Keyed Non-Parametric Hypothesis Tests

The recent popularity of machine learning calls for a deeper understanding of AI security. Amongst the numerous AI threats published so far, poisoning attacks currently attract considerable attention. In a poisoning attack the opponent partially tampers the dataset used for learning to mislead the classifier during the testing phase. This paper proposes a new protection strategy against poisoning attacks. The technique relies on a new primitive called keyed non-parametric hypothesis tests allowing to evaluate under adversarial conditions the training input's conformance with a previously learned distribution $\mathfrak{D}$. To do so we use a secret key $\kappa$ unknown to the opponent. Keyed non-parametric hypothesis tests differs from classical tests in that the secrecy of $\kappa$ prevents the opponent from misleading the keyed test into concluding that a (significantly) tampered dataset belongs to $\mathfrak{D}$.Comment: Paper published in NSS 201

Совместная обработка траекторно измерительной информации при испытаниях сложных информационно-управляющих систем

Рассмотрен метод траекторных измерений, использующий совместную обработку измерительной информации, полученной от полигонных средств внешнетраекторных измерений и специальной бортовой измерительной аппаратуры при натурных испытаниях сложных информационно-управляющих систем на местах их постоянной дислокации.A method of trajectory measurements, which uses a joint processing of the measuring data, obtained from the proving ground means of external trajectory measurements and special onboard measuring equipment with the full-scale tests of the complex information-control systems at their constant disposition is considered

General Principles for the Design of Visible-Light-Responsive Photoswitches:Tetra-ortho-Chloro-Azobenzenes

Molecular photoswitches enable reversible external control of biological systems, nanomachines, and smart materials. Their development is driven by the need for low energy (green-red-NIR) light switching, to allow non-invasive operation with deep tissue penetration. The lack of clear design principles for the adaptation and optimization of such systems limits further applications. Here we provide a design rulebook for tetra-ortho-chloroazobenzenes, an emerging class of visible-light-responsive photochromes, by elucidating the role that substituents play in defining their key characteristics: absorption spectra, band overlap, photoswitching efficiencies, and half-lives of the unstable cis isomers. This is achieved through joint photochemical and theoretical analyses of a representative library of molecules featuring substituents of varying electronic nature. A set of guidelines is presented that enables tuning of properties to the desired application through informed photochrome engineering

Full-field implementation of a perfect eavesdropper on a quantum cryptography system

Quantum key distribution (QKD) allows two remote parties to grow a shared secret key. Its security is founded on the principles of quantum mechanics, but in reality it significantly relies on the physical implementation. Technological imperfections of QKD systems have been previously explored, but no attack on an established QKD connection has been realized so far. Here we show the first full-field implementation of a complete attack on a running QKD connection. An installed eavesdropper obtains the entire 'secret' key, while none of the parameters monitored by the legitimate parties indicate a security breach. This confirms that non-idealities in physical implementations of QKD can be fully practically exploitable, and must be given increased scrutiny if quantum cryptography is to become highly secure.Comment: Revised after editorial and peer-review feedback. This version is published in Nat. Commun. 8 pages, 6 figures, 1 tabl

Concepts of health in different contexts:A scoping review

The rationale of our study was that the World Health Organization’s (WHO) definition of health from 1947 which includes “… complete physical, mental and social wellbeing…” does not fit the current societal viewpoints anymore. The WHO’s definition of health implies that many people with chronic illnesses or disabilities would be considered unhealthy and complete wellbeing would be utopian and unfeasible for them. This is no longer uniformly accepted. Many alternative concepts of health have been discussed in the last decades such as ‘positive health’, which focusses on someone’s capability rather than incapability,. However, the question remains whether a general health concept can guide all healthcare practices. More likely, health concepts need to be specified for professions or settings. The objective of our study was to create a structured overview of published concepts of health from different perspectives by conducting a scoping review using the PRISMA-ScR guideline. A literature search was conducted in Pubmed and Cinahl. Articles eligible for inclusion focussed on the discussion or the conceptualisation of health or health-related concepts in different contexts (such as the perspective of care workers’ or patients’) published since 2009 (the Dutch Health Council raised the discussion about moving towards a more dynamic perspective on health in that year). Seventy-five articles could be included for thematic analyses. The results showed that most articles described a concept of health consisting of multiple subthemes; no consensus was found on one overall concept of health. This implies that healthcare consumers act based on different health concepts when seeking care than care workers when providing care. Having different understandings of the concepts of health can lead to misunderstandings in practice. In conclusion, from every perspective, and even for every individual, health may mean something different. This finding stresses the importance that care workers’ and healthcare consumers’ meaning of ‘health’ has to be clear to all actors involved. Our review supports a more uniform tuning of healthcare between healthcare providers (the organisations), care workers (the professionals) and healthcare consumers (the patients), by creating more awareness of the differences among these actors, which can be a guide in their communication. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12913-022-07702-2

Photomorphogenic mutants of tomato

Photomorphogenesis of tomato is being studied with the aid of mutants which are either modified in their photore- ceptor composition or in their signal transduction chain(s) . Several mutants affecting the phytochrome family of photoreceptors, some of which appear deficient for specific genes encoding phytochrome apoproteins have been isolated . In addition, other mutants, including transgenic lines overexpressing phytochrome A, exhibit exaggerated photomorphogenesis during de-etiolation . Anthocyanin biosynthesis and plastid development are being used as model systems for the dissection of the complex interactions among photomorphogenic photoreceptors and to elucidate the nature of their transduction chains

Long-term exposure to ultrafine particles and natural and cause-specific mortality

BACKGROUND: Health implications of long-term exposure to ubiquitously present ultrafine particles (UFP) are uncertain. The aim of this study was to investigate the associations between long-term UFP exposure and natural and cause-specific mortality (including cardiovascular disease (CVD), respiratory disease, and lung cancer) in the Netherlands. METHODS: A Dutch national cohort of 10.8 million adults aged >/= 30 years was followed from 2013 until 2019. Annual average UFP concentrations were estimated at the home address at baseline, using land-use regression models based on a nationwide mobile monitoring campaign performed at the midpoint of the follow-up period. Cox proportional hazard models were applied, adjusting for individual and area-level socio-economic status covariates. Two-pollutant models with the major regulated pollutants nitrogen dioxide (NO(2)) and fine particles (PM(2)(.)(5) and PM(10)), and the health relevant combustion aerosol pollutant (elemental carbon (EC)) were assessed based on dispersion modelling. RESULTS: A total of 945,615 natural deaths occurred during 71,008,209 person-years of follow-up. The correlation of UFP concentration with other pollutants ranged from moderate (0.59 (PM(2)(.)(5))) to high (0.81 (NO(2))). We found a significant association between annual average UFP exposure and natural mortality [HR 1.012 (95 % CI 1.010-1.015), per interquartile range (IQR) (2723 particles/cm(3)) increment]. Associations were stronger for respiratory disease mortality [HR 1.022 (1.013-1.032)] and lung cancer mortality [HR 1.038 (1.028-1.048)] and weaker for CVD mortality [HR 1.005 (1.000-1.011)]. The associations of UFP with natural and lung cancer mortality attenuated but remained significant in all two-pollutant models, whereas the associations with CVD and respiratory mortality attenuated to the null. CONCLUSION: Long-term UFP exposure was associated with natural and lung cancer mortality among adults independently from other regulated air pollutants

Controlling passively-quenched single photon detectors by bright light

Single photon detectors based on passively-quenched avalanche photodiodes can be temporarily blinded by relatively bright light, of intensity less than a nanowatt. I describe a bright-light regime suitable for attacking a quantum key distribution system containing such detectors. In this regime, all single photon detectors in the receiver Bob are uniformly blinded by continuous illumination coming from the eavesdropper Eve. When Eve needs a certain detector in Bob to produce a click, she modifies polarization (or other parameter used to encode quantum states) of the light she sends to Bob such that the target detector stops receiving light while the other detector(s) continue to be illuminated. The target detector regains single photon sensitivity and, when Eve modifies the polarization again, produces a single click. Thus, Eve has full control of Bob and can do a successful intercept-resend attack. To check the feasibility of the attack, 3 different models of passively-quenched detectors have been tested. In the experiment, I have simulated the intensity diagrams the detectors would receive in a real quantum key distribution system under attack. Control parameters and side effects are considered. It appears that the attack could be practically possible.Comment: Experimental results from a third detector model added. Minor corrections and edits made. 11 pages, 10 figure

Affinity chromatography in dynamic combinatorial libraries: one-pot amplification and isolation of a strongly binding receptor

We report the one-pot amplification and isolation of a nanomolar receptor in a multibuilding block aqueous dynamic combinatorial library using a polymer-bound template. By appropriate choice of a poly(N,N-dimethylacrylamide)-based support, unselective ion-exchange type behaviour between the oppositely charged cationic guest and polyanionic hosts was overcome, such that the selective molecular recognition arising in aqueous solution reactions is manifest also in the analogous templated solid phase DCL syntheses. The ability of a polymer bound template to identify and isolate a synthetic receptor via dynamic combinatorial chemistry was not compromised by the large size of the library, consisting of well over 140 theoretical members, demonstrating the practical advantages of a polymer-supported DCL methodology