elizabeth E.; Kahler, Christopher W.

    2004-01-01

    Ninety men with alcohol problems and their female partners were randomly assigned to 1 of 3 outpatient conjoint treatments: alcohol behavioral couples therapy (ABCT), ABCT with relapse prevention techniques (RP/ABCT), or ABCT with interventions encouraging Alcoholics Anonymous (AA) involvement (AA/ABCT). Couples were followed for 18 months after…

  13. Location Prediction Based on Transition Probability Matrices Constructing from Sequential Rules for Spatial-Temporal K-Anonymity Dataset.

    Directory of Open Access Journals (Sweden)

    Haitao Zhang

    Full Text Available Spatial-temporal k-anonymity has become a mainstream approach among techniques for protection of users' privacy in location-based services (LBS applications, and has been applied to several variants such as LBS snapshot queries and continuous queries. Analyzing large-scale spatial-temporal anonymity sets may benefit several LBS applications. In this paper, we propose two location prediction methods based on transition probability matrices constructing from sequential rules for spatial-temporal k-anonymity dataset. First, we define single-step sequential rules mined from sequential spatial-temporal k-anonymity datasets generated from continuous LBS queries for multiple users. We then construct transition probability matrices from mined single-step sequential rules, and normalize the transition probabilities in the transition matrices. Next, we regard a mobility model for an LBS requester as a stationary stochastic process and compute the n-step transition probability matrices by raising the normalized transition probability matrices to the power n. Furthermore, we propose two location prediction methods: rough prediction and accurate prediction. The former achieves the probabilities of arriving at target locations along simple paths those include only current locations, target locations and transition steps. By iteratively combining the probabilities for simple paths with n steps and the probabilities for detailed paths with n-1 steps, the latter method calculates transition probabilities for detailed paths with n steps from current locations to target locations. Finally, we conduct extensive experiments, and correctness and flexibility of our proposed algorithm have been verified.

  14. Location Prediction Based on Transition Probability Matrices Constructing from Sequential Rules for Spatial-Temporal K-Anonymity Dataset.

    Science.gov (United States)

    Zhang, Haitao; Chen, Zewei; Liu, Zhao; Zhu, Yunhong; Wu, Chenxue

    2016-01-01

    Spatial-temporal k-anonymity has become a mainstream approach among techniques for protection of users' privacy in location-based services (LBS) applications, and has been applied to several variants such as LBS snapshot queries and continuous queries. Analyzing large-scale spatial-temporal anonymity sets may benefit several LBS applications. In this paper, we propose two location prediction methods based on transition probability matrices constructing from sequential rules for spatial-temporal k-anonymity dataset. First, we define single-step sequential rules mined from sequential spatial-temporal k-anonymity datasets generated from continuous LBS queries for multiple users. We then construct transition probability matrices from mined single-step sequential rules, and normalize the transition probabilities in the transition matrices. Next, we regard a mobility model for an LBS requester as a stationary stochastic process and compute the n-step transition probability matrices by raising the normalized transition probability matrices to the power n. Furthermore, we propose two location prediction methods: rough prediction and accurate prediction. The former achieves the probabilities of arriving at target locations along simple paths those include only current locations, target locations and transition steps. By iteratively combining the probabilities for simple paths with n steps and the probabilities for detailed paths with n-1 steps, the latter method calculates transition probabilities for detailed paths with n steps from current locations to target locations. Finally, we conduct extensive experiments, and correctness and flexibility of our proposed algorithm have been verified.

  15. Opinions of Dutch Liver Transplant Recipients on Anonymity of Organ Donation and Direct Contact With the Donors Family

    NARCIS (Netherlands)

    Annema-de Jong, Coby; op den Dries, Sanna; van den Berg, Aad P.; Ranchor, Adelita V.; Porte, Robert J.

    Background. In the Netherlands, anonymity of organ donation, which is currently protected by legislation, has come under discussion. In the Dutch society, a tendency to allow direct contact between transplant recipients and their donor's family is noticeable. As little is known about the opinion of

  16. Increasing Anonymity in Peer Assessment by Using Classroom Response Technology within Face-to-Face Higher Education

    Science.gov (United States)

    Raes, Annelies; Vanderhoven, Ellen; Schellens, Tammy

    2015-01-01

    Peer assessment is becoming more popular in higher education, however it often goes together with undesirable social effects like peer pressure and favoritism, especially when students need to evaluate peers in a face-to-face setting. The present study was set up to investigate increased anonymity in peer assessment to counter these undesirable…

  17. Location Prediction Based on Transition Probability Matrices Constructing from Sequential Rules for Spatial-Temporal K-Anonymity Dataset

    Science.gov (United States)

    Liu, Zhao; Zhu, Yunhong; Wu, Chenxue

    2016-01-01

    Spatial-temporal k-anonymity has become a mainstream approach among techniques for protection of users’ privacy in location-based services (LBS) applications, and has been applied to several variants such as LBS snapshot queries and continuous queries. Analyzing large-scale spatial-temporal anonymity sets may benefit several LBS applications. In this paper, we propose two location prediction methods based on transition probability matrices constructing from sequential rules for spatial-temporal k-anonymity dataset. First, we define single-step sequential rules mined from sequential spatial-temporal k-anonymity datasets generated from continuous LBS queries for multiple users. We then construct transition probability matrices from mined single-step sequential rules, and normalize the transition probabilities in the transition matrices. Next, we regard a mobility model for an LBS requester as a stationary stochastic process and compute the n-step transition probability matrices by raising the normalized transition probability matrices to the power n. Furthermore, we propose two location prediction methods: rough prediction and accurate prediction. The former achieves the probabilities of arriving at target locations along simple paths those include only current locations, target locations and transition steps. By iteratively combining the probabilities for simple paths with n steps and the probabilities for detailed paths with n-1 steps, the latter method calculates transition probabilities for detailed paths with n steps from current locations to target locations. Finally, we conduct extensive experiments, and correctness and flexibility of our proposed algorithm have been verified. PMID:27508502

  18. An Anonymous Survey of Psychosomatic Medicine Fellowship Directors regarding Breaches of Contracts and a Proposal for Prevention

    Science.gov (United States)

    Levenson, James L.; Bialer, Philip

    2010-01-01

    Objective: The authors studied how often applicants accept positions at more than one program, or programs offer positions to applicants who have already signed contracts with other programs. Methods: An anonymous survey was distributed to all psychosomatic medicine fellowship program directors. Results: It is fairly common for applicants to sign…

  19. Long-Term Influence of Duration and Frequency of Participation in Alcoholics Anonymous on Individuals With Alcohol Use Disorders.

    Science.gov (United States)

    Moos, Rudolf H.; Moos, Bernice S.

    2004-01-01

    This study examined the influence of the duration and frequency of a baseline episode of participation in Alcoholics Anonymous (AA) among 473 individuals with alcohol use disorders on 1-year and 8-year outcomes and the effect of additional participation and delayed participation on outcomes. Compared with individuals who did not participate,…

  20. Conducting Anonymous, Incentivized, Online Surveys With Sexual and Gender Minority Adolescents: Lessons Learned From a National Polyvictimization Study.

    Science.gov (United States)

    Sterzing, Paul R; Gartner, Rachel E; McGeough, Briana L

    2018-03-01

    Sexual and gender minority adolescents represent an understudied and hard-to-reach population who experience higher rates of mental and behavioral health problems in comparison to their cisgender, heterosexual peers. Online surveys and the proliferation of Internet-connected devices among adolescents offer an exciting opportunity for researchers to begin addressing research gaps and past methodological limitations with these hard-to-reach populations. The purpose of this article is to provide guidance to researchers who are designing and implementing anonymous, incentivized, online surveys by examining the following critical domains-(a) recruitment and engagement: means of leveraging social media and videos to recruit and engage a more nationally representative sample; (b) safety and protection: strategies for administering informed consent and protecting participant anonymity and well-being; and (c) data integrity: mechanisms to detect dishonest and repeat responders. To facilitate discussion of these aims, concrete examples are used from SpeakOut-a 3-year, national study funded by the National Institute of Justice that utilized an anonymous, incentivized, online survey with a large sample of sexual and gender minority adolescents ( N = 1,177) to identify the prevalence, incidence, and correlates of polyvictimization. The article concludes with lessons learned from this national study and recommendations for technological innovations and future research that will strengthen the utility of anonymous, incentivized, online surveys to study sexual and gender minority adolescents and other hard-to-reach populations.

  1. Attachment Styles and Changes among Women Members of Overeaters Anonymous Who Have Recovered from Binge-Eating Disorder

    Science.gov (United States)

    Hertz, Pnina; Addad, Moshe; Ronel, Natti

    2012-01-01

    In Overeaters Anonymous (OA), the 12-step self-help program for compulsive overeaters, binge eating is regarded as a physical, spiritual, and emotional disorder. Consequently, the program proposes recovery through the adoption of a lifestyle that leads to physical, spiritual, and emotional well-being. A qualitative phenomenological study that…

  2. Early pregnancy angiogenic markers and spontaneous abortion

    DEFF Research Database (Denmark)

    Andersen, Louise B; Dechend, Ralf; Karumanchi, S Ananth

    2016-01-01

    BACKGROUND: Spontaneous abortion is the most commonly observed adverse pregnancy outcome. The angiogenic factors soluble Fms-like kinase 1 and placental growth factor are critical for normal pregnancy and may be associated to spontaneous abortion. OBJECTIVE: We investigated the association between...... maternal serum concentrations of soluble Fms-like kinase 1 and placental growth factor, and subsequent spontaneous abortion. STUDY DESIGN: In the prospective observational Odense Child Cohort, 1676 pregnant women donated serum in early pregnancy, gestational week ..., interquartile range 71-103). Concentrations of soluble Fms-like kinase 1 and placental growth factor were determined with novel automated assays. Spontaneous abortion was defined as complete or incomplete spontaneous abortion, missed abortion, or blighted ovum

  3. The (perceived) meaning of spontaneous thoughts.

    Science.gov (United States)

    Morewedge, Carey K; Giblin, Colleen E; Norton, Michael I

    2014-08-01

    Spontaneous thoughts, the output of a broad category of uncontrolled and inaccessible higher order mental processes, arise frequently in everyday life. The seeming randomness by which spontaneous thoughts arise might give people good reason to dismiss them as meaningless. We suggest that it is precisely the lack of control over and access to the processes by which they arise that leads people to perceive spontaneous thoughts as revealing meaningful self-insight. Consequently, spontaneous thoughts potently influence judgment. A series of experiments provides evidence supporting two hypotheses. First, we hypothesize that the more a thought is perceived to be spontaneous, the more it is perceived to provide meaningful self-insight. Participants perceived more spontaneous kinds of thought (e.g., intuition) to reveal greater self-insight than did more controlled kinds of thought in Study 1 (e.g., deliberation). In Studies 2 and 3, participants perceived thoughts with the same content and target to reveal greater self-insight when spontaneously rather than deliberately generated (i.e., childhood memories and impressions formed). Second, we hypothesize that the greater self-insight attributed to thoughts that are (perceived to be) spontaneous leads those thoughts to more potently influence judgment. Participants felt more sexually attracted to an attractive person whom they thought of spontaneously than deliberately in Study 4, and reported their commitment to a current romantic relationship would be more affected by the spontaneous rather than deliberate recollection of a good or bad experience with their romantic partner in Study 5. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  4. Preference for anonymity in sperm donation for artificial insemination: an experience from low-resource settings in Nigeria

    Science.gov (United States)

    Ezugwu, Euzebus Chinonye; Eleje, George U; Iyoke, Chukwuemeka A; Mba, Sunday G; Nnaji, Henry C; Enechukwu, Chukwunonso I; Nkwo, Peter O

    2018-01-01

    Objective Anonymous sperm donation is a common practice in Nigeria with its associated legal and ethical challenges. This study aimed to investigate infertile couples’ opinions about issues of sperm donor anonymity and to determine factors that might influence their preferences. Methods A cross-sectional, multicentered, questionnaire-based study was conducted among infertile couples attending infertility clinics in three tertiary hospitals in the south-eastern region of Nigeria over a period of 6 months. Results A total of 450 infertile couples were recruited consecutively from the three study centers. However, 450 females and 352 males (total=802) participated in the study. The level of awareness of artificial insemination using donor sperm for the management of male infertility among the respondents was 69.2%, while its acceptability rate was 62.7%. The majority of the respondents indicated their preference for secrecy and anonymity in sperm donation. Approximately 84% of the respondents indicated that the mode of conception should never be disclosed to the donor-conceived child, and ~92% of them indicated that the identity of the sperm donor should never be revealed to the donor-conceived child. Fear of adverse effect of such disclosure on the child and the possible of rejection of the father in order to seek for the donor were the major reasons for their preference for anonymity. Conclusion Although it has been argued that every child has a right to know their genetic parents, the reasons proffered by the respondents for their preference for anonymity cannot be totally ignored. Establishing a regulatory body and enacting laws that will address both the ethical and legal issues associated with gamete donation in the developing world will go a long way in promoting openness and honest communication with donor-conceived children. PMID:29670338

  5. A more secure anonymous user authentication scheme for the integrated EPR information system.

    Science.gov (United States)

    Wen, Fengtong

    2014-05-01

    Secure and efficient user mutual authentication is an essential task for integrated electronic patient record (EPR) information system. Recently, several authentication schemes have been proposed to meet this requirement. In a recent paper, Lee et al. proposed an efficient and secure password-based authentication scheme used smart cards for the integrated EPR information system. This scheme is believed to have many abilities to resist a range of network attacks. Especially, they claimed that their scheme could resist lost smart card attack. However, we reanalyze the security of Lee et al.'s scheme, and show that it fails to protect off-line password guessing attack if the secret information stored in the smart card is compromised. This also renders that their scheme is insecure against user impersonation attacks. Then, we propose a new user authentication scheme for integrated EPR information systems based on the quadratic residues. The new scheme not only resists a range of network attacks but also provides user anonymity. We show that our proposed scheme can provide stronger security.

  6. Evolution of fairness in the one-shot anonymous Ultimatum Game.

    Science.gov (United States)

    Rand, David G; Tarnita, Corina E; Ohtsuki, Hisashi; Nowak, Martin A

    2013-02-12

    Classical economic models assume that people are fully rational and selfish, while experiments often point to different conclusions. A canonical example is the Ultimatum Game: one player proposes a division of a sum of money between herself and a second player, who either accepts or rejects. Based on rational self-interest, responders should accept any nonzero offer and proposers should offer the smallest possible amount. Traditional, deterministic models of evolutionary game theory agree: in the one-shot anonymous Ultimatum Game, natural selection favors low offers and demands. Experiments instead show a preference for fairness: often responders reject low offers and proposers make higher offers than needed to avoid rejection. Here we show that using stochastic evolutionary game theory, where agents make mistakes when judging the payoffs and strategies of others, natural selection favors fairness. Across a range of parameters, the average strategy matches the observed behavior: proposers offer between 30% and 50%, and responders demand between 25% and 40%. Rejecting low offers increases relative payoff in pairwise competition between two strategies and is favored when selection is sufficiently weak. Offering more than you demand increases payoff when many strategies are present simultaneously and is favored when mutation is sufficiently high. We also perform a behavioral experiment and find empirical support for these theoretical findings: uncertainty about the success of others is associated with higher demands and offers; and inconsistency in the behavior of others is associated with higher offers but not predictive of demands. In an uncertain world, fairness finishes first.

  7. Prospective parents' intentions regarding disclosure following the removal of donor anonymity.

    Science.gov (United States)

    Crawshaw, Marilyn

    2008-06-01

    This short survey of UK infertility counsellors was designed to determine whether the removal of donor anonymity resulted in noticeable changes in prospective parents' stated intentions regarding disclosure of their origins to any children conceived through donor conception. Members of the British Infertility Counselling Association working in Human Fertilisation and Embryology Authority (HFEA) -- licensed centres, before and after the legal changes, were sent a short questionnaire that included space for free comments (take-up: 62%). Three-quarters reported changes. Of these, two-thirds said prospective parents were more likely to say they would disclose, while less than a tenth said prospective parents were less likely do so. Where no changes were noted, this was primarily because the majority of prospective parents had stated their intention to be open even prior to the legal changes. Possible influences on intentions included: the culture within the centre, moves towards openness within the wider society, and parents' lack of confidence regarding how to go about disclosure. Follow-up studies are needed to improve understanding of whether influences on decision making carry through to patterns of actual disclosure; whether involvement in counselling affects outcomes; and whether access to professional assistance at the time of planned disclosure is helpful.

  8. Cardinality Estimation Algorithm in Large-Scale Anonymous Wireless Sensor Networks

    KAUST Repository

    Douik, Ahmed

    2017-08-30

    Consider a large-scale anonymous wireless sensor network with unknown cardinality. In such graphs, each node has no information about the network topology and only possesses a unique identifier. This paper introduces a novel distributed algorithm for cardinality estimation and topology discovery, i.e., estimating the number of node and structure of the graph, by querying a small number of nodes and performing statistical inference methods. While the cardinality estimation allows the design of more efficient coding schemes for the network, the topology discovery provides a reliable way for routing packets. The proposed algorithm is shown to produce a cardinality estimate proportional to the best linear unbiased estimator for dense graphs and specific running times. Simulation results attest the theoretical results and reveal that, for a reasonable running time, querying a small group of nodes is sufficient to perform an estimation of 95% of the whole network. Applications of this work include estimating the number of Internet of Things (IoT) sensor devices, online social users, active protein cells, etc.

  9. 20 Questions of Gamblers Anonymous: A Psychometric Study with Population of Spain.

    Science.gov (United States)

    Ursua, María Prieto; Uribelarrea, Luis Llavona

    1998-01-01

    The authors present a psychometric study of the questionnaire proposed by the Gamblers Anonymous organization for the self-assessment of problem gambling. The study was carried out in Spain with two samples: one of 127 problem gamblers (mean age: 41.67; sex: 78.7% men; mean duration of the problem: 5 years) and the other of 142 social gamblers (mean age: 38.46; sex: 60% men). The questionnaire was self-applied, in the presence of one of the investigators in case any doubts arose. The results indicate that it is a good screening instrument, with high reliability (Cronbach's alpha = 0.94), good covergent validity (the correlation with the SOGS questionnaire is high (r = 0.94; p < 0.001)), good factorial validity (the questionnaire's structure is unidimensional and coherent (just one factor explains more than 50% of the variance)), and its discriminative power is high (diagnostic efficacy = 98.88%). The study offers a comparative analysis of this instrument with other measures of problem gambling, emphasizing its extraordinary performance.

  10. Patterns and correlates of Gamblers Anonymous attendance in pathological gamblers seeking professional treatment.

    Science.gov (United States)

    Petry, Nancy M

    2003-08-01

    Although Gamblers Anonymous (GA) is a popular intervention for gamblers, many attendees later present for professional treatment. This study evaluated gambling and psychosocial problems in individuals seeking professional treatment for gambling and compared those with and without a history of GA attendance. At intake to treatment, 342 pathological gamblers completed the Addiction Severity Index (ASI) and South Oaks Gambling Screen (SOGS). Fifty-four percent attended GA previously. Compared to non-GA attendees, GA attendees were older, had higher incomes, and were less likely to be single. They had higher SOGS scores, more years of gambling problems, and larger debts. GA attendees also had more serious family conflicts and less serious drug problems. Individuals with a history of GA attendance were more likely to be abstinent from gambling 2 months after treatment initiation. Logistic regression revealed that the number of professional sessions and GA meetings attended during treatment was independently associated with short-term abstinence. These data suggest that individuals entering professional treatment for gambling with a history of GA attendance differ from those who do not, and these differences may impact treatment recommendations and outcomes.

  11. Psychosocial factors related to gambling abstinence and relapse in members of gamblers anonymous.

    Science.gov (United States)

    Oei, Tian P S; Gordon, Leon M

    2008-03-01

    Problem gamblers account for almost one-third of the industry's total revenue with the adverse effects of problem gambling including significant financial loss, legal and occupational difficulties, family problems, psychological distress and suicide. As such, it is important to understand the influential factors in gambling abstinence and relapse, which will assist in the development of relapse prevention methods in therapeutic treatment regimes. This paper reported the role of a set of seven predictors in distinguishing between abstinent and relapsed gamblers among 75 Gambling Anonymous (GA) members (55 males; 20 females; Mean age 45 years) in Southeast Queensland. The measures taken were meeting Attendance and Participation, Social Support, God Belief, Belief in a Higher Power, Working the 12-steps of Recovery, Gambling Urges and Erroneous Cognitions. Discriminant analysis revealed that the variables separating the two groups were significant, suggesting that GA members achieving abstinence could be distinguished from those who relapsed, with Attendance and Participation, and Social Support contributing the greatest influence on member's ability to abstain from gambling. The findings suggested that GA member's involvement in meetings, and support from family and friends had significant impact on their gambling abstinence. In contrast, increased gambling urges and erroneous cognitions increased the chance of relapse.

  12. Alcoholics Anonymous and twelve-step recovery: a model based on social and cognitive neuroscience.

    Science.gov (United States)

    Galanter, Marc

    2014-01-01

    In the course of achieving abstinence from alcohol, longstanding members of Alcoholics Anonymous (AA) typically experience a change in their addiction-related attitudes and behaviors. These changes are reflective of physiologically grounded mechanisms which can be investigated within the disciplines of social and cognitive neuroscience. This article is designed to examine recent findings associated with these disciplines that may shed light on the mechanisms underlying this change. Literature review and hypothesis development. Pertinent aspects of the neural impact of drugs of abuse are summarized. After this, research regarding specific brain sites, elucidated primarily by imaging techniques, is reviewed relative to the following: Mirroring and mentalizing are described in relation to experimentally modeled studies on empathy and mutuality, which may parallel the experiences of social interaction and influence on AA members. Integration and retrieval of memories acquired in a setting like AA are described, and are related to studies on storytelling, models of self-schema development, and value formation. A model for ascription to a Higher Power is presented. The phenomena associated with AA reflect greater complexity than the empirical studies on which this article is based, and certainly require further elucidation. Despite this substantial limitation in currently available findings, there is heuristic value in considering the relationship between the brain-based and clinical phenomena described here. There are opportunities for the study of neuroscientific correlates of Twelve-Step-based recovery, and these can potentially enhance our understanding of related clinical phenomena. © American Academy of Addiction Psychiatry.

  13. LPPS: A Distributed Cache Pushing Based K-Anonymity Location Privacy Preserving Scheme

    Directory of Open Access Journals (Sweden)

    Ming Chen

    2016-01-01

    Full Text Available Recent years have witnessed the rapid growth of location-based services (LBSs for mobile social network applications. To enable location-based services, mobile users are required to report their location information to the LBS servers and receive answers of location-based queries. Location privacy leak happens when such servers are compromised, which has been a primary concern for information security. To address this issue, we propose the Location Privacy Preservation Scheme (LPPS based on distributed cache pushing. Unlike existing solutions, LPPS deploys distributed cache proxies to cover users mostly visited locations and proactively push cache content to mobile users, which can reduce the risk of leaking users’ location information. The proposed LPPS includes three major process. First, we propose an algorithm to find the optimal deployment of proxies to cover popular locations. Second, we present cache strategies for location-based queries based on the Markov chain model and propose update and replacement strategies for cache content maintenance. Third, we introduce a privacy protection scheme which is proved to achieve k-anonymity guarantee for location-based services. Extensive experiments illustrate that the proposed LPPS achieves decent service coverage ratio and cache hit ratio with lower communication overhead compared to existing solutions.

  14. Identification of genes in anonymous DNA sequences. Annual performance report, February 1, 1991--January 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Fields, C.A.

    1996-06-01

    The objective of this project is the development of practical software to automate the identification of genes in anonymous DNA sequences from the human, and other higher eukaryotic genomes. A software system for automated sequence analysis, gm (gene modeler) has been designed, implemented, tested, and distributed to several dozen laboratories worldwide. A significantly faster, more robust, and more flexible version of this software, gm 2.0 has now been completed, and is being tested by operational use to analyze human cosmid sequence data. A range of efforts to further understand the features of eukaryoyic gene sequences are also underway. This progress report also contains papers coming out of the project including the following: gm: a Tool for Exploratory Analysis of DNA Sequence Data; The Human THE-LTR(O) and MstII Interspersed Repeats are subfamilies of a single widely distruted highly variable repeat family; Information contents and dinucleotide compostions of plant intron sequences vary with evolutionary origin; Splicing signals in Drosophila: intron size, information content, and consensus sequences; Integration of automated sequence analysis into mapping and sequencing projects; Software for the C. elegans genome project.

  15. An initial fMRI study on neural correlates of prayer in members of Alcoholics Anonymous.

    Science.gov (United States)

    Galanter, Marc; Josipovic, Zoran; Dermatis, Helen; Weber, Jochen; Millard, Mary Alice

    2017-01-01

    Many individuals with alcohol-use disorders who had experienced alcohol craving before joining Alcoholics Anonymous (AA) report little or no craving after becoming long-term members. Their use of AA prayers may contribute to this. Neural mechanisms underlying this process have not been delineated. To define experiential and neural correlates of diminished alcohol craving following AA prayers among members with long-term abstinence. Twenty AA members with long-term abstinence participated. Self-report measures and functional magnetic resonance imaging of differential neural response to alcohol-craving-inducing images were obtained in three conditions: after reading of AA prayers, after reading irrelevant news, and with passive viewing. Random-effects robust regressions were computed for the main effect (prayer > passive + news) and for estimating the correlations between the main effect and the self-report measures. Compared to the other two conditions, the prayer condition was characterized by: less self-reported craving; increased activation in left-anterior middle frontal gyrus, left superior parietal lobule, bilateral precuneus, and bilateral posterior middle temporal gyrus. Craving following prayer was inversely correlated with activation in brain areas associated with self-referential processing and the default mode network, and with characteristics reflecting AA program involvement. AA members' prayer was associated with a relative reduction in self-reported craving and with concomitant engagement of neural mechanisms that reflect control of attention and emotion. These findings suggest neural processes underlying the apparent effectiveness of AA prayer.

  16. Parents' perception of self-advocacy of children with myositis: an anonymous online survey

    Directory of Open Access Journals (Sweden)

    Huber Adam M

    2011-06-01

    Full Text Available Abstract Background Children with complex medical issues experience barriers to the transition of care from pediatric to adult providers. We sought to identify these barriers by elucidating the experiences of patients with idiopathic inflammatory muscle disorders. Methods We collected anonymous survey data using an online website. Patients and their families were solicited from the US and Canada through established clinics for children with idiopathic inflammatory muscle diseases as well as with the aid of a nonprofit organization for the benefit of such individuals. The parents of 45 older children/young adults suffering from idiopathic inflammatory muscle diseases were surveyed. As a basis of comparison, we similarly collected data from the parents of 207 younger children with inflammatory muscle diseases. The survey assessed transition of care issues confronting families of children and young adults with chronic juvenile myositis. Results Regardless of age of the patient, respondents were unlikely to have a designated health care provider assigned to aid in transition of care and were unlikely to be aware of a posted policy concerning transition of care at their pediatrician's office. Additionally, regardless of age, patients and their families were unlikely to have a written plan for moving to adult care. Conclusions We identified deficiencies in the health care experiences of families as pertain to knowledge, self-advocacy, policy, and vocational readiness. Moreover, as children with complex medical issues grow up, parents attribute less self-advocacy to their children's level of independence.

  17. A uniqueness-and-anonymity-preserving remote user authentication scheme for connected health care.

    Science.gov (United States)

    Chang, Ya-Fen; Yu, Shih-Hui; Shiao, Ding-Rui

    2013-04-01

    Connected health care provides new opportunities for improving financial and clinical performance. Many connected health care applications such as telecare medicine information system, personally controlled health records system, and patient monitoring have been proposed. Correct and quality care is the goal of connected heath care, and user authentication can ensure the legality of patients. After reviewing authentication schemes for connected health care applications, we find that many of them cannot protect patient privacy such that others can trace users/patients by the transmitted data. And the verification tokens used by these authentication schemes to authenticate users or servers are only password, smart card and RFID tag. Actually, these verification tokens are not unique and easy to copy. On the other hand, biometric characteristics, such as iris, face, voiceprint, fingerprint and so on, are unique, easy to be verified, and hard to be copied. In this paper, a biometrics-based user authentication scheme will be proposed to ensure uniqueness and anonymity at the same time. With the proposed scheme, only the legal user/patient himself/herself can access the remote server, and no one can trace him/her according to transmitted data.

  18. Personality Patterns in Narcotics Anonymous Members versus Individuals with Addiction Receiving Methadone Maintenance Therapy.

    Directory of Open Access Journals (Sweden)

    Shahin Akhondzadeh

    2014-09-01

    Full Text Available Therapeutic interventions can be classified into two distinct approaches: abstinent and maintenance method. Currently, there are no clear criteria for referring addicted patients to one of these modalities. We aimed to compare the personality characteristics of individuals with addiction who attended narcotics anonymous sessions with those who received methadone maintenance therapy.This was a cross- sectional study. The participants were NA members and patients who were undergoing methadone maintenance treatment in outpatient clinics. Using the randomized cluster sampling method, 200 individuals with opioid dependence were selected (each group 100 persons. Data were collected through a demographic questionnaire and the five-factor personality inventory (NEO-FFI. Comparison of the mean scores of NEO-PPI in the two groups was performed by independent t test, and qualitative variables were compared using the Chi-square test.We found a significant difference between the MMT and NA groups with respect to neuroticism, extroversion, and agreeableness. No significant difference was found in the subscales of conscientious and openness.People who regularly attended the NA sessions had lower neuroticism and higher agreeableness than patients who were under the maintenance modality. Whether this is the cause or effect of attending NA sessions requires future large-scale cohort studies.

  19. Intuitive presentation of clinical forensic data using anonymous and person-specific 3D reference manikins.

    Science.gov (United States)

    Urschler, Martin; Höller, Johannes; Bornik, Alexander; Paul, Tobias; Giretzlehner, Michael; Bischof, Horst; Yen, Kathrin; Scheurer, Eva

    2014-08-01

    The increasing use of CT/MR devices in forensic analysis motivates the need to present forensic findings from different sources in an intuitive reference visualization, with the aim of combining 3D volumetric images along with digital photographs of external findings into a 3D computer graphics model. This model allows a comprehensive presentation of forensic findings in court and enables comparative evaluation studies correlating data sources. The goal of this work was to investigate different methods to generate anonymous and patient-specific 3D models which may be used as reference visualizations. The issue of registering 3D volumetric as well as 2D photographic data to such 3D models is addressed to provide an intuitive context for injury documentation from arbitrary modalities. We present an image processing and visualization work-flow, discuss the major parts of this work-flow, compare the different investigated reference models, and show a number of cases studies that underline the suitability of the proposed work-flow for presenting forensically relevant information in 3D visualizations. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  20. Identification of the stimulated-emission threshold in high-β nanoscale lasers through phase-space reconstruction

    International Nuclear Information System (INIS)

    Hachair, X.; Elvira, D.; Le Gratiet, L.; Lemaitre, A.; Abram, I.; Sagnes, I.; Robert-Philip, I.; Beveratos, A.; Braive, R.; Lippi, G. L.

    2011-01-01

    Nanoscale lasers sustain a few optical modes so that the fraction of spontaneous emission β funnelled into the useful (lasing) mode is high (of the order of 10 -1 ) and the threshold, which traditionally corresponds to an abrupt kink in the light-in-light-out curve, becomes ill defined. We propose an alternative definition of the threshold that is based on the dynamical response of the laser and is valid even for β=1 lasers. The laser dynamics is analyzed through a reconstruction of its phase-space trajectory for pulsed excitations. Crossing the threshold, brings about a change in the shape of the trajectory and in the area contained in it. An unambiguous determination of the threshold in terms of this change is shown theoretically and illustrated experimentally in a photonic-crystal laser.

  1. Spontaneous emergence of social influence in online systems.

    Science.gov (United States)

    Onnela, Jukka-Pekka; Reed-Tsochas, Felix

    2010-10-26

    Social influence drives both offline and online human behavior. It pervades cultural markets, and manifests itself in the adoption of scientific and technical innovations as well as the spread of social practices. Prior empirical work on the diffusion of innovations in spatial regions or social networks has largely focused on the spread of one particular technology among a subset of all potential adopters. Here we choose an online context that allows us to study social influence processes by tracking the popularity of a complete set of applications installed by the user population of a social networking site, thus capturing the behavior of all individuals who can influence each other in this context. By extending standard fluctuation scaling methods, we analyze the collective behavior induced by 100 million application installations, and show that two distinct regimes of behavior emerge in the system. Once applications cross a particular threshold of popularity, social influence processes induce highly correlated adoption behavior among the users, which propels some of the applications to extraordinary levels of popularity. Below this threshold, the collective effect of social influence appears to vanish almost entirely, in a manner that has not been observed in the offline world. Our results demonstrate that even when external signals are absent, social influence can spontaneously assume an on-off nature in a digital environment. It remains to be seen whether a similar outcome could be observed in the offline world if equivalent experimental conditions could be replicated.

  2. Origin of spontaneous wave generation in an oscillatory chemical system

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yi-Xue; Foerster, P.; Ross, J. [Stanford Univ., CA (United States)

    1992-10-29

    The origin of spontaneously generated chemical waves in an oscillatory Belousov-Zhabotinskii reaction has been investigated by numerical calculations of the deterministic reaction-diffusion equations of a modified Oregonator model and by equilibrium stochastic calculations. From numerical calculations, we obtain threshold perturbations in the phase of oscillations and in the concentrations of HBrO{sub 2} and Br{sup {minus}} within areas of space with varying radii necessary to initiate trigger waves. Inward propagating trigger waves initiated by a phase shift in the perturbed region with respect to the bulk solution have been observed in the calculations for the first time. Perturbations smaller than the threshold perturbations or in regions with smaller radii lead to phase-diffusion waves. Our equilibrium stochastic calculations show that the recurrence time for a thermal fluctuation to induce a change in the HBrO{sub 2} concentration of sufficient magnitude within a sufficient volume for a trigger wave to propagate is many orders of magnitude larger than the observation time of traveling wave experiments. We concluded that an internal thermal fluctuation is highly unlikely to generate a trigger wave in an oscillatory chemical solution. 22 refs., 5 figs., 7 tabs.

  3. Time-efficient multidimensional threshold tracking method

    DEFF Research Database (Denmark)

    Fereczkowski, Michal; Kowalewski, Borys; Dau, Torsten

    2015-01-01

    Traditionally, adaptive methods have been used to reduce the time it takes to estimate psychoacoustic thresholds. However, even with adaptive methods, there are many cases where the testing time is too long to be clinically feasible, particularly when estimating thresholds as a function of anothe...

  4. Applying Threshold Concepts to Finance Education

    Science.gov (United States)

    Hoadley, Susan; Wood, Leigh N.; Tickle, Leonie; Kyng, Tim

    2016-01-01

    Purpose: The purpose of this paper is to investigate and identify threshold concepts that are the essential conceptual content of finance programmes. Design/Methodology/Approach: Conducted in three stages with finance academics and students, the study uses threshold concepts as both a theoretical framework and a research methodology. Findings: The…

  5. Voting on Thresholds for Public Goods

    DEFF Research Database (Denmark)

    Rauchdobler, Julian; Sausgruber, Rupert; Tyran, Jean-Robert

    2010-01-01

    Introducing a threshold in the sense of a minimal project size transforms a public-good game with an inefficient equilibrium into a coordination game with a set of Pareto-superior equilibria. Thresholds may therefore improve efficiency in the voluntary provision of public goods. In our one-shot e...

  6. Intelligence and Creativity: Over the Threshold Together?

    Science.gov (United States)

    Welter, Marisete Maria; Jaarsveld, Saskia; van Leeuwen, Cees; Lachmann, Thomas

    2016-01-01

    Threshold theory predicts a positive correlation between IQ and creativity scores up to an IQ level of 120 and no correlation above this threshold. Primary school children were tested at beginning (N = 98) and ending (N = 70) of the school year. Participants performed the standard progressive matrices (SPM) and the Test of Creative…

  7. Threshold Concepts, Systems and Learning for Sustainability

    Science.gov (United States)

    Sandri, Orana Jade

    2013-01-01

    This paper presents a framework for understanding the role that systems theory might play in education for sustainability (EfS). It offers a sketch and critique of Land and Meyer's notion of a "threshold concept", to argue that seeing systems as a threshold concept for sustainability is useful for understanding the processes of…

  8. Evaluation of the Detection Threshold of Three ...

    African Journals Online (AJOL)

    A mean count of 39 pigments per microlitre was obtained for these five patients. Both HEXAGON MALARIA and SD-BIOLINE had a detection threshold of 4 pigments per microlitre, while ACCU-STAT MALARIA had 20 pigments per microlitre. This suggests that these three kits have good detection thresholds and could ...

  9. Log canonical thresholds of smooth Fano threefolds

    International Nuclear Information System (INIS)

    Cheltsov, Ivan A; Shramov, Konstantin A

    2008-01-01

    The complex singularity exponent is a local invariant of a holomorphic function determined by the integrability of fractional powers of the function. The log canonical thresholds of effective Q-divisors on normal algebraic varieties are algebraic counterparts of complex singularity exponents. For a Fano variety, these invariants have global analogues. In the former case, it is the so-called α-invariant of Tian; in the latter case, it is the global log canonical threshold of the Fano variety, which is the infimum of log canonical thresholds of all effective Q-divisors numerically equivalent to the anticanonical divisor. An appendix to this paper contains a proof that the global log canonical threshold of a smooth Fano variety coincides with its α-invariant of Tian. The purpose of the paper is to compute the global log canonical thresholds of smooth Fano threefolds (altogether, there are 105 deformation families of such threefolds). The global log canonical thresholds are computed for every smooth threefold in 64 deformation families, and the global log canonical thresholds are computed for a general threefold in 20 deformation families. Some bounds for the global log canonical thresholds are computed for 14 deformation families. Appendix A is due to J.-P. Demailly.

  10. Spontaneous Metacognition in Rhesus Monkeys.

    Science.gov (United States)

    Rosati, Alexandra G; Santos, Laurie R

    2016-09-01

    Metacognition is the ability to think about thinking. Although monitoring and controlling one's knowledge is a key feature of human cognition, its evolutionary origins are debated. In the current study, we examined whether rhesus monkeys (Macaca mulatta; N = 120) could make metacognitive inferences in a one-shot decision. Each monkey experienced one of four conditions, observing a human appearing to hide a food reward in an apparatus consisting of either one or two tubes. The monkeys tended to search the correct location when they observed this baiting event, but engaged in information seeking-by peering into a center location where they could check both potential hiding spots-if their view had been occluded and information seeking was possible. The monkeys only occasionally approached the center when information seeking was not possible. These results show that monkeys spontaneously use information about their own knowledge states to solve naturalistic foraging problems, and thus provide the first evidence that nonhumans exhibit information-seeking responses in situations with which they have no prior experience. © The Author(s) 2016.

  11. Spontaneous flocking in human groups.

    Science.gov (United States)

    Belz, Michael; Pyritz, Lennart W; Boos, Margarete

    2013-01-01

    Flocking behaviour, as a type of self-organised collective behaviour, is described as the spatial formation of groups without global control and explicit inter-individual recruitment signals. It can be observed in many animals, such as bird flocks, shoals or herds of ungulates. Spatial attraction between humans as the central component of flocking behaviour has been simulated in a number of seminal models but it has not been detected experimentally in human groups so far. The two other sub-processes of this self-organised collective movement - collision avoidance and alignment - are excluded or held constant respectively in this study. We created a computer-based, multi-agent game where human players, represented as black dots, moved on a virtual playground. The participants were deprived of social cues about each other and could neither communicate verbally nor nonverbally. They played two games: (1) Single Game, where other players were invisible, and (2) Joint Game, where each player could see players' positions in a local radius around himself/herself. We found that individuals approached their neighbours spontaneously if their positions were visible, leading to less spatial dispersion of the whole group compared to moving alone. We conclude that human groups show the basic component of flocking behaviour without being explicitly instructed or rewarded to do so. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Simultaneous bilateral primary spontaneous pneumothorax

    Directory of Open Access Journals (Sweden)

    Arife Zeybek

    2014-04-01

    Full Text Available Simultaneous bilateral primary pneumothorax is a very rare (1.6 / 100,000 and life-threatening condition. Clinical presentation may vary from mild dyspnea to tension pneumothorax. It may be milder particularly in younger patients, but more severe in patients with advanced age, and tube thoracostomy is a life preserver in the latter group. Since mortality and recurrence rates following tube thoracostomy are high, endoscopic approaches to bilateral hemithorax have been reported in literature. Apical wedge resection and pleural procedures are recommended in video thoracoscopy or mini thoracotomy even if no bulla and/or bleb are detected. Bilateral surgical interventions and additional pleural procedures are associated with increased rate of post-operative complications and longer postoperative hospital-stays. As a first-line approach, the surgical method toward any side of lung with air leakage following a previous tube thoracostomy is considered less invasive, especially in younger patients. Here, we present a case of simultaneous bilateral primary spontaneous pneumothorax (SBPSP in a 21-year old male with no history of smoking and chronic pulmonary disease. A unilateral surgical intervention was performed, and no recurrence was observed during 5-year follow up.

  13. Bilateral spontaneous hemotympanum: Case report

    Directory of Open Access Journals (Sweden)

    Economou Nicolas C

    2006-10-01

    Full Text Available Abstract Background The most common causes of hemotympanum are therapeutic nasal packing, epistaxis, blood disorders and blunt trauma to the head. Hemotympanum is characterized as idiopathic, when it is detected in the presence of chronic otitis media. A rare case of spontaneous bilateral hemotympanum in a patient treated with anticoagulants is presented herein. Case presentation A 72-year-old male presented with acute deterioration of hearing. In the patient's medical history aortic valve replacement 1 year before presentation was reported. Since then he had been administered regularly coumarinic anticoagulants, with INR levels maintained between 3.4 and 4.0. Otoscopy revealed the presence of bilateral hemotympanum. The audiogram showed symmetrical moderately severe mixed hearing loss bilaterally, with the conductive component predominating. Tympanograms were flat bilaterally with absent acoustic reflexes. A computerized tomography scan showed the presence of fluid in the mastoid and middle ear bilaterally. Treatment was conservative and consisted of a 10-day course of antibiotics, anticongestants and temporary interruption of the anticoagulant therapy. After 3 weeks, normal tympanic membranes were found and hearing had returned to previous levels. Conclusion Anticoagulant intake should be included in the differential diagnosis of hemotympanum, because its detection and appropriate treatment may lead to resolution of the disorder.

  14. The dissimilar time course of temporary threshold shifts and reduction of inhibition in the inferior colliculus following intense sound exposure.

    Science.gov (United States)

    Heeringa, A N; van Dijk, P

    2014-06-01

    Excessive noise exposure is known to produce an auditory threshold shift, which can be permanent or transient in nature. Recent studies showed that noise-induced temporary threshold shifts are associated with loss of synaptic connections to the inner hair cells and with cochlear nerve degeneration, which is reflected in a decreased amplitude of wave I of the auditory brainstem response (ABR). This suggests that, despite normal auditory thresholds, central auditory processing may be abnormal. We recorded changes in central auditory processing following a sound-induced temporary threshold shift. Anesthetized guinea pigs were exposed for 1 h to a pure tone of 11 kHz (124 dB sound pressure level). Hearing thresholds, amplitudes of ABR waves I and IV, and spontaneous and tone-evoked firing rates in the inferior colliculus (IC) were assessed immediately, one week, two weeks, and four weeks post exposure. Hearing thresholds were elevated immediately following overexposure, but recovered within one week. The amplitude of the ABR wave I was decreased in all sound-exposed animals for all test periods. In contrast, the ABR wave IV amplitude was only decreased immediately after overexposure and recovered within a week. The proportion of IC units that show inhibitory responses to pure tones decreased substantially up to two weeks after overexposure, especially when stimulated with high frequencies. The proportion of excitatory responses to low frequencies was increased. Spontaneous activity was unaffected by the overexposure. Despite rapid normalization of auditory thresholds, our results suggest an increased central gain following sound exposure and an abnormal balance between excitatory and inhibitory responses in the midbrain up to two weeks after overexposure. These findings may be associated with hyperacusis after a sound-induced temporary threshold shift. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  15. Underestimation of pacing threshold as determined by an automatic ventricular threshold testing algorithm.

    Science.gov (United States)

    Sauer, William H; Cooper, Joshua M; Lai, Rebecca W; Verdino, Ralph J

    2006-09-01

    In this case report, we describe markedly different pacing thresholds determined by a manual threshold test and the automatic Ventricular Capture Management algorithm. The discrepancy in pacing threshold values reported was due to the difference in the AV intervals used with the different testing methods. We propose that the differences in right ventricular dimensions with altered diastolic filling periods affected the threshold in this patient with a new passive fixation lead in the right ventricular apex.

  16. A Threshold Continuum for Aeolian Sand Transport

    Science.gov (United States)

    Swann, C.; Ewing, R. C.; Sherman, D. J.

    2015-12-01

    The threshold of motion for aeolian sand transport marks the initial entrainment of sand particles by the force of the wind. This is typically defined and modeled as a singular wind speed for a given grain size and is based on field and laboratory experimental data. However, the definition of threshold varies significantly between these empirical models, largely because the definition is based on visual-observations of initial grain movement. For example, in his seminal experiments, Bagnold defined threshold of motion when he observed that 100% of the bed was in motion. Others have used 50% and lesser values. Differences in threshold models, in turn, result is large errors in predicting the fluxes associated with sand and dust transport. Here we use a wind tunnel and novel sediment trap to capture the fractions of sand in creep, reptation and saltation at Earth and Mars pressures and show that the threshold of motion for aeolian sand transport is best defined as a continuum in which grains progress through stages defined by the proportion of grains in creep and saltation. We propose the use of scale dependent thresholds modeled by distinct probability distribution functions that differentiate the threshold based on micro to macro scale applications. For example, a geologic timescale application corresponds to a threshold when 100% of the bed in motion whereas a sub-second application corresponds to a threshold when a single particle is set in motion. We provide quantitative measurements (number and mode of particle movement) corresponding to visual observations, percent of bed in motion and degrees of transport intermittency for Earth and Mars. Understanding transport as a continuum provides a basis for revaluating sand transport thresholds on Earth, Mars and Titan.

  17. Clock frequency estimation under spontaneous emission

    Science.gov (United States)

    Qin, Xi-Zhou; Huang, Jia-Hao; Zhong, Hong-Hua; Lee, Chaohong

    2018-02-01

    We investigate the quantum dynamics of a driven two-level system under spontaneous emission and its application in clock frequency estimation. By using the Lindblad equation to describe the system, we analytically obtain its exact solutions, which show three different regimes: Rabi oscillation, damped oscillation, and overdamped decay. From the analytical solutions, we explore how the spontaneous emission affects the clock frequency estimation. We find that under a moderate spontaneous emission rate, the transition frequency can still be inferred from the Rabi oscillation. Our results enable potential practical applications in frequency measurement and quantum control under decoherence.

  18. Spontaneous Bacterial Peritonitis in Subclinical Hypothyroidism

    Directory of Open Access Journals (Sweden)

    Dalip Gupta

    2013-11-01

    Full Text Available Hypothyroidism is an uncommon cause of ascites. Here we describe a case of a 75 year-old female patient with spontaneous bacterial peritonitis and subclinical hypothyroidism that resolved with thyroid replacement and antibiotic therapy respectively. Ascitic fluid analysis revealed a gram-positive bacterium on gram staining. A review of the literature revealed just one other reported case of myxoedema ascites with concomitant spontaneous bacterial peritonitis and no case has till been reported of spontaneous bacterial peritonitis in subclinical hypothyroidism.

  19. Spontaneous regression of an invasive thymoma.

    Science.gov (United States)

    Yutaka, Yojiro; Omasa, Mitsugu; Shikuma, Kei; Okuda, Masato; Taki, Toshihiko

    2009-05-01

    Although there are many reports of spontaneous regression of noninvasive thymoma, there are no reports of spontaneous regression of an invasive thymoma. Moreover, the mechanism of the spontaneous regression is still unknown. The present case concerns a 47-year-old man who presented with chest pain. Computed tomography (CT) showed a large anterior mediastinal mass with left pleural effusion that occluded the innominate vein. The tissue obtained by video-assisted thoracic surgery suggested a diagnosis of invasive thymic carcinoma. One month later CT showed prominent regression of the tumor, and the tumor was completely resected. On pathology, the diagnosis was thymoma type B3.

  20. Spontaneous Dissection of the Superior Mesenteric Artery

    International Nuclear Information System (INIS)

    Sheldon, Patrick J.; Esther, James B.; Sheldon, Elana L.; Sparks, Steven R.; Brophy, David P.; Oglevie, Steven B.

    2001-01-01

    Spontaneous dissection of the superior mesenteric artery (SMA) is a rare occurrence, especially when not associated with aortic dissection. Currently, only 28 cases appear to have been reported. Due to the scarcity of cases in the literature, the natural history of isolated, spontaneous SMA dissection is unclear. CT has been reported to be useful for the initial diagnosis of SMA dissection [2-5]. We present two recent cases of spontaneous SMA dissection in which enhanced spiral CT was instrumental in following the disease process and guiding clinical decision making

  1. Does Spontaneous Favorability to Power (vs. Universalism) Values Predict Spontaneous Prejudice and Discrimination?

    Science.gov (United States)

    Souchon, Nicolas; Maio, Gregory R; Hanel, Paul H P; Bardin, Brigitte

    2017-10-01

    We conducted five studies testing whether an implicit measure of favorability toward power over universalism values predicts spontaneous prejudice and discrimination. Studies 1 (N = 192) and 2 (N = 86) examined correlations between spontaneous favorability toward power (vs. universalism) values, achievement (vs. benevolence) values, and a spontaneous measure of prejudice toward ethnic minorities. Study 3 (N = 159) tested whether conditioning participants to associate power values with positive adjectives and universalism values with negative adjectives (or inversely) affects spontaneous prejudice. Study 4 (N = 95) tested whether decision bias toward female handball players could be predicted by spontaneous attitude toward power (vs. universalism) values. Study 5 (N = 123) examined correlations between spontaneous attitude toward power (vs. universalism) values, spontaneous importance toward power (vs. universalism) values, and spontaneous prejudice toward Black African people. Spontaneous positivity toward power (vs. universalism) values was associated with spontaneous negativity toward minorities and predicted gender bias in a decision task, whereas the explicit measures did not. These results indicate that the implicit assessment of evaluative responses attached to human values helps to model value-attitude-behavior relations. © 2016 The Authors. Journal of Personality Published by Wiley Periodicals, Inc.

  2. Preference for anonymity in sperm donation for artificial insemination: an experience from low-resource settings in Nigeria

    Directory of Open Access Journals (Sweden)

    Ezugwu EC

    2018-04-01

    Full Text Available Euzebus Chinonye Ezugwu,1,2 George U Eleje,3,4 Chukwuemeka A Iyoke,1,2 Sunday G Mba,5 Henry C Nnaji,2 Chukwunonso I Enechukwu,4 Peter O Nkwo1,2 1Department of Obstetrics and Gynecology, Faculty of Medical Sciences, College of Medicine, University of Nigeria, Ittuku Ozalla Campus, Enugu State, Nigeria; 2Department of Obstetrics and Gynecology, University of Nigeria Teaching Hospital, Ituku-Ozalla, Enugu State, Nigeria; 3Department of Obstetrics and Gynecology, Faculty of Medicine, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria; 4Department of Obstetrics and Gynecology, Nnamdi Azikiwe University Teaching Hospital, Nnewi, Anambra State, Nigeria; 5Department of Obstetrics and Gynecology, Enugu State University Teaching Hospital, Enugu State, Nigeria Objective: Anonymous sperm donation is a common practice in Nigeria with its associated legal and ethical challenges. This study aimed to investigate infertile couples’ opinions about issues of sperm donor anonymity and to determine factors that might influence their preferences.Methods: A cross-sectional, multicentered, questionnaire-based study was conducted among infertile couples attending infertility clinics in three tertiary hospitals in the south-eastern region of Nigeria over a period of 6 months.Results: A total of 450 infertile couples were recruited consecutively from the three study centers. However, 450 females and 352 males (total=802 participated in the study. The level of awareness of artificial insemination using donor sperm for the management of male infertility among the respondents was 69.2%, while its acceptability rate was 62.7%. The majority of the respondents indicated their preference for secrecy and anonymity in sperm donation. Approximately 84% of the respondents indicated that the mode of conception should never be disclosed to the donor-conceived child, and ~92% of them indicated that the identity of the sperm donor should never be revealed to the donor

  3. Anonymity Preserving Routing In Location Privacy Schemes In Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    R Regin

    2015-12-01

    Full Text Available Location privacy measures need to be developed to prevent the opponent from determining the physical locations of source sensors and sinks. An opponent can easily intercept network traffic due to the use of a broadcast medium for routing packets and get detailed information such as packet transmission time and frequency to perform traffic analysis and infer the locations of monitored objects and data sinks. On the other hand, sensors usually have limited processing speed and energy supplies. It is very expensive to apply traditional anonymous communication techniques for hiding the communication between sensor nodes and sinks. The existing source-location privacy protects the location of monitored objects to increase the number of messages sent by the source before the object is located by the attacker. The flooding technique has the source node send each packet through numerous paths to a sink making it difficult for an opponent to trace the source. The locations of sinks can be protected from a local eavesdropper by hashing the ID field in the packet header. But opponent can track sinks by carrying out time correlation and rate monitoring attacks. Besides protection some source nodes are transferring relatively large amounts of data in existing system. As a result, these nodes run out of battery faster due to improper position of nodes and sinks. Thus in the proposed system the sinks should be located as optimally as possible to reduce traffic flow and energy consumption for sensor nodes. Hence Sink placement problem is resolved for minimizing the delay as well as maximizing the lifetime of a WSN. Thus proposed system is efficient in terms of overhead and functionality when compared to existing system.

  4. Anonymous authentication and location privacy preserving schemes for LTE-A networks

    Directory of Open Access Journals (Sweden)

    Zaher Jabr Haddad

    2017-11-01

    Full Text Available Long Term Evaluation Advanced (LTE-A is the third generation partnership project for cellular network that allows subscribers to roam into networks (i.e., the Internet and wireless connections using spacial purpose base-stations, such as wireless access points and home node B. In such LTE-A based networks, neither base-stations, nor the Internet and wireless connections are trusted because base-stations are operated by un-trusted subscribers. Attackers may exploit these vulnerabilities to violate the privacy of the LTE-A subscribers. On the other hand, the tradeoff between privacy and authentication is another challenge in such networks. Therefore, in this paper, we propose two anonymous authentication schemes based on one-time pseudonymes and Schnorr Zero Knowledge Protocols. Instead of the international mobile subscriber identity, these schemes enable the user equipment, base-stations and mobility management entity to mutually authenticate each others and update the location of the user equipment without evolving the home subscriber server. The security analysis demonstrate that the proposed schemes thwart security and privacy attacks, such as malicious, international mobile subscriber identity catching, and tracking attacks. Additionally, our proposed schemes preserve the location privacy of user equipment since no entity except the mobility management entity and Gate-Way Mobile Location Center can link between the pseudonymes and the international mobile subscriber identity. Also attackers have no knowledge about international mobile subscriber identity. Hence, the proposed schemes achieve backward/forward secrecy. Furthermore, the performance evaluation shows that the proposed handover schemes impose a small overhead on the mobile nodes and it has smaller computation and communication overheads than those in other schemes.

  5. Risk factors for father-daughter incest: data from an anonymous computerized survey.

    Science.gov (United States)

    Stroebel, Sandra S; Kuo, Shih-Ya; O'Keefe, Stephen L; Beard, Keith W; Swindell, Sam; Kommor, Martin J

    2013-12-01

    Retrospective data from 2,034 female participants, provided anonymously using a computer-assisted self-interview, were used to identify risk factors for father-daughter incest (FDI). A total of 51 participants had reported having experienced FDI. The risk factors identified within the nuclear family by the multiple logistic regression analysis included the following: (a) Having parents whose relationship included verbal or physical fighting or brutality increased the likelihood of FDI by approximately 5 times; (b) families accepting father-daughter nudity as measured by a scale with values ranging from 0 to 4 increased the likelihood of FDI by approximately 2 times for each unit value increase of 1 above 0; (c) demonstrating maternal affection protected against FDI. The likelihood of being a victim of FDI was highest if the participant's mother never kissed or hugged her; it decreased by 0.44 for a 1-unit increase in affection and by 0.19 times for a 2-unit increase; and (d) being in homes headed by single-parent mothers or where divorce or death of the father had resulted in a man other than the biological father living in the home increased the risk of FDI by approximately 3.2 times. The results were consistent with the idea that FDI in many families was the cumulative result of a circular pattern of interactions, a finding that has implications for treatment of the perpetrator, the victim, and the families. The data also suggested it may be possible to design an information program for parents that will result in reducing the risk of FDI in families implementing the program's recommendations.

  6. Etiological Risk Factors for Sibling Incest: Data From an Anonymous Computer-Assisted Self-Interview.

    Science.gov (United States)

    Griffee, Karen; Swindell, Sam; O'Keefe, Stephen L; Stroebel, Sandra S; Beard, Keith W; Kuo, Shih-Ya; Stroupe, Walter

    2016-10-01

    Retrospective data from 1,821 women and 1,064 men with one or more siblings, provided anonymously using a computer-assisted self-interview, were used to identify risk factors for sibling incest (SI); 137 were participants in SI. In order of decreasing predictive power, the risk factors identified by the multiple logistic regression analysis included ever having shared a bed for sleeping with a sibling, parent-child incest (PCI), family nudity, low levels of maternal affection, and ever having shared a tub bath with a sibling. The results were consistent with the idea that SI in many families was the cumulative result of four types of parental behaviors: (a) factors that lower external barriers to sexual behavior (e.g., permitting co-sleeping or co-bathing of sibling dyads), (b) factors that encourage nudity of children within the nuclear family and permit children to see the parent's genitals, (c) factors that lead to the siblings relying on one another for affection (e.g., diminished maternal affection), and (d) factors that eroticize young children (e.g., child sexual abuse [CSA] by a parent). Thirty-eight of the 137 SI participants were participants in coerced sibling incest (CSI). In order of decreasing predictive power, risk factors for CSI identified by multiple logistic regression analysis included ever having shared a bed for sleeping with a brother, PCI, witnessing parental physical fighting, and family nudity. SI was more likely to have been reported as CSI if the sibling had touched the reporting sibling's genitals, and less likely to have been reported as CSI if the siblings had shared a bed. © The Author(s) 2014.

  7. A robust anonymous biometric-based remote user authentication scheme using smart cards

    Directory of Open Access Journals (Sweden)

    Ashok Kumar Das

    2015-04-01

    Full Text Available Several biometric-based remote user authentication schemes using smart cards have been proposed in the literature in order to improve the security weaknesses in user authentication system. In 2012, An proposed an enhanced biometric-based remote user authentication scheme using smart cards. It was claimed that the proposed scheme is secure against the user impersonation attack, the server masquerading attack, the password guessing attack, and the insider attack and provides mutual authentication between the user and the server. In this paper, we first analyze the security of An’s scheme and we show that this scheme has three serious security flaws in the design of the scheme: (i flaw in user’s biometric verification during the login phase, (ii flaw in user’s password verification during the login and authentication phases, and (iii flaw in user’s password change locally at any time by the user. Due to these security flaws, An’s scheme cannot support mutual authentication between the user and the server. Further, we show that An’s scheme cannot prevent insider attack. In order to remedy the security weaknesses found in An’s scheme, we propose a new robust and secure anonymous biometric-based remote user authentication scheme using smart cards. Through the informal and formal security analysis, we show that our scheme is secure against all possible known attacks including the attacks found in An’s scheme. The simulation results of our scheme using the widely-accepted AVISPA (Automated Validation of Internet Security Protocols and Applications tool ensure that our scheme is secure against passive and active attacks. In addition, our scheme is also comparable in terms of the communication and computational overheads with An’s scheme and other related existing schemes. As a result, our scheme is more appropriate for practical applications compared to other approaches.

  8. Hyper-arousal decreases human visual thresholds.

    Directory of Open Access Journals (Sweden)

    Adam J Woods

    Full Text Available Arousal has long been known to influence behavior and serves as an underlying component of cognition and consciousness. However, the consequences of hyper-arousal for visual perception remain unclear. The present study evaluates the impact of hyper-arousal on two aspects of visual sensitivity: visual stereoacuity and contrast thresholds. Sixty-eight participants participated in two experiments. Thirty-four participants were randomly divided into two groups in each experiment: Arousal Stimulation or Sham Control. The Arousal Stimulation group underwent a 50-second cold pressor stimulation (immersing the foot in 0-2° C water, a technique known to increase arousal. In contrast, the Sham Control group immersed their foot in room temperature water. Stereoacuity thresholds (Experiment 1 and contrast thresholds (Experiment 2 were measured before and after stimulation. The Arousal Stimulation groups demonstrated significantly lower stereoacuity and contrast thresholds following cold pressor stimulation, whereas the Sham Control groups showed no difference in thresholds. These results provide the first evidence that hyper-arousal from sensory stimulation can lower visual thresholds. Hyper-arousal's ability to decrease visual thresholds has important implications for survival, sports, and everyday life.

  9. Threshold intensity factors as lower boundaries for crack propagation in ceramics

    Directory of Open Access Journals (Sweden)

    Walter Per-Ole

    2004-11-01

    Full Text Available Abstract Background Slow crack growth can be described in a v (crack velocity versus KI (stress intensity factor diagram. Slow crack growth in ceramics is attributed to corrosion assisted stress at the crack tip or at any pre-existing defect in the ceramic. The combined effect of high stresses at the crack tip and the presence of water or body fluid molecules (reducing surface energy at the crack tip induces crack propagation, which eventually may result in fatigue. The presence of a threshold in the stress intensity factor, below which no crack propagation occurs, has been the subject of important research in the last years. The higher this threshold, the higher the reliability of the ceramic, and consequently the longer its lifetime. Methods We utilize the Irwin K-field displacement relation to deduce crack tip stress intensity factors from the near crack tip profile. Cracks are initiated by indentation impressions. The threshold stress intensity factor is determined as the time limit of the tip stress intensity when the residual stresses have (nearly disappeared. Results We determined the threshold stress intensity factors for most of the all ceramic materials presently important for dental restorations in Europe. Of special significance is the finding that alumina ceramic has a threshold limit nearly identical with that of zirconia. Conclusion The intention of the present paper is to stress the point that the threshold stress intensity factor represents a more intrinsic property for a given ceramic material than the widely used toughness (bend strength or fracture toughness, which refers only to fast crack growth. Considering two ceramics with identical threshold limits, although with different critical stress intensity limits, means that both ceramics have identical starting points for slow crack growth. Fast catastrophic crack growth leading to spontaneous fatigue, however, is different. This growth starts later in those ceramic materials

  10. Right Diaphragm Spontaneous Rupture: A Surgical Approach

    Directory of Open Access Journals (Sweden)

    Duilio Divisi

    2011-01-01

    Full Text Available We present a case of spontaneous rupture of the diaphragm, characterized by nonspecific symptoms. The rapid diagnosis and appropriate surgical approach led to a positive resolution of the pathology.

  11. Spontaneous cecal perforation secondary to acute fulminant ...

    African Journals Online (AJOL)

    Spontaneous cecal perforation secondary to acute fulminant gastroenteritis: report of a rare case. Duvuru Ram, Vilvapathy S. Karthikeyan, Sarath C. Sistla, Sheik M. Ali, Parnandi Sridhar, Nagarajan Rajkumar ...

  12. Spontaneous Trait Inferences on Social Media.

    Science.gov (United States)

    Levordashka, Ana; Utz, Sonja

    2017-01-01

    The present research investigates whether spontaneous trait inferences occur under conditions characteristic of social media and networking sites: nonextreme, ostensibly self-generated content, simultaneous presentation of multiple cues, and self-paced browsing. We used an established measure of trait inferences (false recognition paradigm) and a direct assessment of impressions. Without being asked to do so, participants spontaneously formed impressions of people whose status updates they saw. Our results suggest that trait inferences occurred from nonextreme self-generated content, which is commonly found in social media updates (Experiment 1) and when nine status updates from different people were presented in parallel (Experiment 2). Although inferences did occur during free browsing, the results suggest that participants did not necessarily associate the traits with the corresponding status update authors (Experiment 3). Overall, the findings suggest that spontaneous trait inferences occur on social media. We discuss implications for online communication and research on spontaneous trait inferences.

  13. Spontane abdominale arteriovenøse fistler

    DEFF Research Database (Denmark)

    Flarup, S; Lindholt, Jes Sanddal

    1997-01-01

    Spontaneous arteriovenous fistulas between major abdominal vessels (AAVF) complicates about 1% of abdominal aortic aneurysms. AAVF produces severe circulatory disturbances with high operative mortality. Preoperative diagnosis is important but difficult due to the varied nature of presentation. Fo...

  14. Automatic histogram threshold using fuzzy measures.

    Science.gov (United States)

    Vieira Lopes, Nuno; Mogadouro do Couto, Pedro A; Bustince, Humberto; Melo-Pinto, Pedro

    2010-01-01

    In this paper, an automatic histogram threshold approach based on a fuzziness measure is presented. This work is an improvement of an existing method. Using fuzzy logic concepts, the problems involved in finding the minimum of a criterion function are avoided. Similarity between gray levels is the key to find an optimal threshold. Two initial regions of gray levels, located at the boundaries of the histogram, are defined. Then, using an index of fuzziness, a similarity process is started to find the threshold point. A significant contrast between objects and background is assumed. Previous histogram equalization is used in small contrast images. No prior knowledge of the image is required.

  15. Reaction thresholds in doubly special relativity

    International Nuclear Information System (INIS)

    Heyman, Daniel; Major, Seth; Hinteleitner, Franz

    2004-01-01

    Two theories of special relativity with an additional invariant scale, 'doubly special relativity', are tested with calculations of particle process kinematics. Using the Judes-Visser modified conservation laws, thresholds are studied in both theories. In contrast with some linear approximations, which allow for particle processes forbidden in special relativity, both the Amelino-Camelia and Magueijo-Smolin frameworks allow no additional processes. To first order, the Amelino-Camelia framework thresholds are lowered and the Magueijo-Smolin framework thresholds may be raised or lowered

  16. Digital IP Protection Using Threshold Voltage Control

    OpenAIRE

    Davis, Joseph; Kulkarni, Niranjan; Yang, Jinghua; Dengi, Aykut; Vrudhula, Sarma

    2016-01-01

    This paper proposes a method to completely hide the functionality of a digital standard cell. This is accomplished by a differential threshold logic gate (TLG). A TLG with $n$ inputs implements a subset of Boolean functions of $n$ variables that are linear threshold functions. The output of such a gate is one if and only if an integer weighted linear arithmetic sum of the inputs equals or exceeds a given integer threshold. We present a novel architecture of a TLG that not only allows a single...

  17. Depressive disorder and grief following spontaneous abortion.

    Science.gov (United States)

    Kulathilaka, Susil; Hanwella, Raveen; de Silva, Varuni A

    2016-04-12

    Abortion is associated with moderate to high risk of psychological problems such as depression, use of alcohol or marijuana, anxiety, depression and suicidal behaviours. The increased risk of depression after spontaneous abortion in Asian populations has not been clearly established. Only a few studies have explored the relationship between grief and depression after abortion. A study was conducted to assess the prevalence and risk factors of depressive disorder and complicated grief among women 6-10 weeks after spontaneous abortion and compare the risk of depression with pregnant women attending an antenatal clinic. Spontaneous abortion group consisted of women diagnosed with spontaneous abortion by a Consultant Obstetrician. Women with confirmed or suspected induced abortion were excluded. The comparison group consisted of randomly selected pregnant, females attending the antenatal clinics of the two hospitals. Diagnosis of depressive disorder was made according to ICD-10 clinical criteria based on a structured clinical interview. This assessment was conducted in both groups. The severity of depressive symptoms were assessed using the Patients Health Questionnaire (PHQ-9). Grief was assessed using the Perinatal Grief Scale which was administered to the women who had experienced spontaneous abortion. The sample consisted of 137 women in each group. The spontaneous abortion group (mean age 30.39 years (SD = 6.38) were significantly older than the comparison group (mean age 28.79 years (SD = 6.26)). There were more females with ≥10 years of education in the spontaneous abortion group (n = 54; SD = 39.4) compared to the comparison group (n = 37; SD = 27.0). The prevalence of depression in the spontaneous abortion group was 18.6 % (95 CI, 11.51-25.77). The prevalence of depression in the comparison group was 9.5 % (95 CI, 4.52-14.46). Of the 64 women fulfilling criteria for grief, 17 (26.6 %) also fulfilled criteria for a depressive episode. The relative risk of

  18. Postmenopausal spontaneous uterine perforation: Case report

    Science.gov (United States)

    İşlek Seçen, Elçin; Ağış, Hilal; Altunkaya, Canan; Avşar, Ayşe Filiz

    2015-01-01

    Spontaneous uterine rupture and generalized peritonitis caused by pyometra occurs rarely with high morbidity and mortality. A correct and definite diagnosis can be made with laparotomy or laparoscopy. The clinical findings of perforated pyometra are similar to perforation of the gastrointestinal tract and gynecologic symptoms are less frequent, which makes preoperative diagnosis difficult. We report a case of a patient aged 82 years who underwent surgery for spontaneous uterine rupture and generalized peritonitis as a result of pyometra. PMID:28913055

  19. Endometriosis-related spontaneous diaphragmatic rupture.

    Science.gov (United States)

    Triponez, Frédéric; Alifano, Marco; Bobbio, Antonio; Regnard, Jean-François

    2010-10-01

    Non-traumatic, spontaneous diaphragmatic rupture is a rare event whose pathophysiology is not known. We report the case of endometriosis-related spontaneous rupture of the right diaphragm with intrathoracic herniation of the liver, gallbladder and colon. We hypothesize that the invasiveness of endometriotic tissue caused diaphragm fragility, which finally lead to its complete rupture without traumatic event. The treatment consisted of a classical management of diaphragmatic rupture, with excision of the endometriotic nodule followed by medical ovarian suppression for six months.

  20. Spontaneous regression of metastatic Merkel cell carcinoma.

    LENUS (Irish Health Repository)

    Hassan, S J

    2010-01-01

    Merkel cell carcinoma is a rare aggressive neuroendocrine carcinoma of the skin predominantly affecting elderly Caucasians. It has a high rate of local recurrence and regional lymph node metastases. It is associated with a poor prognosis. Complete spontaneous regression of Merkel cell carcinoma has been reported but is a poorly understood phenomenon. Here we present a case of complete spontaneous regression of metastatic Merkel cell carcinoma demonstrating a markedly different pattern of events from those previously published.

  1. Spontaneous intracranial epidural hematoma during rivaroxaban treatment

    Energy Technology Data Exchange (ETDEWEB)

    Ruschel, Leonardo Gilmone; Rego, Felipe Marques Monteiro do; Milano, Jeronimo Buzetti; Jung, Gustavo Simiano; Silva Junior, Luis Fernando; Ramina, Ricardo, E-mail: leonardoruschel@yahoo.com.br [Instituto de Neurologia de Curitiba (INC), Curitiba, PR (Brazil)

    2016-11-15

    According to our research, this is the first case described in the literature of spontaneous intracranial epidural hematoma secondary to the use of Xarelto®. Spontaneous intracranial epidural hematomas are rarely described in the literature. They are associated with infectious diseases of the skull, coagulation disorders, vascular malformations of the dura mater and metastasis to the skull. Long-term post-marketing monitoring and independent reports will probably detect the full spectrum of hemorrhagic complications of the use of rivaroxaban. (author)

  2. Spontaneous intracranial epidural hematoma during rivaroxaban treatment.

    Science.gov (United States)

    Ruschel, Leonardo Gilmone; Rego, Felipe Marques Monteiro do; Milano, Jerônimo Buzetti; Jung, Gustavo Simiano; Silva, Luis Fernando; Ramina, Ricardo

    2016-11-01

    According to our research, this is the first case described in the literature of spontaneous intracranial epidural hematoma secondary to the use of Xareltor. Spontaneous intracranial epidural hematomas are rarely described in the literature. They are associated with infectious diseases of the skull, coagulation disorders, vascular malformations of the dura mater and metastasis to the skull. Long-term post-marketing monitoring and independent reports will probably detect the full spectrum of hemorrhagic complications of the use of rivaroxaban.

  3. Preserving Smart Objects Privacy through Anonymous and Accountable Access Control for a M2M-Enabled Internet of Things

    Directory of Open Access Journals (Sweden)

    José L. Hernández-Ramos

    2015-07-01

    Full Text Available As we get into the Internet of Things era, security and privacy concerns remain as the main obstacles in the development of innovative and valuable services to be exploited by society. Given the Machine-to-Machine (M2M nature of these emerging scenarios, the application of current privacy-friendly technologies needs to be reconsidered and adapted to be deployed in such global ecosystem. This work proposes different privacy-preserving mechanisms through the application of anonymous credential systems and certificateless public key cryptography. The resulting alternatives are intended to enable an anonymous and accountable access control approach to be deployed on large-scale scenarios, such as Smart Cities. Furthermore, the proposed mechanisms have been deployed on constrained devices, in order to assess their suitability for a secure and privacy-preserving M2M-enabled Internet of Things.

  4. Analysis of Drugs of Abuse in Anonymously Collected Urine and Soil samples from a Music Festival in Scandinavia

    DEFF Research Database (Denmark)

    Mardal, Marie; Ramin, Pedram; Plósz, Benedek G.

    and urine samples were also prepared by adding acetonitrile, shaking, centrifugation, and evaporation. Extracts were then analyzed by UHPLC-MSn (TF LXQ), UHPLC-HRMS/MS (TF Q-Exactive), and GC-MS (TF ISQ). Urine samples were additionally tested for 9-carboxy-THC by immunoassay and ethanol by headspace GC......Aim: Pooled human urine and soil from urinating spots were collected anonymously at a Scandinavian music festival. Samples should be screened for drugs of abuse, particularly novel psychoactive substances (NPS), but also therapeutic drugs and ethanol. Methods: Twenty-one urine samples were...... collected anonymously from urinal and HMMA-d3 and trimipramin-d3 were added as internal standards. Additionally, 12 soil samples were collected near fences where people urinated. Urine samples were processed by enzymatic conjugate cleavage, SPE (HCX and C18), and acetylation prior to GC-MS. Soil samples...

  5. Preserving Smart Objects Privacy through Anonymous and Accountable Access Control for a M2M-Enabled Internet of Things.

    Science.gov (United States)

    Hernández-Ramos, José L; Bernabe, Jorge Bernal; Moreno, M Victoria; Skarmeta, Antonio F

    2015-07-01

    As we get into the Internet of Things era, security and privacy concerns remain as the main obstacles in the development of innovative and valuable services to be exploited by society. Given the Machine-to-Machine (M2M) nature of these emerging scenarios, the application of current privacy-friendly technologies needs to be reconsidered and adapted to be deployed in such global ecosystem. This work proposes different privacy-preserving mechanisms through the application of anonymous credential systems and certificateless public key cryptography. The resulting alternatives are intended to enable an anonymous and accountable access control approach to be deployed on large-scale scenarios, such as Smart Cities. Furthermore, the proposed mechanisms have been deployed on constrained devices, in order to assess their suitability for a secure and privacy-preserving M2M-enabled Internet of Things.

  6. More than addiction: Examining the role of anonymity, endless narrative, and socialization in prolonged gaming and instant messaging practices

    Directory of Open Access Journals (Sweden)

    Kishonna Gray

    2015-06-01

    Full Text Available This ethnographic study explores a user’s prolonged engagement within virtual gaming communities. Likening prolonged engagement with addiction, this research provides an alternative perspective into virtual addiction focusing on three interrelated themes: 1 anonymity, 2 endless narrative, and 3 socialization. By employing narrative interviews and virtual observations, the researchers examine two different cultural, racial and age groups’ user experience within console and computer-based multiplayer environments. More specifically, they explore how the three factors (i.e., anonymity; endless narrative; socialization relate to the prolonged and extended use within these virtual communities and highlight the multifaceted uses of traditional chat services, social media, and the convergence of media existing within these chat communities.

  7. Simple Algorithms for Distributed Leader Election in Anonymous Synchronous Rings and Complete Networks Inspired by Neural Development in Fruit Flies.

    Science.gov (United States)

    Xu, Lei; Jeavons, Peter

    2015-11-01

    Leader election in anonymous rings and complete networks is a very practical problem in distributed computing. Previous algorithms for this problem are generally designed for a classical message passing model where complex messages are exchanged. However, the need to send and receive complex messages makes such algorithms less practical for some real applications. We present some simple synchronous algorithms for distributed leader election in anonymous rings and complete networks that are inspired by the development of the neural system of the fruit fly. Our leader election algorithms all assume that only one-bit messages are broadcast by nodes in the network and processors are only able to distinguish between silence and the arrival of one or more messages. These restrictions allow implementations to use a simpler message-passing architecture. Even with these harsh restrictions our algorithms are shown to achieve good time and message complexity both analytically and experimentally.

  8. FEL gain optimisation and spontaneous radiation

    Energy Technology Data Exchange (ETDEWEB)

    Bali, L.M.; Srivastava, A.; Pandya, T.P. [Lucknow Univ. (India)] [and others

    1995-12-31

    Colson have evaluated FEL gains for small deviations from perfect electron beam injection, with radiation of the same polarisation as that of the wiggler fields. We find that for optimum gain the polarisation of the optical field should be the same as that of the spontaneous emission under these conditions. With a helical wiggler the axial oscillations resulting from small departures from perfect electron beam injection lead to injection dependent unequal amplitudes and phases of the spontaneous radiation in the two transverse directions. Viewed along the axis therefore the spontaneous emission is elliptically polarised. The azimuth of the ellipse varies with the difference of phase of the two transverse components of spontaneous emission but the eccentricity remains the same. With planar wigglers the spontaneous emission viewed in the axial direction is linearly polarised, again with an injection dependent azimuth. For optimum coherent gain of a radiation field its polarisation characteristics must be the same as those of the spontaneous radiation with both types of wiggler. Thus, with a helical wiggler and the data reported earlier, an increase of 10% in the FEL gain at the fundamental frequency and of 11% at the fifth harmonic has been calculated in the small gain per pass limit. Larger enhancements in gain may result from more favourable values of input parameters.

  9. AN EFFECTIVE MULTI-CLUSTERING ANONYMIZATION APPROACH USING DISCRETE COMPONENT TASK FOR NON-BINARY HIGH DIMENSIONAL DATA SPACES

    Directory of Open Access Journals (Sweden)

    L.V. Arun Shalin

    2016-01-01

    Full Text Available Clustering is a process of grouping elements together, designed in such a way that the elements assigned to similar data points in a cluster are more comparable to each other than the remaining data points in a cluster. During clustering certain difficulties related when dealing with high dimensional data are ubiquitous and abundant. Works concentrated using anonymization method for high dimensional data spaces failed to address the problem related to dimensionality reduction during the inclusion of non-binary databases. In this work we study methods for dimensionality reduction for non-binary database. By analyzing the behavior of dimensionality reduction for non-binary database, results in performance improvement with the help of tag based feature. An effective multi-clustering anonymization approach called Discrete Component Task Specific Multi-Clustering (DCTSM is presented for dimensionality reduction on non-binary database. To start with we present the analysis of attribute in the non-binary database and cluster projection identifies the sparseness degree of dimensions. Additionally with the quantum distribution on multi-cluster dimension, the solution for relevancy of attribute and redundancy on non-binary data spaces is provided resulting in performance improvement on the basis of tag based feature. Multi-clustering tag based feature reduction extracts individual features and are correspondingly replaced by the equivalent feature clusters (i.e. tag clusters. During training, the DCTSM approach uses multi-clusters instead of individual tag features and then during decoding individual features is replaced by corresponding multi-clusters. To measure the effectiveness of the method, experiments are conducted on existing anonymization method for high dimensional data spaces and compared with the DCTSM approach using Statlog German Credit Data Set. Improved tag feature extraction and minimum error rate compared to conventional anonymization

  10. An Extended Chaotic Maps-Based Three-Party Password-Authenticated Key Agreement with User Anonymity.

    Science.gov (United States)

    Lu, Yanrong; Li, Lixiang; Zhang, Hao; Yang, Yixian

    2016-01-01

    User anonymity is one of the key security features of an authenticated key agreement especially for communicating messages via an insecure network. Owing to the better properties and higher performance of chaotic theory, the chaotic maps have been introduced into the security schemes, and hence numerous key agreement schemes have been put forward under chaotic-maps. Recently, Xie et al. released an enhanced scheme under Farash et al.'s scheme and claimed their improvements could withstand the security loopholes pointed out in the scheme of Farash et al., i.e., resistance to the off-line password guessing and user impersonation attacks. Nevertheless, through our careful analysis, the improvements were released by Xie et al. still could not solve the problems troubled in Farash et al‥ Besides, Xie et al.'s improvements failed to achieve the user anonymity and the session key security. With the purpose of eliminating the security risks of the scheme of Xie et al., we design an anonymous password-based three-party authenticated key agreement under chaotic maps. Both the formal analysis and the formal security verification using AVISPA are presented. Also, BAN logic is used to show the correctness of the enhancements. Furthermore, we also demonstrate that the design thwarts most of the common attacks. We also make a comparison between the recent chaotic-maps based schemes and our enhancements in terms of performance.

  11. An Extended Chaotic Maps-Based Three-Party Password-Authenticated Key Agreement with User Anonymity.

    Directory of Open Access Journals (Sweden)

    Yanrong Lu

    Full Text Available User anonymity is one of the key security features of an authenticated key agreement especially for communicating messages via an insecure network. Owing to the better properties and higher performance of chaotic theory, the chaotic maps have been introduced into the security schemes, and hence numerous key agreement schemes have been put forward under chaotic-maps. Recently, Xie et al. released an enhanced scheme under Farash et al.'s scheme and claimed their improvements could withstand the security loopholes pointed out in the scheme of Farash et al., i.e., resistance to the off-line password guessing and user impersonation attacks. Nevertheless, through our careful analysis, the improvements were released by Xie et al. still could not solve the problems troubled in Farash et al‥ Besides, Xie et al.'s improvements failed to achieve the user anonymity and the session key security. With the purpose of eliminating the security risks of the scheme of Xie et al., we design an anonymous password-based three-party authenticated key agreement under chaotic maps. Both the formal analysis and the formal security verification using AVISPA are presented. Also, BAN logic is used to show the correctness of the enhancements. Furthermore, we also demonstrate that the design thwarts most of the common attacks. We also make a comparison between the recent chaotic-maps based schemes and our enhancements in terms of performance.

  12. Secure information management using linguistic threshold approach

    CERN Document Server

    Ogiela, Marek R

    2013-01-01

    This book details linguistic threshold schemes for information sharing. It examines the opportunities of using these techniques to create new models of managing strategic information shared within a commercial organisation or a state institution.

  13. Melanin microcavitation threshold in the near infrared

    Science.gov (United States)

    Schmidt, Morgan S.; Kennedy, Paul K.; Vincelette, Rebecca L.; Schuster, Kurt J.; Noojin, Gary D.; Wharmby, Andrew W.; Thomas, Robert J.; Rockwell, Benjamin A.

    2014-02-01

    Thresholds for microcavitation of isolated bovine and porcine melanosomes were determined using single nanosecond (ns) laser pulses in the NIR (1000 - 1319 nm) wavelength regime. Average fluence thresholds for microcavitation increased non-linearly with increasing wavelength. Average fluence thresholds were also measured for 10-ns pulses at 532 nm, and found to be comparable to visible ns pulse values published in previous reports. Fluence thresholds were used to calculate melanosome absorption coefficients, which decreased with increasing wavelength. This trend was found to be comparable to the decrease in retinal pigmented epithelial (RPE) layer absorption coefficients reported over the same wavelength region. Estimated corneal total intraocular energy (TIE) values were determined and compared to the current and proposed maximum permissible exposure (MPE) safe exposure levels. Results from this study support the proposed changes to the MPE levels.

  14. A prototype threshold Cherenkov counter for DIRAC

    CERN Document Server

    Bragadireanu, M; Cima, E; Dulach, B; Gianotti, P; Guaraldo, C; Iliescu, M A; Lanaro, A; Levi-Sandri, P; Petrascu, C; Girolami, B; Groza, L; Kulikov, A; Kuptsov, A; Topilin, N; Trusov, S

    1999-01-01

    We have designed, built and tested a gas threshold Cherenkov counter as prototype for a larger counter foreseen for use in the DIRAC experiment, at CERN. We describe the performances of the counter on a test beam.

  15. Recent progress in understanding climate thresholds

    NARCIS (Netherlands)

    Good, Peter; Bamber, Jonathan; Halladay, Kate; Harper, Anna B.; Jackson, Laura C.; Kay, Gillian; Kruijt, Bart; Lowe, Jason A.; Phillips, Oliver L.; Ridley, Jeff; Srokosz, Meric; Turley, Carol; Williamson, Phillip

    2018-01-01

    This article reviews recent scientific progress, relating to four major systems that could exhibit threshold behaviour: ice sheets, the Atlantic meridional overturning circulation (AMOC), tropical forests and ecosystem responses to ocean acidification. The focus is on advances since the

  16. Effects of chronic furosemide on central neural hyperactivity and cochlear thresholds after cochlear trauma in guinea pig

    Directory of Open Access Journals (Sweden)

    Wilhelmina eMulders

    2014-08-01

    Full Text Available Increased neuronal spontaneous firing rates have been observed throughout the central auditory system after trauma to the cochlea and this hyperactivity is believed to be associated with the phantom perception of tinnitus. Previously we have shown in an animal model of hearing loss, that an acute injection with furosemide can significantly decrease hyperactivity after cochlear trauma and eliminate behavioural evidence of tinnitus of early onset. However, furosemide also has the potential to affect cochlear thresholds. In this paper we measured the effects of a chronic (daily injections for 7 days furosemide treatment on the spontaneous firing rate of inferior colliculus neurons and on cochlear thresholds in order to establish whether a beneficial effect on hyperactivity can be obtained without causing additional hearing loss. Guinea pigs were exposed to a 10 kHz, 124dB, 2 hour acoustic trauma, and after 5 days of recovery, were given daily i.p. injections of 80mg/kg furosemide or an equivalent amount of saline. The activity of single IC neurons was recorded 24 hours following the last injection. The furosemide treatment had no effect on cochlear thresholds compared to saline injections but did result in significant reductions in spontaneous firing rates recorded in inferior colliculus. These results that suggest a long term beneficial effect of furosemide on hyperactivity after cochlear trauma may be achievable without detrimental effects on hearing, which is important when considering therapeutic potential.

  17. Cost?effectiveness thresholds: pros and cons

    OpenAIRE

    Bertram, Melanie Y; Lauer, Jeremy A; De Joncheere, Kees; Edejer, Tessa; Hutubessy, Raymond; Kieny, Marie-Paule; Hill, Suzanne R

    2016-01-01

    Abstract Cost?effectiveness analysis is used to compare the costs and outcomes of alternative policy options. Each resulting cost?effectiveness ratio represents the magnitude of additional health gained per additional unit of resources spent. Cost?effectiveness thresholds allow cost?effectiveness ratios that represent good or very good value for money to be identified. In 2001, the World Health Organization?s Commission on Macroeconomics in Health suggested cost?effectiveness thresholds based...

  18. Latent Feature Models for Uncovering Human Mobility Patterns from Anonymized User Location Traces with Metadata

    KAUST Repository

    Alharbi, Basma Mohammed

    2017-04-10

    In the mobile era, data capturing individuals’ locations have become unprecedentedly available. Data from Location-Based Social Networks is one example of large-scale user-location data. Such data provide a valuable source for understanding patterns governing human mobility, and thus enable a wide range of research. However, mining and utilizing raw user-location data is a challenging task. This is mainly due to the sparsity of data (at the user level), the imbalance of data with power-law users and locations check-ins degree (at the global level), and more importantly the lack of a uniform low-dimensional feature space describing users. Three latent feature models are proposed in this dissertation. Each proposed model takes as an input a collection of user-location check-ins, and outputs a new representation space for users and locations respectively. To avoid invading users privacy, the proposed models are designed to learn from anonymized location data where only IDs - not geophysical positioning or category - of locations are utilized. To enrich the inferred mobility patterns, the proposed models incorporate metadata, often associated with user-location data, into the inference process. In this dissertation, two types of metadata are utilized to enrich the inferred patterns, timestamps and social ties. Time adds context to the inferred patterns, while social ties amplifies incomplete user-location check-ins. The first proposed model incorporates timestamps by learning from collections of users’ locations sharing the same discretized time. The second proposed model also incorporates time into the learning model, yet takes a further step by considering time at different scales (hour of a day, day of a week, month, and so on). This change in modeling time allows for capturing meaningful patterns over different times scales. The last proposed model incorporates social ties into the learning process to compensate for inactive users who contribute a large volume

  19. Spontaneous scalarization with an extremely massive field and heavy neutron stars

    Science.gov (United States)

    Morisaki, Soichiro; Suyama, Teruaki

    2017-10-01

    We investigate the internal structure and the mass-radius relation of neutron stars in a recently proposed scalar-tensor theory dubbed asymmetron in which a massive scalar field undergoes spontaneous scalarization inside neutron stars. We focus on the case where the Compton wavelength is shorter than 10 km, which has not been investigated in the literature. By solving the modified Einstein equations, either purely numerically or by partially using a semianalytic method, we find that not only the weakening of gravity by spontaneous scalarization but also the scalar force affect the internal structure significantly in the massive case. We also find that the maximum mass of neutron stars is larger for certain parameter sets than that in general relativity and reaches 2 M⊙ even if the effect of strange hadrons is taken into account. There is even a range of parameters where the maximum mass of neutron stars largely exceeds the threshold that violates the causality bound in general relativity.

  20. Spontaneous Interfacial Dipole Orientation Effect of Acetic Acid Solubilized PFN.

    Science.gov (United States)

    Wang, Cong; Luo, Yinqi; Zheng, Jieming; Liu, Linlin; Xie, Zengqi; Huang, Fei; Yang, Bing; Ma, Yuguang

    2018-03-28

    Poly[(9,9-dioctyl-2,7-fluorene)- alt-(9,9-bis(3'-( N, N-dimethylamino)propyl)-2,7-fluorene)] (PFN) is a very important interfacial modifier in organic photovoltaic and organic light-emitting diodes to improve device performance, where their molecular dipole has been regarded to play a key role. In this work, we have reported a spontaneous interfacial dipole orientation effect in acetic acid dissolved PFN, which is strongly related to the interfacial dipole and the corresponding device performance. In direct spin-coating, the interfacial dipole is 1.08 Debye with interfacial contact angle 84.8°, whereas after self-assembly of 10 min, the interfacial dipole is balanced at 4.21 Debye, with the interfacial contact angle decreasing to 76.8°. Without strong interaction with the substrate, the energy of upward amine groups is much lower than that of downward ones in theoretical simulation, which would be the driving force of this spontaneous process. The preferred conformations of PFN molecules on hydroxylated substrates have over 99% amine groups outward, and the theoretical average dipole calculated from the weight of these conformations is 4.48 Debye, which is close to the experimental result and indicates a high ratio of upward amine groups in self-assembled films. This effect obviously changes the device performance, such as an obvious positive threshold voltage shift in transistors and a distinct increase of the short-circuit current/open-circuit voltage in organic solar cells. This effect provides a deeper understanding of the PFN interlayer mechanism and has potential application in optoelectronic devices.