300 research outputs found
The Empty Signifier Problem: Towards Clearer Paradigms for Operationalising "Alignment" in Large Language Models
In this paper, we address the concept of "alignment" in large language models
(LLMs) through the lens of post-structuralist socio-political theory,
specifically examining its parallels to empty signifiers. To establish a shared
vocabulary around how abstract concepts of alignment are operationalised in
empirical datasets, we propose a framework that demarcates: 1) which dimensions
of model behaviour are considered important, then 2) how meanings and
definitions are ascribed to these dimensions, and by whom. We situate existing
empirical literature and provide guidance on deciding which paradigm to follow.
Through this framework, we aim to foster a culture of transparency and critical
evaluation, aiding the community in navigating the complexities of aligning
LLMs with human populations.Comment: Socially Responsible Language Modelling Research (SoLaR) @ NeurIPs
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SimpleSafetyTests: a Test Suite for Identifying Critical Safety Risks in Large Language Models
The past year has seen rapid acceleration in the development of large
language models (LLMs). For many tasks, there is now a wide range of
open-source and open-access LLMs that are viable alternatives to proprietary
models like ChatGPT. Without proper steering and safeguards, however, LLMs will
readily follow malicious instructions, provide unsafe advice, and generate
toxic content. This is a critical safety risk for businesses and developers. We
introduce SimpleSafetyTests as a new test suite for rapidly and systematically
identifying such critical safety risks. The test suite comprises 100 test
prompts across five harm areas that LLMs, for the vast majority of
applications, should refuse to comply with. We test 11 popular open LLMs and
find critical safety weaknesses in several of them. While some LLMs do not give
a single unsafe response, most models we test respond unsafely on more than 20%
of cases, with over 50% unsafe responses in the extreme. Prepending a
safety-emphasising system prompt substantially reduces the occurrence of unsafe
responses, but does not completely stop them from happening. We recommend that
developers use such system prompts as a first line of defence against critical
safety risks
A critical review of alternative erection methods for overhead line towers
The construction of overhead power lines in the EHV (Extra High Voltage) category is a costly exercise. For the erection of the towers that supports the conductors, mobile cranes have become the dominant piece of equipment to erect these towers. Although convenient and relatively quick, these mobile cranes do come at a considerable cost and hence, alternative erection methods will be economically beneficial. This paper takes a critical review of alternative options to erect overhead power line towers thereby eliminating mobile cranes. The work presented here is part of a larger study to develop a numerical safety tool for the safe erection of guyed V-towers without cranes. It proposes the use of novel methods like air cushions and a degree of automation to lift these guyed V-towers autonomously. This paper deals with the first part of the study and analyses the different lifting configurations using gin poles and winches and selects the most suitable method to achieve this.http://www.irphouse.comam2020Mechanical and Aeronautical Engineerin
Impact of molecular genetic methods on the initiation of chemotherapy in multiple drug resistant tuberculosis patients in Arkhangelsk Region
In the Arkhangelsk Region, the prevalence of multiple drug-resistant tuberculosis is one of the highest in the world. In 2016, the portion of multiple drug resistant tuberculosis made 33.1% among new cases and 59.5% among relapses. Using new molecular genetic diagnostic techniques allows reducing the time for diagnostics of tuberculosis and drug resistance and should result in the earlier start of adequate treatment.
The goal of the study is to assess the impact of new diagnostic molecular genetic methods on the time period from the first referral for medical care till the start of MDR-TB treatment. It was assumed that the introduction of molecular genetic tests would lead to early initiation of treatment in MDR TB patients (the research project of the International Union Against Tuberculosis and Lung Diseases and Tuberculosis Control Program of Arkhangelsk Region on The PROVE-IT LPA; Policy Relevant Outcomes from Validating Evidence on Impact of Line Probe Assays).
Subjects and Methods. The results of the diagnostic procedure using cultures were compared with the results of the procedure based on molecular genetic tests aimed to detect MDR-TB. 295 MDR TB patients were enrolled into the study, of them, 163 had culture and 132 had molecular genetic tests.
Results. The use of molecular genetic tests in smear-positive patients (AFB+) resulted in the reduction of the time period before initiation of MDRTB treatment by 50 and 66 days (median) versus culture by BacTAlert and absolute concentration on Lowenstein-Jensen medium respectively (p <0.001).
Patients with a negative smear (AFB-), in whom MDR TB was detected by molecular genetic methods started treatment by 78 days earlier (median) versus patients who had culture (Lowenstein-Jensen, p < 0.001). Despite the significant reduction in the time period, even using molecular genetic methods, it took 24 days for cases with AFB+ and 62 days for cases with AFB- to be notified and start treatment of MDR TB
Positron-molecule interactions: resonant attachment, annihilation, and bound states
This article presents an overview of current understanding of the interaction
of low-energy positrons with molecules with emphasis on resonances, positron
attachment and annihilation. Annihilation rates measured as a function of
positron energy reveal the presence of vibrational Feshbach resonances (VFR)
for many polyatomic molecules. These resonances lead to strong enhancement of
the annihilation rates. They also provide evidence that positrons bind to many
molecular species. A quantitative theory of VFR-mediated attachment to small
molecules is presented. It is tested successfully for selected molecules (e.g.,
methyl halides and methanol) where all modes couple to the positron continuum.
Combination and overtone resonances are observed and their role is elucidated.
In larger molecules, annihilation rates from VFR far exceed those explicable on
the basis of single-mode resonances. These enhancements increase rapidly with
the number of vibrational degrees of freedom. While the details are as yet
unclear, intramolecular vibrational energy redistribution to states that do not
couple directly to the positron continuum appears to be responsible for these
enhanced annihilation rates. Downshifts of the VFR from the vibrational mode
energies have provided binding energies for thirty species. Their dependence
upon molecular parameters and their relationship to positron-atom and
positron-molecule binding energy calculations are discussed. Feshbach
resonances and positron binding to molecules are compared with the analogous
electron-molecule (negative ion) cases. The relationship of VFR-mediated
annihilation to other phenomena such as Doppler-broadening of the gamma-ray
annihilation spectra, annihilation of thermalized positrons in gases, and
annihilation-induced fragmentation of molecules is discussed.Comment: 50 pages, 40 figure
Dust and the spectral energy distribution of the OH/IR star OH 127.8+0.0: Evidence for circumstellar metallic iron
We present a fit to the spectral energy distribution of OH 127.8+0.0, a
typical asymptotic giant branch star with an optically thick circumstellar dust
shell. The fit to the dust spectrum is achieved using non-spherical grains
consisting of metallic iron, amorphous and crystalline silicates and water ice.
Previous similar attempts have not resulted in a satisfactory fit to the
observed spectral energy distributions, mainly because of an apparent lack of
opacity in the 3--8 micron region of the spectrum. Non-spherical metallic iron
grains provide an identification for the missing source of opacity in the
near-infrared. Using the derived dust composition, we have calculated spectra
for a range of mass-loss rates in order to perform a consistency check by
comparison with other evolved stars. The L-[12 micron] colours of these models
correctly predict the mass-loss rate of a sample of AGB stars, strengthening
our conclusion that the metallic iron grains dominate the near-infrared flux.
We discuss a formation mechanism for non-spherical metallic iron grains.Comment: 10 pages, 6 figures, accepted for publication by A&
Identification and assessment of cardiolipin interactions with E. coli inner membrane proteins
Integral membrane proteins are localized and/or regulated by lipids present in the surrounding bilayer. While bacteria have relatively simple membranes, there is ample evidence that many bacterial proteins bind to specific lipids, especially the anionic lipid cardiolipin. Here, we apply molecular dynamics simulations to assess lipid binding to 42 different Escherichia coli inner membrane proteins. Our data reveal an asymmetry between the membrane leaflets, with increased anionic lipid binding to the inner leaflet regions of the proteins, particularly for cardiolipin. From our simulations, we identify >700 independent cardiolipin binding sites, allowing us to identify the molecular basis of a prototypical cardiolipin binding site, which we validate against structures of bacterial proteins bound to cardiolipin. This allows us to construct a set of metrics for defining a high-affinity cardiolipin binding site on bacterial membrane proteins, paving the way for a heuristic approach to defining other protein-lipid interactions
Pooling sputum samples for Xpert® MTB/RIF and Xpert® Ultra testing for TB diagnosis
Background
The use of molecular amplification as-says for TB diagnosis is limited by their costs and cartridge stocks. Pooling multiple samples to test them together is reported to have similar accuracy to individual testing and to save costs.
Methods
Two surveys of individuals with presumptive TB were conducted to assess the performance of pooled testing using Xpert® MTB/RIF (MTB/RIF) and Xpert® Ultra (Ultra).
Results
A total of 500 individuals were tested using MTB/RIF, with 72 (14.4%) being MTB-positive. The samples were tested in 125 pools, with 50 pools having 1 MTB-positive and 75 only MTB-negative samples: 46/50 (92%, 95% CI 80.8–97.8) MTB-positive pools tested MTB-positive and 71/75 (94.7%, 95% CI 86.9–98.5) MTB-negative pools tested MTB-negative in the pooled test (agreement: 93.6%, κ = 0.867). Five hundred additional samples were tested using Ultra, with 60 (12%) being MTB-positive. Samples were tested in 125 pools, with 42 having 1 MTB-positive and 83 only MTB-negative samples: 35/42 (83.6%, 95% CI 68.6–93.0) MTB-positive pools tested MTB-positive and 82/83 (98.8%, 95% CI 93.5–100.0) MTB-negative pools tested MTB-negative in the pooled test (agreement: 93.6%, κ = 0.851; P > 0.1 between individual and pooled testing). Pooled testing saved 35% (MTB/RIF) and 46% (Ultra) of cartridges.
Conclusions
Pooled and individual testing has a high level of agreement and improves testing efficiency
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