43 research outputs found

    Cyberprints: Identifying Cyber Attackers by Feature Analysis

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    The problem of attributing cyber attacks is one of increasing importance. Without a solid method of demonstrating the origin of a cyber attack, any attempts to deter would-be cyber attackers are wasted. Existing methods of attribution make unfounded assumptions about the environment in which they will operate: omniscience (the ability to gather, store, and analyze any data relevant to an attack), omnipresence (the ability to place sensors wherever necessary regardless of jurisdiction or ownership), and \emph{a priori} positioning (ignorance of the real costs of placing sensors in speculative locations). The reality is that attribution must be able to occur with only the information available directly to a forensic analyst, gathered within the target network, using budget-conscious placement of sensors and analyzers. These assumptions require a new form of attribution. This work evaluates the use of a number of network-level features as an analog of stylistic markers in literature. We find that principal component analysis is not a useful tool in analyzing these features. We are, however, able to perform Kolmogorov-Smirnov comparisons upon the feature set distributions directly to find a subset of the examined features which hold promise for forming the foundation of a \emph{Cyberprint}. This foundation could be used to examine other potential features for discriminatory power, and to establish a new direction for network forensic analysis

    Correlates of physical activity among community-dwelling adults aged 50 or over in six low- and middle-income countries

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    Background: Considering that physical activity is associated with healthy ageing and helps to delay, prevent, or manage a plethora of non-communicable diseases in older adults, there is a need to investigate the factors that influence physical activity participation in this population. Thus, we investigated physical activity correlates among community-dwelling older adults (aged ≥50 years) in six low- and middle-income countries. Methods: Cross-sectional data were analyzed from the World Health Organization’s Study on Global Ageing and Adult Health. Physical activity was assessed by the Global Physical Activity Questionnaire. Participants were dichotomized into low (i.e., not meeting 150 minutes of moderate physical activity per week) and moderate-to-high physically active groups. Associations between physical activity and a range of correlates were examined using multivariable logistic regressions. Results: The overall prevalence (95%CI) of people not meeting recommended physical activity levels in 34,129 participants (mean age 62.4 years, 52.1% female) was 23.5% (22.3%-24.8%). In the multivariable analysis, older age and unemployment were significant sociodemographic correlates of low physical activity. Individuals with low body mass index (<18.5kg/m2), bodily pain, asthma, chronic back pain, chronic obstructive pulmonary disease, hearing problems, stroke, visual impairment, slow gait, and weak grip strength were less likely to meet physical activity targets in the overall sample (P<0.05). The associations varied widely between countries. Conclusion: Our data illustrates that a multitude of factors influence physical activity target achievement in older adults, which can inform future interventions across low- and middle-income countries to assist people of this age group to engage in regular physical activity. Future prospective cohort studies are also required to investigate the directionality and mediators of the relationships observed

    The Near Infrared Imager and Slitless Spectrograph for the James Webb Space Telescope -- IV. Aperture Masking Interferometry

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    The James Webb Space Telescope's Near Infrared Imager and Slitless Spectrograph (JWST-NIRISS) flies a 7-hole non-redundant mask (NRM), the first such interferometer in space, operating at 3-5 \micron~wavelengths, and a bright limit of 4\simeq 4 magnitudes in W2. We describe the NIRISS Aperture Masking Interferometry (AMI) mode to help potential observers understand its underlying principles, present some sample science cases, explain its operational observing strategies, indicate how AMI proposals can be developed with data simulations, and how AMI data can be analyzed. We also present key results from commissioning AMI. Since the allied Kernel Phase Imaging (KPI) technique benefits from AMI operational strategies, we also cover NIRISS KPI methods and analysis techniques, including a new user-friendly KPI pipeline. The NIRISS KPI bright limit is 8\simeq 8 W2 magnitudes. AMI (and KPI) achieve an inner working angle of 70\sim 70 mas that is well inside the 400\sim 400 mas NIRCam inner working angle for its circular occulter coronagraphs at comparable wavelengths.Comment: 30 pages, 10 figure

    Optogenetic acidification of synaptic vesicles and lysosomes

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    Acidification is required for the function of many intracellular organelles, but methods to acutely manipulate their intraluminal pH have not been available. Here we present a targeting strategy to selectively express the light-driven proton pump Arch3 on synaptic vesicles. Our new tool, pHoenix, can functionally replace endogenous proton pumps, enabling optogenetic control of vesicular acidification and neurotransmitter accumulation. Under physiological conditions, glutamatergic vesicles are nearly full, as additional vesicle acidification with pHoenix only slightly increased the quantal size. By contrast, we found that incompletely filled vesicles exhibited a lower release probability than full vesicles, suggesting preferential exocytosis of vesicles with high transmitter content. Our subcellular targeting approach can be transferred to other organelles, as demonstrated for a pHoenix variant that allows light-activated acidification of lysosomes

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

    The andean cultural model of susto: cultural consonance and historical trauma in the Andes

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    The research presented in these pages on cultural consonance, historical trauma, and susto demonstrates important relationships between risk factors for susto. Susto is a cultural syndrome associated with fright that impacts Andean farmers. Methods of epidemiology and cultural consensus analysis were used to explore the distribution of understandings of susto in the Callejón de Huaylas valley. Andeans link a combination of culturally salient and generalized illness symptoms to susto, and how one classifies these symptoms is dependent upon a number of sociocultural factors. Historical trauma was explored as it related to susto. Historically traumatic events are frightening and are a common cause of susto, suggesting that susto may be a culturally salient model for dealing with cultural trauma. By analyzing the symptomatology of susto from an epidemiologic standpoint one can gain insight into Andean culture and health-seeking behaviors. The Susto Symptom Scale developed for this research is an important diagnostic tool for determining if one has susto. Susto is an idiom for historical trauma and is helpful in assessing the level of exposure to historical trauma that highlanders in the valley have endured. Susto seems to be an "explanatory model" to deal with anxiousness associated with suffering from an illness. There are multiple risk factors that can help to determine if an individual is at an increased risk for developing susto. Susto is the combination between low cultural consonance, age, and a historically traumatic past; and it is these factors that make the cultural model of susto applicable. (Published By University of Alabama Libraries

    Obtaining vector magnetic field maps from single-component measurements of geological samples

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    Maxwell's equations can be used to demonstrate that the components of a static magnetic field in a region of space devoid of sources are not independent. This means that magnetometers that measure a single component of the magnetic field can potentially obtain all of three components of the field external to a source. Here we present an improved technique in the Fourier domain which can obtain the complete vector field planar map from just the planar map of one component. This technique is fast, robust, does not rely on any specific source type or configuration, and does not require the formulation of an inverse problem. An in-depth analysis of the advantages and shortcomings of the technique is presented, demonstrating that high-quality three-component field maps with virtually no information loss can be obtained when proper sensor and mapping configurations are used. Several results derived from both synthetic and experimental data are presented. In particular, practical cases are shown where vector maps can assist the analysis of magnetic properties of geological samples. MATLAB® routines implementing the basic vector map calculation algorithm are available as auxiliary materials and can be readily adapted for processing magnetic data obtained from a variety of magnetic sensors
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