Complexes of silver with histidine and imidazole investigated by the calorimetric and potentiometric methods

The stability constants and enthalpies of formation of silver (I) complexes with histidine and imidazole were determined. Two types of complexes were found: AgL+ and AgL+ 2 . The second is much more stable that is evidenced by the higher stability constants and enthalpies of formation. For the two systems, the respective constants and enthalpies are very close one to another that suggests similar complexation mechanisms. Most probably, the linear complexes through the N-3 pyridinic atoms are being formed. The calorimetric and potentiometric methods gave virtually the same results for the system silver + imidazole. However, the potentiometric method failed for the histidine system. The molecule of histidine has three protonation spots, two of these probably do not take part in the complexation but their protonation equilibria may shift upon joining the ions of silver and influence the pH of the system in that way

A fast and non-degenerate scheme for the evaluation of the 3D fundamental solution and its derivatives for fully anisotropic magneto-electro-elastic materials

A new expression for the fundamental solution is introduced, presenting three relevant characteristics: (i ) it is explicit in terms of the Stroh's eigenvalues, (ii ) it remains well-defined when some Stroh’s eigenvalues are repeated, and (iii ) it is exact. A fast and robust numerical scheme for the evaluation of the fundamental solution and its derivatives developed from double Fourier series representations is presented. The Fourier series representation is possible due to the periodic nature of the solution. The attractiveness of this series solution is that the information of the material properties is contained only in the Fourier coefficients, while the information of the dependence of the evaluation point is contained in simple trigonometric functions. This implies that any order derivatives can be determined by spatial differentiation of the trigonometric functions. Moreover, Fourier coefficients need to be obtained only once for a given material, leading to an efficient methodology

Present and past selves : a steady-state visual evoked potentials approach to self-face processing

The self-face has a prioritized status in the processing of incoming visual inputs. As the self-face changes over the lifespan, this stimulus seems to be well-suited for investigation of the self across time. Here, steady-state visual evoked potentials (SSVEP, oscillatory responses to periodic stimulation with a frequency that mirrors the frequency of stimulation) were used to investigate this topic. Different types of faces (present self, past self, close-other's, unknown, scrambled) flickered four times per second in two types of stimulation (‘identical', with the same image of a given type of face; ‘different', with different images of the same type of face). Each of the 10 stimulation sessions lasted 90 seconds and was repeated three times. EEG data were recorded and analyzed in 20 participants. In general, faces evoked higher SSVEP than scrambled faces. The impact of identical and different stimulation was similar for faces and scrambled faces: SSVEP to different stimuli (faces, scrambled faces) was enhanced in comparison to identical ones. Present self-faces evoked higher SSVEP responses than past self-faces in the different stimulation condition only. Thus, our results showed that the physical aspects of the present and past selves are differentiated on the neural level in the absence of an overt behavior

A³: An Extensible Platform for Application-Aware Anonymity

This paper presents the design and implementation of Application-Aware Anonymity (A³), an extensible platform for deploying anonymity-based services on the Internet. A³ allows applications to tailor their anonymity properties and performance characteristics according to specific communication requirements. To support flexible path construction, A³ exposes a declarative language (A³LOG) that enables applications to compactly specify path selection and instantiation policies executed by a declarative networking engine. We demonstrate that our declarative language is sufficiently expressive to encode novel multi-metric performance constraints as well as existing relay selection algorithms employed by Tor and other anonymity systems, using only a few lines of concise code. We experimentally evaluate the A³ system using a combination of trace-driven simulations and deployment on Planet- Lab. Our experimental results demonstrate that A3 can flexibly support a wide range of path selection and instantiation strategies at low performance overhead

Advances in three-dimensional rapid prototyping of microfluidic devices for biological applications

The capability of 3D printing technologies for direct production of complex 3D structures in a single step has recently attracted an ever increasing interest within the field of microfluidics. Recently, ultrafast lasers have also allowed developing new methods for production of internal microfluidic channels within the bulk of glass and polymer materials by direct internal 3D laser writing. This review critically summarizes the latest advances in the production of microfluidic 3D structures by using 3D printing technologies and direct internal 3D laser writing fabrication methods. Current applications of these rapid prototyped microfluidic platforms in biology will be also discussed. These include imaging of cells and living organisms, electrochemical detection of viruses and neurotransmitters, and studies in drug transport and induced-release of adenosine triphosphate from erythrocytes

Inhalations of 5-ALA in photodynamic diagnosis of bronchial cancer

Background: Photodynamic bronchoscopy (PDD) allows for early detection of bronchial cancer. Adverse effects and high costs, partly related to general application of photosensitisers, are important limitations of the method. The local application of a photosensitiser could help to minimize these problems. In this study the validity and safety of inhaled 5-ALA have been tested. Methods: We examined 49 patients (age 59±11, cigarette consumption 36±17 pack-years) with present or past respiratory neoplasms and other with increased risk of bronchial cancer by photodynamic bronchoscopy (Storz- D-light) after inhaled 5-ALA. Biopsies were taken from the fluorescence-positive and negative foci (control). Symptoms and pre-/post-inhalation spirometry were analysed. Results: The overall sensitivity was 82%, specificity 62%, positive predicted value (PPV) 45% and negative predictive value (NPV) 90%. Specificity decreased to 53% and PPV to 15% when visible tumours were excluded. PDD, when added to white light bronchoscopy increased sensitivity by 2.1% and NPV by 6%, but decreased specificity by 35.4% and PPV by 53.1%. In a group of actual or past tumours the sensitivity increased by 22% and NPV by 34%, whereas specificity decreased by 26% and PPV by 35%. In 2 cases a drop in FEV1 above 10% of pre-inhalation value was observed but no clinically relevant symptoms were reported. Conclusions: Photodynamic bronchoscopy with inhalation of 5-ALA is a relatively safe diagnostic method. The main disadvantage is high percentage of false positive results. Nevertheless, we believe, that it may be a useful adjunct to conventional diagnostic modes, especially in the detection of early lesions in patients operated due to cancer (stump control and detection of metachronous lesions) and those prepared for operation (synchronous lesions and detection of infiltration margins). However all suspected lesions must be verified by histo-pathological examination

RiPKI: The Tragic Story of RPKI Deployment in the Web Ecosystem

Previous arXiv version of this paper has been published under the title "When BGP Security Meets Content Deployment: Measuring and Analysing RPKI-Protection of Websites", Proc. of Fourteenth ACM Workshop on Hot Topics in Networks (HotNets), New York:ACM, 2015Previous arXiv version of this paper has been published under the title "When BGP Security Meets Content Deployment: Measuring and Analysing RPKI-Protection of Websites", Proc. of Fourteenth ACM Workshop on Hot Topics in Networks (HotNets), New York:ACM, 2015Web content delivery is one of the most important services on the Internet. Access to websites is typically secured via TLS. However, this security model does not account for prefix hijacking on the network layer, which may lead to traffic blackholing or transparent interception. Thus, to achieve comprehensive security and service availability, additional protective mechanisms are necessary such as the RPKI, a recently deployed Resource Public Key Infrastructure to prevent hijacking of traffic by networks. This paper argues two positions. First, that modern web hosting practices make route protection challenging due to the propensity to spread servers across many different networks, often with unpredictable client redirection strategies, and, second, that we need a better understanding why protection mechanisms are not deployed. To initiate this, we empirically explore the relationship between web hosting infrastructure and RPKI deployment. Perversely, we find that less popular websites are more likely to be secured than the prominent sites. Worryingly, we find many large-scale CDNs do not support RPKI, thus making their customers vulnerable. This leads us to explore business reasons why operators are hesitant to deploy RPKI, which may help to guide future research on improving Internet security

The need for sustainability, equity, and international exchange: perspectives of early career environmental psychologists on the future of conferences

At the 2019 and 2021 International Conference on Environmental Psychology, discussions were held on the future of conferences in light of the enormous greenhouse gas emissions and inequities associated with conference travel. In this manuscript, we provide an early career researcher (ECR) perspective on this discussion. We argue that travel-intensive conference practices damage both the environment and our credibility as a discipline, conflict with the intrinsic values and motivations of our discipline, and are inequitable. As such, they must change. This change can be achieved by moving toward virtual and hybrid conferences, which can reduce researchers’ carbon footprints and promote equity, if employed carefully and with informal exchange as a priority. By acting collectively and with the support of institutional change, we can adapt conference travel norms in our field. To investigate whether our arguments correspond to views in the wider community of ECRs within environmental psychology, we conducted a community case study. By leveraging our professional networks and directly contacting researchers in countries underrepresented in those networks, we recruited 117 ECRs in 32 countries for an online survey in February 2022. The surveyed ECRs supported a change in conference travel practices, including flying less, and perceived the number of researchers wanting to reduce their travel emissions to be growing. Thirteen percent of respondents had even considered leaving academia due to travel requirements. Concerning alternative conference formats, a mixed picture emerged. Overall, participants had slightly negative evaluations of virtual conferences, but expected them to improve within the next 5 years. However, ECRs with health issues, facing visa challenges, on low funding, living in remote areas, with caretaking obligations or facing travel restrictions due to COVID-19 expected a switch toward virtual or hybrid conferences to positively affect their groups. Participants were divided about their ability to build professional relationships in virtual settings, but believed that maintaining relationships virtually is possible. We conclude by arguing that the concerns of ECRs in environmental psychology about current and alternative conference practices must be taken seriously. We call on our community to work on collective solutions and less travel-intensive conference designs using participatory methods. Copyright © 2022 Köhler, Kreil, Wenger, Darmandieu, Graves, Haugestad, Holzen, Keller, Lloyd, Marczak, Medugorac and Rosa