A nested model for AI design and validation

The growing AI field faces trust, transparency, fairness, and discrimination challenges. Despite the need for new regulations, there is a mismatch between regulatory science and AI, preventing a consistent framework. A five-layer nested model for AI design and validation aims to address these issues and streamline AI application design and validation, improving fairness, trust, and AI adoption. This model aligns with regulations, addresses AI practitioners’ daily challenges, and offers prescriptive guidance for determining appropriate evaluation approaches by identifying unique validity threats. We have three recommendations motivated by this model: (1) Authors should distinguish between layers when claiming contributions to clarify the specific areas in which the contribution is made and to avoid confusion; (2) authors should explicitly state upstream assumptions to ensure that the context and limitations of their AI system are clearly understood, (3) AI venues should promote thorough testing and validation of AI systems and their compliance with regulatory requirements

Disinhibition enables vocal repertoire expansion after a critical period

The efficiency of motor skill acquisition is age-dependent, making it increasingly challenging to learn complex manoeuvres later in life. Zebra finches, for instance, acquire a complex vocal motor programme during a developmental critical period after which the learned song is essentially impervious to modification. Although inhibitory interneurons are implicated in critical period closure, it is unclear whether manipulating them can reopen heightened motor plasticity windows. Using pharmacology and a cell-type specific optogenetic approach, we manipulated inhibitory neuron activity in a premotor area of adult zebra finches beyond their critical period. When exposed to auditory stimulation in the form of novel songs, manipulated birds added new vocal syllables to their stable song sequence. By lifting inhibition in a premotor area during sensory experience, we reintroduced vocal plasticity, promoting an expansion of the syllable repertoire without compromising pre-existing song production. Our findings provide insights into motor skill learning capacities, offer potential for motor recovery after injury, and suggest avenues for treating neurodevelopmental disorders involving inhibitory dysfunctions

Navigating the Digital Age: The gray digital divide and digital inclusion in China

Rapid digitalization and an aging population are leading to an increasingly prominent age-based digital divide among the world’s elderly population. This study focuses on China, one of the most rapidly aging and digitalizing countries in the world. Employing a mixed-method approach, this research examines how elderly individuals experience the digital transformation and the associated digital divide. The findings suggest that the elderly interviewees encounter multiple barriers to learning and using digital technologies, which highlights the significant role of social support and networks in facilitating their adaptation to the digital society and lifestyle. Attitudes toward digital engagement and digitalization vary greatly among the elderly, ranging from being optimistic to feeling left behind and having multiple concerns. Our findings further reveal that the Chinese government has implemented numerous digital apps tailored to the demands of the elderly and provided training opportunities to bridge the gray digital divide. This emphasizes the responsiveness and adaptiveness of Chinese authorities in addressing pressing societal issues. However, we identify a gap in digital outreach, as most elderly interviewees have limited awareness of government digital inclusion policies and programs. This article contributes to digital divide research and offers practical implications for countries grappling with the gray digital divide

The colonial encounter told twice; Parallel accounts of Carl Bock’s 1879 expedition to Borneo

When the Scandinavian explorer Carl Bock, commissioned by the Dutch colonial authorities, undertook to make an expedition overland through Borneo in 1879, the island retained a sense of the exotic in the European imagination. Audiences were especially hungry for tales of the island’s headhunting Dayak inhabitants, a demand that Bock was happy to meet. In fact, he wrote two distinct narratives of the expedition: the Dutch-language report he had been tasked to write for the Dutch but also a longer, more entertainment-focused English-language travelogue for a broader audience. Comparing the two accounts, clearly based on the same underlying text but differing in many details and tone, provides critical insights into the unstable and unreliable nature of the colonial encounter as recounted in written sources. Such an analysis also reveals how these narratives were shaped retrospectively, to meet the expectations of different assumed audiences and quickly changing literary fashions

Nanoporous Au/Ag Catalyzed Benzylic sp3C−H Oxidation of 9H-Fluorene Derivatives and Similar Molecules with TBHP

Nanoporous gold (npAu) was tested as a catalyst for oxidations of various benzylic sp3-carbon positions in 9H-fluorene derivatives and similar hydrocarbons using tertbutyl hydroperoxide (TBHP) as an oxidant. The silver content in the npAu catalyst had a major influence on the overall conversion: Lower silver amounts (0.53 mol%) led to higher conversions, whereas higher amounts of silver increasingly resulted in the disproportionation of TBHP as a competing reaction. Because residual silver from the bulk alloy was oxidized by TBHP and leached into the solution during the reaction, the Ag content diminished over time. Therefore, the recycling of the catalyst had a positive effect on the conversion after each use. Using electron paramagnetic resonance (EPR) spectroscopy, the formation of radicals from TBHP by npAu was evidenced indicating a radical-based reaction mechanism which was further elucidated by NMR spectroscopic and GC-MS (trace) product analysis. Subsequent oxidations of benzylic sp3-carbon positions gave good to excellent conversions and chemoselectivities featuring npAu as a suitable catalyst for such reactions

Global and local perspectives on language contact

Synopsis: This edited volume pays tribute to traditional and innovative language contact research, bringing together contributors with expertise on different languages examining general phenomena of language contact and specific linguistic features which arise in language contact scenarios. A particular focus lies on contact between languages of unbalanced political and symbolic power, language contact and group identity, and the linguistic and societal implications of language contact settings, especially considering contemporary global migration streams. Drawing on various methodological approaches, among others, corpus and contrastive linguistics, linguistic landscapes, sociolinguistic interviews, and ethnographic fieldwork, the contributions describe phenomena of language contact between and with Romance languages, Semitic languages, and English(es)

Coming of voting age. Evidence from a natural experiment on the effects of electoral eligibility

In recent years, several jurisdictions have lowered the voting age, with many more discussing it. Sceptics question whether young people are ready to vote, while supporters argue that allowing them to vote would increase their specific engagement with politics. To test the latter argument, we use a series of register-based surveys of over 10,000 German adolescents. Knowing the exact birthdates of our respondents, we estimate the causal effect of eligibility on their information-seeking behaviour in a regression discontinuity design. While eligible and non-eligible respondents do not differ in their fundamental political dispositions, those allowed to vote are more likely to discuss politics with their family and friends and to use a voting advice application. This effect appears to be stronger for voting age 16 than for 18. The right to vote changes behaviour. Therefore, we cannot conclude from the behaviour of ineligible citizens that they are unfit to vote

Retention modeling of therapeutic peptides in sub-/supercritical fluid chromatography

Chromatographic modeling software packages are valuable tools during method optimization steps. These are well established for reversed-phase applications utilizing retention time (RT) prediction to optimize separations and receive robust methods, which is of high interest for the analysis of pharmaceuticals. In contrast to liquid chromatography, the knowledge of RT prediction in supercritical fluid chromatography is limited to a manageable number of studies. This study uses the software DryLab to predict the RTs of the peptides bacitracin (Bac), colistin, tyrothricin (Tyro), and insulin analogs. Gradient time, column temperature, and the ternary composition (terC) of carbon dioxide, methanol (MeOH), and acetonitrile (ACN) in the gradient elution are varied in a feasibility approach using a neutral (Viridis BEH) and an amino-derivatized aromatic (Torus 2-PIC) stationary phase. In the second part, chromatographic optimization is performed in silico through gradient adjustments to optimize the separation of the fingerprint of Bac. The final gradient method utilizes a Viridis BEH column (100 × 3.0 mm, 1.7 μm), carbon dioxide, and a modifier consisting of ACN/MeOH/water/methanesulfonic acid (60:40:2:0.1, v:v:v:v). In addition, changes in the retention order of Tyro compounds with the proportion of the terC in combination with a Torus Diol column are investigated

Multicenter-Studie zu Veränderungen der äußeren Netzhautschichten in Neuromyelitis Optica Spektrumerkrankungen

Background: Neuromyelitis optica spectrum disorders (NMOSD) is a debilitating autoimmune disease affecting the central nervous system. It often manifests in optic neuritis (ON) which can lead to neuroaxonal damage to the retina. A primary ON-independent astrocytopathy component of the neurodegeneration has been suggested and may contribute to observable changes in the outer layers of the retina. This dissertation will explore this hypothesis in NMOSD patients in a multicentric cross-sectional cohort of patients recruited internationally. Method: 539 participants from 20 international centers were retrospectively included. Of these, 197 aquaporin-4 (AQP4)-IgG seropositive patients and 32 patients with myelin-oligodendrocyte-glycoprotein associated disease (MOG-IgG+) were enrolled together with 75 healthy controls (HC). All participants underwent optical coherence tomography (OCT) scans of the retina. OCT scans were then subject to central postprocessing, image segmentation and analyses of the various layers, including the retinal nerve fiber layer, ganglion cell and inner plexiform layer, inner nuclear layer, outer plexiform layer (OPL), outer nuclear layer (ONL), external limiting membrane and the Bruch’s membrane. Results: AQP4-IgG+ patients showed no significant change of OPL (25.02±2.03µm) or ONL (61.63±7.04µm) when compared to the MOG-IgG+ diseased group (OPL: 25.10±2.00µm, ONL: 64.71±7.87µm) or HC (OPL: 24.58±1.64µm, ONL: 63.59±5.78µm). AQP4-IgG+ (19.84±5.09µm, p=0.027) and MOG-IgG+ (19.82±4.78µm, p=0.004) eyes with a positive history of ON displayed parafoveal OPL thinning compared with HC (OPL: 20.99±5.14µm). ONL, photoreceptor layer and retinal pigment epithelium did not differ between any of the groups. Conclusion: Outer retinal layer loss is not a significant and measurable hallmark of APQ4-IgG+ NMOSD. However, we cannot exclude that there are astrocytic changes in the retina of NMOSD patients which do not manifest with changes in retinal layer thickness. Future advanced imaging techniques or post-mortem studies might be able to shed light on this. Furthermore, longitudinal studies are required to investigate whether there are outer retinal layer changes over time.Hintergrund: Neuromyelitis optica Spektrumerkrankungen (NMOSD) sind eine schwerwiegende Autoimmunerkrankung des zentralen Nervensystems. Sie manifestiert sich häufig mit einer Sehnerventzündung (Optikusneuritis, ON), die neuroaxonale Degeneration der Netzhaut zur Folge haben kann. Eine primäre, von der ON unabhängige Astrozytopathie-Komponente der Neurodegeneration wurde vermutet, welche sich durch Veränderungen in den äußeren Netzhautschichten äußern könnte. In dieser Dissertation wird diese Hypothese seropositiven NMOSD Patient*innen in einer internationalen multizentrischen retrospektiven Querschnittskohorte untersucht. Methode: 539 Teilnehmer*innen aus 20 internationalen Zentren wurden retrospektiv rekrutiert; davon 197 Aquaporin-Antikörper-seropositive AQP4-IgG+-Patient*innen, 32 Patient*innen mit Myelin-Oligodendrozyten-Glykoprotein–Antikörper-assoziierter Erkrankung (MOG-IgG+) und 75 gesunden Kontrollpersonen (HC). Bei allen Teilnehmenden wurden die Netzhaut mit optischer Kohärenztomographie (OCT) untersucht. Die OCT-Scans unterliefen anschließend zentral einer Schichtsegmentierung und -analyse, die die retinale Nervenfaserschicht, die Ganglienzellen und die innere plexiforme Schicht, die innere Kernschicht, die äußere plexiforme Schicht (OPL), die äußere Körnerschicht (ONL), die äußere Grenzmembran und die Bruch’sche Membran umfasste. Ergebnisse: AQP4-IgG+ Patient*innen zeigten keine signifikante Veränderung der OPL (25,02±2,03µm) oder ONL (61,63±7,04µm) im Vergleich zu der MOG-IgG+ Gruppe (OPL: 25,10±2,00µm, ONL: 64,71±7,87µm) oder zu der HC Gruppe (OPL: 24,58±1,64µm, ONL: 63,59±5,78µm). AQP4-IgG+ (19,84±5,09µm, p=0,027) und MOG-IgG+ (19,82±4,78µm, p=0,004) Augen mit positiver ON-Anamnese zeigten eine parafoveale OPL-Ausdünnung im Vergleich zu der HC Gruppe (OPL: 20,99±5,14µm). Die ONL, die Fotorezeptorenschicht und das retinale Pigmentepithel unterschieden sich in keiner der Gruppen. Diskussion: Wir konnten keine Verdünnung der äußeren Netzhautschichten bei APQ4-IgG+ NMOSD nachweisen. Allerdings können wir nicht ausschließen, dass es bei NMOSD-Patienten zu astrozytären Veränderungen der Netzhaut kommt, die sich nicht auf die retinalen Schichtdicken auswirken. Zukünftige fortschrittliche bildgebende Verfahren oder Post-Mortem-Studien könnten hier Licht ins Dunkel bringen. Darüber hinaus sind longitudinale Studien erforderlich, um zu untersuchen, ob Veränderungen der äußeren Netzhautschichten im Verlauf der Erkrankung auftreten

From chiral laser pulses to femto- and attosecond electronic chirality flips in achiral molecules

Chirality is an important topic in biology, chemistry and physics. Here we show that ultrashort circularly polarized laser pulses, which are chiral, can be fired on achiral oriented molecules to induce chirality in their electronic densities, with chirality flips within femtoseconds or even attoseconds. Our results, obtained by quantum dynamics simulations, use the fact that laser pulses can break electronic symmetry while conserving nuclear symmetry. Here two laser pulses generate a superposition of three electronic eigenstates. This breaks all symmetry elements of the electronic density, making it chiral except at the periodic rare events of the chirality flips. As possible applications, we propose the combination of the electronic chirality flips with Chiral Induced Spin Selectivity