12,615 research outputs found
Speciesistic Veganism: An Anthropocentric Argument
The paper proposes an anthropocentric argument for veganism based on a speciesistic premise that most carnists likely affirm: human flourishing should be promoted. I highlight four areas of human suffering promoted by a carnistic diet: (1) health dangers to workers (both physical and psychological), (2) economic dangers to workers, (3) physical dangers to communities around slaughterhouses, and (4) environmental dangers to communities-at-large. Consequently, one could ignore the well-being of non-human animals and nevertheless recognize significant moral failings in the current standard system of meat production
Chlamydial conjunctivitis presenting as pre septal cellulitis
Chlamydia conjuctivitis results from infection by chlamydia trachomatis, the commonest treatable sexually transmitted infection in Europe. Its clinical manifestations involve the conjunctiva and the cornea. The inflammation under the upper eyelid may be sufficient to present as ptosis, however previously it has not been documented to cause a preseptal cellulitis. We present such a case. A 15-year-old girl was diagnosed with a left viral conjunctivitis. Five days later, she returned with marked oedema of the left upper and lower lids accompanied by erythema. The tarsal conjunctiva revealed follicles and large papillae and extra ocular movements revealed discomfort on elevation. A secondary diagnosis of bacterial pre septal cellulitis was made and the treatment was changed a broad spectrum oral antibiotic. On review at two days, the patient now complained of a large amount of purulent discharge in association with the marked pre septal swelling. As previous bacteriology and virology had been negative, the patient was re swabbed for chlamydia. This proved positive and her symptoms completely resolved following administration of Azithromycin. In this particular case recognition of the pathogen is important to alert the patient to the likelihood of unknown genital infestation. In all cases of positive culture, the patient should be counselled to attend a genitourinary clinic and to alert any sexual partners to the need to do likewise
An avalanche-photodiode-based photon-number-resolving detector
Avalanche photodiodes are widely used as practical detectors of single
photons.1 Although conventional devices respond to one or more photons, they
cannot resolve the number in the incident pulse or short time interval.
However, such photon number resolving detectors are urgently needed for
applications in quantum computing,2-4 communications5 and interferometry,6 as
well as for extending the applicability of quantum detection generally. Here we
show that, contrary to current belief,3,4 avalanche photodiodes are capable of
detecting photon number, using a technique to measure very weak avalanches at
the early stage of their development. Under such conditions the output signal
from the avalanche photodiode is proportional to the number of photons in the
incident pulse. As a compact, mass-manufactured device, operating without
cryogens and at telecom wavelengths, it offers a practical solution for photon
number detection.Comment: 12 pages, 4 figure
Evaluation of Risk-based Re-Authentication Methods
Risk-based Authentication (RBA) is an adaptive security measure that improves
the security of password-based authentication by protecting against credential
stuffing, password guessing, or phishing attacks. RBA monitors extra features
during login and requests for an additional authentication step if the observed
feature values deviate from the usual ones in the login history. In
state-of-the-art RBA re-authentication deployments, users receive an email with
a numerical code in its body, which must be entered on the online service.
Although this procedure has a major impact on RBA's time exposure and
usability, these aspects were not studied so far.
We introduce two RBA re-authentication variants supplementing the de facto
standard with a link-based and another code-based approach. Then, we present
the results of a between-group study (N=592) to evaluate these three
approaches. Our observations show with significant results that there is
potential to speed up the RBA re-authentication process without reducing
neither its security properties nor its security perception. The link-based
re-authentication via "magic links", however, makes users significantly more
anxious than the code-based approaches when perceived for the first time. Our
evaluations underline the fact that RBA re-authentication is not a uniform
procedure. We summarize our findings and provide recommendations.Comment: 14 pages, 5 figures. Paper accepted for IFIP SEC 2020. Keywords:
Risk-based Authentication (RBA), Re-authentication, Usable Securit
Epidemics on contact networks: a general stochastic approach
Dynamics on networks is considered from the perspective of Markov stochastic
processes. We partially describe the state of the system through network motifs
and infer any missing data using the available information. This versatile
approach is especially well adapted for modelling spreading processes and/or
population dynamics. In particular, the generality of our systematic framework
and the fact that its assumptions are explicitly stated suggests that it could
be used as a common ground for comparing existing epidemics models too complex
for direct comparison, such as agent-based computer simulations. We provide
many examples for the special cases of susceptible-infectious-susceptible (SIS)
and susceptible-infectious-removed (SIR) dynamics (e.g., epidemics propagation)
and we observe multiple situations where accurate results may be obtained at
low computational cost. Our perspective reveals a subtle balance between the
complex requirements of a realistic model and its basic assumptions.Comment: Main document: 16 pages, 7 figures. Electronic Supplementary Material
(included): 6 pages, 1 tabl
Madness decolonized?: Madness as transnational identity in Gail Hornsteinâs Agnesâs Jacket
The US psychologist Gail Hornsteinâs monograph Agnesâs Jacket: A Psychologistâs Search for the Meanings of Madness (2009) is an important intervention in the identity politics of the mad movement. Hornstein offers a resignified vision of mad identity that embroiders the central trope of an âanti-colonialâ struggle to reclaim the experiential world âcolonizedâ by psychiatry. A series of literal and figurative appeals make recourse to the inner world and (corresponding) cultural world of the mad, as well as to the ethno-symbolic cultural materials of dormant nationhood. This rhetoric is augmented by a model in which the mad comprise a diaspora without an origin, coalescing into a single transnational community. The mad are also depicted as persons displaced from their metaphorical homeland, the âinnerâ world âcolonizedâ by the psychiatric regime. There are a number of difficulties with Hornsteinâs rhetoric, however. Her âethnicity-and-rightsâ response to the oppression of the mad is symptomatic of Western parochialism, while her proposed transmutation of putative psychopathology from limit upon identity to parameter of successful identity is open to contestation. Moreover, unless one accepts Hornsteinâs porous vision of mad identity, her self-ascribed insider status in relation to the mad community may present a problematic âre-colonizationâ of mad experience
Supernova 2007bi as a pair-instability explosion
Stars with initial masses 10 M_{solar} < M_{initial} < 100 M_{solar} fuse
progressively heavier elements in their centres, up to inert iron. The core
then gravitationally collapses to a neutron star or a black hole, leading to an
explosion -- an iron-core-collapse supernova (SN). In contrast, extremely
massive stars (M_{initial} > 140 M_{solar}), if such exist, have oxygen cores
which exceed M_{core} = 50 M_{solar}. There, high temperatures are reached at
relatively low densities. Conversion of energetic, pressure-supporting photons
into electron-positron pairs occurs prior to oxygen ignition, and leads to a
violent contraction that triggers a catastrophic nuclear explosion. Tremendous
energies (>~ 10^{52} erg) are released, completely unbinding the star in a
pair-instability SN (PISN), with no compact remnant. Transitional objects with
100 M_{solar} < M_{initial} < 140 M_{solar}, which end up as iron-core-collapse
supernovae following violent mass ejections, perhaps due to short instances of
the pair instability, may have been identified. However, genuine PISNe, perhaps
common in the early Universe, have not been observed to date. Here, we present
our discovery of SN 2007bi, a luminous, slowly evolving supernova located
within a dwarf galaxy (~1% the size of the Milky Way). We measure the exploding
core mass to be likely ~100 M_{solar}, in which case theory unambiguously
predicts a PISN outcome. We show that >3 M_{solar} of radioactive 56Ni were
synthesized, and that our observations are well fit by PISN models. A PISN
explosion in the local Universe indicates that nearby dwarf galaxies probably
host extremely massive stars, above the apparent Galactic limit, perhaps
resulting from star formation processes similar to those that created the first
stars in the Universe.Comment: Accepted version of the paper appearing in Nature, 462, 624 (2009),
including all supplementary informatio
The effect of early versus late treatment initiation after diagnosis on the outcomes of patients treated for multidrug-resistant tuberculosis: a systematic review.
BACKGROUND: Globally it is estimated that 480 000 people developed multidrug-resistant tuberculosis (MDR-TB) in 2014 and 190 000 people died from the disease. Successful treatment outcomes are achieved in only 50 % of patients with MDR-TB, compared to 86 % for drug susceptible disease. It is widely held that delay in time to initiation of treatment for MDR-TB is an important predictor of treatment outcome. The objective of this review was to assess the existing evidence on the outcomes of multidrug- and extensively drug-resistant tuberculosis patients treated early (â€4 weeks) versus late (>4 weeks) after diagnosis of drug resistance. METHODS: Eight sources providing access to 17 globally representative electronic health care databases, indexes, sources of evidence-based reviews and grey literature were searched using terms incorporating time to treatment and MDR-TB. Two-stage sifting in duplicate was employed to assess studies against pre-specified inclusion and exclusion criteria. Only those articles reporting WHO-defined treatment outcomes were considered for inclusion. Articles reporting on fewer than 10 patients, published before 1990, or without a comparison of outcomes in patient groups experiencing different delays to treatment initiation were excluded. RESULTS: The initial search yielded 1978 references, of which 1475 unique references remained after removal of duplicates and 28 articles published pre-1990. After title and abstract sifting, 64 papers underwent full text review. None of these articles fulfilled the criteria for inclusion in the review. CONCLUSIONS: Whilst there is an inherent logic in the theory that treatment delay will lead to poorer treatment outcomes, no published evidence was identified in this systematic review to support this hypothesis. Reports of programmatic changes leading to reductions in treatment delay exist in the literature, but attribution of differences in outcomes specifically to treatment delay is confounded by other contemporaneous changes. Further primary research on this question is not considered a high priority use of limited resources, though where data are available, improved reporting of outcomes by time to treatment should be encouraged
Interface modiïŹcation of clay and graphene platelets reinforced epoxy nanocomposites: a comparative study
The interface between the matrix phase and dispersed phase of a composite plays a critical role in inïŹuencing its properties. However, the intricate mecha-nisms of interface are not fully understood, and polymer nanocomposites are no exception. This study compares the fabrication, morphology, and mechanical and thermal properties of epoxy nanocomposites tuned by clay layers (denoted as m-clay) and graphene platelets (denoted as m-GP). It was found that a chemical modiïŹcation, layer expansion and dispersion of ïŹller within the epoxy matrix resulted in an improved interface between the ïŹller mate-rial and epoxy matrix. This was conïŹrmed by Fourier transform infrared spectroscopy and transmission electron microscope. The enhanced interface led to improved mechanical properties (i.e. stiffness modulus, fracture toughness) and higher glass transition temperatures (Tg) compared with neat epoxy. At 4 wt% m-GP, the critical strain energy release rate G1c of neat epoxy improved by 240 % from 179.1 to 608.6 J/m2 and Tg increased from 93.7 to 106.4 ïżœC. In contrast to m-clay, which at 4 wt%, only improved the G1c by 45 % and Tg by 7.1 %. The higher level of improvement offered by m-GP is attributed to the strong interaction of graphene sheets with epoxy because the covalent bonds between the carbon atoms of graphene sheets are much stronger than silicon-based clay
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