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Mass surveillance of the population by state agencies and corporate parties is now a well-known fact. Journalists and whistle-blowers still lack means to circumvent global spying for the sake of their investigations. With Spores, we propose a way for journalists and their sources to plan a posteriori file exchanges when they physically meet. We leverage on the multiplication of personal devices per capita to provide a lightweight, robust and fully anonymous decentralised file transfer protocolarXiv:2007.04766v1 fatcat:va3f5wsvsjb5rlk5axczowgakq
more »... etween users. Spores hinges on our novel concept of e-squads: one's personal devices, rendered intelligent by gossip communication protocols, can provide private and dependable services to their user. People's e-squads are federated into a novel onion routing network, able to withstand the inherent unreliability of personal appliances while providing reliable routing. Spores' performances are competitive, and its privacy properties of the communication outperform state of the art onion routing strategies.
As previously reported (Bosking et al. . ... Currently, there is renewed interest in the development of VCP devices (Bosking et al. 2017a , Lewis et al. 2015 , Lewis et al. 2016 . ...doi:10.1101/302547 fatcat:zfxh2qdayzacbpj7vdha36tsh4
High frequency activity (> 30 Hz) in the neocortical local field potential, typically referred to as the gamma range, is thought to have a critical role in visual perception and cognition more broadly. Historically, animal studies recording from visual cortex documented clear narrowband gamma oscillations (NBG; ~20-60 Hz) in response to visual stimuli. However, invasive measurements from human neocortex have highlighted a different broadband or high gamma response (BBG; ~70-150+ Hz). Growingdoi:10.1101/572313 fatcat:m7dve3c6ujefpngicuyv3wb2ee
more »... dence suggests these two forms of gamma response are distinct, but often conceptually or analytically conflated as the same gamma response. Furthermore, recent debate has highlighted that both the occurrence and spectral properties of gamma band activity in visual cortex appears to be dependent on the attributes and class of presented visual stimuli. Using high-density intracranial recordings from human visual cortex, we integrate and extend these findings, dissociating the spectral, temporal and functional properties of NBG and BBG activity. We report results from two experiments, manipulating visual stimulus attributes (contrast-varying gratings) and class (object categories) dissecting the differential properties of NBG and BBG responses. NBG oscillations were only reliably recorded for grating stimuli, while their peak frequency varied with contrast level. Whereas BBG activity was observed in response to all stimulus classes tested, with no systematic change in its spectral features. Temporally, induced NBG was sustained throughout stimulus presentation, in opposition to a more transient response for the BBG. These findings challenge the ubiquity of gamma activity in visual cortex, by clearly dissociating oscillatory and broadband effects.
AbstractNarrowband gamma oscillations (NBG: ∼20-60Hz) in visual cortex reflect rhythmic fluctuations in population activity generated by underlying circuits tuned for stimulus location, orientation, and color. Consequently, the amplitude and frequency of induced NBG activity is highly sensitive to these stimulus features. For example, in the non-human primate, NBG displays biases in orientation and color tuning at the population level. Such biases may relate to recent reports describing thedoi:10.1101/2021.04.23.441193 fatcat:3yjavigtwvbgdpel5qksexrnta
more »... e-scale organization of single-cell orientation and color tuning in visual cortex, thus providing a potential bridge between measurements made at different scales. Similar biases in NBG population tuning have been predicted to exist in the human visual cortex, but this has yet to be fully examined. Using intracranial recordings from human visual cortex, we investigated the tuning of NBG to orientation and color, both independently and in conjunction. NBG was shown to display a cardinal orientation bias (horizontal) and also an end- and mid-spectral color bias (red/blue and green). When jointly probed, the cardinal bias for orientation was attenuated and an end-spectral preference for red and blue predominated. These data both elaborate on the close, yet complex, link between the population dynamics driving NBG oscillations and known feature selectivity biases in visual cortex, adding to a growing set of stimulus dependencies associated with the genesis of NBG. Together, these two factors may provide a fruitful testing ground for examining multi-scale models of brain activity, and impose new constraints on the functional significance of the visual gamma rhythm.Significance StatementOscillations in electrophysiological activity occur in visual cortex in response to stimuli that strongly drive the orientation or color selectivity of visual neurons. The significance of this induced 'gamma rhythm' to brain function remains unclear. Answering this question requires understanding how and why some stimuli can reliably generate gamma activity while others do not. We examined how different orientations and colors independently and jointly modulate gamma oscillations in the human brain. Our data show gamma oscillations are greatest for certain orientations and colors that reflect known biases in visual cortex. Such findings complicate the functional significance of gamma activity, but open new avenues for linking circuits to population dynamics in visual cortex.ClassificationNeuroscience
IFIP Advances in Information and Communication Technology
Lecture Notes in Computer Science
AbstractVisual cortical prosthetics (VCPs) offer the promise of restoring sight to blind patients. Electrical stimulation of a single site in visual cortex can reliably produce a percept of a spot of light in a fixed visual field location, known as a phosphene. Researchers developing VCPs have assumed that multiple phosphenes produced by concurrent stimulation of multiple sites in visual cortex can combine to form a coherent form, like pixels in a visual display. However, existing data do notdoi:10.1101/462697 fatcat:d5hlcbjzp5hi3ia2cucf5v3z4i
more »... pport this assumption. Therefore, we developed a novel stimulation paradigm for VCPs termed dynamic current steering in which the visual form to be conveyed is traced on the surface of visual cortex by electrically stimulating electrodes in a dynamic sequence. When tested in sighted and blind subjects, this method of stimulating visual cortex allowed for the immediate recognition of a variety of letter shapes without training and with high accuracy.One Sentence SummaryStimulating human visual cortex using dynamic patterns of activity allows both blind and sighted patients to perceive visual percepts of useful forms.
Electrical recording and stimulation of visual cortex provides an opportunity to test this tenet (Bosking et al. 2017) (Figure 9 ). ... www.annualreviews.org • Electrical Stimulation of Visual Cortex Bosking · Beauchamp · Yoshor Annu. Rev. Vis. Sci. 2017.3:141-166. ...doi:10.1146/annurev-vision-111815-114525 pmid:28753382 pmcid:PMC6916716 fatcat:lq2uka64g5cmhlnzr5db3jpik4
., July 26, 2017 • 37(30):7188 -7197 Bosking et al. • Phosphene Sizes Produced by Electrical Stimulation ... ., July 26, 2017 • 37(30):7188 -7197 Bosking et al. • Phosphene Sizes Produced by Electrical Stimulation • J. ...doi:10.1523/jneurosci.2896-16.2017 pmid:28652411 pmcid:PMC5546398 fatcat:ykeeb64bmbh4rg2oln4sf74mei
Neocortical gamma activity has long been hypothesized as a mechanism for synchronizing brain regions to support visual perception and cognition more broadly. Although early studies focused on narrowband gamma oscillations (∼20-60 Hz), recent work has emphasized a more broadband "high-gamma" response (∼70-150+ Hz). These responses are often conceptually or analytically treated as synonymous markers of gamma activity. Using high-density intracranial recordings from the human visual cortex, wedoi:10.1016/j.cub.2019.08.004 pmid:31588003 pmcid:PMC6810857 fatcat:sitbspxbxrazbnac5ifhxk7uxi
more »... lenge this view by showing distinct spectral, temporal, and functional properties of narrow and broadband gamma. Across four experiments, narrowband gamma was strongly selective for gratings and long-wavelength colors, displaying a delayed response onset, sustained temporal profile, and contrast-dependent peak frequency. In addition, induced narrowband gamma oscillations lacked phase consistency across stimulus repetitions and displayed highly focal inter-site synchronization. In contrast, broadband gamma was consistently observed for all presented stimuli, displaying a rapid response onset, transient temporal profile, and invariant spectral properties. We exploited stimulus tuning to highlight the functional dissociation of these distinct signals, reconciling prior inconsistencies across species and stimuli regarding the ubiquity of visual gamma oscillations during natural vision. The occurrence of visual narrowband gamma oscillations, unlike broadband high gamma, appears contingent on specific structural and chromatic stimulus attributes intersecting with the receptive field. Together, these findings have important implications for the study, analysis, and functional interpretation of neocortical gamma-range activity.
[Bosk 2001-212] Bosk argues that cthnographers rarcly inform: participants that the world from their point of view is only the starting point for the analytic work of ethnography. ... In an intriguing analogy (one | will return to), Daniel Bradburd has observed that at the very least, the open-ended nature ol the ethnographic cn counter radically changes the conditions under which one ...
Journal of Health Politics, Policy and Law
Armstrong Princeton University Daniel P. Carpenter Harvard University Marie Hojnacki Pennsylvania State University Abstract Diseases capture public attention in varied ways and to varying degrees. ... DiMaggio, Charles Bosk, Christina Paxson, and colloquia participants at the University of Michigan, the University of North Carolina—Chapel Hill, the University of Pennsylvania, and Princeton University ...
British Critic, and Quarterly Theological Review
and during of hefitation the worthy Editor Sei. ave confefs —s not forry . fee that the work is now refamed, a¢cording Yo thé Grdér of the hiftorical bosks. ... *_The fubfequent lst ion of Daniel, according to the texts of Thenisties ind the Septuagint, we hefitated to notice, becaufe we did not exafily compre how it was to be conneéted with the eneral plan ; ...
Wisconsin Law Review
Div. 187, 234 N.Y5S. 454 (4th Dep’t 1929); Daniel v. Tyrell & Garth Co., 93 S.W. (2d) 372 (Tex. Civ. S.E. (1936). Massaponax Sencel & B. Corp. v. Va. Elect. & P. ... Basteson  1 K.B. 829 (Order prohibiting proceeding to eject tenant without previous consent of Minister of Munitions held ultra vires). * Rule construed: Boske v. ...
Wilfon’s Bosks of the Apocrypha. 239 tory of the cruclties inflicted upon the Jews by Antiochus Epiphanes, who conquered Egypt and Judea about 170 years: before the birth of Chrift. ... .~ To Cirittianity tiis book is of great value, ior the predictions recorded in Daniel vill, 8. concerning the he goat, who is evidently Antiochus Epiphanes, were ainply fulfilled in the events mentioned ...
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